Identification And Characterization Of Novel PI3-kinase Signal Transducing Elements In Platelets
Funder
National Health and Medical Research Council
Funding Amount
$457,500.00
Summary
Platelets play an important role in blood clotting and blood vessel repair. Upon vessel injury, platelets rapidly adhere to the site of damage where they undergo dramatic shape change to spread over the site of injury. Activation and regulation of these processes relies on a complex network of signal transduction processes, involving the integration of multiple receptors and pathways. One pathway demonstrated to play a role in regulating platelet responses is the enzyme phosphatidylinositol 3-ki ....Platelets play an important role in blood clotting and blood vessel repair. Upon vessel injury, platelets rapidly adhere to the site of damage where they undergo dramatic shape change to spread over the site of injury. Activation and regulation of these processes relies on a complex network of signal transduction processes, involving the integration of multiple receptors and pathways. One pathway demonstrated to play a role in regulating platelet responses is the enzyme phosphatidylinositol 3-kinase (PI3-kinase) and its lipid products PtdIns(3,4,5)P3 and PtdIns(3,4)P2. However, very little is known about exactly how PI3-kinase and its products regulate the platelet responses. Our research studies aim to gain a deeper understanding into the molecular mechanisms of PI3-kinase signal transduction in platelets, through the identification and characterization of novel platelet proteins that bind to PI3-kinase lipid products, and to define what role these proteins play in platelet PI3-kinase dependent responses.Read moreRead less
The regulation of signalling molecules in Saccharomyces Cerevisiae by inositol polyphosphate 5-phosphatases. Phosphoinositide signalling molecules regulate the actin cytoskeleton, secretion, vesicular trafficking and cell growth and death. We have identified, cloned and characterised a family of signal terminating enzymes called inositol polyphosphate 5-phosphatases (5-phosphatases) that regulate phosphoinositide signalling molecules. We have cloned and characterised four distinct 5-phosphatases ....The regulation of signalling molecules in Saccharomyces Cerevisiae by inositol polyphosphate 5-phosphatases. Phosphoinositide signalling molecules regulate the actin cytoskeleton, secretion, vesicular trafficking and cell growth and death. We have identified, cloned and characterised a family of signal terminating enzymes called inositol polyphosphate 5-phosphatases (5-phosphatases) that regulate phosphoinositide signalling molecules. We have cloned and characterised four distinct 5-phosphatases in the yeast Saccharomyces Cerevisiae and demonstrated by both deletion and overexpression studies that these enzymes regulate the actin cytoskeleton, endocytosis and secretion. This research proposal aims to investigate the signalling complexes the 5-phosphatases form with specific actin binding and or regulatory proteins, investigate the complex interactions of phosphoinositide lipid phosphatases and the roles they play in regulating secretion from the endoplasmic reticulum and finally characterize a novel 5-phosphatase that we have recently identified. Collectively the outcome of these studies will provide novel information about the functionallly significant signalling pathways regulated by this important enzyme family.Read moreRead less
The role of PtdIns(4,5)P2 in cellular responses in Saccharomyces cerevisiae. This grant application falls under the criteria of frontier technologies in genomics/phenomics and complex systems. We are characterizing a highly conserved network of signaling molecules regulated by complex large families of enzymes that regulate the bending of membranes, and cellular events including cell division in plants, yeast and mammalian cells. We have developed cutting edge novel technologies to localize sign ....The role of PtdIns(4,5)P2 in cellular responses in Saccharomyces cerevisiae. This grant application falls under the criteria of frontier technologies in genomics/phenomics and complex systems. We are characterizing a highly conserved network of signaling molecules regulated by complex large families of enzymes that regulate the bending of membranes, and cellular events including cell division in plants, yeast and mammalian cells. We have developed cutting edge novel technologies to localize signaling on specific intracellular membranes and visualise the role cellular lipids play in forming tubules in cells. This project will result in the presentation of Australian research at international forums and support the training of PhD students.Read moreRead less
Investigation of a Phagocytic Synapse in the Uptake of Apoptotic Cells. Rapid clearance of cells that die by apoptosis is crucial for embryonic development, tissue turnover, and after inflammatory events. Specialised phagocytes engulf the apoptotic cell corpses in a way that minimises inflammation and prevents autoimmunity. Genetic studies have identified the key evolutionary receptors involved, but the molecular basis of this phagocytosis is still poorly understood. We have developed, and seek ....Investigation of a Phagocytic Synapse in the Uptake of Apoptotic Cells. Rapid clearance of cells that die by apoptosis is crucial for embryonic development, tissue turnover, and after inflammatory events. Specialised phagocytes engulf the apoptotic cell corpses in a way that minimises inflammation and prevents autoimmunity. Genetic studies have identified the key evolutionary receptors involved, but the molecular basis of this phagocytosis is still poorly understood. We have developed, and seek to establish, an integrated model that incorporates new findings to explain how the distinctive functions of specialised receptors can be orchestrated to achieve this function. A successful outcome to the project will provide new knowledge of value to human health.Read moreRead less
