ORCID Profile
0000-0001-7126-9814
Current Organisations
University of South Australia
,
University of Adelaide
,
Govind Ballabh Pant University of Agriculture and Technology
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Biochemistry and Cell Biology | Developmental Genetics (incl. Sex Determination) | Enzymes | Cellular Nervous System | Cell Physiology | Membrane Biology | Cell Development, Proliferation and Death | Comparative Physiology | Medical Biochemistry: Proteins And Peptides | Biological And Medical Chemistry | Genetics | Enzymes | Signal Transduction |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Biological Sciences | Biological sciences | Nervous system and disorders | Expanding Knowledge in the Agricultural and Veterinary Sciences | Diagnostics | Treatments (e.g. chemicals, antibiotics)
Related Links
Publications
Prodomain-dependent nuclear localization of the caspase-2 (Nedd2) precursor: A novel function for a caspase prodomain
Publisher: Elsevier BV
Date: 09-1998
Autophagy-dependent cell death
Publisher: Springer Science and Business Media LLC
Date: 19-12-2019
Deletion of Nedd4-2 results in progressive kidney disease in mice
Publisher: Springer Science and Business Media LLC
Date: 09-2017
DOI: 10.1038/CDD.2017.137
Physicians can justifiably euthanize certain severely impaired neonates
Publisher: Elsevier BV
Date: 02-2015
A tumor suppressor function for caspase-2
Publisher: Proceedings of the National Academy of Sciences
Date: 31-03-2009
Abstract: Apoptosis is mediated by the caspase family of proteases that act as effectors of cell death by cleaving many cellular substrates. Caspase-2 is one of the most evolutionarily conserved caspases, yet its physiological function has remained enigmatic because caspase-2-deficient mice develop normally and are viable. We report here that the caspase-2 −/− mouse embryonic fibroblasts (MEFs) show increased proliferation. When transformed with E1A and Ras oncogenes, caspase-2 −/− MEFs grew significantly faster than caspase-2 +/+ MEFs and formed more aggressive and accelerated tumors in nude mice. To assess whether the loss of caspase-2 predisposes animals to tumor development, we used the mouse Eμ- Myc lymphoma model. Our findings suggest that loss of even a single allele of caspase-2 resulted in accelerated tumorigenesis, and this was further enhanced in caspase-2 −/− mice. The caspase-2 −/− cells showed resistance to apoptosis induced by chemotherapeutic drugs and DNA damage. Furthermore, caspase-2 −/− MEFs had a defective apoptotic response to cell-cycle checkpoint regulation and showed abnormal cycling following γ-irradiation. These data show that loss of caspase-2 results in an increased ability of cells to acquire a transformed phenotype and become malignant, indicating that caspase-2 is a tumor suppressor protein.
The role of caspases as executioners of apoptosis
Publisher: Portland Press Ltd.
Date: 23-12-2022
DOI: 10.1042/BST20210751
Abstract: Caspases are a family of cysteine aspartyl proteases mostly involved in the execution of apoptotic cell death and in regulating inflammation. This article focuses primarily on the evolutionarily conserved function of caspases in apoptosis. We summarise which caspases are involved in apoptosis, how they are activated and regulated, and what substrates they target for cleavage to orchestrate programmed cell death by apoptosis.
Buffy, a Drosophila Bcl-2 protein, has anti-apoptotic and cell cycle inhibitory functions
Publisher: Wiley
Date: 15-07-2003
DOI: 10.1093/EMBOJ/CDG355
Crosstalk between cGAS–STING signaling and cell death
Publisher: Springer Science and Business Media LLC
Date: 18-09-2020
A cytochrome c-free fly apoptosome
Publisher: Springer Science and Business Media LLC
Date: 07-04-2006
Roles of the C termini of alpha -, beta -, and gamma -subunits of epithelial Na+ channels (ENaC) in regulating ENaC and mediating its inhibition by cytosolic Na+.
Publisher: Elsevier BV
Date: 04-2001
Crystallization and preliminary X-ray diffraction studies of the WW4 domain of the Nedd4-2 ubiquitin-protein ligase
Publisher: International Union of Crystallography (IUCr)
Date: 24-11-2005
DECAY, a novel Drosophila caspase related to mammalian caspase-3 and caspase-7
Publisher: Elsevier BV
Date: 10-1999
Nedd1 expression as a marker of dynamic centrosomal localization during mouse embryonic development
Publisher: Springer Science and Business Media LLC
Date: 02-2008
DOI: 10.1007/S00418-008-0392-0
Abstract: As the primary microtubule-organizing centre of the mammalian cell, the centrosome plays many important roles during cell growth and organization. This is evident across a broad range of cell types and processes, such as the proliferation, differentiation and polarity of neural cells. Additionally, given its localization and function, there are likely to be many more processes that rely on the centrosome that have not yet been characterized. Currently, little is known about centrosomal dynamics during mammalian development. In this study, we have analyzed Nedd1 protein expression to characterize the localization of the centrosome during some aspects of mouse embryogenesis. Using a Nedd1 antibody we have demonstrated the colocalization of Nedd1 with centrosomal markers. We found strong expression of Nedd1, and therefore the centrosome, in highly proliferating cells during neural development. Additionally, Nedd1 was found to have high expression in the cytoplasm of a subset of cells in the dorsal root ganglia. We have also shown a distinct, polarized centrosomal localization of Nedd1 in the developing lens, retina and other polarized tissues. This study reveals the localization of Nedd1 and the centrosome during important processes in mouse embryogenesis and provides a basis for further study into its role in development.
Comparative analysis of vaccinia virus promoter activity in fowlpox and vaccinia virus recombinants
Publisher: Elsevier BV
Date: 04-1990
DOI: 10.1016/0168-1702(90)90042-A
Abstract: A quantitative and qualitative comparison of vaccinia virus (VV) promoter activity in fowlpox virus (FPV) and VV recombinants was performed. The VV PL11 late promoter was used to express beta-galactosidase from the E. coli LacZ gene in FPV (FPV-LacZ) and VV (VV-LacZ) recombinants. Time courses of FPV-LacZ beta-galactosidase expression in chicken embryo skin (CES) cells demonstrated temporal regulation of the PL11 promoter with maximum enzyme activity nine- and four-fold lower than those obtained in VV-LacZ infected 143B and CES cells, respectively. The level of beta-galactosidase activity per LacZ DNA gene copy was determined for each recombinant and found to be greater for VV-LacZ than FPV-LacZ. The VV P7.5 early/late promoter was used to express the E. coli xanthine-guanine phosphoribosyl transferase (Ecogpt) gene in FPV and VV recombinants. Northern blot analysis showed early Ecogpt RNA transcripts to be of defined lengths. Transcript size estimations mapped the termination sites to regions containing sequences associated with VV early transcript termination, providing supportive evidence for a common poxvirus early transcript termination signal. Late LacZ and Ecogpt transcripts were heterogeneous in length. S1 nuclease mapping of the 5'-ends of early and late Ecogpt RNA transcripts produced by FPV and VV recombinants showed transcription initiation occurred at the same sites in both poxviruses and corresponded to the regions previously identified as the early and late start sites of the P7.5 promoter. These results would indicate a high level of conservation in the expression and regulation of genes by poxviruses.
The role of cytochrome c in caspase activation in Drosophila melanogaster cells
Publisher: Rockefeller University Press
Date: 18-03-2002
Abstract: The release of cytochrome c from mitochondria is necessary for the formation of the Apaf-1 apoptosome and subsequent activation of caspase-9 in mammalian cells. However, the role of cytochrome c in caspase activation in Drosophila cells is not well understood. We demonstrate here that cytochrome c remains associated with mitochondria during apoptosis of Drosophila cells and that the initiator caspase DRONC and effector caspase DRICE are activated after various death stimuli without any significant release of cytochrome c in the cytosol. Ectopic expression of the proapoptotic Bcl-2 protein, DEBCL, also fails to show any cytochrome c release from mitochondria. A significant proportion of cellular DRONC and DRICE appears to localize near mitochondria, suggesting that an apoptosome may form in the vicinity of mitochondria in the absence of cytochrome c release. In vitro, DRONC was recruited to a & -kD complex, similar to the mammalian apoptosome in cell extracts supplemented with cytochrome c and dATP. These results suggest that caspase activation in insects follows a more primitive mechanism that may be the precursor to the caspase activation pathways in mammals.
Caspase-2 protects against ferroptotic cell death
Publisher: Cold Spring Harbor Laboratory
Date: 24-08-2023
DOI: 10.1101/2023.08.22.553791
Abstract: Caspase-2, one of the most evolutionarily conserved member of the caspase family, is an important regulator of the cellular response to oxidative stress. Given that ferroptosis is suppressed by antioxidant defense pathways, such as that involving selenoenzyme glutathione peroxidase 4 (GPX4), we hypothesised that caspase-2 may play a role in regulating ferroptosis. This study provides the first demonstration of an important and unprecedented function of caspase-2 in protecting cancer cells from undergoing ferroptotic cell death. Specifically, we show that depletion of caspase-2 leads to downregulation of stress response genes including SESN2, HMOX1, SLC7A11 and sensitises mutant-p53 cancer cells to cell death induced by various ferroptosis inducing compounds. Importantly, the canonical catalytic activity of caspase-2 is not required for its role and suggests that caspase-2 regulates ferroptosis via non-proteolytic interaction with other proteins. Using an unbiased BioID proteomics screen, we identified novel caspase-2 interacting proteins (including heat shock proteins and co-chaperones) that regulate cellular responses to stress. Finally, we demonstrate that caspase-2 limits chaperone mediated autophagic degradation of GPX4 to promote survival of mutant-p53 cancer cells. In conclusion, we document a novel role for caspase-2 as a negative regulator of ferroptosis in cells with mutant-p53. Our results provide evidence for a novel function of caspase-2 functions in cell death regulation and open potential new avenues to exploit ferroptosis in cancer therapy.
The function of the Drosophila caspase DRONC in cell death and development.
Publisher: Informa UK Limited
Date: 13-04-2005
DOI: 10.4161/CC.4.6.1740
Abstract: dronc, the only apical caspase in Drosophila, is thought to be essential and non-redundant for apoptosis. Recent analyses of several independently derived dronc mutants have demonstrated that DRONC is required for normal development. Interestingly, analysis of these mutants show that DRONC is not essential for cell death in all tissues and that in some cases, DRONC-independent effector caspase activation and apoptosis can occur. These mutants provide a valuable resource to investigate the recently reported roles of DRONC in nonapoptotic pathways. Insights gained from the dronc mutants will help in advancing our understanding of caspase function in various developmental pathways.
Autophagy in malignant transformation and cancer progression
Publisher: EMBO
Date: 23-02-2015
ATG8ylation of proteins: A way to cope with cell stress?
Publisher: Rockefeller University Press
Date: 20-10-2021
Abstract: The ATG8 family of proteins regulates autophagy in a variety of ways. Recently, ATG8s were demonstrated to conjugate directly to cellular proteins in a process termed “ATG8ylation,” which is lified by mitochondrial damage and antagonized by ATG4 proteases. ATG8s may have an emerging role as small protein modifiers.
Terminal deoxynucleotidyl transferase (TdT)-mediated dutp nick-end labeling (TUNEL) for detection of apoptotic cells in Drosophila
Publisher: Cold Spring Harbor Laboratory
Date: 06-2015
Abstract: A characteristic feature of apoptosis is DNA fragmentation. This fragmentation can be detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) of DNA in dying cells. Here, we present a protocol for TUNEL detection of apoptosis in Drosophila larval tissue, but these techniques can be adapted for other tissues and developmental stages.
Arrdc4‐dependent extracellular vesicle biogenesis is required for sperm maturation
Publisher: Wiley
Date: 06-2021
DOI: 10.1002/JEV2.12113
Abstract: Extracellular vesicles (EVs) are important players in cell to cell communication in reproductive systems. Notably, EVs have been found and characterized in the male reproductive tract, however, direct functional evidence for their importance in mediating sperm function is lacking. We have previously demonstrated that Arrdc4, a member of the α‐arrestin protein family, is involved in extracellular vesicle biogenesis and release. Here we show that Arrdc4‐mediated extracellular vesicle biogenesis is required for proper sperm function. Sperm from Arrdc4 –/– mice develop normally through the testis but fail to acquire adequate motility and fertilization capabilities through the epididymis, as observed by reduced motility, premature acrosome reaction, reduction in zona pellucida binding and two‐cell embryo production. We found a significant reduction in extracellular vesicle production by Arrdc4 –/‐ epididymal epithelial cells, and further, supplementation of Arrdc4 –/– sperm with additional vesicles d ened the acrosome reaction defect and restored zona pellucida binding. These results indicate that Arrdc4 is important for proper sperm maturation through the control of extracellular vesicle biogenesis.
Role of BCL-2 family of proteins in malignancy
Publisher: Wiley
Date: 2002
DOI: 10.1002/HON.685
Abstract: B cell lymphoma gene-2 (Bcl-2) is the prototypic member of a growing family of proteins that play evolutionarily conserved, key regulatory roles in apoptosis. The Bcl-2 family members are characterized by the presence of one or more Bcl-2 homology domains and are comprised of both the prosurvival and proapoptotic proteins. Bcl-2 itself is a prosurvival member of the family and its aberrant expression has been linked to a variety of different cancers, including several hematological malignancies. Although the exact mechanism of action of Bcl-2 family of proteins in regulating apoptosis is still a matter of some debate, these proteins appear to act upstream of caspase activation. Many recent studies have shown the therapeutic potential of targeting Bcl-2 family members for the treatment of cancer. This article summarizes what is currently known about Bcl-2-like proteins and how the evolving understanding of the biology of these proteins is paving way for the development of novel cancer therapeutics.
NEDD4-2 (NEDD4L): The ubiquitin ligase for multiple membrane proteins
Publisher: Elsevier BV
Date: 02-2015
Cp1/cathepsin L is required for autolysosomal clearance in Drosophila
Publisher: Informa UK Limited
Date: 28-10-2020
Learning, memory and long-term potentiation are altered in Nedd4 heterozygous mice
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.BBR.2016.01.054
Abstract: The consolidation of short-term memory into long-term memory involves changing protein level and activity for the synaptic plasticity required for long-term potentiation (LTP). AMPA receptor trafficking is a key determinant of LTP and recently ubiquitination by Nedd4 has been shown to play an important role via direct action on the GluA1 subunit, although the physiological relevance of these findings are yet to be determined. We therefore investigated learning and memory in Nedd4(+/-) mice that have a 50% reduction in levels of Nedd4. These mice showed decreased long-term spatial memory as evidenced by significant increases in the time taken to learn the location of and subsequently find a platform in the Morris water maze. In contrast, there were no significant differences between Nedd4(+/+) and Nedd4(+/-) mice in terms of short-term spatial memory in a Y-maze test. Nedd4(+/-) mice also displayed a significant reduction in post-synaptic LTP measured in hippoc al brain slices. Immunofluorescence of Nedd4 in the hippoc us confirmed its expression in hippoc al neurons of the CA1 region. These findings indicate that reducing Nedd4 protein by 50% significantly impairs LTP and long-term memory thereby demonstrating an important role for Nedd4 in these processes.
Ecdysone-induced expression of the caspase DRONC during hormone-dependent programmed cell death in Drosophila is regulated by Broad-Complex
Publisher: Rockefeller University Press
Date: 03-06-2002
Abstract: The steroid hormone ecdysone regulates both cell differentiation and cell death during insect metamorphosis, by hierarchical transcriptional regulation of a number of genes, including the Broad-Complex (BR-C), the zinc finger family of transcription factors. These genes in turn regulate the transcription of a number of downstream genes. DRONC, a key apical caspase in Drosophila, is the only known caspase that is transcriptionally regulated by ecdysone during development. We demonstrate that dronc gene expression is ablated or reduced in BR-C mutant flies. Using RNA interference in an ecdysone-responsive Drosophila cell line, we show that DRONC is essential for ecdysone-mediated cell death, and that dronc upregulation in these cells is controlled by BR-C. Finally, we show that the dronc promoter has BR-C interaction sites, and that it can be transactivated by a specific isoform of BR-C. These results indicate that BR-C plays a key role in ecdysone-mediated caspase regulation.
Nedd4-like proteins: An emerging family of ubiquitin-protein ligases implicated in diverse cellular functions
Publisher: Elsevier BV
Date: 05-1999
DOI: 10.1016/S0962-8924(99)01541-X
Abstract: The members of an emerging family of proteins similar to Nedd4 have a unique modular structure consisting of a Ca2+/lipid-binding domain, multiple protein-protein interaction modules and a ubiquitin-protein ligase domain. Although little is known about the physiological roles of these proteins, studies in both mammals and yeast are providing evidence that members of this family might be involved in erse cellular functions, such as regulation of membrane channels and permeases, the cell cycle and transcription. This article attempts to bring together what is currently known about these evolutionarily conserved ubiquitin-protein ligases.
Physiological functions of the HECT family of ubiquitin ligases
Publisher: Springer Science and Business Media LLC
Date: 13-05-2009
DOI: 10.1038/NRM2690
Abstract: The ubiquitylation of proteins is carried out by E1, E2 and E3 (ubiquitin ligase) enzymes, and targets them for degradation or for other cellular fates. The HECT enzymes, including Nedd4 family members, are a major group of E3 enzymes that dictate the specificity of ubiquitylation. In addition to ubiquitylating proteins for degradation by the 26S proteasome, HECT E3 enzymes regulate the trafficking of many receptors, channels, transporters and viral proteins. The physiological functions of the yeast HECT E3 ligase Rsp5 are the best known, but the functions of HECT E3 enyzmes in metazoans are now becoming clearer from in vivo studies.
The Nedd4-2/Ndfip1 axis is a negative regulator of IgE-mediated mast cell activation
Publisher: Springer Science and Business Media LLC
Date: 27-10-2016
DOI: 10.1038/NCOMMS13198
Abstract: Cross-linkage of the high-affinity immunoglobulin E (IgE) receptor (FcɛRI) on mast cells by antigen ligation has a critical role in the pathology of IgE-dependent allergic disorders, such as anaphylaxis and asthma. Restraint of intracellular signal transduction pathways that promote release of mast cell-derived pro-inflammatory mediators is necessary to d en activation and restore homoeostasis. Here we show that the ligase Nedd4-2 and the adaptor Ndfip1 (Nedd4 family interacting protein 1) limit the intensity and duration of IgE-FcɛRI-induced positive signal transduction by ubiquitinating phosphorylated Syk, a tyrosine kinase that is indispensable for downstream FcɛRI signalosome activity. Importantly, loss of Nedd4-2 or Ndfip1 in mast cells results in exacerbated and prolonged IgE-mediated cutaneous anaphylaxis in vivo . Our findings reveal an important negative regulatory function for Nedd4-2 and Ndfip1 in IgE-dependent mast cell activity.
