Defining The Role And Contribution Of Cdc37 To Signal Transduction And Tumourigenesis By Src-family Kinases
Funder
National Health and Medical Research Council
Funding Amount
$411,430.00
Summary
Cells respond to extracellular stimuli, such as growth factors and hormones, by activating intracellular networks of signaling molecules. It is the activation of these signaling networks that is ultimately responsible for mediating the biological responses of cells to extracellular stimuli (e.g. insulin stimulating glucose metabolism by cells). Members of the Src-family of tyrosine kinases are paramount among signaling molecules, as they are able to directly initiate the activation of a cascade ....Cells respond to extracellular stimuli, such as growth factors and hormones, by activating intracellular networks of signaling molecules. It is the activation of these signaling networks that is ultimately responsible for mediating the biological responses of cells to extracellular stimuli (e.g. insulin stimulating glucose metabolism by cells). Members of the Src-family of tyrosine kinases are paramount among signaling molecules, as they are able to directly initiate the activation of a cascade of signaling networks that regulate the activity of the cell. Significantly though, the inappropriate activation of Src-family kinases has been implicated in the development of cancer, particularly breast and colon cancer, in humans. To fulfill their signaling functions however, Src-family kinases must first be folded into an active conformation upon their synthesis in the cell then be maintained in this conformation. Although previous studies, including our own, have implicated a class of proteins called molecular chaperones in this process, little is known about how the folding of Src-family kinases by these proteins is achieved and regulated. The overall aim of this study is to determine how the folding of Hck, one member of the Src-family of tyrosine kinases, into a conformation that enables it to participate in signaling networks is achieved and regulated. It is expected that the results from this study will provide significant new insight into how this process might influence the ability of cells to respond to extracellular stimuli and potentially contribute to the conversion of a normal cell into one with tumourigenic properties. Findings from this project may be particularly important in the context of human cancer. A better knowledge of how the signaling activity of Src-family kinases is regulated by molecular chaperones might provide a new avenue of investigation for the identification of novel chemotherapeutic agents.Read moreRead less
Mature red cells develop from hemopoietic stem cells in the adult bone marrow. The production of red blood cells is primarily controlled by the hormone erythropoietin (Epo). Previously we had identified that the protein Lyn must be present inside primitive red blood cells for Epo to stimulate them to become mature functional cells. We will determine the role of several molecules that interact with Lyn including Cbp, Liar and LACM, towards apects of red blood cell development.
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.
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.
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
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
Regulation Of Nuclear Import Of Viral Oncoproteins And Transcription Factors By Protein-protein Interactions
Funder
National Health and Medical Research Council
Funding Amount
$650,383.00
Summary
The present application examines the controls that exerted over proteins that localize in the nucleus of eukaryotic cells. This relates relates integrally to cellular processes such as growth, development and oncogenesis. This research area is not represented elsewhere in Australia, and the particular experimental strategies to approach the problem, revolving around the use of special quantitative microscopic techniques are novel internationally. One part of the application seeks to examine tran ....The present application examines the controls that exerted over proteins that localize in the nucleus of eukaryotic cells. This relates relates integrally to cellular processes such as growth, development and oncogenesis. This research area is not represented elsewhere in Australia, and the particular experimental strategies to approach the problem, revolving around the use of special quantitative microscopic techniques are novel internationally. One part of the application seeks to examine transport within the cell of complexes of interacting proteins, rather than single proteins, under as close as possible to physiologically relevant conditions. This will be truly unique, and of great importance to our comprehension of eukaryotic cell function. This application examines particular types of negative control over protein nuclear localization. Since many proteins show such regulation, and in particular important proteins controlling cell growth and division, the results are fundamentally important to our understanding of how cells function in general. Further, this understanding may be applied in disease situations, such as viral-mediated oncogenesis. In the work we propose to do, viral proteins with functions relating to cancer will be examined in detail, as well as a cellular protein which is recognised by them - the tumor suppressor Rb. We intend to examine several viral oncoproteins which target Rb; one is a protein (E7) from the Human Papilloma Virus which has been frequently associated with cervical carcinomas and other cancers. Accordingly, the results may have direct application to viral-induced cancer, and our work may lead to understanding of the regulation of protein transport to the nucleus. This may thus afford a new approach at the pharmacological level to combat transformation.Read moreRead less