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
Regulation of MHC-I and ICAM-1 by flavivirus, West Nile. This project investigates the intracellular signalling pathway responsible for the expression of genes which are critical to our immune response. We have demonstrated in a mouse model that high levels of expression of two of these genes in flavivirus encephalitis are associated with a survival advantage. We would expect this project to provide basic new information about the mechanisms of expression of these genes as well as information ab ....Regulation of MHC-I and ICAM-1 by flavivirus, West Nile. This project investigates the intracellular signalling pathway responsible for the expression of genes which are critical to our immune response. We have demonstrated in a mouse model that high levels of expression of two of these genes in flavivirus encephalitis are associated with a survival advantage. We would expect this project to provide basic new information about the mechanisms of expression of these genes as well as information about the interaction of this family of viruses, flavivirus with the host.Read moreRead less
Examination of the Calcium Signalling Dynamics Linked to Integrin Adhesion Utilising a Novel Micro-imaging System. This study aims at increasing our understanding of the fundamental cell processes that allow cells to adhere to surfaces. The proposed study will lead to a greater understanding of the calcium signalling mechanisms that are fundamental to diverse biological phenomena such as, tissue regeneration and repair, blood clotting, cancer metastasis, and neuronal cell function. From a preven ....Examination of the Calcium Signalling Dynamics Linked to Integrin Adhesion Utilising a Novel Micro-imaging System. This study aims at increasing our understanding of the fundamental cell processes that allow cells to adhere to surfaces. The proposed study will lead to a greater understanding of the calcium signalling mechanisms that are fundamental to diverse biological phenomena such as, tissue regeneration and repair, blood clotting, cancer metastasis, and neuronal cell function. From a preventative health perspective, the investigation of platelet calcium signalling will greatly accelerate the development of new pharmaceuticals to tackle acute and chronic cardiovascular diseases, such as stroke, heart attack and artherosclerosis. Read moreRead less
A novel role for the proteins Scribble & Dlg in the formation of cell protrusions and their effects on cell function. Dlg and Scribble are recently discovered proteins that are required during development, immune regulation, neural signalling and tumour suppression. Understanding how they work will enable the development of diagnostic and therapeutic tools that have the potential to influence an enormous range of diseases, from cancer to immunodeficiencies and autoimmune diseases. Researchers at ....A novel role for the proteins Scribble & Dlg in the formation of cell protrusions and their effects on cell function. Dlg and Scribble are recently discovered proteins that are required during development, immune regulation, neural signalling and tumour suppression. Understanding how they work will enable the development of diagnostic and therapeutic tools that have the potential to influence an enormous range of diseases, from cancer to immunodeficiencies and autoimmune diseases. Researchers at the PeterMac perform world-leading research into the biology of Scribble and Dlg, and their role in cancer biology and immune function. The mechanistic insight provided by this project will continue that tradition, and facilitate translation of our basic research into clinical applications in important disease areas.Read moreRead less
Lipid raft and cyotoskeleton organization: How membrane domains give cells direction. For a large number of cells in our body it is imperative that they are able to orientate themselves relative to their environment, sense direction and translate incoming signals. To do so it is hypothesised that lipids on the cell surface are redistributed to form specialized domains. An asymmetric distribution of membrane domains can provide cells with a front and rear end and can further concentrate and co-or ....Lipid raft and cyotoskeleton organization: How membrane domains give cells direction. For a large number of cells in our body it is imperative that they are able to orientate themselves relative to their environment, sense direction and translate incoming signals. To do so it is hypothesised that lipids on the cell surface are redistributed to form specialized domains. An asymmetric distribution of membrane domains can provide cells with a front and rear end and can further concentrate and co-ordinate signalling molecules to a specific site. The project will determine the role of lipid domain in stabilizing cell shape and their remodelling during cell migration, the digestion of foreign particles and the formation of cell-cell contacts.Read moreRead less