Caspase-2 deficiency enhances whole-body carbohydrate utilisation and prevents high-fat diet-induced obesity
Publisher: Springer Science and Business Media LLC
Date: 26-10-2017
Abstract: Caspase-2 has been shown to be involved in metabolic homeostasis. Here, we show that caspase-2 deficiency alters basal energy metabolism by shifting the balance in fuel choice from fatty acid to carbohydrate usage. At 4 weeks of age, whole-body carbohydrate utilisation was increased in Casp2 −/− mice and was maintained into adulthood. By 17 weeks of age, Casp2 −/− mice had reduced white adipose mass, smaller white adipocytes decreased fasting blood glucose and plasma triglycerides but maintained normal insulin levels. When placed on a 12-week high-fat diet (HFD), Casp2 −/− mice resisted the development of obesity, fatty liver, hyperinsulinemia and insulin resistance. In addition, HFD-fed Casp2 −/− mice had reduced white adipocyte hypertrophy, apoptosis and expansion of both subcutaneous and visceral adipose depots. Increased expression of UCP1 and the maintenance of adiponectin levels in white adipose tissue of HFD-fed Casp2 −/− mice indicated increased browning and adipocyte hyperplasia. We found that while the preference for whole-body carbohydrate utilisation was maintained, HFD-fed Casp2 −/− mice were not impaired in their ability to switch to utilising fats as a fuel source. Our findings suggest that caspase-2 impacts basal energy metabolism by regulating adipocyte biology and fat expansion, most likely via a non-apoptotic function. Furthermore, we show that caspase-2 deficiency shifts the balance in fuel choice towards increased carbohydrate utilisation and propose that this is due to mild energy stress. As a consequence, Casp2 −/− mice show an adaptive remodelling of adipose tissue that protects from HFD-induced obesity and improves glucose homeostasis while paradoxically increasing their susceptibility to oxidative stress induced damage and premature ageing.
The kinase Grk2 regulates Nedd4/Nedd4-2-dependent control of epithelial Na+ channels
Publisher: Proceedings of the National Academy of Sciences
Date: 29-07-2004
Abstract: Epithelial Na + channels mediate the transport of Na across epithelia in the kidney, gut, and lungs and are required for blood pressure regulation. They are inhibited by ubiquitin protein ligases, such as Nedd4 and Nedd4-2, with loss of this inhibition leading to hypertension. Here, we report that these channels are maintained in the active state by the G protein-coupled receptor kinase, Grk2, which has been previously implicated in the development of essential hypertension. We also show that Grk2 phosphorylates the C terminus of the channel β subunit and renders the channels insensitive to inhibition by Nedd4-2. This mechanism has not been previously reported to regulate epithelial Na + channels and provides a potential explanation for the observed association of Grk2 overactivity with hypertension. Here, we report a G protein-coupled receptor kinase regulating a membrane protein other than a receptor and provide a paradigm for understanding how the interaction between membrane proteins and ubiquitin protein ligases is controlled.
Ribophagy: New receptor discovered
Publisher: Springer Science and Business Media LLC
Date: 06-06-2018
Peripubertal high-fat diet promotes c-Myc stabilization in mammary gland epithelium
Publisher: Wiley
Date: 29-06-2020
DOI: 10.1111/CAS.14492
Autophagy, Not Apoptosis, Is Essential for Midgut Cell Death in Drosophila
Publisher: Elsevier BV
Date: 11-2009
Respiratory distress and perinatal lethality in Nedd4-2-deficient mice
Publisher: Springer Science and Business Media LLC
Date: 19-04-2011
DOI: 10.1038/NCOMMS1284
Chimeric caspase molecules with potent cell killing activity in apoptosis-resistant cells
Publisher: Elsevier BV
Date: 04-2001
Conversion of procaspase-3 to an autoactivating caspase by fusion to the caspase-2 prodomain
Publisher: Elsevier BV
Date: 10-1998
N4WBP5, a potential target for ubiquitination by the Nedd4 family of proteins, is a novel Golgi-associated protein
Publisher: Elsevier BV
Date: 03-2002
An arginine-histone methyltransferase, CARMER, coordinates ecdysone-mediated apoptosis in Drosophila cells
Publisher: Elsevier BV
Date: 04-2004
Drosophila Ndfip is a novel regulator of Notch signaling
Publisher: Springer Science and Business Media LLC
Date: 22-10-2011
DOI: 10.1038/CDD.2010.130
The Apoptosis-inducing Granulocyte-Macrophage Colony-stimulating Factor (GM-CSF) Analog E21R Functions through Specific Regions of the Heterodimeric GM-CSF Receptor and Requires Interleukin-1β-convert
Publisher: Elsevier BV
Date: 04-1997
TP53 mutation variant allele frequency of ≥10% is associated with poor prognosis in therapy-related myeloid neoplasms.
Publisher: Springer Science and Business Media LLC
Date: 11-04-2023
DOI: 10.1038/S41408-023-00821-X
Abstract: Revised diagnostic criteria for myeloid neoplasms (MN) issued by the International Consensus Classification (ICC) and the World Health Organization (WHO) recommended major change pertaining to TP53 -mutated ( TP53 mut ) MN. However, these assertions have not been specifically examined in therapy-related myeloid neoplasm (t-MN), a subset enriched with TP53 mut . We analyzed 488 t-MN patients for TP53 mut . At least one TP53 mut with variant allele frequency (VAF) ≥ 2% with or without loss of TP53 locus was noted in 182 (37.3%) patients and 88.2% of TP53 mut t-MN had a VAF ≥10%. TP53 mut t-MN with VAF ≥ 10% had a distinct clinical and biological profile compared to both TP53 mut VAF 10% and wild-type TP53 ( TP53 wt ) cases. Notably, TP53 mut VAF ≥ 10% had a significantly shorter survival compared to TP53 wt (8.3 vs. 21.6 months P 0.001), while the survival of TP53 mut VAF 10% was comparable to TP53 wt . Within TP53 mut VAF ≥ 10% cohort, the inferior outcomes persisted irrespective of the single- or multi-hit status, co-mutation pattern, or treatments received. Finally, survival of TP53 mut patients was poor across all the blast categories and MDS patients with % blasts had inferior survival compared to %. In summary, TP53 mut VAF ≥10% signified a clinically and molecularly homogenous cohort regardless of the allelic status.
Dpp regulates autophagy-dependent midgut removal and signals to block ecdysone production
Publisher: Springer Science and Business Media LLC
Date: 29-06-2019
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018
Publisher: Springer Science and Business Media LLC
Date: 23-01-2018
Caspase-2 is not required for thymocyte or neuronal apoptosis even though cleavage of caspase-2 is dependent on both Apaf-1 and caspase-9
Publisher: Springer Science and Business Media LLC
Date: 16-07-2002
Abstract: We have generated rat monoclonal antibodies that specifically recognise caspase-2 from many species, including mouse, rat and humans. Using these antibodies, we have investigated caspase-2 expression, subcellular localisation and processing. We demonstrate that caspase-2 is expressed in most tissues and cell types. Cell fractionation and immunohistochemistry experiments show that caspase-2 is found in the nuclear and cytosolic fractions, including a significant portion present in the Golgi complex. We found that caspase-2 is processed in response to many apoptotic stimuli but experiments with caspase-2 deficient mice demonstrated that it is not required for apoptosis of thymocytes or dorsal root ganglia (DRG) neurons in response to a variety of cytotoxic stimuli. Caspase-2 processing does not occur in thymocytes lacking Apaf-1 or caspase-9, suggesting that in this cell type, activation of caspase-2 occurs downstream of apoptosome formation.
The role of individual Nedd4-2 (KIAA0439) WW domains in binding and regulating epithelial sodium channels.
Publisher: Wiley
Date: 11-2002
Age-related proteostasis and metabolic alterations in Caspase-2-deficient mice
Publisher: Springer Science and Business Media LLC
Date: 22-01-2015
Abstract: Ageing is a complex biological process for which underlying biochemical changes are still largely unknown. We performed comparative profiling of the cellular proteome and metabolome to understand the molecular basis of ageing in Caspase-2- deficient ( Casp2 −/− ) mice that are a model of premature ageing in the absence of overt disease. Age-related changes were determined in the liver and serum of young (6–9 week) and aged (18–24 month) wild-type and Casp2 −/− mice. We identified perturbed metabolic pathways, decreased levels of ribosomal and respiratory complex proteins and altered mitochondrial function that contribute to premature ageing in the Casp2 −/− mice. We show that the metabolic profile changes in the young Casp2 −/− mice resemble those found in aged wild-type mice. Intriguingly, aged Casp2 −/− mice were found to have reduced blood glucose and improved glucose tolerance. These results demonstrate an important role for caspase-2 in regulating proteome and metabolome remodelling during ageing.
Relationship between growth arrest and autophagy in midgut programmed cell death in Drosophila
Publisher: Springer Science and Business Media LLC
Date: 04-05-2012
DOI: 10.1038/CDD.2012.43
Caspase-2 protects against oxidative stress in vivo
Publisher: Springer Science and Business Media LLC
Date: 22-12-2014
DOI: 10.1038/ONC.2014.413
Abstract: Caspase-2 belongs to the caspase family of cysteine proteases with established roles in apoptosis. Recently, caspase-2 has been implicated in nonapoptotic functions including maintenance of genomic stability and tumor suppression. Our previous studies demonstrated that caspase-2 also regulates cellular redox status and delays the onset of several ageing-related traits. In the current study, we tested stress tolerance ability in caspase-2-deficient (Casp2(-/-)) mice by challenging both young and old mice with a low dose of the potent reactive oxygen species (ROS) generator, PQ that primarily affects lungs. In both groups of mice, PQ induced pulmonary damage. However, the lesions in caspase-2 knockout mice were consistently and reproducibly more severe than those in wild-type (WT) mice. Furthermore, serum interleukin (IL)-1β and IL-6 levels were higher in PQ-exposed aged Casp2(-/-) mice indicating increased inflammation. Interestingly, livers from Casp2(-/-) mice displayed karyomegaly, a feature commonly associated with ageing and aneuploidy. Given that Casp2(-/-) mice show impaired antioxidant defense, we tested oxidative damage in these mice. Protein oxidation significantly increased in PQ-injected old Casp2(-/-) mice. Moreover, FoxO1, SOD2 and Nrf2 expression levels were reduced and induction of superoxide dismutase (SOD) and glutathione peroxidase activity was not observed in PQ-treated Casp2(-/-) mice. Strong c-Jun amino-terminal kinase (JNK) activation was observed in Casp2(-/-) mice, indicative of increased stress. Together, our data strongly suggest that caspase-2 deficiency leads to increased cellular stress largely because these mice fail to respond to oxidative stress by upregulating their antioxidant defense mechanism. This makes the mice more vulnerable to exogenous challenges and may partly explain the shorter lifespan of Casp2(-/-) mice.
A senescence stress secretome is a hallmark of therapy-related myeloid neoplasm stromal tissue occurring soon after cytotoxic exposure
Publisher: Springer Science and Business Media LLC
Date: 29-08-2022
DOI: 10.1038/S41375-022-01686-Y
Abstract: Therapy-related myeloid neoplasm (tMN) is considered a direct consequence of DNA damage in hematopoietic stem cells. Despite increasing recognition that altered stroma can also drive leukemogenesis, the functional biology of the tMN microenvironment remains unknown. We performed multiomic (transcriptome, DNA damage response, cytokine secretome and functional profiling) characterization of bone marrow stromal cells from tMN patients. Critically, we also compared (i) patients with myeloid neoplasm and another cancer but without cytotoxic exposure, (ii) typical primary myeloid neoplasm, and (iii) age-matched controls to decipher the microenvironmental changes induced by cytotoxics vs. neoplasia. Strikingly, tMN exhibited a profoundly senescent phenotype with induction of CDKN1A and β-Galactosidase, defective phenotype, and proliferation. Moreover, tMN stroma showed delayed DNA repair and defective adipogenesis. Despite their dormant state, tMN stromal cells were metabolically highly active with a switch toward glycolysis and secreted multiple pro-inflammatory cytokines indicative of a senescent-secretory phenotype that inhibited adipogenesis. Critically, senolytics not only eliminated dormant cells, but also restored adipogenesis. Finally, sequential patient s ling showed senescence phenotypes are induced within months of cytotoxic exposure, well prior to the onset of secondary cancer. Our data underscores a role of senescence in the pathogenesis of tMN and provide a valuable resource for future therapeutics.
Cell death by autophagy: Facts and apparent artefacts
Publisher: Springer Science and Business Media LLC
Date: 04-11-2012
DOI: 10.1038/CDD.2011.146
Methods and protocols for studying cell death in Drosophila
Publisher: Elsevier
Date: 2008
Nedd4 mediates control of an epithelial Na+ channel in salivary duct cells by cytosolic Na+
Publisher: Proceedings of the National Academy of Sciences
Date: 09-06-1998
Abstract: Epithelial Na + channels are expressed widely in absorptive epithelia such as the renal collecting duct and the colon and play a critical role in fluid and electrolyte homeostasis. Recent studies have shown that these channels interact via PY motifs in the C terminals of their α, β, and γ subunits with the WW domains of the ubiquitin-protein ligase Nedd4. Mutation or deletion of these PY motifs (as occurs, for ex le, in the heritable form of hypertension known as Liddle’s syndrome) leads to increased Na + channel activity. Thus, binding of Nedd4 by the PY motifs would appear to be part of a physiological control system for down-regulation of Na + channel activity. The nature of this control system is, however, unknown. In the present paper, we show that Nedd4 mediates the ubiquitin-dependent down-regulation of Na + channel activity in response to increased intracellular Na + . We further show that Nedd4 operates downstream of G o in this feedback pathway. We find, however, that Nedd4 is not involved in the feedback control of Na + channels by intracellular anions. Finally, we show that Nedd4 has no influence on Na + channel activity when the Na + and anion feedback systems are inactive. We conclude that Nedd4 normally mediates feedback control of epithelial Na + channels by intracellular Na + , and we suggest that the increased Na + channel activity observed in Liddle’s syndrome is attributable to the loss of this regulatory feedback system.
STRICA, a novel Drosophila melanogaster caspase with an unusual serine/threonine-rich prodomain, interacts with DIAP1 and DIAP2
Publisher: Springer Science and Business Media LLC
Date: 04-2001
Abstract: The recently published genome sequence of Drosophila melanogaster predicts seven caspases in the fly. Five of these caspases have been previously characterised. Here, we describe the Drosophila caspase, STRICA. STRICA is a caspase with a long amino-terminal prodomain that lacks any caspase recruitment domain or death effector domain. Instead, the prodomain of STRICA consists of unique serine/threonine stretches. Low levels of strica expression were detected in embryos, larvae, pupae and adult animals. STRICA is a cytoplasmic protein that, upon overexpression, caused apoptosis in cultured Drosophila SL2 cells that was partially suppressed by DIAP1. Interestingly, unlike other fly caspases, STRICA showed physical association with DIAP2, in cotransfection experiments. These results suggest that STRICA may have a unique cellular function.
Stimulation of the epithelial sodium channel (ENaC) by the serum- and glucocorticoid-inducible kinase (Sgk) involves the PY motifs of the channel but is independent of sodium feedback inhibition
Publisher: Springer Science and Business Media LLC
Date: 17-01-2006
DOI: 10.1007/S00424-005-0026-5
Abstract: The epithelial sodium channel (ENaC) is the major mediator of sodium transport across the apical membranes of the distal nephron, the distal colon, the respiratory tract and the ducts of exocrine glands. It is subject to feedback inhibition by increased intracellular Na+, a regulatory system wherein the ubiquitin protein ligases, Nedd4 and Nedd4-2, bind to conserved PY motifs in the C-termini of ENaC and inactivate the channel. It has been proposed recently that the kinase Sgk activates the channel as a consequence of phosphorylating Nedd4-2, thus preventing it from inhibiting the channels. This proposal predicts that Sgk should interfere with Na+ feedback regulation of ENaC. We have tested this prediction in Xenopus laevis oocytes and in mouse salivary duct cells and found that in neither system did increased activity of Sgk interrupt Na+ feedback inhibition of ENaC. We found, however, that Sgk stimulation was largely abolished in oocytes expressing ENaC channels with C-terminal truncations or mutated PY motifs. We were also unable to confirm that Sgk directly interacts with Nedd4-2 in vitro. We conclude that the stimulatory effect of Sgk on ENaC requires the presence of the channel's PY motifs, but it is not due to the interruption of Na+ feedback regulation.
Regulation of the Epithelial Sodium Channel by N4WBP5A, a Novel Nedd4/Nedd4-2-interacting Protein
Publisher: Elsevier BV
Date: 08-2002
Larval midgut destruction in Drosophila: Not dependent on caspases but suppressed by the loss of autophagy
Publisher: Informa UK Limited
Date: 2010
Apaf-1/cytochrome c apoptosome: An essential initiator of caspase activation or just a sideshow?
Publisher: Springer Science and Business Media LLC
Date: 2003
Recombinant caspase-3 expressed in Pichia pastoris is fully activated and kinetically indistinguishable from the native enzyme
Publisher: Elsevier BV
Date: 09-1997
Abstract: Intracellular cysteine proteinases (caspases) play key roles in inflammation and apoptosis. Recombinant caspases are typically produced in Escherichia coli expression systems with the attendant problems of solubilization, re-folding and activation of the protease. Here we describe the expression of hexahistidine-tagged caspase-3 (CPP32/Yama/Apopain) in the methylotropic yeast Pichia pastoris, and the purification of soluble enzyme from yeast lysates using cobalt affinity chromatography. The recombinant protease is fully activated, stable, and cleaves the synthetic substrate DEVD-AFC (Km 16.8 microM) but not YVAD-AFC. It mediates the cleavage of the apoptotic death substrate poly(ADP-ribose) polymerase in cell extracts, but does not cleave pro-interleukin-1beta. It is inhibited by the peptide DEVD-CHO (Ki 2.2 nM), far less efficiently by YVAD-CMK (Ki 0.3 microM), and not detectably by CrmA. By these criteria, recombinant caspase-3 is indistinguishable from native caspase-3 purified from apoptotic cell extracts. Activation of recombinant caspase-3 occurs in yeast in the absence of any intrinsic caspase activity, suggesting that caspase-3 can auto-activate. However, the purified enzyme was incapable of cleaving pro-caspase-3 indicating that autoactivation of caspase-3 in vivo is not likely to occur unless very high concentrations are achieved.
Subcellular localization and CARD-dependent oligomerization of the death adaptor RAIDD.
Publisher: Springer Science and Business Media LLC
Date: 02-2000
Abstract: RAIDD, a caspase recruitment domain (CARD) containing molecule, interacts with procaspase-2 in a CARD-dependent manner. This interaction has been suggested to mediate the recruitment of caspase-2 to the tumour necrosis factor receptor 1 (TNFR1). In this paper we have studied the subcellular localization of RAIDD and its interaction with caspase-2. We demonstrate that endogenous RAIDD is mostly localized in the cytoplasm and to some extent in the nucleus. RAIDD localization is not affected by TNF-treatment of HeLa cells, but in cells ectopically expressing caspase-2, a fraction of RAIDD is recruited to the nucleus. In transfected cells, coexpression of RAIDD and caspase-2 leads to CARD-dependent colocalization of the two proteins to discrete subcellular structures. We further show that overexpression of the RAIDD-CARD results in the formation of filamentous structures due to CARD-mediated oligomerization. These structures were similar to death effector filaments (DEFs) formed by FADD and FLICE death effector domains (DEDs), and partially colocalized with DEFs. Our results suggest that similar to the DED, the RAIDD-CARD has the ability to form higher order complexes, believed to be important in apoptotic execution. We also present evidence that RAIDD-CARD oligomerization may be regulated by intramolecular folding of the RAIDD molecule.
