Discovery And Mechanisms Of Host Cell Factors In HIV Uncoating
Funder
National Health and Medical Research Council
Funding Amount
$635,098.00
Summary
HIV entry into the host cell involves release of its capsid, a protein shell protecting the viral genome. The capsid hijacks host proteins to cloak itself from cellular defenses while the cell has evolved sensors that can block viral infection. This proposal aims to discover proteins involved in this arms race between host and virus and decipher how they control capsid disassembly. This insight will help design new drugs against HIV infection and new ways to deliver genes for gene therapies.
Plasmin is a complex enzyme that performs major roles in removal of blood clots, wound healing and in tumor metastasis. Here we will understand how plasmin function is regulated at the molecular level. These key insights will be of future use in the development of therapeutics targeting the plasmin system in cancer and clotting diseases.
Enhancing The Cardioprotective Effect Of Diadenosine Tetraphosphate: Designing Inhibitors Against Ap4A Hydrolase
Funder
National Health and Medical Research Council
Funding Amount
$442,500.00
Summary
Ischemia describes the condition where blood flow in the blood vessels of the heart is decreased or blocked, preventing delivery of oxygen and nutrients to the heart. Ischemic preconditioning is a phenomenon where short bursts of ischemia, followed by reperfusion, actually protect the heart from a subsequent longer period of ischemia. The biochemical signalling events involved in preconditioning are complex and incompletely defined, but most likely involve multiple pathways, although the mitocho ....Ischemia describes the condition where blood flow in the blood vessels of the heart is decreased or blocked, preventing delivery of oxygen and nutrients to the heart. Ischemic preconditioning is a phenomenon where short bursts of ischemia, followed by reperfusion, actually protect the heart from a subsequent longer period of ischemia. The biochemical signalling events involved in preconditioning are complex and incompletely defined, but most likely involve multiple pathways, although the mitochondrial ATP-dependent potassium channel may be in common with most pathways. Pretreatment with the compound diadenosine tetraphosphate (Ap4A) mimics ischemic preconditioning with noticeable reductions in tissue necrosis (cell death). This treatment has been shown in experimental work to protect the heart during periods of stress such as in heart surgery or recovery from an ischemic event. The biological site of action by Ap4A may be the mitochondria ATP-dependent potassium channel or an associated protein. Ap4A can be degraded by enzymes located inside and on the outside of heart cells, notably by two forms of Ap4A hydrolase. We will use antibody assays to understand the specific localization and amount of Ap4A hydrolase before and after ischemia and after ischemic preconditioning in human heart muscle and blood vessels. We propose to determine the structure of the enzyme and use novel computer methods to screen databases for potential inhibitors. These inhibitors of Ap4A hydrolase activity could aid the design of a potent inhibitor that would prevent Ap4A hydrolase from degrading Ap4A and therefore enhance the cardioprotective properties of Ap4A as well as minimizing side effects from the break down of Ap4A. We will also use these inhibitors and other known non-degradable Ap4A analogues in bioassays to test the relative significance of Ap4A hydrolase present in different cellular locations.Read moreRead less
Heme oxygenase integrates cellular responses to oxygen stress. A deficiency in the protein heme oxygenase-1 causes severe biological consequences including retarded development, chronic inflammation and increased susceptibility to age-associated diseases. By illuminating how heme oxygenase-1 improves cell function the project will eventually assist in preventing or slowing the serious age-associated disorders.
New inhibitors of HIV based on cellular enzymes. Over 39 million people are infected with HIV worldwide. However, none of the most highly affected countries have yet reached the peak in AIDS-related illness and death, thus the global impact of HIV/AIDS will get significantly worse, before it gets better.
In Australia, HIV is again on the rise. Ironically, improved treatments that have extended life expectancy will cause the number of HIV infected Australians to rise for many years to come. ....New inhibitors of HIV based on cellular enzymes. Over 39 million people are infected with HIV worldwide. However, none of the most highly affected countries have yet reached the peak in AIDS-related illness and death, thus the global impact of HIV/AIDS will get significantly worse, before it gets better.
