Regulation Of Signal Transduction By Cbl: Investigation Of Effects On The Cytoskeleton, Cell Adhesion And Cell Motility
Funder
National Health and Medical Research Council
Funding Amount
$256,527.00
Summary
Changes in cell adhesion and motility have been implicated in a wide range of human pathologies (e.g. immune, reproductive, mental, and cancerous disorders) . Cell adhesion and motility are tightly regulated by a group of proteins known as Rho-GTPases. Novel pharmacological agents that target signalling by Rho-GTPases have been demonstrated to profoundly affect tumour metastasis, as well as central nervous system regeneration following injury. Further exploitation of Rho-GTPase signal modulation ....Changes in cell adhesion and motility have been implicated in a wide range of human pathologies (e.g. immune, reproductive, mental, and cancerous disorders) . Cell adhesion and motility are tightly regulated by a group of proteins known as Rho-GTPases. Novel pharmacological agents that target signalling by Rho-GTPases have been demonstrated to profoundly affect tumour metastasis, as well as central nervous system regeneration following injury. Further exploitation of Rho-GTPase signal modulation, by detailed studies of the molecular mechanisms involved, could lead to significant advances in medical sciences. In particular, treatment of cancer and spinal injuries are likely to benefit from further development of Rho-signalling research.Read moreRead less
Following a meal glucose circulates in the blood and is taken up into cells via movement of an intracellular glucose transporter from the inside of the cell to fuse with the cell membrane and subsequent transfer of the glucose into the cell. This process is triggered by insulin. One of the commonest diseases resulting from a failure of this cellular process is diabetes. A common form of diabetes which occurs in many adults in Australia results from insulin resistance, whereby the effects of insu ....Following a meal glucose circulates in the blood and is taken up into cells via movement of an intracellular glucose transporter from the inside of the cell to fuse with the cell membrane and subsequent transfer of the glucose into the cell. This process is triggered by insulin. One of the commonest diseases resulting from a failure of this cellular process is diabetes. A common form of diabetes which occurs in many adults in Australia results from insulin resistance, whereby the effects of insulin are diminished and cells become increasingly unable to uptake glucose. Recent studies have demonstrated that a novel enzyme known as SHIP-2 may play a role in regulating insulin action in cells. Deletion of SHIP-2 in mice results in these animals have increased sensitivity to insulin, low blood glucose levels, and a greatly enhanced ability to take up glucose in cells in response to low dose insulin. Our laboratory has been working on the cellular mechanisms regulating SHIP-2 function. We have recently revealed the intracellular location of SHIP-2 and also demonstrated how SHIP-2 is localized in the cell. These studies have shown that SHIP-2, via interactions with other proteins, regulates the actin cytoskeleton immediately beneath the cell membrane and this may be a mechanism for facilitating cellular glucose uptake. This research proposal aims to determine how SHIP-2 facilitates glucose uptake into cells. We will make cell lines and transgenic animals which express high levels of this enzyme and determine the functional consequences on insulin stimulated glucose uptake. Collectively these studies in the long term may facilitate better treatment strategies for diabetic patients.Read moreRead less
Cytokine Secretion: A Model For Protein Trafficking.
Funder
National Health and Medical Research Council
Funding Amount
$204,111.00
Summary
TNF-a is an inflammatory cytokine with important roles in host defense, tumour regulation and energy homeostatis, however the oversecretion of TNF-a is also a major cause of septic shock, rheumatoid arthritis, Chron?s disease and the cachexia of cancer. TNF-a synthesis and its release from the surface of cells are relatively well understood. However little is known about its trafficking through the secretory pathway of cells. Understanding this process has the potential to provide new ways of co ....TNF-a is an inflammatory cytokine with important roles in host defense, tumour regulation and energy homeostatis, however the oversecretion of TNF-a is also a major cause of septic shock, rheumatoid arthritis, Chron?s disease and the cachexia of cancer. TNF-a synthesis and its release from the surface of cells are relatively well understood. However little is known about its trafficking through the secretory pathway of cells. Understanding this process has the potential to provide new ways of controlling the secretion of TNF-a. In previous work we have characterized transport vesicles and cytoskeletal proteins involved in secretory pathways of epithelial cells. We now propose to focus on the characterization of transport vesicles, and the roles of actin and myosins involved in TNF-a secretion in macrophages. These studies will rely on introducing new technology to this line of research. Fluorescent tagged constructs of TNF-a will be expressed and viewed in living cells to analyse the secretory pathway and measure the transport of TNF-a from its site of accumulation in the Golgi complex to the cell surface. This work aims to identify membrane-bound vesicles and vesicle-associated proteins that target TNF-a for secretion. We will begin to investigate the role of actin and myosins, using drugs and microinjected peptides to block their function. Overall these studies will provide important cell biological information about protein trafficking in cells. Cytokine secretion is important in immunity and cancer, information important to both fields will be gained from these studies.Read moreRead less