Blocking cytokine signaling along with intense Bcr-Abl kinase inhibition induces apoptosis in primary CML progenitors
Publisher: Springer Science and Business Media LLC
Date: 04-02-2010
DOI: 10.1038/LEU.2009.299
Abstract: In chronic myeloid leukemia (CML) cell lines, brief exposure to pharmacologically relevant dasatinib concentrations results in apoptosis. In this study, we assess the impact of intensity and duration of Bcr-Abl kinase inhibition on primary CD34(+) progenitors of chronic phase CML patients. As CML cells exposed to dasatinib in vivo are in a cytokine-rich environment, we also assessed the effect of cytokines (six growth factors cocktail or granulocyte-macrophage colony-stimulating factor (CSF) or granulocyte-CSF) in combination with dasatinib. In the presence of cytokines, short-term intense Bcr-Abl kinase inhibition (>or=90% p-Crkl inhibition) with 100 nM dasatinib did not reduce CD34(+) colony-forming cells (CFCs). In contrast, without cytokines, short-term exposure to dasatinib reduced CML-CD34(+) CFCs by 70-80%. When cytokines were added immediately after short-term exposure to dasatinib, CML-CD34(+) cells remained viable, suggesting that oncogene dependence of these cells can be overcome by concomitant or subsequent exposure to cytokines. Additional inhibition of Janus tyrosine kinase (Jak) activity re-established the sensitivity of CML progenitors to intense Bcr-Abl kinase inhibition despite the presence of cytokines. These findings support the contention that therapeutic strategies combining intense Bcr-Abl kinase inhibition and blockade of cytokine signaling pathways can be effective for eradication of CML progenitors.
TP53 mutation in therapy-related myeloid neoplasm defines a distinct molecular subtype.
Publisher: American Society of Hematology
Date: 02-03-2022
Caspase-2 deficiency promotes aberrant DNA-damage response and genetic instability
Publisher: Springer Science and Business Media LLC
Date: 13-04-2012
DOI: 10.1038/CDD.2012.36
A poxvirus bidirectional promoter element with early/late and late functions
Publisher: Elsevier BV
Date: 11-1990
DOI: 10.1016/0042-6822(90)90284-X
Abstract: A novel bidirectional promoter element of fowlpox virus (FPV) was characterized by transcription analysis, transient expression assays, and recombinant virus construction. This promoter element contained an early/late and a late function in opposite orientation, all within 42 bp of the DNA sequence. The 42-bp sequence was sufficient to express two reporter genes simultaneously in a temporally regulated manner. Both early and late mRNA from the early/late promoter originated at the same TAAAT motif and lacked a long 5'poly(A) leader sequence. Late mRNA, initiated from a TAAAT motif of the oppositely oriented late promoter strand, had a leader sequence of approximately 26 bases. Sequence alignment of two strands of the bidirectional element showed that 28 of 42 bases matched. Because of its small and defined size as well as unique structure, this bidirectional promoter should prove to be an important tool in defining the sequences required for the temporal regulation of poxvirus genes.
Dietary sodium modulates nephropathy in Nedd4-2-deficient mice.
Publisher: Springer Science and Business Media LLC
Date: 04-12-2020
DOI: 10.1038/S41418-019-0468-5
Abstract: Salt homeostasis is maintained by tight control of Na + filtration and reabsorption. In the distal part of the nephron the ubiquitin protein ligase Nedd4-2 regulates membrane abundance and thus activity of the epithelial Na + channel (ENaC), which is rate-limiting for Na + reabsorption. Nedd4-2 deficiency in mouse results in elevated ENaC and nephropathy, however the contribution of dietary salt to this has not been characterized. In this study we show that high dietary Na + exacerbated kidney injury in Nedd4-2 -deficient mice, significantly perturbing normal postnatal nephrogenesis and resulting in multifocal areas of renal dysplasia, increased markers of kidney injury and a decline in renal function. In control mice, high dietary Na + resulted in reduced levels of ENaC. However, Nedd4-2 -deficient kidneys maintained elevated ENaC even after high dietary Na + , suggesting that the inability to efficiently downregulate ENaC is responsible for the salt-sensitivity of disease. Importantly, low dietary Na + significantly ameliorated nephropathy in Nedd4-2 -deficient mice. Our results demonstrate that due to dysregulation of ENaC, kidney injury in Nedd4-2 -deficient mice is sensitive to dietary Na + , which may have implications in the management of disease in patients with kidney disease.
Expression of DRG during murine embryonic development
Publisher: Elsevier BV
Date: 11-1992
DOI: 10.1016/0006-291X(92)91568-B
Abstract: We had previously characterised a cDNA which encodes a novel GTP-binding protein DRG. The expression of drg gene is down-regulated during the embryonic development of murine central nervous system. Further analysis of drg mRNA and protein in adult mouse tissues and various cell lines of different origins indicated that it is expressed widely, albeit at low and variable levels. In situ hybridisation analysis of mRNA expression in sections of mouse embryos indicated that drg is expressed strongly in various embryonic tissues. The expression of drg mRNA is greatly reduced in newborn animals. At cellular level, DRG protein can be detected in the cytoplasm. These observations suggest that DRG may play multiple roles in development and normal cell metabolism.
Divalent metal transporter 1 (DMT1) regulation by Ndfip1 prevents metal toxicity in human neurons
Publisher: Proceedings of the National Academy of Sciences
Date: 08-09-2009
Abstract: The regulation of metal ion transport within neurons is critical for normal brain function. Of particular importance is the regulation of redox metals such as iron (Fe), where excess levels can contribute to oxidative stress and protein aggregation, leading to neuronal death. The alent metal transporter 1 (DMT1) plays a central role in the regulation of Fe as well as other metals hence, failure of DMT1 regulation is linked to human brain pathology. However, it remains unclear how DMT1 is regulated in the brain. Here, we show that DMT1 is regulated by Ndfip1 (Nedd4 family-interacting protein 1), an adaptor protein that recruits E3 ligases to ubiquitinate target proteins. Using human neurons we show the Ndfip1 is upregulated and binds to DMT1 in response to Fe and cobalt (Co) exposure. This interaction results in the ubiquitination and degradation of DMT1, resulting in reduced metal entry. Induction of Ndfip1 expression protects neurons from metal toxicity, and removal of Ndfip1 by shRNAi results in hypersensitivity to metals. We identify Nedd4–2 as an E3 ligase recruited by Ndfip1 for the ubiquitination of DMT1 within human neurons. Comparison of brains from Ndfip1 −/− with Ndfip1 +/+ mice exposed to Fe reveals that Ndfip1 −/− brains accumulate Fe within neurons. Together, this evidence suggests a critical role for Ndfip1 in regulating metal transport in human neurons.
Targeted disruption of caspase genes in mice: What they tell us about the functions of individual caspases in apoptosis
Publisher: Wiley
Date: 02-1999
DOI: 10.1046/J.1440-1711.1999.00788.X
Abstract: Cysteine proteases of the caspase family are crucial mediators of apoptosis. All mammalian cells contain a large number of caspases. Although many caspases are activated in a cell committed to apoptosis, recent data from caspase gene knockout mice suggest that in idual caspases may be involved in the cell and stimulus-specific pathways of cell death. The gene disruption studies also establish the functional hierarchy between two structurally distinct classes of caspases. The present review discusses these recent findings and elaborates on how these mutant mouse models have helped the understanding of the mechanisms that govern programmed cell death in the immune and other systems.
The ubiquitin-protein ligases Nedd4 and Nedd4-2 show similar ubiquitin-conjugating enzyme specificities
Publisher: Elsevier BV
Date: 03-2006
DOI: 10.1016/J.BIOCEL.2005.11.006
Abstract: Nedd4 and Nedd4-2 are closely related HECT-type ubiquitin-protein ligases (E3) implicated in the regulation of a number of proteins and pathways. Given the close homology between these E3 enzymes it would be predicted that a conserved ubiquitin-conjugating enzyme (E2) specificity exists between the two proteins. However, E2 specificities for Nedd4 and Nedd4-2 are not well established. In the present studies we aimed at clarifying the E2-specificities of Nedd4 and Nedd4-2 using in vitro ubiquitination assays. We demonstrate strong substrate ubiquitination in the presence of UbcH5b by both Nedd4 and Nedd4-2. We also found that Ube2e3, an E2 previously shown to be used by Nedd4-2, is used less efficiently than UbcH5b. Our results suggest that for optimal ubiquitination Nedd4 and Nedd4-2 require the same E2 enzymes.
Caspase-2 deficiency accelerates chemically induced liver cancer in mice
Publisher: Springer Science and Business Media LLC
Date: 12-08-2016
DOI: 10.1038/CDD.2016.81
Nedd4-2 (NEDD4L) controls intracellular Na(+)-mediated activity of voltage-gated sodium channels in primary cortical neurons.
Publisher: Portland Press Ltd.
Date: 10-12-2014
DOI: 10.1042/BJ20131275
Abstract: Nedd4-2, a HECT (homologous with E6-associated protein C-terminus)-type ubiquitin protein ligase, has been implicated in regulating several ion channels, including Navs (voltage-gated sodium channels). In Xenopus oocytes Nedd4-2 strongly inhibits the activity of multiple Navs. However, the conditions under which Nedd4-2 mediates native Nav regulation remain uncharacterized. Using Nedd4-2-deficient mice, we demonstrate in the present study that in foetal cortical neurons Nedd4-2 regulates Navs specifically in response to elevated intracellular Na+, but does not affect steady-state Nav activity. In dorsal root ganglia neurons from the same mice, however, Nedd4-2 does not control Nav activities. The results of the present study provide the first physiological evidence for an essential function of Nedd4-2 in regulating Navs in the central nervous system.
The fly caspases.
Publisher: Springer Science and Business Media LLC
Date: 11-2000
Abstract: Caspases, a group of cysteine proteases, constitute the effector arm of the cell death machinery. There are seven caspases known in Drosophila, three of which contain long amino-terminal prodomains. Although, compared to mammalian caspases, much less is known about the biology of Drosophila caspases, many studies have shown that caspases are essential for programmed cell death in the fly and are likely to be regulated in ways similar to their mammalian counterparts. Studies on fly caspases have revealed some new insights on cell death regulation. For ex le, the transcript for the fly caspase DRONC is regulated by the hormone ecdysone during programmed cell death in specific tissues. Recent data on DRONC also suggest that some fly caspases may have unique substrate specificities not ascribed to mammalian caspases. The presence of multiple caspases in Drosophila indicates that apoptotic pathways in insects are likely to be as complex as in vertebrates.
Ndfip2 is a potential regulator of the iron transporter DMT1 in the liver
Publisher: Springer Science and Business Media LLC
Date: 06-04-2016
DOI: 10.1038/SREP24045
Abstract: The regulation of alent metal ion transporter DMT1, the primary non-heme iron importer in mammals, is critical for maintaining iron homeostasis. Previously we identified ubiquitin-dependent regulation of DMT1 involving the Nedd4 family of ubiquitin ligases and the Ndfip1 and Ndfip2 adaptors. We also established the in vivo function of Ndfip1 in the regulation of DMT1 in the duodenum of mice. Here we have studied the function of Ndfip2 using Ndfip2-deficient mice. The DMT1 protein levels in the duodenum were comparable in wild type and Ndfip2 −/− mice, as was the transport activity of isolated enterocytes. A complete blood examination showed no significant differences between wild type and Ndfip2 −/− mice in any of the hematological parameters measured. However, when fed a low iron diet, female Ndfip2 −/− mice showed a decrease in liver iron content, although they maintained normal serum iron levels and transferrin saturation, compared to wild type female mice that showed a reduction in serum iron and transferrin saturation. Ndfip2 −/− female mice also showed an increase in DMT1 expression in the liver, with no change in male mice. We suggest that Ndfip2 controls DMT1 in the liver with female mice showing a greater response to altered dietary iron than the male mice.
Prevalence of ocular signs and subclinical vitamin A deficiency and its determinants among rural pre-school children in India
Publisher: Cambridge University Press (CUP)
Date: 02-09-2012
DOI: 10.1017/S136898001100214X
Abstract: To assess the magnitude and determinants of vitamin A deficiency (VAD) and coverage of vitamin A supplementation (VAS) among pre-school children. A community-based cross-sectional study was carried out by adopting a multistage, stratified, random s ling procedure. Rural areas of eight states in India. Pre-school children and their mothers were covered. A total of 71 591 pre-school children were clinically examined for ocular signs of VAD. Serum retinol concentrations in dried blood spots were assessed in a sub-s le of 3954 children using HPLC. The prevalence of Bitot spots was 0·8 %. The total ocular signs were significantly higher ( P 0·001) among boys (2·6 %) compared with girls (1·9 %) and in older children (3–4 years) compared ( P 0·001) with younger (1–2 years), and were also high in children of labourers, scheduled castes and illiterate mothers. The odds of having Bitot spots was highest in children of scheduled caste (OR = 3·8 95 % CI 2·9, 5·0), labourers (OR = 2·9 95 % CI 2·1, 3·9), illiterate mothers (OR = 2·7 95 % CI 2·2, 2·3) and households without a sanitary latrine (OR = 5·9 95 % CI 4·0, 8·7). Subclinical VAD (serum retinol level μg/dl) was observed in 62 % of children. This was also relatively high among scheduled caste and scheduled tribe children. The rate of coverage of VAS was 58 %. The study revealed that VAD is a major nutritional problem and coverage of VAS was poor. The important determinants of VAD were illiteracy, low socio-economic status, occupation and poor sanitation. Strengthening the existing VAS programme and focused attention on dietary ersification are essential for prevention of VAD.
Retromer dysfunction at the nexus of tauopathies.
Publisher: Springer Science and Business Media LLC
Date: 20-01-2021
Genetic background and tumour susceptibility in mouse models
Publisher: Springer Science and Business Media LLC
Date: 26-04-2013
DOI: 10.1038/CDD.2013.35
Identification of septins in neurofibrillary tangles in Alzheimer's disease.
Publisher: Elsevier BV
Date: 11-1998
The ubiquitin-protein ligase Nedd4-2 differentially interacts with and regulates members of the tweety family of chloride ion channels
Publisher: Elsevier BV
Date: 08-2008
New insights into apoptosome structure and function
Publisher: Springer Science and Business Media LLC
Date: 15-05-2018
GRK2 interacts with and phosphorylates Nedd4 and Nedd4-2
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.BBRC.2007.05.134
Abstract: Epithelial Na(+) channels (ENaC) mediate the transport of sodium (Na) across epithelia in the kidney, gut, and lungs and are required for blood pressure regulation. They are inhibited by ubiquitin protein ligases, such as Nedd4 and Nedd4-2, which bind to proline-rich motifs (PY motifs) present in the C-termini of ENaC subunits. Loss of inhibition leads to hypertension. ENaC channels are maintained in the active state by G-protein-coupled receptor kinase 2 (GRK2), an enzyme implicated in the development of essential hypertension. Here, we report that GRK2 interacts not only with ENaC, but also with both Nedd4 and Nedd4-2. Additionally, GRK2 is capable of phosphorylating both Nedd4 and Nedd4-2 at multiple sites. Of possible significance is the phosphorylation of the threonine at position 466 in Nedd4, which is located in the area of the ww3 domain that binds ENaC. These results support and extend the role of GRK2 in sodium transport regulation.
Mapping of a major early/late gene of fowlpox virus
Publisher: Elsevier BV
Date: 02-1990
DOI: 10.1016/0168-1702(90)90007-X
Abstract: Identification, cloning and mapping of a major gene expressed during the early and late stages of infection with fowlpox virus is described. The gene is located within a 17.3 kb PstI fragment of the fowlpox virus genome and has an open reading frame of 501 bp. Analysis of the 5'-ends of mRNA transcribed from this gene showed that the start sites of both early and late transcripts map to the sequence TAAAT near the translation start site (ATG). This is the first poxvirus early/late gene described in which both early and late transcription start sites map to same DNA sequence. From northern hybridization analysis it was shown that the early function of this gene gives rise to the most abundant early mRNA coded by 17% of the fowlpox virus genome. The strong early function of this gene promoter will be useful in the construction of recombinant fowlpox viruses.
The biochemical mechanism of caspase-2 activation
Publisher: Springer Science and Business Media LLC
Date: 06-08-2004
Molecular definitions of autophagy and related processes
Publisher: EMBO
Date: 08-06-2017
Abstract: Over the past two decades, the molecular machinery that underlies autophagic responses has been characterized with ever increasing precision in multiple model organisms. Moreover, it has become clear that autophagy and autophagy‐related processes have profound implications for human pathophysiology. However, considerable confusion persists about the use of appropriate terms to indicate specific types of autophagy and some components of the autophagy machinery, which may have detrimental effects on the expansion of the field. Driven by the overt recognition of such a potential obstacle, a panel of leading experts in the field attempts here to define several autophagy‐related terms based on specific biochemical features. The ultimate objective of this collaborative exchange is to formulate recommendations that facilitate the dissemination of knowledge within and outside the field of autophagy research.
Differential inhibitory effects of CrmA, P35, IAP and three mammalian IAP homologues on apoptosis in NIH3T3 cells following various death stimuli.
Publisher: Springer Science and Business Media LLC
Date: 10-1997
Global ubiquitinome profiling identifies NEDD4 as a regulator of Profilin 1 and actin remodelling in neural crest cells
Publisher: Springer Science and Business Media LLC
Date: 19-04-2022
DOI: 10.1038/S41467-022-29660-3
Abstract: The ubiquitin ligase NEDD4 promotes neural crest cell (NCC) survival and stem-cell like properties to regulate craniofacial and peripheral nervous system development. However, how ubiquitination and NEDD4 control NCC development remains unknown. Here we combine quantitative analysis of the proteome, transcriptome and ubiquitinome to identify key developmental signalling pathways that are regulated by NEDD4. We report 276 NEDD4 targets in NCCs and show that loss of NEDD4 leads to a pronounced global reduction in specific ubiquitin lysine linkages. We further show that NEDD4 contributes to the regulation of the NCC actin cytoskeleton by controlling ubiquitination and turnover of Profilin 1 to modulate filamentous actin polymerization. Taken together, our data provide insights into how NEDD4-mediated ubiquitination coordinates key regulatory processes during NCC development.
DRONC, an ecdysone-inducible Drosophila caspase
Publisher: Proceedings of the National Academy of Sciences
Date: 13-04-1999
Abstract: Caspases play an essential role in the execution of programmed cell death in metazoans. Although 14 caspases are known in mammals, only a few have been described in other organisms. Here we describe the identification and characterization of a Drosophila caspase, DRONC, that contains an amino terminal caspase recruitment domain. Ectopic expression of DRONC in cultured cells resulted in apoptosis, which was inhibited by the caspase inhibitors p35 and MIHA. DRONC exhibited a substrate specificity similar to mammalian caspase-2. DRONC is ubiquitously expressed in Drosophila embryos during early stages of development. In late third instar larvae, dronc mRNA is dramatically up-regulated in salivary glands and midgut before histolysis of these tissues. Exposure of salivary glands and midgut isolated from second instar larvae to ecdysone resulted in a massive increase in dronc mRNA levels. These results suggest that DRONC is an effector of steroid-mediated apoptosis during insect metamorphosis.
Enhancing DNA vaccine potency by coadministration of DNA encoding antiapoptotic proteins
Publisher: American Society for Clinical Investigation
Date: 07-2003
DOI: 10.1172/JCI200317293
Mechanisms mediating caspase activation in cell death.
Publisher: Springer Science and Business Media LLC
Date: 11-1999
Abstract: The initial activation of a caspase in a caspase cascade is a crucial event that determines whether a cell will ultimately undergo cell death. Although each cell contains a number of different caspases, only a small subset may be required for apoptosis in response to a specific stimulus. It now seems that each caspase cascade has two types of caspases involved, the upstream or class I caspases, and the downstream or class II caspases. Class I caspases are characterised by long amino-terminal prodomains that carry specific protein - protein interaction domains which mediate oligomerisation of caspases, often assisted by specific adaptor molecules. Oligomerisation appears to be sufficient for autocatalytic activation of class I caspases. Once the first caspase in the pathway has been activated, it processes downstream caspases initiating a cascade of lifying events that lead to the apoptotic death of a cell. This article reviews our current understanding of mechanisms that mediate the activation of caspases.
