The Interaction Between CD46 And PSD-95/Dlg-4: Roles In Cell Polarisation And CD46 Signalling.
Funder
National Health and Medical Research Council
Funding Amount
$70,000.00
Summary
Immune defence against pathogens is primarily achieved by the activities of a range of blood cells, including T cells. T cells have specialised functions involving direct killing of the pathogen, and recruitment and activation of other immune cells. Many of these functions require the lymphocyte to become polarised, or asymmetric, in order to concentrate the appropriate cellular machinery towards the site of activity. Examples of polarisation in lymphocytes includes (i) the formation of a single ....Immune defence against pathogens is primarily achieved by the activities of a range of blood cells, including T cells. T cells have specialised functions involving direct killing of the pathogen, and recruitment and activation of other immune cells. Many of these functions require the lymphocyte to become polarised, or asymmetric, in order to concentrate the appropriate cellular machinery towards the site of activity. Examples of polarisation in lymphocytes includes (i) the formation of a single protrusion, or uropod, that forms the basis for cell-cell interactions, (ii) the formation of an immune synapse which allows a T cell to recognise a pathogen, and (iii) the direction of the cellular killing machinery towards the target. The process of cell polarisation is best characterised in neurons and epithelial cells, both of which are asymmetric. In each cell type, a major mechanism of regulating polarisation is the expression and targeting of a family of proteins containing regions called PDZ domains. PDZ domains mediate protein-protein interactions and so allow the assembly of large molecular scaffolds which hold proteins in specific cell sites. The loss of cell polarity in some cells is thought to cause uncontrolled proliferation and tumour progression, and some of the PDZ-containing proteins are tumour suppressors. We have identified a PDZ-containing protein that is polarised in T cells, and have evidence that this protein interacts with and controls the polarisation of a cell surface receptor whose functions include the regulation of T cell function and proliferation. The aim of this proposal is to determine the mechanisms and functional consequences of polarisation of these two proteins in T cells, and to determine whether their interaction or polarisation is important for T cell proliferation.Read moreRead less
Immune defence against pathogens is primarily achieved by the activities of a range of blood cells, including T cells. T cells have specialised functions involving direct killing of the pathogen, and recruitment and activation of other immune cells. Many of these functions require the lymphocyte to become polarised, or asymmetric, in order to concentrate the appropriate cellular machinery towards the site of activity. Examples of polarisation in lymphocytes includes (i) the formation of a single ....Immune defence against pathogens is primarily achieved by the activities of a range of blood cells, including T cells. T cells have specialised functions involving direct killing of the pathogen, and recruitment and activation of other immune cells. Many of these functions require the lymphocyte to become polarised, or asymmetric, in order to concentrate the appropriate cellular machinery towards the site of activity. Examples of polarisation in lymphocytes includes (i) the formation of a single protrusion, or uropod, that forms the basis for cell-cell interactions, (ii) the formation of an immune synapse which allows a T cell to recognise a pathogen, and (iii) the direction of the cellular killing machinery towards the target. The process of cell polarisation is best characterised in neurons and epithelial cells, both of which are asymmetric. In each cell type, a major mechanism of regulating polarisation is the expression and targeting of a family of proteins containing regions called PDZ domains. PDZ domains mediate protein-protein interactions and so allow the assembly of large molecular scaffolds which hold proteins in specific cell sites. The loss of cell polarity in some cells is thought to cause uncontrolled proliferation and tumour progression, and some of the PDZ-containing proteins are tumour suppressors. We have identified a PDZ-containing protein that is polarised in T cells, and have evidence that this protein interacts with and controls the polarisation of a cell surface receptor whose functions include the regulation of T cell function and proliferation. The aim of this proposal is to determine the mechanisms and functional consequences of polarisation of these two proteins in T cells, and to determine whether their interaction or polarisation is important for T cell proliferation.Read moreRead less
Regulation Of Nuclear Import Of Viral Oncoproteins And Transcription Factors By Protein-protein Interactions
Funder
National Health and Medical Research Council
Funding Amount
$650,383.00
Summary
