Role Of Conformational Change In Activation Of The Growth Hormone Receptor
Funder
National Health and Medical Research Council
Funding Amount
$242,545.00
Summary
Growth hormone is an important hormone therapeutic for treating dwarfism. Recently, many new therapeutic applications for growth hormone have been discovered, particularly in relation to its role as an anabolic agent. These include post surgery recovery, enhanced bone fracture healing, Crohns disease, dilated cardiomyopathy, infertility and of course, ageing. This project seeks to find out how growth hormone sends its signal into the target cell through its surface receptor. It is believed that ....Growth hormone is an important hormone therapeutic for treating dwarfism. Recently, many new therapeutic applications for growth hormone have been discovered, particularly in relation to its role as an anabolic agent. These include post surgery recovery, enhanced bone fracture healing, Crohns disease, dilated cardiomyopathy, infertility and of course, ageing. This project seeks to find out how growth hormone sends its signal into the target cell through its surface receptor. It is believed that the primary event in signalling is the ability of the hormone to bring two receptors together (receptor dimerization). However, it may be that the receptor already is dimerized, and the role of the hormone is to induce a specific change in shape of the receptor, which transfers the signal of hormone binding into the cell to initiate signalling to the genome. We have good evidence that a specific shape change is required for activation of an important signalling pathway by growth hormone, and the closely structurally related receptor for erythropoietin is already dimerized before hormone binds. We want to find out exactly how the shape change acts, and whether the receptor is predimerized. This information is vital for designing small orally active mimics of growth hormone which could be of great value as an anabolic supplement for the frail elderly.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
The project aims to understand how a factor responsible for the production of a type of white blood cell interacts with its receptor. If we knew the molecular details of how this factor works then we would be able to control better diseases, such as osteoporosis and arthritis, where such cells can play havoc by destroying tissue. The project also has implications for certain leukaemias which lose growth control mechanisms in response to this factor.