The Nedd4-like Protein KIAA0439 is a Potential Regulator of the Epithelial Sodium Channel
Publisher: Elsevier BV
Date: 03-2001
The two cytochrome c species, DC3 and DC4, are not required for caspase activation and apoptosis in Drosophila cells
Publisher: Rockefeller University Press
Date: 08-11-2004
Abstract: In Drosophila, activation of the apical caspase DRONC requires the apoptotic protease-activating factor homologue, DARK. However, unlike caspase activation in mammals, DRONC activation is not accompanied by the release of cytochrome c from mitochondria. Drosophila encodes two cytochrome c proteins, Cytc-p (DC4) the predominantly expressed species, and Cytc-d (DC3), which is implicated in caspase activation during spermatogenesis. Here, we report that silencing expression of either or both DC3 and DC4 had no effect on apoptosis or activation of DRONC and DRICE in Drosophila cells. We find that loss of function mutations in dc3 and dc4, do not affect caspase activation during Drosophila development and that ectopic expression of DC3 or DC4 in Drosophila cells does not induce caspase activation. In cell-free studies, recombinant DC3 or DC4 failed to activate caspases in Drosophila cell lysates, but remarkably induced caspase activation in extracts from human cells. Overall, our results argue that DARK-mediated DRONC activation occurs independently of cytochrome c.
The role of extracellular vesicles in sperm function and male fertility
Publisher: Springer International Publishing
Date: 2021
Drosophila as a model to understand autophagy deregulation in human disorders
Publisher: Elsevier
Date: 2020
Regulation of neuronal voltage-gated sodium channels by the ubiquitin-protein ligases Nedd4 and Nedd4-2.
Publisher: Elsevier BV
Date: 07-2004
cDNA cloning, expression analysis, and mapping of the mouse Nedd4 gene
Publisher: Elsevier BV
Date: 03-1997
Abstract: The Nedd4 gene was initially identified by a subtraction cloning approach as a highly expressed transcript in the mouse embryonic brain. Cloning of the Nedd4 cDNA indicated that it can encode a protein of approximately 103 kDa, consisting of a Ca2+ and phospholipid binding domain, three putative protein-protein interaction domains (the WW domains), and a carboxyl-terminus region similar to the ubiquitin-protein ligase domain (hect domain). In mouse embryos, the expression of Nedd4 in the central nervous system is highest during neurogenesis and decreases as development progresses. In addition to the central nervous system, the expression of Nedd4 is detected in various embryonic tissues and persists in most adult tissues. Using an antibody raised against a fusion protein, we show that Nedd4 protein is localized to the cellular cytoplasm. We have mapped the mouse Nedd4 gene to chromosome 9 using an interspecific backcross panel. Nedd4 maps to a previously defined homologous region between human and mouse chromosomes and thus provides additional information regarding interspecies comparative mapping.
Mammalian HECT ubiquitin-protein ligases: Biological and pathophysiological aspects
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.BBAMCR.2013.03.024
Abstract: Members of the HECT family of E3 ubiquitin-protein ligases are characterized by a C-terminal HECT domain that catalyzes the covalent attachment of ubiquitin to substrate proteins and by N-terminal extensions of variable length and domain architecture that determine the substrate spectrum of a respective HECT E3. Since their discovery in 1995, it has become clear that deregulation of distinct HECT E3s plays an eminent role in human disease or disease-related processes including cancer, cardiovascular and neurological disorders, viral infections, and immune response. Thus, a detailed understanding of the structure-function aspects of HECT E3s as well as the identification and characterization of the substrates and regulators of HECT E3s is critical in developing new approaches in the treatment of respective diseases. In this review, we summarize what is currently known about mammalian HECT E3s, with a focus on their biological functions and roles in pathophysiology.This article is part of a Special Issue entitled: Ubiquitin-Proteasome System. Guest Editors: Thomas Sommer and Dieter H. Wolf.
Guidelines for the use and interpretation of assays for monitoring autophagy
Publisher: Informa UK Limited
Date: 04-2012
DOI: 10.4161/AUTO.19496
Regulation of the divalent metal ion transporter via membrane budding.
Publisher: Springer Science and Business Media LLC
Date: 21-06-2016
Abstract: The release of extracellular vesicles (EVs) is important for both normal physiology and disease. However, a basic understanding of the targeting of EV cargoes, composition and mechanism of release is lacking. Here we present evidence that the alent metal ion transporter (DMT1) is unexpectedly regulated through release in EVs. This process involves the Nedd4-2 ubiquitin ligase, and the adaptor proteins Arrdc1 and Arrdc4 via different budding mechanisms. We show that mouse gut explants release endogenous DMT1 in EVs. Although we observed no change in the relative amount of DMT1 released in EVs from gut explants in Arrdc1 or Arrdc4 deficient mice, the extent of EVs released was significantly reduced indicating an adaptor role in biogenesis. Furthermore, using Arrdc1 or Arrdc4 knockout mouse embryonic fibroblasts, we show that both Arrdc1 and Arrdc4 are non-redundant positive regulators of EV release. Our results suggest that DMT1 release from the plasma membrane into EVs may represent a novel mechanism for the maintenance of iron homeostasis, which may also be important for the regulation of other membrane proteins.
Characterization of autophagic responses in Drosophila melanogaster.
Publisher: Elsevier
Date: 2017
DOI: 10.1016/BS.MIE.2016.09.089
Abstract: Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of in idual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and in idual steps in Drosophila melanogaster, will be discussed.
Regulation of functional diversity within the Nedd4 family by accessory and adaptor proteins
Publisher: Wiley
Date: 2006
DOI: 10.1002/BIES.20422
Abstract: Ubiquitination is essential in mediating erse cellular functions including protein degradation and trafficking. Ubiquitin-protein (E3) ligases determine the substrate specificity of the ubiquitination process. The Nedd4 family of E3 ligases is an evolutionarily conserved family of proteins required for the ubiquitination of a large number of cellular targets. As a result, this family regulates a wide variety of cellular processes including transcription, stability and trafficking of plasma membrane proteins, and the degradation of misfolded proteins. The modular architecture of the proteins, comprising a C2 domain, multiple WW domains and a catalytic domain, enables erse intermolecular interactions and recruitment to various subcellular locations. The WW domains commonly mediate interaction with substrate proteins however, an increasing number of Nedd4 targets do not contain obvious WW domain-interaction motifs suggesting the involvement of accessory proteins. This review discusses recent insights into how accessory and adaptor proteins modulate the activities of Nedd4 family members, including recruitment of novel substrates, alteration of subcellular localisation and effects on ubiquitination.
Regulation of the epithelial Na+ channel by the RH domain of G protein-coupled receptor kinase, GRK2, and Gαq/11
Publisher: Elsevier BV
Date: 06-2011
The activity of the epithelial sodium channels is regulated by caveolin-1 via a Nedd4-2-dependent mechanism
Publisher: Elsevier BV
Date: 05-2009
Crosstalk between Dpp and Tor signaling coordinates autophagy-dependent midgut degradation
Publisher: Springer Science and Business Media LLC
Date: 08-02-2019
DOI: 10.1038/S41419-019-1368-9
Abstract: The majority of developmentally programmed cell death (PCD) is mediated by caspase-dependent apoptosis however, additional modalities, including autophagy-dependent cell death, have important spatiotemporally restricted functions. Autophagy involves the engulfment of cytoplasmic components in a double membrane vesicle for delivery to the lysosome. An established model for autophagy-dependent PCD is Drosophila larval midgut removal during metamorphosis. Our previous work demonstrated that growth arrest is required to initiate autophagy-dependent midgut degradation and Target of rapamycin (Tor) limits autophagy induction. In further studies, we uncovered a role for Decapentaplegic (Dpp) in coordinating midgut degradation. Here, we provide new data to show that Dpp interacts with Tor during midgut degradation. Inhibiting Tor rescued the block in midgut degradation due to Dpp signaling. We propose that Dpp is upstream of Tor and down-regulation promotes growth arrest and autophagy-dependent midgut degradation. These findings underscore a relationship between Dpp and Tor signaling in the regulation of cell growth and tissue removal.
Ticket to a bubble ride: Cargo sorting into exosomes and extracellular vesicles
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.BBAPAP.2019.02.005
Abstract: Extracellular vesicles (EVs) are released by cells into the extracellular milieu to facilitate intercellular communication in both physiological and pathological condition. EVs contain selective repertoires of proteins, RNAs, lipids and metabolites that moderate signalling pathways in the recipient cells. The enrichment of a particular set of proteins or RNAs within the EVs highlights the existence of specific sorting mechanisms that orchestrate the selective packaging of the cargo. The molecular machinery of cargo sorting has remained obscure over the years and functional studies are required to understand this complex mechanism. In this article, we offer a brief overview of the molecular mechanisms that are known to regulate sorting of various molecules into EVs. We also discuss how different pathways of biogenesis alter the exosomal cargo as well and the implications of the cellular state on the content of the EVs. Understanding the sorting of exosomal cargo could further be exploited in clinical settings for targeted drug delivery and to block disease progression.
Coupling of histone mRNA levels to radioresistant DNA synthesis in ataxia-telangiectasia cells
Publisher: Springer Science and Business Media LLC
Date: 1987
DOI: 10.1007/BF00229375
Abstract: Acyclic nucleoside phosphonates (ANPs), such as (S)-1-[(3-hydroxy-2-phosphonomethoxy)propyl)]cytosine (HPMPC), are an important group of broad-spectrum antiviral agents with activity against DNA viruses. In this report, we present the in vitro potencies of novel ANPs against gammaherpesviruses, including Kaposi's sarcoma-associated herpesvirus, Epstein-Barr virus (EBV), and three animal gammaherpesviruses. 1-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-5-azacytosine (HPMP-5-azaC), (S)-9-[3-hydroxy-2-(phosphonomethoxy)propyl]-3-deazaadenine (3-deaza-HPMPA), and their cyclic derivatives have emerged as highly potent antigammaherpesvirus agents. Interestingly, cyclic prodrugs of ANPs exhibited reduced activities against EBV strain P3HR-1, but not against EBV strain Akata. Cell culture metabolism studies with HPMPC and cyclic HPMPC revealed that these differences were attributable to an altered drug metabolism in P3HR-1 cells after EBV reactivation and, more specifically, to a reduced hydrolysis of cyclic HPMPC by cyclic CMP phosphodiesterase. We did not correlate this effect with phosphodiesterase downregulation, or to functional mutations. Instead, altered cyclic AMP levels in P3HR-1 cells indicated a competitive inhibition of the phosphodiesterase by this cyclic nucleotide. Finally, both HPMPC and HPMP-5-azaC emerged as highly effective inhibitors in vivo through significant inhibition of murine gammaherpesvirus replication and dissemination. With the current need for potent antigammaherpesvirus agents, our findings underline the requirement of appropriate surrogate viruses for antiviral susceptibility testing and highlight HPMP-5-azaC as a promising compound for future clinical development.
Structure of the Drosophila Apoptosome at 6.9 Å Resolution
Publisher: Elsevier BV
Date: 2011
A biochemical analysis of the activation of the Drosophila caspase DRONC
Publisher: Springer Science and Business Media LLC
Date: 14-12-2008
Abstract: The activation of caspases is the principal event in the execution of apoptosis. Initiator caspases are activated through an autocatalytic mechanism often involving dimerisation or oligomerisation. In Drosophila, the only initiator caspase DRONC, is tightly inhibited by DIAP1 and removal of DIAP1 permits activation of DRONC by the Drosophila Apaf-1-related killer, ARK. ARK is proposed to facilitate DRONC oligomerisation and autoprocessing at residue E352. This study examines whether autoprocessing of DRONC is required for its activation and for DRONC-mediated cell death. Using purified recombinant proteins, we show here that while DRONC autocleaves at residue E352, mutation of this site did not abolish enzyme activation, DRICE-induced cleavage of DRONC or DRONC-mediated activation of DRICE. We performed a detailed mutational analysis of DRONC cleavage sites and show that overexpression of DRONC cleavage mutants in Drosophila cells retain pro-apoptotic activity. Using an in vitro cell-free assay, we found ARK alone did not activate DRONC and demonstrate a requirement for an additional cytosolic factor in ARK-mediated DRONC activation. These results suggest that, similar to mammalian caspase-2 and caspase-9, the initial cleavage of DRONC is not essential for its activation and suggest a mechanism of ARK-mediated DRONC activation different from that proposed previously.
NEDD4-2-dependent control of Na+ homeostasis and renal disease
Publisher: Informa UK Limited
Date: 26-12-2017
The apical caspase dronc governs programmed and unprogrammed cell death in drosophila
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.DEVCEL.2004.09.016
Abstract: Among the seven caspases encoded in the fly genome, only dronc contains a caspase recruitment domain. To assess the function of this gene in development, we produced a null mutation in dronc. Animals lacking zygotic dronc are defective for programmed cell death (PCD) and arrest as early pupae. These mutants present a range of defects, including extensive hyperplasia of hematopoietic tissues, supernumerary neuronal cells, and head involution failure. dronc genetically interacts with the Ced4/Apaf1 counterpart, Dark, and adult structures lacking dronc are disrupted for fine patterning. Furthermore, in erse models of metabolic injury, dronc- cells are completely insensitive to induction of cell killing. These findings establish dronc as an essential regulator of cell number in development and illustrate broad requirements for this apical caspase in adaptive responses during stress-induced apoptosis.
Selective regulation of apoptosis: the cytotoxic lymphocyte serpin proteinase inhibitor 9 protects against granzyme B-mediated apoptosis without perturbing the Fas cell death pathway.
Publisher: Informa UK Limited
Date: 11-1998
p53 accumulation following cytokinesis failure in the absence of caspase-2
Publisher: Springer Science and Business Media LLC
Date: 06-08-2018
Drosophila caspase DRONC is required for specific developmental cell death pathways and stress-induced apoptosis
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.DEVCEL.2004.09.018
Abstract: Proteases of the caspase family play key roles in the execution of apoptosis. In Drosophila there are seven caspases, but their roles in cell death have not been studied in detail due to a lack of availability of specific mutants. Here, we describe the generation of a specific mutant of the Drosophila gene encoding DRONC, the only caspase recruitment domain (CARD) containing apical caspase in the fly. dronc mutants are pupal lethal and our studies show that DRONC is required for many forms of developmental cell deaths and apoptosis induced by DNA damage. Furthermore, we demonstrate that DRONC is required for the autophagic death of larval salivary glands during metamorphosis, but not for histolysis of larval midguts. Our results indicate that DRONC is involved in specific developmental cell death pathways and that in some tissues, effector caspase activation and cell death can occur independently of DRONC.
Caspase-2 and the oxidative stress response
Publisher: Informa UK Limited
Date: 23-01-2015
Caspase-mediated cleavage of the ubiquitin-protein ligase Nedd4 during apoptosis
Publisher: Elsevier BV
Date: 05-1998
Apaf-1 and caspase-9 accelerate apoptosis, but do not determine whether factor-deprived or drug-treated cells die
Publisher: Rockefeller University Press
Date: 21-06-2004
Abstract: Apoptosis after growth factor withdrawal or drug treatment is associated with mitochondrial cytochrome c release and activation of Apaf-1 and caspase-9. To determine whether loss of Apaf-1, caspase-2, and caspase-9 prevented death of factor-starved cells, allowing them to proliferate when growth factor was returned, we generated IL-3–dependent myeloid lines from gene-deleted mice. Long after growth factor removal, cells lacking Apaf-1, caspase-9 or both caspase-9 and caspase-2 appeared healthy, retained intact plasma membranes, and did not expose phosphatidylserine. However, release of cytochrome c still occurred, and they failed to form clones when IL-3 was restored. Cells lacking caspase-2 alone had no survival advantage. Therefore, Apaf-1, caspase-2, and caspase-9 are not required for programmed cell death of factor-dependent cells, but merely affect its rate. In contrast, transfection with Bcl-2 provided long-term, clonogenic protection, and could act independently of the apoptosome. Unlike expression of Bcl-2, loss of Apaf-1, caspase-2, or caspase-9 would therefore be unlikely to enhance the survival of cancer cells.
Caspases in developmental cell death
Publisher: Informa UK Limited
Date: 08-1999
ICE-like proteases in apoptosis
Publisher: Elsevier BV
Date: 05-1995
DOI: 10.1016/S0968-0004(00)89007-6
Abstract: The discovery of structural and functional similarities between the product of the nematode cell-death gene ced-3 and mammalian interleukin-1 beta-converting enzyme (ICE) is providing important insights into the molecular mechanism of apoptosis. This article summarizes the current knowledge of ICE and its homologues, and how these may be involved in regulating apoptosis.
Caspases connect cell-death signaling to organismal homeostasis
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.IMMUNI.2016.01.020
Abstract: Some forms of regulated cell death, such as apoptosis, are precipitated by the activation of cysteine proteases of the caspase family, including caspase 8, 9, and 3. Other caspases, such as caspase 1 and 4, are well known for their pro-inflammatory functions but regulate cell death in a limited number of pathophysiological settings. Accumulating evidence suggests that the most conserved function of mammalian caspases is not to control cell death sensu stricto, but to regulate inflammatory and immune reactions to dying cells and infectious challenges. Here, we review the molecular and cellular mechanisms though which mammalian caspases connect cell-death signaling to the maintenance of organismal homeostasis.
Heteronuclear ribonucleoproteins C1 and C2, components of the spliceosome, are specific targets of interleukin 1β-converting enzyme-like proteases in apoptosis
Publisher: Elsevier BV
Date: 11-1996
Nedd4 and Nedd4-2: Closely related ubiquitin-protein ligases with distinct physiological functions
Publisher: Springer Science and Business Media LLC
Date: 26-06-2010
DOI: 10.1038/CDD.2009.84
Prodomains - adaptors - oligomerization: The pursuit of caspase activation in apoptosis
Publisher: Elsevier BV
Date: 1999
A cinderella caspase takes center stage
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-08-2002
The histone deacetylase SIRT2 stabilizes Myc oncoproteins
Publisher: Springer Science and Business Media LLC
Date: 23-11-2012
DOI: 10.1038/CDD.2012.147
Receptor Recycling by Retromer
Publisher: Informa UK Limited
Date: 23-06-2023
Arrestin-domain containing protein 1 (Arrdc1) regulates the protein cargo and release of extracellular vesicles
Publisher: Wiley
Date: 20-08-2018
Abstract: Extracellular vesicles (EVs) are lipid-bilayered vesicles that are released by multiple cell types and contain nucleic acids and proteins. Very little is known about how the cargo is packaged into EVs. Ubiquitination of proteins is a key posttranslational modification that regulates protein stability and trafficking to subcellular compartments including EVs. Recently, arrestin-domain containing protein 1 (Arrdc1), an adaptor for the Nedd4 family of ubiquitin ligases, has been implicated in the release of ectosomes, a subtype of EV that buds from the plasma membrane. However, it is currently unknown whether Arrdc1 can regulate the release of exosomes, a class of EVs that are derived endocytically. Furthermore, it is unclear whether Arrdc1 can regulate the sorting of protein cargo into the EVs. Exosomes and ectosomes are isolated from mouse embryonic fibroblasts isolated from wild type and Arrdc1-deficient (Arrdc1
The Caspase Family of Proteases
Publisher: Elsevier
Date: 2023
Role of prodomain in importin-mediated nuclear localization and activation of caspase-2
Publisher: Elsevier BV
Date: 02-2003
Patch-clamp studies on epithelial sodium channels in salivary duct cells
Publisher: Springer Science and Business Media LLC
Date: 2002
Abstract: Mouse mandibular salivary duct cells contain an amiloride-sensitive Na+ current and express all three subunits of the epithelial Na+ channel, ENaC. This amiloride-sensitive Na+ current is subject to feedback regulation by intracellular Na+ and we have previously demonstrated that this regulation is mediated by an ubiquitin-protein ligase, which we identified as Nedd4. The evidence supporting this identification is as follows: (1) antibodies raised against murine Nedd4 block Na+ feedback inhibition (2) a mutant of murine Nedd4 containing the WW domains but no HECT domain (ubiquitin-protein ligase) blocks Na+ feedback inhibition and (3) Nedd4 is expressed in mouse mandibular salivary duct cells. In the present studies, we have used whole-cell patch-cl methods to further investigate the mechanisms by which ubiquitin-protein ligases regulate the amiloride-sensitive Na+ conductance in mouse salivary duct cells. In particular, we have examined the possibility that the ubiquitin-protein ligase, KIAA0439, which is closely related to Nedd4, may mediate Na+ feedback control of amiloride-sensitive Na+ channels. Furthermore, we have attempted to define the mechanism by which ubiquitin-protein ligases inhibit Na+ channels. We have found that KIAA0439 is expressed in mouse mandibular ducts and interacts with the PY motifs of the alpha-, beta-, and gamma-subunits of ENaC in vitro. Furthermore, in whole-cell patch-cl studies, a glutathione-S-transferase (GST)-fusion protein containing the WW motifs of human KIAA0439 was able to inhibit feedback regulation of the amiloride-sensitive Na+ current by intracellular Na+. We also examined whether GST-fusion proteins containing the C-termini of the alpha-, beta-, and gamma-subunits of ENaC are able to interrupt Na+ feedback regulation of the amiloride-sensitive Na+ current. We found that the C-termini of the beta- and gamma-subunits were able to do so, whereas the C-terminus of the alpha-subunit was not. We conclude that KIAA0439 is, together with Nedd4, a potential mediator of the control of epithelial Na+ channels in salivary duct cells by intracellular Na+. We further conclude that ubiquitin-protein ligases interact with the Na+ channels through the C-termini of the beta- and gamma-subunits of the Na+ channels.
