Regulation Of Pre-mRNA And MRNA Processing By The Neuron-specific Hu RNA-binding Proteins
Funder
National Health and Medical Research Council
Funding Amount
$477,750.00
Summary
The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, t ....The precise control of protein expression is absolutely critical in biology, and the key decisions about which genes are turned on or off at any one moment control the proper growth and maturation of an organism during development, and are responsible for the organism's homeostasis and proper response to environmental changes as an adult. Many gene expression programs are highly complex and controlled by regulating the activation of individual genes as they are copied from DNA to RNA. However, this activation is just the start of the process to produce an active protein. In higher organisms, these RNA copies almost always contain interruptions called introns, which must be excised from the RNA. Also, protein factors bound to specific RNAs can dictate whether the RNA is used to make protein or not, and these factors can also affect the localisation of the RNA to a specific sub-cellular destination, giving rise to highly localised protein expression. Evidence suggests that neurons are a cell type that rely heavily on mechanisms of RNA regulation. During development neurons become highly polarised, acquiring an axon which can elongate and find distant synaptic targets. While much is known about how axon growth cones respond to various guidance cues, the mechanisms by which the axon is able to translate this guidance cue information into structural changes which allow the growth cone to expand or collapse is largely unexplored. Recent evidence suggests that accurate growth cone guidance is absolutely dependent upon local protein synthesis. The functional corollary of this finding is that axon guidance requires RNA localisation and control of protein synthesis of RNAs in the growth cone. This phenomenon of spatial gene regulation within an individual cell is a central research interest for understanding how the brain functions.Read moreRead less
MRNA Surveillance In Human Disease: Molecular Determinants Of Nonsense-mediated MRNA Decay
Funder
National Health and Medical Research Council
Funding Amount
$474,517.00
Summary
Inherited diseases are a common cause of human disability, illness and suffering. It has been estimated that 5-10% of the population will be affected by disorders with a genetic component. Thus studies on mechanisms of inherited diseases, especially those relating to genetic mechanisms with relevance across a wide range of individual disorders and gene mutations, are of great significance in diagnosis, molecular pathology and the eventual development of therapeutics. While there are many types o ....Inherited diseases are a common cause of human disability, illness and suffering. It has been estimated that 5-10% of the population will be affected by disorders with a genetic component. Thus studies on mechanisms of inherited diseases, especially those relating to genetic mechanisms with relevance across a wide range of individual disorders and gene mutations, are of great significance in diagnosis, molecular pathology and the eventual development of therapeutics. While there are many types of mutations, one relatively common type is called a premature termination mutation. Premature termination mutations introduce an inappropriate genetic signal that tells the cells to stop the formation of proteins before they are complete. This would result in the production of a protein that is shorter than normal, and these short proteins could be quite abnormal and drastically affect the normal function of cells. To overcome this, cells have developed elegant strategies that involve the deployment of quality control, or surveillance, mechanisms to remove the mutant gene product before it can be converted into an abnormal protein. This process is called nonsense mediated decay. Nonsense mediated decay is a complex process and some of the key components have been identified by studies on a small number of genes. However, our studies have identified several previously unknown aspects of the process that suggest that the currently held view of how nonsense mediated decay works is only the beginning of the story and further important complexity exists. The proposed research will explore the basic mechanisms of the surveillance process and determine the signals that initiate nonsense mediated decay. Since premature termination mutations cause one-third of all inherited genetic disorders, our studies will provide new insights into the surveillance mechanisms and will have wide applicability to our understanding of the basis of inherited disease.Read moreRead less
Characterization of erythroid differentiation related factor (EDRF): a novel a-globin binding protein. Hemoglobin, a four-subunit protein comprising two alpha and two beta polypeptide chains, is the essential oxygen transporter found in all mammals. Problems with the synthesis of hemoglobin can give rise to a range of common and serious human disorders, including thalassaemia and anemia. We have discovered a protein, EDRF, that appears to interact directly with alpha-globin (but not beta-globin) ....Characterization of erythroid differentiation related factor (EDRF): a novel a-globin binding protein. Hemoglobin, a four-subunit protein comprising two alpha and two beta polypeptide chains, is the essential oxygen transporter found in all mammals. Problems with the synthesis of hemoglobin can give rise to a range of common and serious human disorders, including thalassaemia and anemia. We have discovered a protein, EDRF, that appears to interact directly with alpha-globin (but not beta-globin) and to play a role in the regulation of hemoglobin production. We now seek to understand the nature of this interaction at a molecular level and mechanistic level.Read moreRead less
Deciphering The Molecular Basis Of SM Regulation Of Exocytosis
Funder
National Health and Medical Research Council
Funding Amount
$515,564.00
Summary
