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
Receptors form a basic intermediary as the acceptor site for signals that are transmitted between the cells that make up our body. Modulation of receptors, therefore, forms a key target in our ability to treat disease. The largest class of receptors is the superfamily of G protein-coupled receptors (GPCRs), which transmit signals within a cell via proteins called G proteins. GPCRs form between 1 and 5% of the entire repertoire of human genes. One group of GPCRs provide the target for small prote ....Receptors form a basic intermediary as the acceptor site for signals that are transmitted between the cells that make up our body. Modulation of receptors, therefore, forms a key target in our ability to treat disease. The largest class of receptors is the superfamily of G protein-coupled receptors (GPCRs), which transmit signals within a cell via proteins called G proteins. GPCRs form between 1 and 5% of the entire repertoire of human genes. One group of GPCRs provide the target for small protein molecules that circulate through the body. One such circulating molecule is calcitonin, a peptide that plays an important role in maintaining circulating calcium levels in the body, which is essential for proper maintenance of the skeleton. As a consequence of this action, calcitonin is an important clinically used tool in the treatment of bone disease such as osteoporosis and Paget's disease. Due to the molecular nature of calcitonin and its receptor (and other related receptors) that have a broad, complex mechanism of interaction, we have very little definitive information on how calcitonin interfaces with its receptor to signal to target cells. The current project utilises a novel method of permanently linking calcitonin to its receptor, allowing identification of how the two components come together. This information provides important fundamentals for understanding how this and related receptors work and the potential for rational design of improved therapeutic tools.Read moreRead less
Allosteric Modulation Of GPCR-mediated Intracellular Signalling In Human Embryonic Stem Cell Derived Cardiomyocytes.
Funder
National Health and Medical Research Council
Funding Amount
$324,598.00
Summary
Adenosine and muscarinic receptors are cell-surface proteins that represent promising targets for a number of conditions. However, the mechanisms linking the activation of these receptors to cellular responsiveness have not been thoroughly investigated in cells of human origin. This study will use novel cutting-edge methods to measure the effects of different classes of drugs on receptor-mediated intracellular signalling in embryonic stem cell derived human cardiac cells.
Understanding G Protein-Coupled Receptors (GPCRs): Accelerating Discovery From Concept To Clinic.
Funder
National Health and Medical Research Council
Funding Amount
$6,871,789.00
Summary
G Protein-Coupled Receptors (GPCRs) form the largest family of receptors (and thus drug targets) in living organisms. Currently, the major reason that new drugs fail to reach the clinic is lack of appropriate drug effect (approx. 30%). Thus, we need a better understanding of how GPCRs work and how this relates to disease. Our Program addresses this knowledge gap, using GPCR models that are relevant to treatment of metabolic, cardiovascular and central nervous system disease.
Novel Aspects Of Angiotensin AT1 Receptor Signalling Pathways
Funder
National Health and Medical Research Council
Funding Amount
$219,750.00
Summary
Hormones are chemicals released into the blood to influence tissue function by binding to specific sites (receptors) located on the cells found in a particular tissue. In general, it has been considered that a specific receptor activates a specific response when bound by the hormone. However, it is now clear that closely related hormones can activate different patterns of response even when they bind the one type of receptor. The full consequence of this phenomenon is still unknown. Its signific ....Hormones are chemicals released into the blood to influence tissue function by binding to specific sites (receptors) located on the cells found in a particular tissue. In general, it has been considered that a specific receptor activates a specific response when bound by the hormone. However, it is now clear that closely related hormones can activate different patterns of response even when they bind the one type of receptor. The full consequence of this phenomenon is still unknown. Its significance will be investigated in this project for important hormones which are involved in blood pressure control. The renin-angiotensin system makes the hormone angiotensin II which increases blood pressure through actions the heart, blood vessels, nerves and kidneys. One particular receptor type, the AT1 receptor, is responsible for the majority of effects of angiotensin II on these tissues and drugs that inhibit the activity of this receptor are very useful therapies for diseases such as hypertension and heart failure. However, Angiotensin III is a second hormone of the renin-angiotensin system that may also have important effects on tissue function when it activates the AT1 receptor. We have evidence that the type of tissue response that results from angiotensin III activated AT1 receptors is different from the response that results from angiotensin II activation of the same receptors. This raises the possibility that the effects of the AT1 receptor in cardiovascular disease might be differentially promoted by the two angiotensins. This project will investigate the mechanisms by which angiotensin II and anagiotensin III can elicit different activation via the AT1 receptor, and will determine the consequences of this differntial activation to tissue function.Read moreRead less