Regulation Of PtdIns(3,4,5)P3 By Inositol Polyphosphate 5-phosphatases
Funder
National Health and Medical Research Council
Funding Amount
$200,880.00
Summary
Growing cells respond to growth factors by dividing and proliferating. Uncontrolled cell growth leads to cancer. Signals are released from the cell membrane following growth factor stimulation, that communicate via a complex network of intracellular signalling molecules, that instruct the nucleus to divide. One critical signalling network that mediates cell growth are the phosphoinositide messenger molecules. These signals are switched off by a family of proteins called inositol polyphosphate 5- ....Growing cells respond to growth factors by dividing and proliferating. Uncontrolled cell growth leads to cancer. Signals are released from the cell membrane following growth factor stimulation, that communicate via a complex network of intracellular signalling molecules, that instruct the nucleus to divide. One critical signalling network that mediates cell growth are the phosphoinositide messenger molecules. These signals are switched off by a family of proteins called inositol polyphosphate 5-phosphatases. We propose the 5-phosphatases are essential for normal cell growth. Several studies have suggested in their absence tumour formation may occurr. We have identified a new member of this enzyme family called SHIP-2. This proposal aims to investigate the mechanisms by which this enzyme family metabolises signalling molecules and thereby regulates cell growth. We will also characterize how the 5-phosphatases control the normal pathways by which primitive cells differeniate into mature cells.Read moreRead less
Analysis Of Intracellular Signalling And Biological Activities Of The GM-CSF Receptor Family Using Constitutive Mutants
Funder
National Health and Medical Research Council
Funding Amount
$505,699.00
Summary
The cytokines GM-CSF, IL-3 and IL-5 stimulate the growth and actions of a wide range of blood cells. Each binds to a receptor on the cell surface which then triggers the generation of a number of signals inside the cell; it is these signals that are responsible for the cytokine?s actions. We have previously generated a panel of constitutive mutant forms of the beta subunit which is shared by the GM-CSF, IL-3 and IL-5 receptors. These constitutive mutants trigger signals even in the absence of th ....The cytokines GM-CSF, IL-3 and IL-5 stimulate the growth and actions of a wide range of blood cells. Each binds to a receptor on the cell surface which then triggers the generation of a number of signals inside the cell; it is these signals that are responsible for the cytokine?s actions. We have previously generated a panel of constitutive mutant forms of the beta subunit which is shared by the GM-CSF, IL-3 and IL-5 receptors. These constitutive mutants trigger signals even in the absence of the cytokine; importantly, the different mutants appear to trigger only a subset of the signals generated by the normal receptor. The aim of this project is to use our panel of constitutive beta subunit mutants to determine how the GM-CSF, IL-3 and IL-5 receptors generate signals inside the cell and how these signals lead to the various biological actions of the receptors on blood cell growth and maturation. Findings from this research will be relevant to the understanding and treatment of diseases which involve abnormal growth or function of blood cells such as leukaemia and inflammatory diseases.Read moreRead less
This established team of investigators will research into the molecular control of white blood cell formation and function, using a multidisciplinary, team approach to fundamental biological questions with a focus on potential clinical and commercial outcomes. The team will also attempt to identify new validated targets for therapeutic intervention by using both forward and reverse genetic approaches in mice coupled with complete phenotypic analyses of the blood cell system.
Characterization Of Novel Regulators Of Erythropoiesis
Funder
National Health and Medical Research Council
Funding Amount
$437,545.00
Summary
Mature red and white blood 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). The availability of this hormone in a recombinant form has aided in the treatment of numerous forms of anaemia resulting from kidney failure, malignancies, and AIDS. Previously we had identified that the protein Lyn must be present inside primitive red blood cells for epo to stimulate them to become mature fu ....Mature red and white blood 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). The availability of this hormone in a recombinant form has aided in the treatment of numerous forms of anaemia resulting from kidney failure, malignancies, and AIDS. 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 have identified six molecules which interact with Lyn in red blood cells. We have shown that amolecule called HS1 is important for epo function in individual red blood cells and now we plan to investigate its functions in whole animals, including mice that lack the HS1 gene. We have also shown that a molecule called Trip1 is important for red blood cell development. Interestingly, this molecule also interacts with the thyroid hormone receptor and can influence the effects of epo and thyroid hormone on red blood cell development. The interplay between these two hormones will be looked at in more detail both at the cell and whole animal levels in normal mice and those lacking the thyroid hormone receptor gene. The third Lyn binding molecule we isolated is a novel gene-we have named it ankyrin repeat protein in line with the molecules it is related to. This gene is expressed in red blood cells and we aim to investigate what role it plays in the development of these cells. The fourth gene is also novel and is closely related to another called AFAP-110, which can exert effects on the structure of a cell. Its role in red blood cell structure will also be investigated. Finally, the last two molecule we have identified are both novel and are unrelated to any other known proteins. As above, the effects of these two molecules on red blood cell development will be investigated.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