In Australia, HIV is again on the rise. Ironically, improved treatments that have extended life expectancy will cause the number of HIV infected Australians to rise for many years to come. Therefore many Australians will suffer from the combined impact of the AIDS illness itself, opportunistic infections, the side-effects of treatment and natural aging. We aim to develop new drugs to combat this disease to help people everywhere lead happier, healthier and more productive lives.Read moreRead less
Sensing atmosphere: Understanding the HNOX-protein gas-sensing capability and how it is affected by heme-oxidation. The project investigates how gas sensing heme-proteins from the novel HNOX (Heme-Nitric Oxide) family are able to discriminate between different gaseous ligands such as O2 and NO and how oxidation of the heme alters this response. The gas-sensing capability of the HNOX proteins is crucial for organisms ranging from bacteria to humans. Thus, understanding of these signalling mechani ....Sensing atmosphere: Understanding the HNOX-protein gas-sensing capability and how it is affected by heme-oxidation. The project investigates how gas sensing heme-proteins from the novel HNOX (Heme-Nitric Oxide) family are able to discriminate between different gaseous ligands such as O2 and NO and how oxidation of the heme alters this response. The gas-sensing capability of the HNOX proteins is crucial for organisms ranging from bacteria to humans. Thus, understanding of these signalling mechanisms will have a strong impact on many scientific fields from the control of pathogen growth to human blood pressure regulation. This collaboration will establish Australian scientists and as world-leading in the field of NO and redox signalling. This development will also be of substantial benefit for the training of the next generation of Australian students and scientists.Read moreRead less
Hierarchical Phosphorylation of Tyrosine Hydroxylase is Dependent on the Activation Sequence of Signaling Pathways. Protein phosphorylation is a fundamental process in biology. It controls protein expression and function in all cells. Hierarchical phosphorylation is defined as the phosphorylation of a protein at one site leading to an altered phosphorylation at another site on the same protein and an altered biological outcome. We have discovered that the enzyme tyrosine hydroxylase undergoes a ....Hierarchical Phosphorylation of Tyrosine Hydroxylase is Dependent on the Activation Sequence of Signaling Pathways. Protein phosphorylation is a fundamental process in biology. It controls protein expression and function in all cells. Hierarchical phosphorylation is defined as the phosphorylation of a protein at one site leading to an altered phosphorylation at another site on the same protein and an altered biological outcome. We have discovered that the enzyme tyrosine hydroxylase undergoes a form of hierarchical phosphorylation not previously reported. Here we examine hierarchical phosphorylation in rat and human tyrosine hydroxylase and its functional consequence in intact cells. The approaches and methods developed will also be applicable to investigation of hierarchical phosphorylation in other proteins.Read moreRead less
The regulation of signalling molecules in Saccharomyces Cerevisiae by inositol polyphosphate 5-phosphatases. Phosphoinositide signalling molecules regulate the actin cytoskeleton, secretion, vesicular trafficking and cell growth and death. We have identified, cloned and characterised a family of signal terminating enzymes called inositol polyphosphate 5-phosphatases (5-phosphatases) that regulate phosphoinositide signalling molecules. We have cloned and characterised four distinct 5-phosphatases ....The regulation of signalling molecules in Saccharomyces Cerevisiae by inositol polyphosphate 5-phosphatases. Phosphoinositide signalling molecules regulate the actin cytoskeleton, secretion, vesicular trafficking and cell growth and death. We have identified, cloned and characterised a family of signal terminating enzymes called inositol polyphosphate 5-phosphatases (5-phosphatases) that regulate phosphoinositide signalling molecules. We have cloned and characterised four distinct 5-phosphatases in the yeast Saccharomyces Cerevisiae and demonstrated by both deletion and overexpression studies that these enzymes regulate the actin cytoskeleton, endocytosis and secretion. This research proposal aims to investigate the signalling complexes the 5-phosphatases form with specific actin binding and or regulatory proteins, investigate the complex interactions of phosphoinositide lipid phosphatases and the roles they play in regulating secretion from the endoplasmic reticulum and finally characterize a novel 5-phosphatase that we have recently identified. Collectively the outcome of these studies will provide novel information about the functionallly significant signalling pathways regulated by this important enzyme family.Read moreRead less
The role of PtdIns(4,5)P2 in cellular responses in Saccharomyces cerevisiae. This grant application falls under the criteria of frontier technologies in genomics/phenomics and complex systems. We are characterizing a highly conserved network of signaling molecules regulated by complex large families of enzymes that regulate the bending of membranes, and cellular events including cell division in plants, yeast and mammalian cells. We have developed cutting edge novel technologies to localize sign ....The role of PtdIns(4,5)P2 in cellular responses in Saccharomyces cerevisiae. This grant application falls under the criteria of frontier technologies in genomics/phenomics and complex systems. We are characterizing a highly conserved network of signaling molecules regulated by complex large families of enzymes that regulate the bending of membranes, and cellular events including cell division in plants, yeast and mammalian cells. We have developed cutting edge novel technologies to localize signaling on specific intracellular membranes and visualise the role cellular lipids play in forming tubules in cells. This project will result in the presentation of Australian research at international forums and support the training of PhD students.Read moreRead less
Mitochondrial proteases and their contribution to protein homeostasis. This research will examine how a critically important cellular organelle known as the mitochondrion maintains its functional integrity by sensing and signalling protein perturbations. As mitochondrial dysfunction is central to a number of neurodegenerative diseases understanding the molecular biology of this fundamentally important cellular process could, in the future, provide for better health outcomes for an aging Australi ....Mitochondrial proteases and their contribution to protein homeostasis. This research will examine how a critically important cellular organelle known as the mitochondrion maintains its functional integrity by sensing and signalling protein perturbations. As mitochondrial dysfunction is central to a number of neurodegenerative diseases understanding the molecular biology of this fundamentally important cellular process could, in the future, provide for better health outcomes for an aging Australian population. The training of post-graduate students is an integral component of this study and thus will contribute to building national research capacity. International collaborations and new discoveries will also contribute to the recognition of Australian research.Read moreRead less