The present application examines the controls that exerted over proteins that localize in the nucleus of eukaryotic cells. This relates relates integrally to cellular processes such as growth, development and oncogenesis. This research area is not represented elsewhere in Australia, and the particular experimental strategies to approach the problem, revolving around the use of special quantitative microscopic techniques are novel internationally. One part of the application seeks to examine tran ....The present application examines the controls that exerted over proteins that localize in the nucleus of eukaryotic cells. This relates relates integrally to cellular processes such as growth, development and oncogenesis. This research area is not represented elsewhere in Australia, and the particular experimental strategies to approach the problem, revolving around the use of special quantitative microscopic techniques are novel internationally. One part of the application seeks to examine transport within the cell of complexes of interacting proteins, rather than single proteins, under as close as possible to physiologically relevant conditions. This will be truly unique, and of great importance to our comprehension of eukaryotic cell function. This application examines particular types of negative control over protein nuclear localization. Since many proteins show such regulation, and in particular important proteins controlling cell growth and division, the results are fundamentally important to our understanding of how cells function in general. Further, this understanding may be applied in disease situations, such as viral-mediated oncogenesis. In the work we propose to do, viral proteins with functions relating to cancer will be examined in detail, as well as a cellular protein which is recognised by them - the tumor suppressor Rb. We intend to examine several viral oncoproteins which target Rb; one is a protein (E7) from the Human Papilloma Virus which has been frequently associated with cervical carcinomas and other cancers. Accordingly, the results may have direct application to viral-induced cancer, and our work may lead to understanding of the regulation of protein transport to the nucleus. This may thus afford a new approach at the pharmacological level to combat transformation.Read moreRead less
The Interactions Of Dengue Virus RNA Dependent RNA Polymerase (NS5) With Other Viral And Host Factors.
Funder
National Health and Medical Research Council
Funding Amount
$170,165.00
Summary
Dengue fever is a mosquito-borne disease that is prevalent in tropical countries. It is estimated that 40% of the global population is at risk of dengue infection. Classical dengue fever is not life threatening. However, the more serious disease, dengue haemorrhagic fever-shock syndrome requires intensive medical attention to prevent fatality. A significant number of deaths are recorded each year especially in the underdeveloped countries. Dengue is periodically also a problem in northern Austra ....Dengue fever is a mosquito-borne disease that is prevalent in tropical countries. It is estimated that 40% of the global population is at risk of dengue infection. Classical dengue fever is not life threatening. However, the more serious disease, dengue haemorrhagic fever-shock syndrome requires intensive medical attention to prevent fatality. A significant number of deaths are recorded each year especially in the underdeveloped countries. Dengue is periodically also a problem in northern Australia. There is no cure for dengue fever. The present research aims to use a knowledge-based approach to develop novel antiviral strategies based on preventing the critical protein interactions required for the normal virus life cycle. Two of the most important proteins involved in dengue virus replication are called the NS3 and NS5 proteins. The protein-protein interaction (contact) that occurs between NS5 and NS3 is crucial for the replication of the virus. Little is known about this interaction at present, and the studies we propose will directly address this issue. We have previously shown that a 37 amino acid in the middle of NS5 contains a nuclear localisation signal that can target the normally cytoplasmic protein to the nucleus of the infected cell. What the function of this protein is in the nucleus is not known. We will use a technique called the yeast two-hybrid test to address the question of dengue virus protein interactions in the common bakers yeast. This method is very sensitive and powerful and will provide important insights that will contribute to the development of a rapid high-throughput test to screen the extensive extract collection from Australia's marine biodiversity, held by the Australian Institute of Marine Sciences, to discover suitable inhibitors of NS3-NS5 interaction.Read moreRead less
Myofibroblast differentiation: from haemopoietic cells to smooth muscle. Until very recently the ability of adult cells with specific differentiated functions to re-differentiate for another function was thought to be extremely limited. However we have shown that cells ultimately derived from the bone marrow can differentiate into fibroblasts, then into myofibroblasts and then into smooth muscle cells. This project will build on these unique findings and determine the molecular mechanisms cont ....Myofibroblast differentiation: from haemopoietic cells to smooth muscle. Until very recently the ability of adult cells with specific differentiated functions to re-differentiate for another function was thought to be extremely limited. However we have shown that cells ultimately derived from the bone marrow can differentiate into fibroblasts, then into myofibroblasts and then into smooth muscle cells. This project will build on these unique findings and determine the molecular mechanisms controlling this process. We hypothesise that the local environment of a cell is critical and will involve a combination of particular extracellular matrix and growth factors as well as mechanical tension and the presence of other cell types.Read moreRead less
