C-Kit Signalling And Cellular Responses In Haemopoietic Cells
Funder
National Health and Medical Research Council
Funding Amount
$731,115.00
Summary
Growth factors acting on cell surface receptors activate multiple intracellular signalling pathways that regulate cellular growth and function. Mutations in the genes that code for these receptors or their downstream signalling pathways contribute to many human cancers. The contributions of different signalling pathways linked to these receptors to the various cellular responses (growth, maturation, functional activation) are not understood. In this project we aim to use cell and molecular biolo ....Growth factors acting on cell surface receptors activate multiple intracellular signalling pathways that regulate cellular growth and function. Mutations in the genes that code for these receptors or their downstream signalling pathways contribute to many human cancers. The contributions of different signalling pathways linked to these receptors to the various cellular responses (growth, maturation, functional activation) are not understood. In this project we aim to use cell and molecular biology approaches to determine the role of different signalling pathways in cellular responses mediated by the growth factor receptor c-Kit. The c-Kit receptor has essential functions in blood cell development, skin and hair pigmentation, gut function and the reproductive system. It is also essential for the development and function of mast cells which trigger allergic responses such as asthma and eczema. Mutant forms of the receptor have been identified in certain leukaemias and colon cancers. Many new drugs that target specific intracellular signalling pathways have recently been developed and are beginning to be evaluated in clinical trials. Better understanding of how individual pathways contribute to the function of c-Kit and other receptors is essential for optimal use of these new drugs. For example, it may enable the choice of drugs to block c-Kit dependent cancer cell growth or allergic reactions without affecting the growth of normal blood cells.Read moreRead less
Shaping a signal: studies on non-contiguous residues in an intracellular serpin that constitute a novel nuclear protein import signal. Eukaryotic cells contain membrane-bound organelles like the nucleus, endoplasmic reticulum and mitochondria, and use specific mechanisms to direct proteins from their site of synthesis to their target organelle. In nuclear proteins, sequence motifs termed nuclear localization signals (NLSs) direct engagement with the nuclear pore complex and translocation from cy ....Shaping a signal: studies on non-contiguous residues in an intracellular serpin that constitute a novel nuclear protein import signal. Eukaryotic cells contain membrane-bound organelles like the nucleus, endoplasmic reticulum and mitochondria, and use specific mechanisms to direct proteins from their site of synthesis to their target organelle. In nuclear proteins, sequence motifs termed nuclear localization signals (NLSs) direct engagement with the nuclear pore complex and translocation from cytoplasm to nucleus. All NLSs described so far consist of 5-7 contiguous basic residues. We propose to study a novel NLS that we recently discovered on an intracellular serpin. This comprises non-contiguous residues that together form a basic "patch" on the mature protein, and is the first example of a conformational NLS.Read moreRead less
The Molecular Basis of Copper Metabolism in Sheep. The unusual copper metabolism of sheep represents a significant agricultural problem. They are very susceptible to copper deficiency, but readily accumulate copper to toxic levels in the liver leading to fatal liver failure. We propose to elucidate the reason for the copper accumulation phenotype of sheep. We are focussing on WND, a copper transporter responsible for copper excretion into bile. We discovered a novel form of sheep WND designated ....The Molecular Basis of Copper Metabolism in Sheep. The unusual copper metabolism of sheep represents a significant agricultural problem. They are very susceptible to copper deficiency, but readily accumulate copper to toxic levels in the liver leading to fatal liver failure. We propose to elucidate the reason for the copper accumulation phenotype of sheep. We are focussing on WND, a copper transporter responsible for copper excretion into bile. We discovered a novel form of sheep WND designated WNDb to distinguish it from the normal form, WNDa. The experiments outlined are designed to understand the function of both proteins in the sheep and their role in copper sequestration.Read moreRead less
Tumour cells are often characterized by defects in signaling pathways. One of the most important signaling cascades involved in the development of cancer is the EGFR-Ras-MAPK pathway. EGFR is often overexpressed in breast cancer, leading to enhanced Ras signaling (hyperactive Ras) and cell transformation. The proposed project aims to identify the molecular mechanisms that can downregulate hyperactive Ras and will make a valuable contribution to our understanding of EGFR-Ras related cancers.
Post-genomic investigation of the relict plastid and mitochondrion of malaria parasites. Malaria is a major global health problem. The malaria parasite has two substructures, a relict chloroplast and a mitochondrion, that are excellent targets for new and existing drugs. However, we do not know the key functions of these two compartments. The entire genetic blueprint (genome) is now available for the malaria parasite and I propose to determine exactly which parts of the genome service the rel ....Post-genomic investigation of the relict plastid and mitochondrion of malaria parasites. Malaria is a major global health problem. The malaria parasite has two substructures, a relict chloroplast and a mitochondrion, that are excellent targets for new and existing drugs. However, we do not know the key functions of these two compartments. The entire genetic blueprint (genome) is now available for the malaria parasite and I propose to determine exactly which parts of the genome service the relict chloroplast and mitochondria. This will sketch out a picture of their inner workings. Armed with this information we can take a rational approach to seeking an Achilles? Heel of malaria against which parasite-specific drugs can be developed.Read moreRead less
Inhibition of pro-inflammatory cytokine secretion- A new route to therapeutics of chronic inflammatory disease. Chronic inflammatory diseases, including rheumatoid arthritis and inflammatory bowel disease, affect millions of people leading to considerable suffering, economic loss and premature death. Anti-TNF treatments have recently shown success in the treatment of rheumatoid arthritis, inflammatory bowel disease and other conditions, however, a substantial number of patients (~50%) do not re ....Inhibition of pro-inflammatory cytokine secretion- A new route to therapeutics of chronic inflammatory disease. Chronic inflammatory diseases, including rheumatoid arthritis and inflammatory bowel disease, affect millions of people leading to considerable suffering, economic loss and premature death. Anti-TNF treatments have recently shown success in the treatment of rheumatoid arthritis, inflammatory bowel disease and other conditions, however, a substantial number of patients (~50%) do not respond to the current TNF treatments. Improved anti-TNF strategies would provide enhanced health outcomes and welcome relief to many Australians. In addition, the economic benefit of the TNF market is very substantial. Therefore the potential impact of this research is very high both for health care and economical potential.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