Caspases in cell death.
Publisher: Springer Berlin Heidelberg
Date: 1998
Apoptosis regulatory gene NEDD2 maps to human chromosome segment 7q34-35, a region frequently affected in haematological neoplasms
Publisher: Springer Science and Business Media LLC
Date: 06-1995
DOI: 10.1007/BF00209480
Putative functions of caspase-2
Publisher: Faculty Opinions Ltd
Date: 15-12-2009
DOI: 10.3410/B1-96
Transcriptome profiling of caspase-2 deficient EμMyc and Th-MYCN mouse tumors identifies distinct putative roles for caspase-2 in neuronal differentiation and immune signaling.
Publisher: Springer Science and Business Media LLC
Date: 22-01-2019
DOI: 10.1038/S41419-018-1296-0
Abstract: Caspase-2 is a highly conserved cysteine protease with roles in apoptosis and tumor suppression. Our recent findings have also demonstrated that the tumor suppression function of caspase-2 is context specific. In particular, while caspase-2 deficiency augments lymphoma development in the EμMyc mouse model, it leads to delayed neuroblastoma development in Th-MYCN mice. However, it is unclear how caspase-2 mediates these differential outcomes. Here we utilized RNA sequencing to define the transcriptomic changes caused by caspase-2 ( Casp2 −/− ) deficiency in tumors from EμMyc and Th-MYCN mice. We describe key changes in both lymphoma and neuroblastoma-associated genes and identified differential expression of the EGF-like domain-containing gene, Megf6 , in the two tumor types that may contribute to tumor outcome following loss of Casp2 . We identified a panel of genes with altered expression in Th-MYCN/Casp2 −/− tumors that are strongly associated with neuroblastoma outcome, with roles in melanogenesis, Wnt and Hippo pathway signaling, that also contribute to neuronal differentiation. In contrast, we found that key changes in gene expression in the EμMyc/Casp2 −/− tumors, are associated with increased immune signaling and T-cell infiltration previously associated with more aggressive lymphoma progression. In addition, Rap1 signaling pathway was uniquely enriched in Casp2 deficient EμMyc tumors. Our findings suggest that Casp2 deficiency augments immune signaling pathways that may be in turn, enhance lymphomagenesis. Overall, our study has identified new genes and pathways that contribute to the caspase-2 tumor suppressor function and highlight distinct roles for caspase-2 in different tissues.
NEDD4-2 as a potential candidate susceptibility gene for epileptic photosensitivity.
Publisher: Wiley
Date: 09-01-2007
A novel Apaf-1-independent putative caspase-2 activation complex
Publisher: Rockefeller University Press
Date: 02-12-2002
Abstract: CVaspase activation is a key event in apoptosis execution. In stress-induced apoptosis, the mitochondrial pathway of caspase activation is believed to be of central importance. In this pathway, cytochrome c released from mitochondria facilitates the formation of an Apaf-1 apoptosome that recruits and activates caspase-9. Recent data indicate that in some cells caspase-9 may not be the initiator caspase in stress-mediated apoptosis because caspase-2 is required upstream of mitochondria for the release of cytochrome c and other apoptogenic factors. To determine how caspase-2 is activated, we have studied the formation of a complex that mediates caspase-2 activation. Using gel filtration analysis of cell lysates, we show that caspase-2 is spontaneously recruited to a large protein complex independent of cytochrome c and Apaf-1 and that recruitment of caspase-2 to this complex is sufficient to mediate its activation. Using substrate-binding assays, we also provide the first evidence that caspase-2 activation may occur without processing of the precursor molecule. Our data are consistent with a model where caspase-2 activation occurs by oligomerization, independent of the Apaf-1 apoptosome.
Isoform specific regulation of divalent metal (ion) transporter (DMT1) by proteasomal degradation
Publisher: Springer Science and Business Media LLC
Date: 07-02-2012
A potential role for NEDD1 and the centrosome in senescence of mouse embryonic fibroblasts
Publisher: Springer Science and Business Media LLC
Date: 15-04-2010
Nedd4-WW domain-binding protein 5 (Ndfip1) is associated with neuronal survival after acute cortical brain injury.
Publisher: Society for Neuroscience
Date: 05-07-2006
DOI: 10.1523/JNEUROSCI.1398-06.2006
Abstract: Understanding the transcriptional response to neuronal injury after trauma is a necessary prelude to formulation of therapeutic strategies. We used Serial Analysis of Gene Expression (SAGE) to identify 50,000 sequence tags representing 18,000 expressed genes in the cortex 2 h after traumatic brain injury (TBI). A similar tag library was obtained from sham-operated cortex. The SAGE data were validated on biological replicates using quantitative real-time-PCR on multiple s les at 2, 6, 12, and 24 h after TBI. This analysis revealed that the vast majority of genes showed a downward trend in their pattern of expression over 24 h. This was confirmed for a subset of genes using in situ hybridization and immunocytochemistry on brain sections. Of the overexpressed genes in the trauma library, Nedd4-WW (neural precursor cell expressed, developmentally downregulated) domain-binding protein 5 (N4WBP5) (also known as Ndfip1) is strongly expressed in surviving neurons around the site of injury. Overexpression of N4WBP5 in cultured cortical neurons increased the number of surviving neurons after gene transfection and growth factor starvation compared with control transfections. These results identify N4WBP5 as a neuroprotective protein and, based on its known interaction with the ubiquitin ligase Nedd4, would suggest protein ubiquitination as a possible survival strategy in neuronal injury.
Ecdysone receptor directly binds the promoter of the Drosophila caspase dronc, regulating its expression in specific tissues
Publisher: Rockefeller University Press
Date: 06-2004
Abstract: The steroid hormone ecdysone regulates moulting, cell death, and differentiation during insect development. Ecdysone mediates its biological effects by either direct activation of gene transcription after binding to its receptor EcR–Usp or via hierarchical transcriptional regulation of several primary transcription factors. In turn, these transcription factors regulate the expression of several downstream genes responsible for specific biological outcomes. DRONC, the Drosophila initiator caspase, is transcriptionally regulated by ecdysone during development. We demonstrate here that the dronc promoter directly binds EcR–Usp. We further show that mutation of the EcR–Usp binding element (EcRBE) reduces transcription of a reporter and abolishes transactivation by an EcR isoform. We demonstrate that EcRBE is required for temporal regulation of dronc expression in response to ecdysone in specific tissues. We also uncover the participation of a putative repressor whose function appears to be coupled with EcR–Usp. These results indicate that direct binding of EcR–Usp is crucial for controlling the timing of dronc expression in specific tissues.
Debcl, a proapoptotic Bcl-2 homologue, is a component of the Drosophila melanogaster cell death machinery
Publisher: Rockefeller University Press
Date: 21-02-2000
Abstract: Bcl-2 family of proteins are key regulators of apoptosis. Both proapoptotic and antiapoptotic members of this family are found in mammalian cells, but no such proteins have been described in insects. Here, we report the identification and characterization of Debcl, the first Bcl-2 homologue in Drosophila melanogaster. Structurally, Debcl is similar to Bax-like proapoptotic Bcl-2 family members. Ectopic expression of Debcl in cultured cells and in transgenic flies causes apoptosis, which is inhibited by coexpression of the baculovirus caspase inhibitor P35, indicating that Debcl is a proapoptotic protein that functions in a caspase-dependent manner. debcl expression correlates with developmental cell death in specific Drosophila tissues. We also show that debcl genetically interacts with diap1 and dark, and that debcl-mediated apoptosis is not affected by gene dosage of rpr, hid, and grim. Biochemically, Debcl can interact with several mammalian and viral prosurvival Bcl-2 family members, but not with the proapoptotic members, suggesting that it may regulate apoptosis by antagonizing prosurvival Bcl-2 proteins. RNA interference studies indicate that Debcl is required for developmental apoptosis in Drosophila embryos. These results suggest that the main components of the mammalian apoptosis machinery are conserved in insects.
Using synthetic peptide substrates to measure Drosophila caspase activity
Publisher: Cold Spring Harbor Laboratory
Date: 07-2015
Abstract: Central to the apoptotic pathway is the activation of caspases that are members of a highly conserved family of cysteine proteases. Caspases are synthesized as inactive zymogens and are generally activated by proteolytic cleavage to form the catalytically active enzyme. Caspase activity in apoptotic cells can be measured by assessing the cleavage of commercially available synthetic caspase substrates. The synthetic substrates contain a caspase cleavage site conjugated to a fluorochrome, such as 7-amino-4-methylcoumarin (AMC), or a chromophore, such as p -nitroaniline (pNA), for colorimetric detection. Here, we present a protocol for the measurement of caspase activity in Drosophila cell extracts by cleavage of the target peptide in the synthetic substrate that releases a fluorochrome or color-producing agent. The signal is measured by a spectrophotometer, with the intensity of the signal being proportional to the amount of substrate cleaved.
The biology of caspases
Publisher: Humana Press
Date: 2007
Old, new and emerging functions of caspases
Publisher: Springer Science and Business Media LLC
Date: 19-12-2015
DOI: 10.1038/CDD.2014.216
Dimerization and autoprocessing of the Nedd2 (Caspase-2) precursor requires both the prodomain and the carboxyl-terminal regions
Publisher: Elsevier BV
Date: 03-1998
TRIM21 Is Targeted for Chaperone-Mediated Autophagy during Salmonella Typhimurium Infection
Publisher: The American Association of Immunologists
Date: 11-2020
Abstract: Salmonella enterica serovar Typhimurium (S. Typhimurium) is a Gram-negative bacterium that induces cell death of macrophages as a key virulence strategy. We have previously demonstrated that the induction of macrophage death is dependent on the host’s type I IFN (IFN-I) response. IFN-I signaling has been shown to induce tripartite motif (TRIM) 21, an E3 ubiquitin ligase with critical functions in autoimmune disease and antiviral immunity. However, the importance and regulation of TRIM21 during bacterial infection remains poorly understood. In this study, we investigated the role of TRIM21 upon S. Typhimurium infection of murine bone marrow–derived macrophages. Although Trim21 expression was induced in an IFN-I–dependent manner, we found that TRIM21 levels were mainly regulated posttranscriptionally. Following TLR4 activation, TRIM21 was transiently degraded via the lysosomal pathway by chaperone-mediated autophagy (CMA). However, S. Typhimurium–induced mTORC2 signaling led to phosphorylation of Akt at S473, which subsequently impaired TRIM21 degradation by attenuating CMA. Elevated TRIM21 levels promoted macrophage death associated with reduced transcription of NF erythroid 2–related factor 2 (NRF2)–dependent antioxidative genes. Collectively, our results identify IFN-I–inducible TRIM21 as a negative regulator of innate immune responses to S. Typhimurium and a previously unrecognized substrate of CMA. To our knowledge, this is the first study reporting that a member of the TRIM family is degraded by the lysosomal pathway.
Retromer regulates the lysosomal clearance of MAPT/tau.
Publisher: Informa UK Limited
Date: 22-09-2020
Ecdysone-mediated up-regulation of the effector caspase DRICE Is required for hormone-dependent apoptosis in drosophila cells
Publisher: Elsevier BV
Date: 03-2005
The ubiquitin ligase NEDD4-2/NEDD4L regulates both sodium homeostasis and fibrotic signaling to prevent end-stage renal disease
Publisher: Springer Science and Business Media LLC
Date: 14-04-2021
DOI: 10.1038/S41419-021-03688-7
Abstract: Kidney disease progression can be affected by Na + abundance. A key regulator of Na + homeostasis is the ubiquitin ligase NEDD4-2 and its deficiency leads to increased Na + transport activity and salt-sensitive progressive kidney damage. However, the mechanisms responsible for high Na + induced damage remain poorly understood. Here we show that a high Na + diet compromised kidney function in Nedd4-2 -deficient mice, indicative of progression toward end-stage renal disease. Injury was characterized by enhanced tubule dilation and extracellular matrix accumulation, together with sustained activation of both Wnt/β-catenin and TGF-β signaling. Nedd4-2 knockout in cortical collecting duct cells also activated these pathways and led to epithelial–mesenchymal transition. Furthermore, low dietary Na + rescued kidney disease in Nedd4-2 -deficient mice and silenced Wnt/β-catenin and TGF-β signaling. Our study reveals the important role of NEDD4-2-dependent ubiquitination in Na + homeostasis and protecting against aberrant Wnt/β-catenin/TGF-β signaling in progressive kidney disease.
Induction of apoptosis by the mouse Nedd2 gene, which encodes a protein similar to the product of the Caenorhabditis elegans cell death gene ced-3 and the mammalian IL-1 beta-converting enzyme.
Publisher: Cold Spring Harbor Laboratory
Date: 15-07-1994
Abstract: By subtraction cloning we previously identified a set of mouse genes (named Nedd1 through Nedd10) with developmentally down-regulated expression in brain. We now show that one such gene, Nedd2, encodes a protein similar to the mammalian interleukin-1 beta-converting enzyme (ICE) and the product of the Caenorhabditis elegans cell death gene ced-3 (CED-3). Both ICE and CED-3 are known to encode putative cysteine proteases and induce apoptosis when overexpressed in cultured cells. Overexpression of Nedd2 in cultured fibroblast and neuroblastoma cells also resulted in cell death by apoptosis, which was suppressed by the expression of the human bcl-2 gene, indicating that Nedd2 is functionally similar to the ced-3 gene in C. elegans. We also show that during embryonic development, Nedd2 is highly expressed in several types of mouse tissue undergoing high rates of programmed cell death such as central nervous system and kidney. Our data suggest that Nedd2 is an important component of the mammalian programmed cell death machinery.
dLKR/SDH regulates hormone-mediated histone arginine methylation and transcription of cell death genes
Publisher: Rockefeller University Press
Date: 11-08-2008
Abstract: The sequential modifications of histones form the basis of the histone code that translates into either gene activation or repression. Nuclear receptors recruit a cohort of histone-modifying enzymes in response to ligand binding and regulate proliferation, differentiation, and cell death. In Drosophila melanogaster, the steroid hormone ecdysone binds its heterodimeric receptor ecdysone receptor/ultraspiracle to spatiotemporally regulate the transcription of several genes. In this study, we identify a novel cofactor, Drosophila lysine ketoglutarate reductase (dLKR)/saccharopine dehydrogenase (SDH), that is involved in ecdysone-mediated transcription. dLKR/SDH binds histones H3 and H4 and suppresses ecdysone-mediated transcription of cell death genes by inhibiting histone H3R17me2 mediated by the Drosophila arginine methyl transferase CARMER. Our data suggest that the dynamic recruitment of dLKR/SDH to ecdysone-regulated gene promoters controls the timing of hormone-induced gene expression. In the absence of dLKR/SDH, histone methylation occurs prematurely, resulting in enhanced gene activation. Consistent with these observations, the loss of dLKR/SDH in Drosophila enhances hormone-regulated gene expression, affecting the developmental timing of gene activation.
Ndfip1 regulates nuclear Pten import in vivo to promote neuronal survival following cerebral ischemia
Publisher: Rockefeller University Press
Date: 02-01-2012
Abstract: PTEN (phosphatase and tensin homologue deleted on chromosome TEN) is the major negative regulator of phosphatidylinositol 3-kinase signaling and has cell-specific functions including tumor suppression. Nuclear localization of PTEN is vital for tumor suppression however, outside of cancer, the molecular and physiological events driving PTEN nuclear entry are unknown. In this paper, we demonstrate that cytoplasmic Pten was translocated into the nuclei of neurons after cerebral ischemia in mice. Critically, this transport event was dependent on a surge in the Nedd4 family–interacting protein 1 (Ndfip1), as neurons in Ndfip1-deficient mice failed to import Pten. Ndfip1 binds to Pten, resulting in enhanced ubiquitination by Nedd4 E3 ubiquitin ligases. In vitro, Ndfip1 overexpression increased the rate of Pten nuclear import detected by photobleaching experiments, whereas Ndfip1−/− fibroblasts showed negligible transport rates. In vivo, Ndfip1 mutant mice suffered larger infarct sizes associated with suppressed phosphorylated Akt activation. Our findings provide the first physiological ex le of when and why transient shuttling of nuclear Pten occurs and how this process is critical for neuron survival.
Renal tubular NEDD4-2 defciency causes NCC-mediated salt-dependent hypertension
Publisher: American Society for Clinical Investigation
Date: 25-01-2013
DOI: 10.1172/JCI61110
Chemokine receptors CXCR4 and CCR7 promote metastasis by preventing anoikis in cancer cells
Publisher: Springer Science and Business Media LLC
Date: 09-01-2009
DOI: 10.1038/CDD.2008.190
Abstract: Chemokine receptors are essential mediators of the metastatic spread in various cancer types however their precise function in the development of secondary tumors remains poorly understood. We report here a novel property of the chemokine receptors CXCR4 and CCR7 in inhibiting detachment-induced cell death--anoikis, which is believed to be one of the major blocks in the metastatic spread of various neoplasms. Activation of these chemokine receptors by their respective ligands, CXCL12 and CCL21 specifically reduced the sensitivity of metastatic breast cancer cells to anoikis by a distinct mechanism of selective regulation of pro-apoptotic Bmf and anti-apoptotic Bcl-xL proteins. Consequently, functional CXCR4 and CCR7 increased cell survival in the absence of correct ECM attachment both in vitro and in vivo. We also demonstrated that preventing chemokine-induced reduction in Bmf levels significantly attenuated breast cancer metastasis in an experimental mouse model. These results provide evidence for a previously unknown axis in malignant tumors, which connects chemokine receptors with deregulated apoptosis in the absence of the appropriate cell--ECM interaction and may offer novel targets for therapeutic intervention for the treatment of metastatic breast and potentially other tumors.
Ecdysone controlled cell and tissue deletion.
