ORCID Profile
0000-0002-5732-700X
Current Organisation
Newcastle University
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Publisher: EMBO
Date: 16-10-2015
Abstract: Mutations in the PTEN ‐induced kinase 1 ( PINK 1) are causative of autosomal recessive Parkinson's disease ( PD ). We have previously reported that PINK 1 is activated by mitochondrial depolarisation and phosphorylates serine 65 (Ser 65 ) of the ubiquitin ligase Parkin and ubiquitin to stimulate Parkin E3 ligase activity. Here, we have employed quantitative phosphoproteomics to search for novel PINK 1‐dependent phosphorylation targets in HEK (human embryonic kidney) 293 cells stimulated by mitochondrial depolarisation. This led to the identification of 14,213 phosphosites from 4,499 gene products. Whilst most phosphosites were unaffected, we strikingly observed three members of a sub‐family of Rab GTP ases namely Rab8A, 8B and 13 that are all phosphorylated at the highly conserved residue of serine 111 (Ser 111 ) in response to PINK 1 activation. Using phospho‐specific antibodies raised against Ser 111 of each of the Rabs, we demonstrate that Rab Ser 111 phosphorylation occurs specifically in response to PINK 1 activation and is abolished in HeLa PINK 1 knockout cells and mutant PINK 1 PD patient‐derived fibroblasts stimulated by mitochondrial depolarisation. We provide evidence that Rab8A GTP ase Ser 111 phosphorylation is not directly regulated by PINK 1 in vitro and demonstrate in cells the time course of Ser 111 phosphorylation of Rab8A, 8B and 13 is markedly delayed compared to phosphorylation of Parkin at Ser 65 . We further show mechanistically that phosphorylation at Ser 111 significantly impairs Rab8A activation by its cognate guanine nucleotide exchange factor ( GEF ), Rabin8 (by using the Ser111Glu phosphorylation mimic). These findings provide the first evidence that PINK 1 is able to regulate the phosphorylation of Rab GTP ases and indicate that monitoring phosphorylation of Rab8A/8B/13 at Ser 111 may represent novel biomarkers of PINK 1 activity in vivo . Our findings also suggest that disruption of Rab GTP ase‐mediated signalling may represent a major mechanism in the neurodegenerative cascade of Parkinson's disease.
Publisher: EMBO
Date: 25-10-2022
Abstract: Phagocytosis is a key process in innate immunity and homeostasis. After particle uptake, newly formed phagosomes mature by acquisition of endolysosomal enzymes. Macrophage activation by interferon gamma (IFN-γ) increases microbicidal activity, but delays phagosomal maturation by an unknown mechanism. Using quantitative proteomics, we show that phagosomal proteins harbour high levels of typical and atypical ubiquitin chain types. Moreover, phagosomal ubiquitylation of vesicle trafficking proteins is substantially enhanced upon IFN-γ activation of macrophages, suggesting a role in regulating phagosomal functions. We identified the E3 ubiquitin ligase RNF115, which is enriched on phagosomes of IFN-γ activated macrophages, as an important regulator of phagosomal maturation. Loss of RNF115 protein or ligase activity enhanced phagosomal maturation and increased cytokine responses to bacterial infection, suggesting that both innate immune signalling from the phagosome and phagolysosomal trafficking are controlled through ubiquitylation. RNF115 knock-out mice show less tissue damage in response to S. aureus infection, indicating a role of RNF115 in inflammatory responses in vivo. In conclusion, RNF115 and phagosomal ubiquitylation are important regulators of innate immune functions during bacterial infections.
Publisher: Public Library of Science (PLoS)
Date: 02-2016
Publisher: Cold Spring Harbor Laboratory
Date: 14-04-2023
DOI: 10.1101/2023.04.14.536870
Abstract: Pathogenic heterozygous missense mutations in the DNM1 gene result in a novel form of epileptic encephalopathy. DNM1 encodes for the large GTPase dynamin-1, an enzyme with an obligatory role in the endocytosis of synaptic vesicles (SVs) at mammalian nerve terminals. Pathogenic DNM1 mutations cluster within regions required for its essential GTPase activity, implicating disruption of this enzyme activity as being central to epileptic encephalopathy. We reveal that the most prevalent pathogenic mutation of DNM1 , R237W, disrupts dynamin-1 enzyme activity and SV endocytosis when overexpressed in central neurons. To determine how this dominant-negative heterozygous mutant impacted cell, circuit and behaviour when expressed from its endogenous locus, we generated a mouse carrying the R237W mutation. Neurons isolated from heterozygous mice displayed dysfunctional SV endocytosis, which translated into altered excitatory neurotransmission and seizure-like phenotypes. Importantly, these phenotypes were corrected at the cell, circuit and in vivo level by the drug, BMS-204352, which accelerates SV endocytosis. This study therefore provides the first direct link between dysfunctional SV endocytosis and epilepsy, and importantly reveals that SV endocytosis is a viable therapeutic route for monogenic intractable epilepsies.
Publisher: EMBO
Date: 28-09-2018
Publisher: American Association for the Advancement of Science (AAAS)
Date: 30-04-2021
Abstract: VAMP4 is a molecular rheostat that adjusts neurotransmitter release to both the activity and degradative status of neurons.
Publisher: Proceedings of the National Academy of Sciences
Date: 09-10-2018
Abstract: The maintenance of neurotransmission by synaptic vesicle (SV) recycling is critical to brain function. The dominant SV recycling mode during intense activity is activity-dependent bulk endocytosis (ADBE), suggesting it will perform a pivotal role in neurotransmission. However, the role of ADBE is still undetermined, due to the absence of identified molecules specific for this process. The determination of the bulk endosome proteome (a key ADBE organelle) revealed that it has a unique molecular signature and identified a role for Rab11 in presynaptic function. This work provides the molecular inventory of ADBE, a resource that will be of significant value to researchers wishing to modulate neurotransmission during intense neuronal activity in both health and disease.
Publisher: Cold Spring Harbor Laboratory
Date: 17-02-2021
DOI: 10.1101/2021.02.17.431591
Abstract: The nasal epithelium is a plausible entry point for SARS-CoV-2, a site of pathogenesis and transmission, and may initiate the host response to SARS-CoV-2. Antiviral interferon (IFN) responses are critical to outcome of SARS-CoV-2. Yet little is known about the interaction between SARS-CoV-2 and innate immunity in this tissue. Here we applied single-cell RNA sequencing and proteomics to a primary cell model of human nasal epithelium differentiated at air-liquid interface. SARS-CoV-2 demonstrated widespread tropism for nasal epithelial cell types. The host response was dominated by type I and III IFNs and interferon-stimulated gene products. This response was notably delayed in onset relative to viral gene expression and compared to other respiratory viruses. Nevertheless, once established, the paracrine IFN response began to impact on SARS-CoV-2 replication. When provided prior to infection, recombinant IFNβ or IFNλ1 induced an efficient antiviral state that potently restricted SARS-CoV-2 viral replication, preserving epithelial barrier integrity. These data suggest that the IFN-I/III response to SARS-CoV-2 initiates in the nasal airway and suggest nasal delivery of recombinant IFNs to be a potential chemoprophylactic strategy.
Publisher: Springer Science and Business Media LLC
Date: 22-10-2018
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Matthias Trost.