Novel G-protein Coupled Receptors LGR7 And LGR8; The Receptors For Relaxin And Insulin-like Peptide 3 (INSL3)
Funder
National Health and Medical Research Council
Funding Amount
$496,500.00
Summary
Relaxin is a hormone which has long been known to have essential roles in pregnancy and birth. However it has also been demonstrated to have far broader involvement in the functioning of the kidney, heart and central nervous system. Furthermore, mice lacking relaxin show increased collagen, or fibrosis, in their internal organs and skin as they age. This progressive fibrosis leads to problems with bodily functions. Treatment of these mice with relaxin reverses the fibrosis and restores function, ....Relaxin is a hormone which has long been known to have essential roles in pregnancy and birth. However it has also been demonstrated to have far broader involvement in the functioning of the kidney, heart and central nervous system. Furthermore, mice lacking relaxin show increased collagen, or fibrosis, in their internal organs and skin as they age. This progressive fibrosis leads to problems with bodily functions. Treatment of these mice with relaxin reverses the fibrosis and restores function, hence relaxin has great potential as a treatment for fibrotic diseases. Anti-fibrotic drugs are a major target for drug companies as suitable compounds are not currently available. Research into the mechanisms whereby relaxin exerts its cellular effects has been limited by the inability of researchers to identify its receptor. We now know that relaxin acts through a novel G-protein coupled receptor (GPCR) LGR7 and will also act on a related receptor LGR8. The LGR8 receptor is actually the receptor for a hormone with similarities to relaxin, INSL3. It is essential that an appreciation of relaxin receptor function is obtained not only for its important actions in pregnancy, but also for its clinical applications. In this regard, improved understanding of how relaxin interacts with these two receptors is essential. We will use our expertise in producing these hormones together with molecular techniques to produce the receptor, to study the interaction of relaxin and INSL3 with these receptors and the subsequent cellular events that occur. Furthermore, to more effectively use relaxin as a drug, we need to discover a smaller, more potent and orally active form of the hormone. We will develop novel technologies to aid in the discovery of the next generation of relaxin drugs. This multi-disciplinary approach will allow us to fully maximise the clinical potential of this enigmatic hormone.Read moreRead less
Molecular Mechanisms Of G Protein-Coupled Receptor Cross Talk
Funder
National Health and Medical Research Council
Funding Amount
$256,980.00
Summary
The normal function of all living cells depends on how they respond to the multitude of physical and chemical stimuli to which they are constantly exposed. The majority of chemical stimuli acting on cells do so not by directly entering the cell, but rather by acting on specific types of receiver proteins on the cell's surface called receptors. One important family of receptors transmit their message to the inside of the cell by coupling to yet another type of protein known as the G protein. Aber ....The normal function of all living cells depends on how they respond to the multitude of physical and chemical stimuli to which they are constantly exposed. The majority of chemical stimuli acting on cells do so not by directly entering the cell, but rather by acting on specific types of receiver proteins on the cell's surface called receptors. One important family of receptors transmit their message to the inside of the cell by coupling to yet another type of protein known as the G protein. Aberrations in the normal function of these G protein-coupled receptors have been implicated in a wide variety of disorders, such as schizophrenia, pain and dementia. To date, most therapeutic approaches to treating these disorders have targeted individual types of G protein-coupled receptors thought to play a role in each disease state, but this has met with mixed success. One of the reasons for this is that each disorder actually involves more than one type of G protein-coupled receptor communicating with other types in a complex way. Our current proposal specifically focuses on some of the newer mechanisms that have been suggested to play an important role in the communication between different types of G protein-coupled receptors located in the same type of cell. An understanding of how such receptor proteins can communicate with one another in this situation is absolutely vital in unravelling processes involved in the maintenance of health, abnormalities that lead to disease and in the development of more effective treatments.Read moreRead less
The maintenance of optimum health and function of living cells, and consequently that of the whole organism, depends on how cells respond to a multitude of physical and chemical stimuli that continually bombard them. The majority of the chemical stimuli such as hormones and neurotransmitters impart their actions not by directly entering the cell, but instead, by binding to a specific receiver protein at the cell surface called a receptor. In one class of such receptors called G protein coupled r ....The maintenance of optimum health and function of living cells, and consequently that of the whole organism, depends on how cells respond to a multitude of physical and chemical stimuli that continually bombard them. The majority of the chemical stimuli such as hormones and neurotransmitters impart their actions not by directly entering the cell, but instead, by binding to a specific receiver protein at the cell surface called a receptor. In one class of such receptors called G protein coupled receptors, the transmission of the message to the interior of the cell involves yet another protein called G protein. It is extremely important to unravel how each of these components, the stimulating agent, the receptor and G protein, works in order to understand how the cells respond to various chemical signals. To make this process even more complex, it was recently shown that another newly discovered group of proteins called receptor activity modifying proteins (RAMPs) too play a critical role in some systems. Understanding what actually is the role of these new players, and how they team-up with the other components to elicit a specific response to a chemical stimulus, forms the basis of this proposal. Such knowledge is central to the unraveling of the processes involved in the maintenance of health, abnormalities that lead to disease, and in the development of new treatments.Read moreRead less
Alteration Of Glucose Metabolism By GPCR Activation
Funder
National Health and Medical Research Council
Funding Amount
$444,796.00
Summary
In type 2 diabetes the effect of insulin to stimulate glucose transport in fat cells and skeletal muscle is impaired so there is great interest in identifying insulin-independent mechanisms that increase glucose transport. Several G protein-coupled receptors (GPCRs) regulate glucose transport independently of insulin but the mechanisms involved in these effects are largely unknown. This project investigates how GPCRs regulate glucose homeostasis and will evaluate them as potential treatments.
Understanding The Mechanisms Used By G-protein Coupled Receptors To Regulate Insulin-independent Glucose Transport
Funder
National Health and Medical Research Council
Funding Amount
$105,590.00
Summary
In type 2 diabetes, stimulation of glucose transport in fat cells and skeletal muscle by insulin is impaired. As a result there is great interest in identifying insulin-independent mechanisms that increase glucose transport. Several G-protein coupled receptors (GPCRs) regulate glucose transport independently of insulin but the mechanisms involved in these effects are largely unknown. This project investigates how GPCRs regulate glucose transport for potential as treatments.