The Role Of Plasma Membrane Microdomains In Cellualar Function
Funder
National Health and Medical Research Council
Funding Amount
$4,083,868.00
Summary
The planned research program relates to novel hypotheses regarding the role of cell surface domains in organising signalling pathways at the cell surface. The proposal will involve identifying the domains and molecules involved in specific signalling pathways and dissecting the formation and function of surface structures called caveolae. The findings will have huge importance for therapeutic strategies aimed at combating the cellular changes associated with cell transformation in cancer and oth ....The planned research program relates to novel hypotheses regarding the role of cell surface domains in organising signalling pathways at the cell surface. The proposal will involve identifying the domains and molecules involved in specific signalling pathways and dissecting the formation and function of surface structures called caveolae. The findings will have huge importance for therapeutic strategies aimed at combating the cellular changes associated with cell transformation in cancer and other human diseases.Read moreRead less
Prof Parton is a cell biologist studying how the plasma membrane functions in health and in disease. These studies have provided new insights into potential vehicles that can be used to introduce therapeutic agents into cells.
Molecular And Functional Characterisation Of Cell Surface Microdomains
Funder
National Health and Medical Research Council
Funding Amount
$4,803,731.00
Summary
This research program aims to gain a detailed understanding of the organisation of the cell surface at the molecular level. The cell surface is organised into domains with distinct functions. Visualisation of these domains, identifying their important components, and understanding how they form and function will have huge importance for therapeutic strategies aimed at combating the changes associated with cell transformation in cancer and in other human diseases such as muscular dystrophy.
Analysis Of The C-terminal Hypervariable Region Of Ras Proteins
Funder
National Health and Medical Research Council
Funding Amount
$419,241.00
Summary
In human cancers one or more of the signaling pathways leading from growth factor receptors at the cell surface to the nucleus where cell division is initiated are subverted. For example, a protein called Ras, that regulates one major signaling pathway, is mutated in 90% of pancreatic cancers, 50% of colon cancers and 30% of acute leukaemias. This leaves Ras and the signaling pathway permanently switched on causing uncontrolled cell proliferation. The clinical impact of drugs that could neutrali ....In human cancers one or more of the signaling pathways leading from growth factor receptors at the cell surface to the nucleus where cell division is initiated are subverted. For example, a protein called Ras, that regulates one major signaling pathway, is mutated in 90% of pancreatic cancers, 50% of colon cancers and 30% of acute leukaemias. This leaves Ras and the signaling pathway permanently switched on causing uncontrolled cell proliferation. The clinical impact of drugs that could neutralise Ras function in these tumours is potentially enormous. Our previous work demonstrated that Ras must be attached to the inner surface of the cell membrane in order to function properly. This project now seeks to understand exactly how Ras gets to and attaches to the cell membrane. Once we understand this mechanism drugs can be designed to block Ras getting to the membrane. Such drugs should neutralize the effect of Ras in tumours and control cell proliferation. In fact, our previous study has already led to the identification of the first generation of anti-Ras drugs that work on this principle.Read moreRead less
The Role Of Plasma Membrane Microdomains In Regulating Ras-dependent Raf Activation
Funder
National Health and Medical Research Council
Funding Amount
$216,100.00
Summary
In human cancers one or more of the signaling pathways leading from growth factor receptors at the cell surface to the nucleus where cell division is initiated are subverted. For example, a protein called Ras, that regulates a series of major signaling pathways, is mutated in 25% of all human tumours. This leaves Ras and the signaling pathways permanently switched on causing uncontrolled cell proliferation. Our previous work has demonstrated that Ras must be attached to the inner surface of the ....In human cancers one or more of the signaling pathways leading from growth factor receptors at the cell surface to the nucleus where cell division is initiated are subverted. For example, a protein called Ras, that regulates a series of major signaling pathways, is mutated in 25% of all human tumours. This leaves Ras and the signaling pathways permanently switched on causing uncontrolled cell proliferation. Our previous work has demonstrated that Ras must be attached to the inner surface of the cell membrane in order to function properly. This project now seeks to understand exactly how Ras attaches to and interacts with specific sites in the plasma membrane. Its is becoming clear that different isoforms of Ras, called H-, N- and K-ras have different functions in the cell which may in turn result from their different sites of attachment to the cell membrane. This is important because by understanding the precise micro-environment in which the different Ras proteins operate and how they activate subsequent proteins in their signaling networks we will be in a good position to design drugs that selectively compromise the function of each specific Ras isoform. A highly relevant example is provided by K-ras which is mutated in 90% of all pancreatic cancers and 50% of all colon cancers. Clearly the clinical impact of a drug that could selectively neutralise K-Ras function in these tumours is potentially enormous.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.