Publisher: Springer Science and Business Media LLC
Date: 19-11-2020
An unexpected role for caspase-2 in neuroblastoma
Publisher: Springer Science and Business Media LLC
Date: 21-08-2014
A direct interaction with NEDD1 regulates γ-tubulin recruitment to the centrosome
Publisher: Public Library of Science (PLoS)
Date: 10-03-2010
Transcriptional control of the core cell-death machinery
Publisher: Elsevier BV
Date: 04-2004
NEDD4: The founding member of a family of ubiquitin-protein ligases
Publisher: Elsevier BV
Date: 02-2015
The apoptotic cysteine protease CPP32
Publisher: Elsevier BV
Date: 03-1997
DOI: 10.1016/S1357-2725(96)00146-X
Abstract: CPP32 (also called Yama and apopain) is a member of a growing family of cysteine proteases which includes the interleukin-1 beta-converting enzyme (ICE) and the product of the Caenorhabditis elegans cell death gene ced-3. CPP32 has been consistently implicated as a key protease of the ICE/CED-3 family that is activated in response to a variety of death stimuli. Active CPP32 consists of P17 and p12 subunits derived from a 32 kDa pro-enzyme. This activation can be mediated by some ICE-like proteases and the cytotoxic T-cell (CTL) protease granzyme B. Once activated, CPP32 can process some of the other ICE family members and cleaves several cellular proteins in apoptotic cells. Inhibitors of CPP32 and other ICE-like proteases are potent inhibitors of apoptosis and promise to be important therapeutic molecules for the treatment of diseases, such as neurodegenerative and autoimmune disorders, that arise from excessive ell death.
Phosphorylation by Aurora B kinase regulates caspase-2 activity and function
Publisher: Cold Spring Harbor Laboratory
Date: 05-03-2020
DOI: 10.1101/2020.03.05.978056
Abstract: Mitotic catastrophe (MC) is an important oncosuppressive mechanism that serves to eliminate cells that become polyploid or aneuploidy due to aberrant mitosis. Previous studies have demonstrated that the activation and catalytic function of caspase-2 are key steps in MC to trigger apoptosis and/or cell cycle arrest of mitotically defective cells. However, the molecular mechanisms that regulate caspase-2 activation and its function are unclear. Here we identify six new phosphorylation sites in caspase-2 and show that a key mitotic kinase, Aurora B kinase (AURKB), phosphorylates caspase-2 at the highly conserved residue S384. We demonstrate that phosphorylation at S384 blocks caspase-2 catalytic activity and apoptosis function in response to mitotic insults, without affecting caspase-2 dimerisation. Moreover, molecular modelling suggests that phosphorylation at S384 may affect substrate binding by caspase-2. We propose that caspase-2 S384 phosphorylation by AURKB is a key mechanism that controls caspase-2 activation during mitosis.
An insulin-regulated arrestin domain protein controls hepatic glucagon action
Publisher: Elsevier BV
Date: 08-2023
Caspase-2 protocols.
Publisher: Springer New York
Date: 2014
DOI: 10.1007/978-1-4939-0357-3_4
Abstract: Caspase-2 has been shown to function in apoptosis and in some non-apoptotic pathways, including tumor suppression and aging. Caspase-2 has some unique features and is the only caspase that constitutively localizes to the nucleus, although its nuclear function remains unknown. During apoptosis signaling, caspase-2 rapidly homodimerizes, which leads to its activation and proteolytic processing. The activation of caspase-2 can be measured by assessing its dimerization and/or cleavage of the caspase-2 zymogen and its substrates. This chapter outlines commonly used methods to purify recombinant caspase-2 and assess its activity and function in vitro and in cultured cells or tissue extracts.
N4WBP5A (Ndfip2), a Nedd4-interacting protein, localizes to multivesicular bodies and the Golgi, and has a potential role in protein trafficking
Publisher: The Company of Biologists
Date: 15-07-2004
DOI: 10.1242/JCS.01212
Abstract: N4WBP5A (Ndfip2) belongs to an evolutionarily conserved group of Nedd4-interacting proteins with two homologues in mammalian species. We have previously shown that N4WBP5A expression in Xenopus oocytes results in increased cell-surface expression of the epithelial sodium channel. N4WBPs are characterized by one or two amino terminal PPxY motifs and three transmembrane domains. Here we show that both PPxY motifs of N4WBP5A mediate interaction with WW domains of Nedd4 and that N4WBP5A can physically interact with the WW domains of several Nedd4-family proteins. N4WBP5A is ubiquitinated and ubiquitination does not significantly affect the turnover of N4WBP5A protein. Ubiquitination of N4WBP5A is enhanced by Nedd4 and Nedd4-2 expression. N4WBP5A localizes to the Golgi, vesicles associated with the Golgi complex and to multivesicular bodies. We show that the ectopic expression of N4WBP5A inhibits receptor-mediated endocytosis of labelled epidermal growth factor. N4WBP5A overexpression inhibits accumulation of EGF in large endocytic/lysosomal vesicles suggestive of a role for N4WBP5A in protein trafficking. We propose that N4WBP5A acts as an adaptor to recruit Nedd4 family ubiquitin-protein ligases to the protein trafficking machinery.
Analyzing the response of RNAI-treated Drosophila cells to death stimuli by quantitative real-time polymerase chain reaction
Publisher: Cold Spring Harbor Laboratory
Date: 07-2015
Abstract: A useful complement to animal studies is the use of Drosophila cell lines to analyze cell-death responses. There are numerous Drosophila cell lines available, such as S2 cells, which possess the advantages of being semi-adherent, fast growing, relatively robust, and useful for transfection and knockdown studies, whereas other lines, such as mbn2, are more suitable for analyzing hormone-induced cell death and gene expression. Drosophila cell lines are very amenable to knockdown studies as the cells take up double-stranded RNA (dsRNA) from the medium, initiating gene silencing and resulting in a high level of gene knockdown. This means that the cell lines are useful for investigating the response to death stimuli, following gene knockdown, by examining the expression of cell-death genes. This protocol describes the synthesis of dsRNA for treatment of Drosophila cells and the subsequent analysis of cell-death gene expression by quantitative real-time polymerase chain reaction (qPCR).
K-29 linked ubiquitination of Arrdc4 regulates its function in extracellular vesicle biogenesis.
Publisher: Wiley
Date: 02-2022
DOI: 10.1002/JEV2.12188
Abstract: Extracellular vesicles (EVs) are important mediators of intercellular communication. However, EV biogenesis remains poorly understood. We previously defined a role for Arrdc4 (Arrestin domain containing protein 4), an adaptor for Nedd4 family ubiquitin ligases, in the biogenesis of EVs. Here we report that ubiquitination of Arrdc4 is critical for its role in EV secretion. We identified five potential ubiquitinated lysine residues in Arrdc4 using mass spectrometry. By analysing Arrdc4 lysine mutants we discovered that lysine 270 (K270) is critical for Arrdc4 function in EV biogenesis. Arrdc4 K270R mutation caused a decrease in the number of EVs released by cells compared to Arrdc4 WT , and a reduction in trafficking of alent metal transporter (DMT1) into EVs. Furthermore, we also observed a decrease in DMT1 activity and an increase in its intracellular degradation in the presence of Arrdc4 K270R . K270 was found to be ubiquitinated with K‐29 polyubiquitin chains by the ubiquitin ligase Nedd4‐2. Thus, our results uncover a novel role of K‐29 polyubiquitin chains in Arrdc4‐mediated EV biogenesis and protein trafficking.
An essential role for the caspase Dronc in developmentally programmed cell death in Drosophila
Publisher: Elsevier BV
Date: 12-2000
Subtle gait abnormalities in Nedd4 heterozygous mice
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.BBR.2013.11.024
Abstract: Nedd4 is a widely expressed ubiquitin ligase that is necessary for normal neuronal development and function. However, largely due to the lethality of Nedd4 homozygous knockout mice, little is known about the physiological roles of Nedd4 in the adult brain. In this study we used Nedd4 heterozygous mice, which are viable and live to maturity, to assess for motor function and gait. Global motor function was not altered in these mice, a result consistent with the low level of Nedd4 expression observed in motor neurons of the spinal cord. However, Nedd4 heterozygous mice showed significant age-dependent changes in gait. The gait abnormalities included an overall extension of gait that was only evident in the 6 month old mice. We also observed distinct expression patterns of Nedd4, with pronounced staining in the Purkinje neurons of the cerebellum that are crucial for normal gait, and lower levels in other motor areas of the CNS. It has been recently shown that Nedd4 directly interacts with GluR1 containing AMPA receptors in an activity dependent manner to modulate receptor levels at the post-synaptic membrane. Using confocal immunohistochemistry, we found that there were subtle changes in GluR1 expression in 6 month old Nedd4 heterozygous mice. There appeared to be a redistribution of GluR1 into larger puncta in the molecular layer and in the membrane of the soma of the Purkinje neurons. This study is the first to show that a 50% reduction in Nedd4 levels is sufficient to produce significant gait defects in 6 month old mice. These defects may arise in part, from altered distribution of GluR1 in cerebellar neurons.
mGrb10 interacts with Nedd4
Publisher: Elsevier BV
Date: 08-1999
Migrate, differentiate, proliferate, or die: pleiotropic functions of an apical apoptotic caspase.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 12-10-2004
Abstract: Caspases, the cysteine proteases that cleave their substrates following an aspartate residue, primarily carry out two distinct functions: (i) activation of proinflammatory cytokines and (ii) execution of apoptosis. These two functions are considered to be unique to in idual caspases thus, some caspases act in apoptosis, whereas others have a role in inflammation. However, this dogma is now being challenged as nonapoptotic functions are ascribed to caspases that, until recently, were only known to function in cell death pathways. Recent work suggests that DRONC, the only initiator cell death caspase in Drosophila , may play a direct or indirect role in cell migration, sperm differentiation, and cell proliferation in addition to its function in cell death.
Impaired antioxidant defence and accumulation of oxidative stress in caspase-2-deficient mice
Publisher: Springer Science and Business Media LLC
Date: 17-02-2012
DOI: 10.1038/CDD.2012.13
Nedd4-2 functionally interacts with ClC-5: involvement in constitutive albumin endocytosis in proximal tubule cells.
Publisher: Elsevier BV
Date: 12-2004
Pharmacologically targetable vulnerability in prostate cancer carrying RB1-SUCLA2 deletion
Publisher: Springer Science and Business Media LLC
Date: 21-07-2020
DOI: 10.1038/S41388-020-1381-6
Abstract: RB1 gene is often homozygously deleted or mutated in prostate adenocarcinomas following acquirement of castration resistance and/or metastatic ability. We found that SUCLA2 gene is frequently involved in the deletion of the RB1 gene region in advanced prostate cancer. SUCLA2 constitutes the β-subunit of succinate CoA ligase heterodimer that reversibly converts succinyl CoA into succinate. We sought the possibility that deletion of SUCLA2 gives rise to a metabolic vulnerability that could be targeted therapeutically. We found a significant metabolic shift in SUCLA2-deleted prostate cancer cells, including lower mitochondrial respiratory activity. By screening a number of libraries for compounds that induce cell death selectively in SUCLA2-deficient prostate cancer cells, we identified thymoquinone (2-isopropyl-5-methylbenzo-1,4-quinone) and PMA (phorbol-12-myristate-13-acetate) from a natural compound library. These findings indicate that the metabolic vulnerability in SUCLA2-deficient prostate cancer cells is pharmacologically targetable.
The p53-caspase-2 axis in the cell cycle and DNA damage response
Publisher: Springer Science and Business Media LLC
Date: 04-2021
DOI: 10.1038/S12276-021-00590-2
Abstract: Caspase-2 was discovered almost three decades ago. It was one of the first two mammalian homologs of CED-3, the other being interleukin 1β-converting enzyme (ICE/caspase-1). Despite high similarity with CED-3 and its fly and mammalian counterparts (DRONC and caspase-9, respectively), the function of caspase-2 in apoptosis has remained enigmatic. A number of recent studies suggest that caspase-2 plays an important role in the regulation of p53 in response to cellular stress and DNA damage to prevent the proliferation and accumulation of damaged or aberrant cells. Here, we review these recent observations and their implications in caspase-2-mediated cellular death, senescence, and tumor suppression.
DRG: A novel developmentally regulated GTP-binding protein
Publisher: Elsevier BV
Date: 11-1992
DOI: 10.1016/0006-291X(92)91567-A
Abstract: Using a subtraction cloning approach we had previously isolated a series of murine cDNA clones representing the genes predominantly expressed in the embryonic brain and down-regulated during development. We now report that one of these cDNA clones encodes a novel type of GTP-binding protein. The predicted protein of 40.5 kD, named DRG, contains five structural motifs characteristic of the GTP-binding proteins. Consistently, bacterially expressed and cellular DRG proteins are capable of binding GTP in vitro. Sequences closely related to the DRG protein are found in other species including Drosophila and Halobacterium. Based on these observations, we propose that DRG represents an evolutionarily conserved novel class of GTP-binding protein which may play an important role in cell physiology.
Activity of a fowlpox virus late gene promoter in vaccinia and fowlpox virus recombinants
Publisher: Springer Science and Business Media LLC
Date: 09-1990
DOI: 10.1007/BF01323160
Developmentally programmed cell death in Drosophila
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.BBAMCR.2013.06.014
Abstract: During the development of metazoans, programmed cell death (PCD) is essential for tissue patterning, removal of unwanted cells and maintaining homeostasis. In the past 20 years Drosophila melanogaster has been one of the systems of choice for studies involving developmental cell death, providing an ideal genetically tractable model of intermediary complexity between Caenorhabditis elegans and mammals. The lessons learned from studies using Drosophila indicate both the conserved nature of the many cell death pathways as well as novel and unexpected mechanisms. In this article we review the understanding of PCD during Drosophila development, highlighting the key mechanisms that are evolutionarily conserved as well as apparently unusual pathways, which indicate ergence, but provide evidence of complexity acquired during organismic evolution. This article is part of a Special Section entitled: Cell Death Pathways.
Regulation of the voltage-gated K+ channels KCNQ2/3 and KCNQ3/5 by serum- and glucocorticoid-regulated kinase-1
Publisher: American Physiological Society
Date: 07-2008
DOI: 10.1152/AJPCELL.00146.2008
Abstract: The voltage-gated KCNQ2/3 and KCNQ3/5 K + channels regulate neuronal excitability. We recently showed that KCNQ2/3 and KCNQ3/5 channels are regulated by the ubiquitin ligase Nedd4-2. Serum- and glucocorticoid-regulated kinase-1 (SGK-1) plays an important role in regulation of epithelial ion transport. SGK-1 phosphorylation of Nedd4-2 decreases the ability of Nedd4-2 to ubiquitinate the epithelial Na + channel, which increases the abundance of channel protein in the cell membrane. In this study, we investigated the mechanism(s) of SGK-1 regulation of M-type KCNQ channels expressed in Xenopus oocytes. SGK-1 significantly upregulated the K + current litudes of KCNQ2/3 and KCNQ3/5 channels ∼1.4- and ∼1.7-fold, respectively, whereas the kinase-inactive SGK-1 mutant had no effect. The cell surface levels of KCNQ2-hemagglutinin/3 were also increased by SGK-1. Deletion of the KCNQ3 channel COOH terminus in the presence of SGK-1 did not affect the K + current litude of KCNQ2/3/5-mediated currents. Coexpression of Nedd4-2 and SGK-1 with KCNQ2/3 or KCNQ3/5 channels did not significantly alter K + current litudes. Only the Nedd4-2 mutant S448A Nedd4-2 exhibited a significant downregulation of the KCNQ2/3/5 K + current litudes. Taken together, these results demonstrate a potential mechanism for regulation of KCNQ2/3 and KCNQ3/5 channels by SGK-1 regulation of the activity of the ubiquitin ligase Nedd4-2.
Identification of novel interacting partners of the NEDD4 ubiquitin ligase in mouse testis
Publisher: Elsevier BV
Date: 07-2020
Processing of the Nedd2 precursor by ICE-like proteases and granzyme B.
Publisher: Wiley
Date: 07-1996
DOI: 10.1046/J.1365-2443.1996.00255.X
Abstract: The Nedd2/Ich-1 protein belongs to a growing family of mammalian cysteine proteases similar to interleukin-1 beta converting enzyme (ICE). Because of their similarity to the Cacnorhabditis elegans cell death protein CED-3, the ICE-like proteins are thought to play a key role in the execution of apoptosis. The active form of ICE is a tetramer consisting of two heterodimers (p20 + p10)2 derived from the cleavage of the pro-enzyme. In the present communication we show that the p51 Nedd2 precursor (pro-Nedd2) is also cleaved into p20-like (p19) and p10-like (p12) subunits by extracts prepared from cultured cell lines. Extracts from apoptotic NIH-3T3 cells but not normal growing NIH-3T3 cells also contained pro-Nedd2 cleaving activity. The processing of pro-Nedd2 by cell extracts was inhibited by characteristic inhibitors of ICE-like proteases. Additionally we show that pro-Nedd2 (p51) can be processed in vitro by active CPP32 and ICE, and to a lesser extent by Mch2 and Nedd2. Granzyme B, a serine protease required for cytotoxic T lymphocyte (CTL) mediated killing of target cells, also cleaved pro-Nedd2 to p19 + p12 subunits. Our observations suggest that Nedd2 activation requires cleavage by one or more ICE-like proteases that lie upstream in the proteolytic cascade. Cleavage of pro-Nedd2 by granzyme B indicates that Nedd2 may be one of the downstream effectors in the CTL-mediated killing of target cells.
ER stress does not cause upregulation and activation of caspase-2 to initiate apoptosis
Publisher: Springer Science and Business Media LLC
Date: 29-11-2014
DOI: 10.1038/CDD.2013.168
Ndfip1 mediates peripheral tolerance to self and exogenous antigen by inducing cell cycle exit in responding CD4 + T cells
Publisher: Proceedings of the National Academy of Sciences
Date: 13-01-2014
Abstract: Advances in organ transplantation and treatment of allergy and autoimmune disease hinge upon harnessing a physiological switch that allows T cells to decide between proliferating extensively or actively becoming tolerant. The experiments presented here illuminate a critical element of this natural switch, Ndfip1 (neural precursor cell expressed, developmentally down-regulated protein 4 family-interacting protein 1), a partner protein of ubiquitin ligases induced during the first several isions after T cells encounter antigen. They define the cellular action of Ndfip1 in vivo, acting within iding helper T cells that have responded to innocuous foreign or self-antigen that should normally be tolerated, to force their exit from cell cycle before they have ided so many times that they acquire tissue-damaging effector functions.
Immunostaining using an antibody against active caspase-3 to detect apoptotic cells in Drosophila
Publisher: Cold Spring Harbor Laboratory
Date: 06-2015
Abstract: The activation of mammalian caspase-3 after proteolytic cleavage adjacent to residue Asp175 produces a large (17/19-kDa), active subunit. A commercially available antibody recognizes the large, active subunit of caspase-3 but not the full-length inactive caspase-3. This antibody has also been shown to detect active Drosophila effector caspases. Here, we present a protocol showing how this antibody can be used to detect apoptotic cells in various Drosophila tissues and developmental stages and discuss the specificity of the antibody.
