Inhibition Of Nef-activated Src-family Kinases By CHK
Funder
National Health and Medical Research Council
Funding Amount
$514,307.00
Summary
HIV hijacks infected blood cells to produce its own proteins. Nef is one of these proteins and Nef alone is sufficient to cause an AIDS-like disease. Recently, we discovered that a protein called CHK can inhibit Nef. Our research will determine how CHK inhibits Nef and test the feasibility of drugs based on CHK. Such drugs would slow AIDS progression, assisting conventional therapies and patients' immune systems to combat the infection, leading to longer, healthier, more productive lives.
Analysis Of APC And APC Protein Complexes In Colon Cancer
Funder
National Health and Medical Research Council
Funding Amount
$110,786.00
Summary
Colorectal cancer is one of the foremost causes of death in Australia. A defective form of a protein called APC has been shown to be present in more than 80% of colon tumours. How APC contributes to colon cancer is still not known. We aim to determine the function of the APC protein by studying the APC protein and proteins that interact with APC in normal and cancerous colon epithelial cells. We will use cells derived from normal colon epithelium as well as from colon carcinomas. Once we have id ....Colorectal cancer is one of the foremost causes of death in Australia. A defective form of a protein called APC has been shown to be present in more than 80% of colon tumours. How APC contributes to colon cancer is still not known. We aim to determine the function of the APC protein by studying the APC protein and proteins that interact with APC in normal and cancerous colon epithelial cells. We will use cells derived from normal colon epithelium as well as from colon carcinomas. Once we have identified proteins that interact with APC in normal colonic cells, we will have a more complete understanding of the function of APC and its role in the development of colonic tumours.Read moreRead less
Analysis Of The Role Of Vesicle Docking/Fusion Proteins In Trafficking Of The Glut4 Glucose Transporter In Adipocytes
Funder
National Health and Medical Research Council
Funding Amount
$212,036.00
Summary
The objective of these studies is to understand the molecular mechanisms that are involved in the control of blood glucose levels by the hormone insulin. Elevated blood glucose levels following a meal stimulate the pancreas to release insulin into the circulation. Insulin acts to reduce blood sugar levels by stimulating the uptake of glucose into fat and muscle and suppressing glucose production by the liver. Defects in insulin action in these tissues are the primary cause of Type II diabetes. T ....The objective of these studies is to understand the molecular mechanisms that are involved in the control of blood glucose levels by the hormone insulin. Elevated blood glucose levels following a meal stimulate the pancreas to release insulin into the circulation. Insulin acts to reduce blood sugar levels by stimulating the uptake of glucose into fat and muscle and suppressing glucose production by the liver. Defects in insulin action in these tissues are the primary cause of Type II diabetes. The debilitating effects of Type II diabetes, the dramatic increase its incidence, and the expense of treating the symptoms of diabetic complications have lead to the realization that the disease represents a major health problem requiring substantial research and development efforts. The project will focus on insulin regulation of glucose uptake in fat cells. Insulin promotes glucose uptake into fat by activating an intracellular signaling pathway that triggers the translocation of a unique glucose transporter protein (Glut4) from storage sites inside the cell to the cell surface. Glut4 translocation is mediated by small membrane vesicles that function to sequester the glucose transporter inside cells in the absence of insulin, and to shuttle Glut4 to the cell surface in response to the hormone. Despite the central importance of this event to the maintenance of normal blood glucose levels, it is poorly understood. The studies will be directed towards investigating the cellular machinery involved in the latter stages of insulin-stimulated glucose uptake- the vesicle-mediated delivery of Glut4 to the cell surface. The objective of these studies is to better understand the molecular basis for Glut4 translocation, and regulation by the insulin signaling cascade. Accomplishment of this goal may suggest potential drug intervention strategies aimed at enhancing insulin-stimulated Glut4 translocation and promoting improved control of blood glucose levels in Type II diabetes.Read moreRead less
The Structural Basis Of Ligand-Induced Activation Of The Insulin Receptor
Funder
National Health and Medical Research Council
Funding Amount
$640,825.00
Summary
We aim to understand how insulin binds to and activates its cell-surface receptor. This information has implications for the design of anti-diabetic agents targetted directly to the insulin receptor. Diabetes is a global health problem and is classified by the World Health Organization as an epidemic. The results also have implications for the insulin-like growth factor receptor system and the design of anti-cancer therapeutics directed towards it .