Functional Characterization Of Caveolae And Caveolins
Funder
National Health and Medical Research Council
Funding Amount
$140,660.00
Summary
This project aims to study the cellular machinery that allows a cell to respond to its external environment. Specifically, this project focusses on the function of a family of membrane proteins, called caveolins, which are the major protein components of caveolae small pits which cover the surface of many mammalian cells. Caveolins are believed to regulate signalling from the external environment to the cell interior and loss of this regulation leads to uncontrolled growth leading to cancer. Sig ....This project aims to study the cellular machinery that allows a cell to respond to its external environment. Specifically, this project focusses on the function of a family of membrane proteins, called caveolins, which are the major protein components of caveolae small pits which cover the surface of many mammalian cells. Caveolins are believed to regulate signalling from the external environment to the cell interior and loss of this regulation leads to uncontrolled growth leading to cancer. Signalling from the cell surface relies on organisation of signalling components into modules. Our studies suggest that these modules are dependent on specific lipid molecules which form discrete patches, called lipid rafts, on the cell surface. We have hypothesised that caveolins control the lipid molecules associated with lipid rafts and so, indirectly, control signalling pathways. In particular, we have shown that caveolin is important in the regulation of cellular cholesterol, a vital molecule involved in maintaining the function of lipid raft domains. As numerous human diseases are associated with cholesterol imbalance, studies of caveolins can give fundamental new insights into this process, and the previously unidentified links between the cellular lipid balance and signal transduction. This project aims to use mutant caveolin molecules to disrupt caveolin function and so determine the role of caveolin in lipid regulation and in signal transduction. We will then use a lower vertebrate model system, which is amenable to experimental manipulation, to determine the role of caveolins and rafts in the development of the whole embryo.Read moreRead less
The Regulation Of PI 3-kinase Second Messenger Molecules, PtdIns(3,4)P2 And PtdIns 3-P.
Funder
National Health and Medical Research Council
Funding Amount
$406,980.00
Summary
Cells respond to the external environment, hormones, and growth factors by generating messages inside the cell that send a signal to the nucleus that stimulates cell growth. One such signalling network is that produced by membrane lipids known as phosphoinositides. Enzymes that produce these signals are known as kinases. There has been considerable interest in the PI 3-kinase as the signals generated by this enzyme are increased in many human cancers. Inherited cancer syndromes have been describ ....Cells respond to the external environment, hormones, and growth factors by generating messages inside the cell that send a signal to the nucleus that stimulates cell growth. One such signalling network is that produced by membrane lipids known as phosphoinositides. Enzymes that produce these signals are known as kinases. There has been considerable interest in the PI 3-kinase as the signals generated by this enzyme are increased in many human cancers. Inherited cancer syndromes have been described that have lost the ability to switch off PI 3-kinase signals. The current project aims to investigate a recently identified enzyme called the 4-phosphatase that has the ability to terminate PI 3-kinase signals. Recent studies have shown this enzyme regulates cell growth. In addition key experiments have shown the enzyme is important as it may regulate certain strains of bacterial infection. This research proposal aims to investigate how the enzyme works to regulate these growth promoting signals. This may help us develop novel therapeutic strategies to control cell growth.Read moreRead less