Dasatinib cellular uptake and efflux in chronic myeloid leukemia cells: therapeutic implications
Publisher: American Association for Cancer Research (AACR)
Date: 15-06-2008
DOI: 10.1158/1078-0432.CCR-07-5095
Abstract: Purpose: The organic cation transporter OCT-1 mediates active transport of imatinib. We recently showed that low OCT-1 activity is a major contributor to suboptimal response in chronic myeloid leukemia (CML) patients treated with imatinib. The relevance of OCT-1 activity and efflux pumps in determining intracellular uptake and retention (IUR) of dasatinib was assessed. Experimental Design: The effect of OCT inhibitors on [14C]dasatinib and [14C]imatinib IUR was compared using peripheral blood mononuclear cells from newly diagnosed CML patients. The role of efflux transporters was studied using ABCB1- and ABCG2-overexpressing cell lines and relevant inhibitors. Results: Unlike imatinib, there was no significant difference in the dasatinib IUR at 37°C and 4°C (P = 0.8), and OCT-1 inhibitors including prazosin did not reduce dasatinib IUR significantly. In CML mononuclear cells, prazosin inhibitable IUR was significantly higher for imatinib than dasatinib (6.38 versus 1.48 ng/200,000 cells P = 0.002 n = 11). Patients with high OCT-1 activity based on their imatinib uptake had IC50dasatinib values equivalent to patients with low OCT-1 activity. Dasatinib IUR was significantly lower in ABCB1-overexpressing cell lines compared with parental cell lines (P & 0.05). PSC833 (ABCB1 inhibitor) significantly increased the dasatinib IUR (P & 0.05) and reduced IC50dasatinib (from 100 to 8 nmol/L) in K562-DOX cell line. The ABCG2 inhibitor Ko143 significantly increased dasatinib IUR in ABCG2-overexpressing cell lines and reduced IC50dasatinib. Conclusion: Unlike imatinib, dasatinib cellular uptake is not significantly affected by OCT-1 activity, so that expression and function of OCT-1 is unlikely to affect response to dasatinib. Dasatinib is a substrate of both efflux proteins, ABCB1 and ABCG2.
Using the vital dye acridine orange to detect dying cells in drosophila
Publisher: Cold Spring Harbor Laboratory
Date: 06-2015
Abstract: Acridine orange is a cell-permeable fluorescent dye that binds to nucleic acids, resulting in an altered spectral emission. Acridine orange staining has been shown to be highly selective for apoptotic cells in Drosophila however, the precise mechanism underlying this effect is not known. Advantages of acridine orange staining include the speed and ease of the staining. But there are disadvantages: It should be performed on unfixed tissue that therefore must be examined immediately, and multiple labeling cannot be performed. Slightly different protocols for the uptake of acridine orange are required for different developmental stages. Here, we present protocols for use of acridine orange to detect apoptosis in Drosophila embryos and in larval tissue. Slight modifications might be required for other Drosophila tissues.
Distinct promoter regions regulate spatial and temporal expression of the Drosophila caspase dronc
Publisher: Springer Science and Business Media LLC
Date: 29-08-2003
Molecular determinants of the subcellular localization of the Drosophila Bcl-2 homologues DEBCL and BUFFY
Publisher: Springer Science and Business Media LLC
Date: 05-01-2007
Abstract: The Bcl-2-family of proteins localize to intracellular membranes via a C-terminal hydrophobic membrane anchor (MA) domain, to exert their antiapoptotic or proapoptotic functions. In Drosophila, both Bcl-2 family members, DEBCL and BUFFY, contain an MA. In DEBCL the MA is necessary for the localization of protein to mitochondria and for its proapoptotic activity. BUFFY is highly similar to DEBCL but its localization and function are not clearly defined. Here, we report on comparative analysis of BUFFY and DEBCL to decipher the molecular basis for their subcellular localization. We show that these two proteins localize to distinct intracellular membranes, DEBCL predominantly to mitochondria and BUFFY to endoplasmic reticula (ER). Our results suggest that the MA-flanking residues in DEBCL, homologous to Bcl-X(L), are required for the targeting of DEBCL to mitochondria. The C-terminal positively charged residues present in DEBCL are absent in BUFFY, which allows for its localization to ER. The MA in both proteins is required for the correct targeting and proapoptotic activities of these proteins. Interestingly, a functional nuclear localization signal was identified in the N-terminal region of BUFFY and in the absence of the MA, BUFFY accumulated in the nucleus. The functional implications of these findings are discussed.
Functional activation of Nedd2/ICH-1 (caspase-2) is an early process in apoptosis
Publisher: Elsevier BV
Date: 05-1997
Na+ and K+ transport in Nitrosomonas europaea and Nitrobacter agilis
Publisher: Elsevier BV
Date: 06-1984
DOI: 10.1016/0005-2728(84)90165-8
Abstract: Potassium-depleted cells of Nitrosomonas europaea and Nitrobacter agilis were prepared by diethanolamine treatment and contained less than 5 mM intracellular K+. The addition of K+ to K+-depleted cells of N. europaea and N. agilis resulted in a depolarization of membrane potential (delta psi) by about 5 and 10 mV, respectively. This depolarization was, however, compensated by an equivalent increase in transmembrane pH gradient (delta pH), so that the total proton-motive force (delta p) remained constant, indicating that K+ transport was electrogenic in both bacteria. Using 22Na+-loaded cells, it is shown that both bacteria lack a respiration-dependent Na+ pump however, antiporters for Na+/H+, K+/Na+ and K+/H+ were detected. Of these, at least the K+/Na+ antiporter required an electrochemical gradient for its operation. It is also shown that the unprotonated form of NH+4 is transported into these bacteria by a simple diffusion mechanism.
Analysing caspase activation and caspase activity in apoptotic cells.
Publisher: Humana Press
Date: 2009
DOI: 10.1007/978-1-60327-017-5_1
Abstract: Apoptotic cell death is characterised by various morphological and biochemical changes. Cysteine proteases of the caspase family play key roles in the execution of apoptosis and in the maturation of proinflammatory cytokines. During apoptosis signalling, caspase precursors undergo rapid proteolytic processing and activation. Activated caspases then function to cleave various vital cellular proteins, resulting in the death of the cell. Thus, the measurement of caspase activation and caspase activity provides a quick and convenient method to assess apoptosis. This chapter outlines various commonly used assays for measuring caspase activity and detecting active caspases in cultured cells or tissue extracts.
Phosphorylation by Aurora B kinase regulates caspase-2 activity and function
Publisher: Springer Science and Business Media LLC
Date: 18-08-2020
DOI: 10.1038/S41418-020-00604-Y
Abstract: Mitotic catastrophe (MC) is an important oncosuppressive mechanism that serves to eliminate cells that become polyploid or aneuploid due to aberrant mitosis. Previous studies have demonstrated that the activation and catalytic function of caspase-2 are key steps in MC to trigger apoptosis and/or cell cycle arrest of mitotically defective cells. However, the molecular mechanisms that regulate caspase-2 activation and its function are unclear. Here, we identify six new phosphorylation sites in caspase-2 and show that a key mitotic kinase, Aurora B kinase (AURKB), phosphorylates caspase-2 at the highly conserved residue S384. We demonstrate that phosphorylation at S384 blocks caspase-2 catalytic activity and apoptosis function in response to mitotic insults, without affecting caspase-2 dimerisation. Moreover, molecular modelling suggests that phosphorylation at S384 may affect substrate binding by caspase-2. We propose that caspase-2 S384 phosphorylation by AURKB is a key mechanism that controls caspase-2 activation during mitosis.
The role of caspases in apoptosis.
Publisher: Springer Berlin Heidelberg
Date: 1998
DOI: 10.1007/BFB0102307
Inhibition of apoptosis by the expression of antisense Nedd2
Publisher: Wiley
Date: 10-07-1995
DOI: 10.1016/0014-5793(95)00602-6
Abstract: Nedd2 belongs to a family of mammalian cysteine proteases which share similarity with the Caenorhabditis elegans cell death protein, Ced-3. Overexpression of Nedd2 has been shown to induce apoptosis in mammalian cells but in the absence of a specific known inhibitor, it remains to be seen whether this represents cytotoxic effects of the Nedd2 protease or the specific activation of an apoptotic pathway. The present work shows that the factor-dependent cell line FDC-P1 expressing mouse antisense Nedd2 mRNA, exhibits significant inhibition of cell death upon removal of the cytokines, thus providing evidence for a direct role of Nedd2 in mediating apoptosis.
All three WW domains of murine Nedd4 are involved in the regulation of epithelial sodium channels by intracellular Na+
Publisher: Elsevier BV
Date: 04-1999
The Drosophila melanogaster Apaf-1 homologue ARK is required for most, but not all, programmed cell death
Publisher: Rockefeller University Press
Date: 13-03-2006
Abstract: The Apaf-1 protein is essential for cytochrome c–mediated caspase-9 activation in the intrinsic mammalian pathway of apoptosis. Although Apaf-1 is the only known mammalian homologue of the Caenorhabditis elegans CED-4 protein, the deficiency of apaf-1 in cells or in mice results in a limited cell survival phenotype, suggesting that alternative mechanisms of caspase activation and apoptosis exist in mammals. In Drosophila melanogaster, the only Apaf-1/CED-4 homologue, ARK, is required for the activation of the caspase-9/CED-3–like caspase DRONC. Using specific mutants that are deficient for ark function, we demonstrate that ARK is essential for most programmed cell death (PCD) during D. melanogaster development, as well as for radiation-induced apoptosis. ark mutant embryos have extra cells, and tissues such as brain lobes and wing discs are enlarged. These tissues from ark mutant larvae lack detectable PCD. During metamorphosis, larval salivary gland removal was severely delayed in ark mutants. However, PCD occurred normally in the larval midgut, suggesting that ARK-independent cell death pathways also exist in D. melanogaster.
Expression of bovine leukaemia virus envelope gene by recombinant vaccinia viruses
Publisher: Elsevier BV
Date: 10-1990
DOI: 10.1016/0168-1702(90)90074-L
Abstract: Recombinant vaccinia viruses (VV) containing the envelope gene of bovine leukaemia virus (BLV) were constructed. Three virus constructs were designed: VV-BLV1 which contained the open reading frame for envelope glycoprotein gp51 alone, under control of VVP7.5 promoter VV-BLV2 and VV-BLV3 contained the entire gene (gp51 + gp30) coding sequence downstream of VP7.5 and the fowlpox virus early/late promoter (PFE/L) respectively. All three VV recombinants expressed envelope glycoproteins as determined by the agar gel diffusion assay. By immunofluorescence techniques it was shown that while VV-BLV2 and VV-BLV3 expressed envelope glycoprotein on the surface of virus-infected cells, VV-BLV1 failed to do so. Rabbits inoculated with VV-BLV1 failed to show an anti envelope glycoprotein antibody response, however, significant levels of antibodies against envelope glycoprotein were detected in sera from rabbits inoculated with VV-BLV2 and VV-BLV3.
Cloning of a cDNA Which Encodes a Novel Ubiquitin-like Protein
Publisher: Elsevier BV
Date: 08-1993
Abstract: The cloning of a mouse cDNA, Nedd-8, which encodes a small novel protein of 81 amino acid residues with a relative molecular mass of 9 kDa, is described. The putative Nedd-8 product is approximately 60% identical to ubiquitin protein. The 0.6 kb mRNA for Nedd-8 gene can be detected in various mouse tissues and cell lines derived from various sources. Nedd-8 probe hybridizes to genomic DNA from various vertebrate species as well as yeast, indicating high degree of interspecies conservation. These data suggest that like ubiquitin, the product of this gene may play some essential role in eukaryotic cellular metabolism.
An essential function for the centrosomal protein NEDD1 in zebrafish development
Publisher: Springer Science and Business Media LLC
Date: 12-02-2010
DOI: 10.1038/CDD.2010.12
Abstract: The centrosome is the primary microtubule organising centre of the cell. It is composed of many proteins, some of which make up the core of the centrosome, whereas others are used for specific functions. Although the cellular roles of many centrosomal proteins are well defined, much less is known about their functions and the role of the centrosome in development. In this study we investigated the function of NEDD1, a critical component of the centrosome essential for microtubule nucleation, in zebrafish (Danio rerio) development. The zebrafish homologue of NEDD1 (zNEDD1) was cloned and found to have a similar localisation and function to mammalian NEDD1. We show that zNEDD1 is essential for survival, as a high level of knockdown was embryonic lethal. Partial knockdown of zNEDD1 caused abnormalities including an increase in mitotic and apoptotic cells. Pronounced phenotypic defects were seen in the brain, with a lack of defined brain structures, incomplete neural tube formation and a disorganisation of neurons. In addition, we show that a reduction in zNEDD1 resulted in the loss of gamma-tubulin at the centrosome. Our data thus demonstrate that zNEDD1 is critical for the recruitment of gamma-tubulin to the centrosome, and is essential for the proper development of zebrafish.
Caspase-2 is required for cell death induced by cytoskeletal disruption
Publisher: Springer Science and Business Media LLC
Date: 14-01-2008
Abstract: Caspase-2 is one of the most conserved caspases, yet its biological function remains a matter of controversy. In the present article we analysed mouse embryonic fibroblasts (MEFs) from caspase-2 knockout mice for their sensitivity to various apoptosis inducing agents. We found that cell death induced by drugs that disrupt cytoskeleton is significantly inhibited in Casp2(-/-) MEFs. These drugs included zoledronic acid, vincristine, cytochalasin D and paclitaxel. We demonstrate that MEFs lacking Casp2 show clonogenic survival following drug treatment, whereas all Casp2(+/+) MEFs die, indicating that caspase-2 is required for apoptosis induced by cytoskeletal disruption. We further found that caspase-2 mediates apoptosis via Piddosome, Bid and Bax activation, and cytochrome c release. In the absence of caspase-2, Bid and Bax activation, and cytochrome c release are significantly delayed following drug treatment. Our data provide strong support for a context-dependent function of caspase-2 in apoptosis.
Definitive 15N NMR evidence that water serves as a source of 'O' during nitrite oxidation by Nitrobacter agilis
Publisher: Wiley
Date: 07-02-1983
Distinct requirements of Autophagy-related genes in programmed cell death
Publisher: Springer Science and Business Media LLC
Date: 17-04-2015
DOI: 10.1038/CDD.2015.28
Caspase-2 as a tumour suppressor
Publisher: Springer Science and Business Media LLC
Date: 28-06-2013
DOI: 10.1038/CDD.2013.87
Assignment of the developmentally regulated gene NEDD1 to human chromosome 12q22 by fluorescence in situ hybridization
Publisher: Springer Science and Business Media LLC
Date: 1995
DOI: 10.1007/BF00225082
NEDD1: Function in microtubule nucleation, spindle assembly and beyond
Publisher: Elsevier BV
Date: 2007
DOI: 10.1016/J.BIOCEL.2006.08.012
Abstract: Nedd1 was originally identified as a developmentally regulated gene in the mouse central nervous system. NEDD1 has homologues across a range of species, being particularly conserved in a region of WD40 repeats contained in the amino-terminal half of the protein. Human NEDD1 was recently found to localise to the centrosome and mitotic spindle. It binds to the components of the gamma-tubulin ring complex and target this complex to the centrosome and spindle. Depletion of NEDD1 causes loss of the gamma-tubulin ring complex from the centrosome and results in the failure of microtubule nucleation and spindle assembly. In addition, phosphorylation of NEDD1 during mitosis is critical for targeting gamma-tubulin to the spindle, but not the centrosome. There is still much unknown about the function of this protein and how it may be involved in development and disease. This short review summarises some of the recent work on NEDD1 and discusses how this interesting protein may have additional yet unexplored functions.
Caspase-2-mediated cell death is required for deleting aneuploid cells.
Publisher: Springer Science and Business Media LLC
Date: 19-12-2017
DOI: 10.1038/ONC.2016.423
Treatment of retinoblastoma 1-intact hepatocellular carcinoma with cyclin-dependent kinase 4/6 inhibitor combination therapy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 25-08-2021
DOI: 10.1002/HEP.31872
Abstract: Synthetic cyclin-dependent kinase (CDK) 4/6 inhibitors exert antitumor effects by forcing RB1 in unphosphorylated status, causing not only cell cycle arrest but also cellular senescence, apoptosis, and increased immunogenicity. These agents currently have an indication in advanced breast cancers and are in clinical trials for many other solid tumors. HCC is one of promising targets of CDK4/6 inhibitors. RB family dysfunction is often associated with the initiation of HCC however, this is revivable, as RB family members are not frequently mutated or deleted in this malignancy. Loss of all Rb family members in transformation related protein 53 (Trp53) In conclusion, CDK4/6 inhibitors have a potential to treat a wide variety of RB1-intact cancers including HCC when combined with an appropriate kinase inhibitor.
UTX coordinates steroid hormone-mediated autophagy and cell death
Publisher: Springer Science and Business Media LLC
Date: 13-12-2013
DOI: 10.1038/NCOMMS3916
Short-term intense Bcr-Abl kinase inhibition with nilotinib is adequate to trigger cell death in BCR-ABL+ cells
Publisher: Springer Science and Business Media LLC
Date: 05-03-2009
DOI: 10.1038/LEU.2009.45
Characterization of the Drosophila Caspase, DAMM
Publisher: Elsevier BV
Date: 2001
Caspases in metabolic disease and their therapeutic potential
Publisher: Springer Science and Business Media LLC
Date: 09-05-2018
Role of multiple cellular proteases in the execution of programmed cell death
Publisher: Wiley
Date: 20-11-1995
DOI: 10.1016/0014-5793(95)01186-I
Abstract: A family of mammalian homologues of the Caenorhabditis elegans cell death protein Ced-3 has been recently discovered. These mammalian proteins encode novel cysteine proteases with homology to the interleukin-1 beta converting enzyme (ICE). Although several studies support a role for one or more of these proteases in mediating apoptosis, their mechanism of action is far from understood. The presence of multiple mammalian ICE-like proteases, with apparently similar apoptotic function indicates that, despite its conservation during evolution, the cell death pathway is much more complex in mammals than in the worm. In addition to ICE-like proteases, several other proteases of different cleavage specificities have been implicated in apoptosis. There is now a growing body of evidence suggesting that apoptosis involves the activation of a cascade of proteases. This article summarises the presently available evidence and discusses how multiple proteases might be required in the effector phase of cell death.
Identification of a set of genes with developmentally down-regulated expression in the mouse brain
Publisher: Elsevier BV
Date: 06-1992
DOI: 10.1016/0006-291X(92)91747-E
Abstract: Using a subtraction cloning approach, we have isolated a set of cDNA clones from mouse neural precursor cells whose respective mRNA levels are down-regulated during the development of mouse brain. Single stranded DNA prepared from neuronal precursor cell cDNA library in lambda Zap vector was subtracted with poly (A)+ RNA prepared from postnatal and adult mouse brain to obtain several clones which show developmental down-regulation of expression. Their patterns of expression indicate that these genes may play important roles during the embryonic development and differentiation of central nervous system.
Ubiquitination and the regulation of membrane proteins
Publisher: American Physiological Society
Date: 2017
DOI: 10.1152/PHYSREV.00012.2016
Abstract: Newly synthesized transmembrane proteins undergo a series of steps to ensure that only the required amount of correctly folded protein is localized to the membrane. The regulation of protein quality and its abundance at the membrane are often controlled by ubiquitination, a multistep enzymatic process that results in the attachment of ubiquitin, or chains of ubiquitin to the target protein. Protein ubiquitination acts as a signal for sorting, trafficking, and the removal of membrane proteins via endocytosis, a process through which multiple ubiquitin ligases are known to specifically regulate the functions of a number of ion channels, transporters, and signaling receptors. Endocytic removal of these proteins through ubiquitin-dependent endocytosis provides a way to rapidly downregulate the physiological outcomes, and defects in such controls are directly linked to human pathologies. Recent evidence suggests that ubiquitination is also involved in the shedding of membranes and associated proteins as extracellular vesicles, thereby not only controlling the cell surface levels of some membrane proteins, but also their potential transport to neighboring cells. In this review, we summarize the mechanisms and functions of ubiquitination of membrane proteins and provide specific ex les of ubiquitin-dependent regulation of membrane proteins.
