Activin Type II Receptor Antagonists: Mechanism Of Action And Biological Applications
Funder
National Health and Medical Research Council
Funding Amount
$507,270.00
Summary
Activin is a member of the TGF- family of growth and differentiation factors. Over-expression in mice leads to muscle and liver wasting, scarring during wound healing, disturbances to the reproductive system and various endocrine disorders. Activin's biological activity is promoted by its binding in series to two receptors termed Type I and II. Previous studies by this investigator have shown that selective modification of activin's protein structure can result in activin forms (in this instance ....Activin is a member of the TGF- family of growth and differentiation factors. Over-expression in mice leads to muscle and liver wasting, scarring during wound healing, disturbances to the reproductive system and various endocrine disorders. Activin's biological activity is promoted by its binding in series to two receptors termed Type I and II. Previous studies by this investigator have shown that selective modification of activin's protein structure can result in activin forms (in this instance called activin-M108A) which bind to Type II receptors but fail to promote binding to the Type I receptor. This has led to the hypothesis that activin-M108A may compete for native activin binding to Type II receptors and thus prevent activin's recruitment of the Type I receptor with the consequence that activin's biological activity is inhibited. It is proposed to test this hypothesis by producing sufficient amounts of activin-M108A and testing its inhibitory effects in several mouse models of liver damage, muscular degeneration and ovarian and testicular disease. If activin-M108A, or related modified forms of activin, decrease the morbidity and mortality associated with these murine diseases, then we envisage that these activin type II receptor antagonists will also be beneficial for the treatment of related human conditions.Read moreRead less
Factors Regulating The Temporal And Spatial Assembly Of G-protein Coupled Receptor-mediated Arrestin Complexes
Funder
National Health and Medical Research Council
Funding Amount
$472,770.00
Summary
G-protein coupled receptors are proteins that are present at the surface of most cells in the human body. They recognise and bind to specific molecules, such as hormones, the act of which results in a specific signal being transmitted into the cell. This signal alters the function of the cell and so it is critical that it is appropriate, both in type and duration. G-protein coupled receptors and the molecules that activate them provide an essential function within the human body for communicatin ....G-protein coupled receptors are proteins that are present at the surface of most cells in the human body. They recognise and bind to specific molecules, such as hormones, the act of which results in a specific signal being transmitted into the cell. This signal alters the function of the cell and so it is critical that it is appropriate, both in type and duration. G-protein coupled receptors and the molecules that activate them provide an essential function within the human body for communicating between cells, and consequently between organs. They are a major mechanism by which nerve signals are transmitted and hormones regulate bodily functions. They are therefore an important target for pharmaceuticals, with up to 50% of ethical drugs and many drugs of abuse acting upon them. It is critical to understand how these receptors alter cellular function once they receive an appropriate signal, but it is also essential to know how such responses are switched off. Arrestins are proteins within cells that interact with G-protein coupled receptors to 'arrest' their signalling. They desensitise the cell to continuous stimulation, but also act to resensitise the cell to respond to future, separate signals. Recently, they have also been shown to provide alternative mechanisms of altering cellular activity by interacting with other cellular proteins. These interactions greatly increase the potential ways in which a cell can respond once a G-protein coupled receptor is activated. Understanding the resulting complexity is essential if we are to fully exploit the vast therapeutic potential of this important receptor family.Read moreRead less