Diabetes, obesity, heart disease and physical inactivity are major and escalating health problems within western societies. These problems are all linked to, or aggravate, the condition known as insulin resistance. Insulin resistance occurs when normal levels of insulin are insufficient to remove glucose from the blood. In the normal situation, insulin regulates glucose uptake into muscle and fat cells by stimulating the movement of a glucose transport protein from inside the cell to the cell su ....Diabetes, obesity, heart disease and physical inactivity are major and escalating health problems within western societies. These problems are all linked to, or aggravate, the condition known as insulin resistance. Insulin resistance occurs when normal levels of insulin are insufficient to remove glucose from the blood. In the normal situation, insulin regulates glucose uptake into muscle and fat cells by stimulating the movement of a glucose transport protein from inside the cell to the cell surface. The trafficking of this protein is somehow disrupted in insulin resistance. The purpose of this research is to follow up our exciting preliminary results on this system to shed light on the molecular processes that regulate the trafficking of the glucose transporter. Information resulting from our studies will lead to a better understanding of insulin-stimulated glucose transport and may also unravel the details of a related cellular secretion system that regulates neurotransmission. Our hope is that by understanding at the molecular level how cells regulate secretion, we can in the future develop therapeutics to counteract many of today s major health problems.Read moreRead less
Cellular Mechanisms And Physiological Roles Of GLUT12 Mediated Glucose Transport In Glucose Homeostasis
Funder
National Health and Medical Research Council
Funding Amount
$499,000.00
Summary
Diabetes affects almost one million Australians, although only 50% are aware they have the disease. Type 2 diabetes accounts for about 90% of diabetes and usually occurs after the age of 40. As a leading cause of death, adult blindness, lower limb amputation, kidney failure, stroke and heart attack, diabetes has huge economic and social consequences and has been designated an Australian National Health priority. A clinical feature of Type 2 diabetes is high blood glucose levels. This occurs beca ....Diabetes affects almost one million Australians, although only 50% are aware they have the disease. Type 2 diabetes accounts for about 90% of diabetes and usually occurs after the age of 40. As a leading cause of death, adult blindness, lower limb amputation, kidney failure, stroke and heart attack, diabetes has huge economic and social consequences and has been designated an Australian National Health priority. A clinical feature of Type 2 diabetes is high blood glucose levels. This occurs because insulin does not effectively stimulate the transfer of glucose from the blood into muscle and fat. The reasons for this are not fully understood. Insulin normally works to move glucose transporter (GLUT) proteins to the surface of muscle and fat cells. One GLUT that has been studied extensively in muscle and fat is GLUT4. GLUT4 moves to the cell surface in response to insulin and this response is one of the defects that is known to occur in Type 2 diabetes. Glucose then accumulates in the blood, leading to many of the complications of diabetes. We have discovered a novel glucose transporter, GLUT12, that is also present in muscle and fat. We have shown that GLUT12, like GLUT4, responds to insulin. GLUT12 could therefore be a critical backup for GLUT4. We have also found that GLUT12 responds to glucose itself, suggesting a unique role in controlling blood glucose levels. We will explore how GLUT12 acts in muscle and fat cells to find whether GLUT12 can act as a backup for GLUT4. We will also study GLUT12 in tissue from normal animals and in animals with features of Type 2 diabetes. To determine the role of GLUT12 in maintaining normal blood glucose levels, we will produce mice with an inactive GLUT12 gene. Our research could identify novel ways of increasing GLUT12 activity. The eventual goal will be to find a pharmaceutical compound that can improve glucose transport into muscle, reduce high blood glucose levels and thus the complications of Type 2 diabetes.Read moreRead less
REGULATION OF MICROTUBULE DYNAMICS BY LIM KINASE1 (LIMK1)
Funder
National Health and Medical Research Council
Funding Amount
$386,020.00
Summary
Disseminated cancer, unlike the localized disease, can rarely be cured by drug therapy. We have found that LIM kinase (LIMK1), a protein that was discovered in our laboratory, plays an important role in controlling the ability of tumour cells to spread, a process called metastasis. Thus, this protein becomes an important target for the development of new drug therapies to prevent the spread of cancer. We have found that LIMK1 is very important in controlling the polymerisation of one of the most ....Disseminated cancer, unlike the localized disease, can rarely be cured by drug therapy. We have found that LIM kinase (LIMK1), a protein that was discovered in our laboratory, plays an important role in controlling the ability of tumour cells to spread, a process called metastasis. Thus, this protein becomes an important target for the development of new drug therapies to prevent the spread of cancer. We have found that LIMK1 is very important in controlling the polymerisation of one of the most abundant molecules in the cell, actin. We have now preliminary data to show that LIMK1 also controls another important cellular protein, tubulin. Changes in tubulin polymerisation are of extreme importance for cell division and drugs affecting the state of tubulin are very potent as anti-cancer drugs. The goals of this research are: (1) To confirm that LIMK1 regulates the polymerisation of tubulin and (2) To demonstrate that LIMK1 regulates tubulin polymerisation by controlling the activity of p25, a protein involved in tubulin polymerisation that is modified by LIMK1. The results from this research will be highly significant because LIMK1 is a novel drug development target. Drugs that inhibit this protein may block the ability of tumours to invade and metastasise. Therefore, we have to identify the other functions of LIMK1 to eliminate the possibility that drugs that inhibit LIMK1 and metastasis don't affect other organs and cells in the body. New molecules regulated by LIMK1 may also be suitable targets for drug development because through their inhibition we may also regulate other LIMK1 activities and possibly metastasis.Read moreRead less