Identification And Characterization Of Substrates Of Tyrosine Kinases Involved In Hematopoiesis And Leukemia
Funder
National Health and Medical Research Council
Funding Amount
$241,527.00
Summary
The development and maintenance of tissues in mammals are tightly controlled and complex processes involving the growth, maturation and survival of vast numbers of cells of various types. In cancer, the cell's capacity to faithfully regulate these processes is diminished or lost. Many of the proteins that are essential for growth control are produced by an important class of genes called proto-oncogenes; literally, the prototypes of cancer-causing genes. Naturally occurring mutations in these ge ....The development and maintenance of tissues in mammals are tightly controlled and complex processes involving the growth, maturation and survival of vast numbers of cells of various types. In cancer, the cell's capacity to faithfully regulate these processes is diminished or lost. Many of the proteins that are essential for growth control are produced by an important class of genes called proto-oncogenes; literally, the prototypes of cancer-causing genes. Naturally occurring mutations in these genes have been identified in man and are likely to play a major role in the initiation and progression of distinct human malignancies. A significant number of proto-oncogenes are enzymes called protein tyrosine kinases (PTKs). Research has shown that the function of PTKs is to relay growth signals or other regulatory signals from the outer surface of the cell to specific target proteins inside the cell. These target proteins are needed to relay the signal to other target molecules and so on. This highly ordered process, involving a specific sequence of proteins, ensures that cells respond appropriately to a given signal. Our research focuses on identifying and studying the immediate targets of PTKs with the broad aim of understanding how PTKs control growth in normal and cancerous cells. We have recently developed a method that has enabled us to identify a new protein that may regulate the growth of blood cells. The research proposed here aims to extend our preliminary observations showing that the growth of specific types of blood cells is inhibited by this protein. We also plan to search for new targets of a PTK that is involved in leukemia. The findings of this research will provide important insight into how blood cells are regulated in health and disease.Read moreRead less
Inside our cells is a complex traffic system. The vehicles are vesicles that come in different shapes and sizes and travel to specific destinations in the cell to deliver cargo such as: surface growth factor receptors that are to have their signalling terminated, proteins and lipids destined for the cell wall for growth or development (like neurite outgrowth) and proteins and hormones destined for secretion (like neurotransmitter release). More than 100 human genetic disorders map to defects in ....Inside our cells is a complex traffic system. The vehicles are vesicles that come in different shapes and sizes and travel to specific destinations in the cell to deliver cargo such as: surface growth factor receptors that are to have their signalling terminated, proteins and lipids destined for the cell wall for growth or development (like neurite outgrowth) and proteins and hormones destined for secretion (like neurotransmitter release). More than 100 human genetic disorders map to defects in one of the components of this system. Proteins called small GTPases provide order for this traffic and allow specific cargo to reach specific destinations. They regulate cell functions by acting as switches, turning biochemical processes on and off inside the cell. Ral is a small GTPase enzyme found in brain and broadly distributed in other cells. We have discovered that Ral is part of a large signalling complex. When activated Ral stimulates effectors, either the exocyst or RalBP1. In turn, mild oxidative stress controls a Ral inhibitor protein called ERp57. The research proposed aims to establish the functional role for the Ral signalling complex in cells. We will determine with which vesicle trafficking events Ral is associated, which effector it utilises in that pathway, and how that effector directs the traffic. We will also map the steps that may lead to inactivation of Ral via ERp57 in cells, and propose that this is mediated by mild oxidative stress. Techniques of molecular biology, biochemistry, molecular biology, proteomics and microscopy will be used to establish these functions. The research will lead to increased knowledge of the significance of this protein to cellular and particularly neuronal cell function. This forms the basis for understanding normal cell function and for identification of further factors causing diseases of vesicle transport. In time, such research aids in the development of specific therapies for sufferers of such diseases.Read moreRead less
Recycling Endosomes Governing Cell Polarity And Cytokine Secretion.