Factors involved in release of cytochrome c from mitochondria during apoptosis. Mitochondria are energy-producing organelles that activate cell death by selective release of constituents, notably cytochrome c, which participate in death-signalling cascades. I aim to probe such mitochondrial release mechanisms in intact cells, by focussing on features of translocated proteins relevant to release. Cultured mouse cells lacking cytochrome c are uniquely suited to these studies. A series of cytochrom ....Factors involved in release of cytochrome c from mitochondria during apoptosis. Mitochondria are energy-producing organelles that activate cell death by selective release of constituents, notably cytochrome c, which participate in death-signalling cascades. I aim to probe such mitochondrial release mechanisms in intact cells, by focussing on features of translocated proteins relevant to release. Cultured mouse cells lacking cytochrome c are uniquely suited to these studies. A series of cytochrome c derivatives will be engineered in elongated or aggregated forms and their release studied (including interactions with putative release machinery components) following death-signal activation. The project will elucidate a central mechanism in the cell death process, highly significant in many biological contexts.Read moreRead less
Identification of Proteins that Regulate Apoptosis Through Interaction With IAPS. Apoptosis is the process by which multicellular organisms eliminate unwanted cells. Identifying proteins involved in cell death regulation is central to our understanding of disease states arising from aberrations in this process. The mammalian protein DIABLO, promotes cell death by interacting with and antagonising inhibitor of apoptosis proteins (IAPS). Given the existence of several IAP regulatory proteins (IRPs ....Identification of Proteins that Regulate Apoptosis Through Interaction With IAPS. Apoptosis is the process by which multicellular organisms eliminate unwanted cells. Identifying proteins involved in cell death regulation is central to our understanding of disease states arising from aberrations in this process. The mammalian protein DIABLO, promotes cell death by interacting with and antagonising inhibitor of apoptosis proteins (IAPS). Given the existence of several IAP regulatory proteins (IRPs) in insects, other mammalian IRPs probably also exist. These may be of equal importance in regulating apoptosis, especially in tissues where DIABLO is not expressed. The main aim of the proposed study is to idenitify and characterise other IRPs in mammalian cells.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0226463
Funder
Australian Research Council
Funding Amount
$160,000.00
Summary
Fluorescence Lifetime Imaging Facility. The aim of this proposal is to establish the first fluorescence lifetime imaging facility (FLIM) in Australia. The imaging technique provided by the new facility when combined with the use of novel fluorescent protein technology will enable many different events, represented by protein-protein interactions, to be non-invasively, visualised spatially and temporally inside the living cell. The new facility will provide timely state-of -the-art infrastructu ....Fluorescence Lifetime Imaging Facility. The aim of this proposal is to establish the first fluorescence lifetime imaging facility (FLIM) in Australia. The imaging technique provided by the new facility when combined with the use of novel fluorescent protein technology will enable many different events, represented by protein-protein interactions, to be non-invasively, visualised spatially and temporally inside the living cell. The new facility will provide timely state-of -the-art infrastructure necessary for research groups to further develop and maintain their international reputations, will build stronger research collaborations between partner institutions and will attract researchers from overseas.Read moreRead less
Combined genetic and cellular analysis of melanisation to study variation in human pigmentation. This investigation examines variations in the genes that are important determinants of human skin pigmentation and are likely to be associated with skin cancer risk. Our research program will form the basis of future diagnostics based on major genes that determine a persons skin type. Current skin cancer prevention strategies rely predominantly on broad spectrum campaigns that are aimed at increasi ....Combined genetic and cellular analysis of melanisation to study variation in human pigmentation. This investigation examines variations in the genes that are important determinants of human skin pigmentation and are likely to be associated with skin cancer risk. Our research program will form the basis of future diagnostics based on major genes that determine a persons skin type. Current skin cancer prevention strategies rely predominantly on broad spectrum campaigns that are aimed at increasing the general community awareness of the damaging effects of UV radiation. A better understanding of the genetic basis of UV-sensitive skin types will greatly enhance the targeting of such skin cancer-prevention campaigns, provide an understanding of changes that occur in skin pathology, and the mechanisms of sun induced tanning.Read moreRead less