Loss of NEDD4 causes complete XY gonadal sex reversal in mice
Publisher: Springer Science and Business Media LLC
Date: 24-01-2022
DOI: 10.1038/S41419-022-04519-Z
Abstract: Gonadogenesis is the process wherein two morphologically distinct organs, the testis and the ovary, arise from a common precursor. In mammals, maleness is driven by the expression of Sry . SRY subsequently upregulates the related family member Sox9 which is responsible for initiating testis differentiation while repressing factors critical to ovarian development such as FOXL2 and β-catenin. Here, we report a hitherto uncharacterised role for the ubiquitin-protein ligase NEDD4 in this process. XY Nedd4 -deficient mice exhibit complete male-to-female gonadal sex reversal shown by the ectopic upregulation of Foxl2 expression at the time of gonadal sex determination as well as insufficient upregulation of Sox9 . This sex reversal extends to germ cells with ectopic expression of SYCP3 in XY Nedd4-/- germ cells and significantly higher Sycp3 transcripts in XY and XX Nedd4- deficient mice when compared to both XY and XX controls. Further, Nedd4-/ - mice exhibit reduced gonadal precursor cell formation and gonadal size as a result of reduced proliferation within the developing gonad as well as reduced Nr5a1 expression. Together, these results establish an essential role for NEDD4 in XY gonadal sex determination and development and suggest a potential role for NEDD4 in orchestrating these cell fate decisions through the suppression of the female pathway to ensure proper testis differentiation.
Rearrangements of t-cell receptor β-chain genes in human leukaemias
Publisher: Elsevier BV
Date: 12-1986
DOI: 10.1016/0161-5890(86)90020-9
Abstract: Rearrangements of the T-cell receptor (TCR), beta-chain genes and immunoglobulin (Ig) heavy chain genes in several T-cell leukaemias (T-ALL and ATL), and some B-cell and myelogenous leukaemias were investigated. Two out of 15 cases of T-cell leukaemia tested failed to show a rearrangement pattern of TCR beta genes although both expressed mRNA for this gene. The remaining 13 cases showed erse patterns of rearrangements involving either C beta 1, C beta 2 or both. C beta 1 but not C beta 2 was deleted in some of the T-cell leukaemias. Polyclonal T cells from four normal in iduals showed the germ line pattern and an additional two bands in Hind III digested DNA. Except for one, all cases of C-ALL (B-cell leukaemia) showed a rearranged JH locus which was not evident in any of T-cell leukaemias studied. One case of B-cell leukaemia showed a rearrangement of both TCR beta genes and JH genes. The results of these studies suggest that rearrangement of TCR and Ig genes occurs at a very early stage of differentiation of stem cells and does not appear to play a direct role in leukaemogenesis per se.
Caspase function in programmed cell death
Publisher: Springer Science and Business Media LLC
Date: 03-11-2007
Abstract: The first proapoptotic caspase, CED-3, was cloned from Caenorhabditis elegans in 1993 and shown to be essential for the developmental death of all somatic cells. Following the discovery of CED-3, caspases have been cloned from several vertebrate and invertebrate species. As reviewed in other articles in this issue of Cell Death and Differentiation, many caspases function in nonapoptotic pathways. However, as is clear from the worm studies, the evolutionarily conserved role of caspases is to execute programmed cell death. In this article, I will specifically focus on caspases that function primarily in cell death execution. In particular, the physiological function of caspases in apoptosis is discussed using ex les from the worm, fly and mammals.
Physiological functions of Nedd4-2: lessons from knockout mouse models
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.TIBS.2018.06.004
Abstract: Protein modification by ubiquitination plays a key evolutionarily conserved role in regulating membrane proteins. Nedd4-2, a ubiquitin ligase, targets membrane proteins such as ion channels and transporters for ubiquitination. This Nedd4-2-mediated ubiquitination provides a crucial step in controlling the membrane availability of these proteins, thus affecting their signaling and physiological outcomes. In one well-studied ex le, Nedd4-2 fine-tunes the physiological function of the epithelial sodium channel (ENaC), thus modulating Na
Caspases and their many biological functions
Publisher: Springer Science and Business Media LLC
Date: 03-11-2007
Akt mediates the effect of insulin on epithelial sodium channels by inhibiting Nedd4-2
Publisher: Elsevier BV
Date: 10-2007
Nedd4 controls animal growth by regulating IGF-1 signaling
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-09-2008
DOI: 10.1126/SCISIGNAL.1160940
Abstract: Nedd4 acts through Grb10 to enhance insulin-like growth factor signaling and control animal growth.
Loss of caspase-2 augments lymphomagenesis and enhances genomic instability in Atm-deficient mice.
Publisher: Proceedings of the National Academy of Sciences
Date: 18-11-2013
Abstract: The cysteine protease caspase-2 has been implicated in the suppression of oncogene-mediated tumor formation. However, the mechanisms underlying the function of caspase-2 as a tumor suppressor are not well defined. In this study, we use a well-characterized mouse lymphoma model and demonstrate a critical role for caspase-2 in maintaining genome stability and in the suppression of tumorigenesis following loss of the essential DNA repair gene ataxia telangiectasia mutated ( Atm ). Our findings suggest that caspase-2 cooperates with ATM to suppress genomic instability, oxidative stress, and tumor progression.
Ecdysone-mediated programmed cell death in Drosophila
Publisher: UPV/EHU Press
Date: 2015
Abstract: During Drosophila development, the steroid hormone ecdysone plays a key role in the transition from embryo into larva and then into pupa. It is during larval-pupal metamorphosis that extensive programmed cell death occurs to remove large obsolete larval tissues. During this transition, ecdysone pulses control the expression of specific transcription factors which drive the expression of key genes involved in cell death, thus spatially and temporally controlling programmed cell death. Ecdysone also controls cell death in specific larval and adult tissues. This review focuses on the current knowledge of ecdysone-mediated cell death in Drosophila.
Death to flies: Drosophila as a model system to study programmed cell death
Publisher: Elsevier BV
Date: 07-2002
DOI: 10.1016/S0022-1759(02)00068-6
Abstract: Programmed cell death (PCD) is essential for the removal of unwanted cells and is critical for both restricting cell numbers and for tissue patterning during development. Components of the cell death machinery are remarkably conserved through evolution, from worms to mammals. Central to the PCD process is the family of cysteine proteases, known as caspases, which are activated by death-inducing signals. Comparisons between C. elegans and mammalian PCD have shown that there is additional complexity in the regulation of PCD in mammals. The fruitfly, Drosophila melanogaster, is proving an ideal genetically tractable model organism, of intermediary complexity between C. elegans and mammals, in which to study the intricacies of PCD. Here, we review the literature on PCD during Drosophila development, highlighting the methods used in these studies.
Regulation of the voltage-gated K(+) channels KCNQ2/3 and KCNQ3/5 by ubiquitination. Novel role for Nedd4-2.
Publisher: Elsevier BV
Date: 04-2007
The ubiquitin ligase Nedd4 regulates craniofacial development by promoting cranial neural crest cell survival and stem-cell like properties
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.YDBIO.2013.09.024
Abstract: The integration of multiple morphogenic signalling pathways and transcription factor networks is essential to mediate neural crest (NC) cell induction, delamination, survival, stem-cell properties, fate choice and differentiation. Although the transcriptional control of NC development is well documented in mammals, the role of post-transcriptional modifications, and in particular ubiquitination, has not been explored. Here we report an essential role for the ubiquitin ligase Nedd4 in cranial NC cell development. Our analysis of Nedd4(-/-) embryos identified profound deficiency of cranial NC cells in the absence of structural defects in the neural tube. Nedd4 is expressed in migrating cranial NC cells and was found to positively regulate expression of the NC transcription factors Sox9, Sox10 and FoxD3. We found that in the absence of these factors, a subset of cranial NC cells undergo apoptosis. In accordance with a lack of cranial NC cells, Nedd4(-/-) embryos have deficiency of the trigeminal ganglia, NC derived bone and malformation of the craniofacial skeleton. Our analyses therefore uncover an essential role for Nedd4 in a subset of cranial NC cells and highlight E3 ubiquitin ligases as a likely point of convergence for multiple NC signalling pathways and transcription factor networks.
The Bcl-2 family of proteins and activation of the ICE-CED-3 family of proteases: a balancing act in apoptosis?
Publisher: Springer Science and Business Media LLC
Date: 1997
Measurement of caspase activity in cells undergoing apoptosis.
Publisher: Humana Press
Date: 2004
DOI: 10.1385/1-59259-812-9:019
Abstract: Cysteine proteases of the caspase family play key roles in the execution of apoptosis and in the maturation of proinflammatory cytokines. During apoptosis signaling, the latent forms of caspase precursors undergo rapid proteolytic processing and activation. Thus, the measurement of caspase activation provides a quick and convenient mean to assess apoptosis. This chapter outlines the various commonly used assays for determining caspase activity in cultured cells or tissue extracts.
Identification of a developmentally regulated gene in the mouse central nervous system which encodes a novel proline rich protein
Publisher: Elsevier BV
Date: 10-1992
DOI: 10.1016/0167-4781(92)90156-T
Abstract: A full length cDNA whose corresponding mRNA is down-regulated during the mouse embryonic brain development was isolated. The cDNA contains a single long open reading frame which could encode a protein with relative molecular mass of 41 kDa. The predicted gene product contains long stretches of prolines towards the NH2-terminus, followed by a leucine roline rich region. The cDNA probe detected a number of mRNA species in Northern blot analysis. The reverse transcriptase-polymerase chain reaction analysis of mRNA from adult mouse tissues indicated that heart and testis expressed this gene (named NDPP-1) at relatively high levels, while lower levels of mRNA were detected in a number of other tissues. Expression of NDPP-1 was also detected in embryonic carcinoma and pheochromocytoma cell lines, but not in fibroblasts. The cDNA hybridized to genomic DNA from several vertebrates species in Southern blot analysis indicating interspecies conservation of this gene. The interesting pattern of expression of the NDPP-1 gene during mouse brain development and the structure of its putative protein product indicate that this gene may play an important biological role in the development of mouse central nervous system.
A defect in DNA topoisomerase II activity in ataxia-telangiectasia cells
Publisher: Elsevier BV
Date: 11-1987
DOI: 10.1016/0006-291X(87)91629-9
Abstract: DNA topoisomerase type I and II activities were determined by serial dilution in nuclear extracts from control and ataxia-telangiectasia lymphoblastoid cells. Topoisomerase I activity, assayed by relaxation of supercoiled plasmid DNA, was found to be approximately the same in both cell types. In order to remove interference from topoisomerase I, the activity of topoisomerase II was measured by the unknotting of knotted P4 phage DNA in the presence of ATP. The activity of topoisomerase II was markedly reduced in two ataxia-telangiectasia cell lines, AT2ABR and AT8ABR, compared to controls. This reduction in activity was detected with increasing concentration of protein and in time course experiments at a single protein concentration. A third cell line, AT3ABR, did not have a detectably lower activity of topoisomerase II when assayed under these conditions. The difference in topoisomerase II activity in the ataxia-telangiectasia cell lines examined may reflect to some extent the heterogeneity observed in this syndrome.
Grb10 prevents Nedd4-mediated vascular endothelial growth factor receptor-2 degradation
Publisher: Elsevier BV
Date: 06-2004
Autophagy in major human diseases
Publisher: EMBO
Date: 30-08-2021
Caspase 2 in apoptosis, the DNA damage response and tumour suppression: Enigma no more?
Publisher: Springer Science and Business Media LLC
Date: 05-11-2009
DOI: 10.1038/NRC2745
Abstract: Aberrations in proteins that control apoptosis and cell survival are common in cancer. These aberrations often reside in signalling proteins that control the activation of the apoptotic machinery or in the Bcl-2 family of proteins that control caspase activation. Recent evidence suggests that caspase 2, one of the most evolutionarily conserved caspases, may have multiple roles in the DNA damage response, cell cycle regulation and tumour suppression. These findings are unexpected and have important implications for our understanding of tumorigenesis and the treatment of cancer.
Hedgehog and wingless signaling are not essential for autophagy-dependent cell death
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.BCP.2018.10.027
Abstract: Autophagy-dependent cell death is a distinct mode of regulated cell death required in a context specific manner. One of the best validated genetic models of autophagy-dependent cell death is the removal of the Drosophila larval midgut during larval-pupal transition. We have previously shown that down-regulation of growth signaling is essential for autophagy induction and larval midgut degradation. Sustained growth signaling through Ras and PI3K blocks autophagy and consequently inhibits midgut degradation. In addition, the morphogen Dpp plays an important role in regulating the correct timing of midgut degradation. Here we explore the potential roles of Hh and Wg signaling in autophagy-dependent midgut cell death. We demonstrate that Hh and Wg signaling are not involved in the regulation of autophagy-dependent cell death. However, surprisingly we found that one key component of these pathways, the Drosophila Glycogen Synthase Kinase 3, Shaggy (Sgg), may regulate midgut cell size independent of Hh and Wg signaling.
Regulation of caspase activation in apoptosis: Implications in pathogenesis and treatment of disease
Publisher: Wiley
Date: 04-1999
DOI: 10.1046/J.1440-1681.1999.03031.X
Abstract: 1. Apoptosis is an essential process to remove excess, unwanted and harmful cells and maintain homeostasis. One of the key steps in apoptosis is activation of a group of proteases termed caspases. 2. Caspases are cysteine proteases that cleave their substrates after an aspartate residue. Approximately one dozen such proteases have been cloned during the past few years. While some caspases are largely responsible for the proteolytic processing of proinflammatory cytokines, such as interleukin (IL)-1 beta, others are directly involved in the execution of apoptosis. 3. Once apoptotic upstream caspases are activated in response to specific apoptotic stimuli, they can activate the downstream or effector class of caspases. Most proteins that are cleaved during apoptosis leading to the characteristic apoptotic morphology are targeted by the downstream caspases. The cleavage of these proteins by caspases can be either an activating or inactivating event for the function of a protein however, in most cases, it contributes to the apoptotic phenotype of the cell. 4. Because caspase cleavage is the initiating event in most forms of apoptosis, it is a tightly controlled process with many checks and balances. An understanding of the regulation of caspases is providing novel ways for therapeutic intervention to modulate apoptotic behaviour of cells in many diseases that arise due to inappropriate apoptosis. 5. The present article will endeavour to discuss recent advances in our understanding of caspase regulation and will elaborate on how this knowledge is being used in the development of new classes of therapeutic molecules that can be used for the treatment of human ailments.
Nedd4 family-interacting protein 1 (Ndfip1) is required for the exosomal secretion of Nedd4 family proteins
Publisher: Elsevier BV
Date: 11-2008
Na+-H+ exchange in salivary secretory cells is controlled by an intracellular Na+ receptor
Publisher: Proceedings of the National Academy of Sciences
Date: 17-08-1999
Abstract: It recently has been shown that epithelial Na + channels are controlled by a receptor for intracellular Na + , a G protein (G o ), and a ubiquitin-protein ligase (Nedd4). Furthermore, mutations in the epithelial Na + channel that underlie the autosomal dominant form of hypertension known as Liddle’s syndrome inhibit feedback control of Na + channels by intracellular Na + . Because all epithelia, including those such as secretory epithelia, which do not express Na + channels, need to maintain a stable cytosolic Na + concentration ([Na + ] i ) despite fluctuating rates of transepithelial Na + transport, these discoveries raise the question of whether other Na + transporting systems in epithelia also may be regulated by this feedback pathway. Here we show in mouse mandibular secretory (endpiece) cells that the Na + -H + exchanger, NHE1, which provides a major pathway for Na + transport in salivary secretory cells, is inhibited by raised [Na + ] i acting via a Na + receptor and G o . This inhibition involves ubiquitination, but does not involve the ubiquitin protein ligase, Nedd4. We conclude that control of membrane transport systems by intracellular Na + receptors may provide a general mechanism for regulating intracellular Na + concentration.
Studying apoptosis in Drosophila
Publisher: Cold Spring Harbor Laboratory
Date: 07-2015
Abstract: The apoptotic machinery is highly conserved throughout evolution, and central to the regulation of apoptosis is the caspase family of cysteine proteases. Insights into the regulation and function of apoptosis in mammals have come from studies using model organisms. Drosophila provides an exceptional model system for identifying the function of conserved mechanisms regulating apoptosis, especially during development. The characteristic patterns of apoptosis during Drosophila development have been well described, as has the apoptotic response following DNA damage. The focus of this discussion is to introduce methodologies for monitoring apoptosis during Drosophila development and also in Drosophila cell lines.
Regulation of the divalent metal ion transporter DMT1 and iron homeostasis by a ubiquitin-dependent mechanism involving Ndfips and WWP2
Publisher: American Society of Hematology
Date: 15-11-2008
DOI: 10.1182/BLOOD-2008-04-150953
Abstract: Many ion channels and transporters are regulated by ubiquitination mediated by the Nedd4 family of HECT-type ubiquitin ligases (E3s). These E3s commonly interact with substrates via their WW domains that bind to specific motifs in target proteins. However, not all potential targets of these E3s contain WW-binding motifs. Therefore, accessory proteins may mediate the interaction between Nedd4 family members and their targets. Here we report that the alent metal ion transporter DMT1, the primary nonheme iron transporter in mammals, is regulated by ubiquitination mediated by the Nedd4 family member WWP2. DMT1 interacts with 2 WW domain-interacting proteins, Ndfip1 and Ndfip2, previously proposed to have roles in protein trafficking. This promotes DMT1 ubiquitination and degradation by WWP2. Consistent with these observations, Ndfip1−/− mice show increased DMT1 activity and a concomitant increase in hepatic iron deposition, indicating an essential function of Ndfip1 in iron homeostasis. This novel mechanism of regulating iron homeostasis suggests that Ndfips and WWP2 may contribute to diseases involving aberrant iron transport.
Apoptotic cell death in disease—Current understanding of the NCCD 2023
Publisher: Springer Science and Business Media LLC
Date: 26-04-2023
Underwater noise from geotechnical drilling and standard penetration testing.
Publisher: Acoustical Society of America (ASA)
Date: 09-2017
DOI: 10.1121/1.5003328
Abstract: Geotechnical site investigations prior to marine construction typically involve shallow, small-core drilling and standard penetration testing (SPT), during which a small tube is hammered into the ground at the bottom of the borehole. Drilling (120 kW, 83 mm diameter drillbit, 1500 rpm, 16-17 m drill depth in sand and mudstone) and SPT (50 mm diameter test tube, 15 mm wall thickness, 100 kg hammer, 1 m drop height) by a jack-up rig in 7-13 m of water were recorded with a drifting hydrophone at 10-50 m range. Source levels were 142-145 dB re 1 μPa rms @ 1 m (30-2000 Hz) for drilling and 151-160 dB re 1 μPa
A single cut to pyroptosis.
Publisher: Impact Journals, LLC
Date: 16-10-2015
Autophagy as a pro-death pathway
Publisher: Wiley
Date: 21-10-2015
DOI: 10.1038/ICB.2014.85
Abstract: The evolutionarily conserved catabolic process of autophagy involves the degradation of cytoplasmic components through lysosomal enzymes. Basal levels of autophagy maintain cellular homeostasis and under stress conditions high levels of autophagy are induced. It is often under such stress conditions that high levels of autophagy and cell death have been observed, leading to the idea that autophagy may act as an executioner of cell death. However the notion of autophagy as a cell death mechanism has been controversial and remains mechanistically undefined. There is now growing evidence that in specific contexts autophagy can indeed facilitate cell death. The pro-death role of autophagy is however complicated due to the extensive cross-talk between different signalling pathways. This review summarises the ex les of where autophagy acts as a means of cell death and discusses the association of autophagy with the different cell death pathways.
Related Organisations
Govind Ballabh Pant University Of Agriculture And Technology
Location: India
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