Funder
National Health and Medical Research Council
Funding Amount
$958,412.00
Summary
Cytokines are chemical messengers released by cells to mount inflammatory responses to fight infections. The timing and direction of cytokine release must be tightly regulated. We investigate the cellular compartments and molecules that control cytokine secretion using sophisticated live cell imaging. Uncontrolled cytokine release is the main cause of ongoing inflammation in arthritis and inflammatory bowel disease and our studies aim to identify cellular targets for new drug development.
Regulated Shuttling Of Beta-catenin And IQGAP1 Between Nucleus And Plasma Membrane In Migrating Cells
Funder
National Health and Medical Research Council
Funding Amount
$511,703.00
Summary
Inherited gene mutations that cause colon cancer kill 4,700 Australians every year. About 1 in 21 Australians develop colorectal cancer by age 75. Activation of the beta-catenin protein is a critical switch in the path to colon cancer. We discovered that beta-catenin, and another protein it interacts with called IQGAP1, move between different cellular compartments. We plan to study this process in more detail, as it relates to how beta-catenin works and to understanding its role in cancer.
Targeting Of The APC Tumour Suppressor To Mitochondria: Implications For APC Regulation And Cellular Function
Funder
National Health and Medical Research Council
Funding Amount
$390,116.00
Summary
Inherited mutations in the APC gene cause colon cancer, and kills 4,700 Australians every year. About 1 in 21 Australians develop colorectal cancer by the age of 75. APC mutations change cells in different ways, triggering the cancer process. We have discovered a new pathway, involving altered movement of APC to mitochondria in tumour cells. This study will investigate how this cancerous change may help our understanding of colon cancer progression.
Understanding The Role Of Tec In Fcgamma Receptor Mediated Phagocytosis
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
The recognition and destruction of bacterial pathogens and other foreign particles by specific immune cells (macrophages) is principally mediated by the Fcgamma class of cell surface antibody receptors. This proposal aims to understand the molecular mechanisms which link receptor activation to the cellular rearrangements required to invaginate or swallow the offending particle. We have used immunofluorescent microscopy and biochemical methods to show that the intracellular tyrosine kinase Tec is ....The recognition and destruction of bacterial pathogens and other foreign particles by specific immune cells (macrophages) is principally mediated by the Fcgamma class of cell surface antibody receptors. This proposal aims to understand the molecular mechanisms which link receptor activation to the cellular rearrangements required to invaginate or swallow the offending particle. We have used immunofluorescent microscopy and biochemical methods to show that the intracellular tyrosine kinase Tec is an important component of the phagocytosis mechanism. Here we plan to use highly selective gene targeting methods to generate a mouse cell culture model system which is devoid of Tec protein. This will allow us to determine whether Tec is essential for Fcgamma-mediated phagocytosis. Reintroduction of mutant versions of the Tec protein into this null background will provide detailed information on the molecular partners of Tec and the individual roles of the various domains within the Tec protein. By studying the molecular mechanism of phagocytosis, we expect to gain an understanding of how to influence the Fcgamma signalling pathway, either to enhance the ability to deal with pathogens, or to restrict the consequences of excessive phagocytosis associated with autoimmune diseases. Tec is an enzyme likely to play an important role between the Fcgamma receptor and actin cytoskeleton rearrangements and therefore is a potentially important drug target.Read moreRead less