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
Regulation and function of a novel protein tyrosine phosphatase. A cell's ability to respond to its extracellular environment involves a complex and highly organised series of events referred to as cellular signalling. These signalling processes regulate fundamental cellular processes that underlie the growth and development of all living organisms. This proposal focuses on a group of enzymes known as the protein tyrosine phosphatases and their ability to regulate tyrosine phosphorylation-depe ....Regulation and function of a novel protein tyrosine phosphatase. A cell's ability to respond to its extracellular environment involves a complex and highly organised series of events referred to as cellular signalling. These signalling processes regulate fundamental cellular processes that underlie the growth and development of all living organisms. This proposal focuses on a group of enzymes known as the protein tyrosine phosphatases and their ability to regulate tyrosine phosphorylation-dependent signalling. We have identified a novel human protein tyrosine phosphatase and we aim to characterise its regulation and biological function.Read moreRead less
Characterisation of a novel protein tyrosine phosphatase. A cells ability to respond to its extracellular environment involves a complex and highly organised series of events referred to as cellular signalling. These signalling processes regulate fundamental cellular events that underlie the growth and development of all living organisms. This proposal focuses on a group of enzymes known as the protein tyrosine phosphatases and their ability to regulate tyrosine phosphorylation-dependent signa ....Characterisation of a novel protein tyrosine phosphatase. A cells ability to respond to its extracellular environment involves a complex and highly organised series of events referred to as cellular signalling. These signalling processes regulate fundamental cellular events that underlie the growth and development of all living organisms. This proposal focuses on a group of enzymes known as the protein tyrosine phosphatases and their ability to regulate tyrosine phosphorylation-dependent signalling. We have identified a novel human protein tyrosine phosphatase and we aim to characterise its function and the mechanism by which it is regulated.Read moreRead less
Identification of functionally important autophosphorylation site(s) on ataxia telangiectasia and Rad 3 - related (ATR) protein kinase. The integrity of our genetic material must be maintained so that it can be passed on from one generation to the next and also to minimize the risk of cancer and other pathologies in an individual. There are multiple proteins involved in protecting our DNA including several enzymes that detect and signal DNA damage to a series of pathways involved in halting the ....Identification of functionally important autophosphorylation site(s) on ataxia telangiectasia and Rad 3 - related (ATR) protein kinase. The integrity of our genetic material must be maintained so that it can be passed on from one generation to the next and also to minimize the risk of cancer and other pathologies in an individual. There are multiple proteins involved in protecting our DNA including several enzymes that detect and signal DNA damage to a series of pathways involved in halting the passage of cells through the cell cycle so that repair can occur. This project studies the mechanism of action of one of these enzymes which will be of benefit in designing new compounds to fight disease. Read moreRead less
Probing JNK MAPK function with peptide inhibitors. It has generally been accepted that the JNK MAPK family of protein kinases is rapidly and potently activated following the exposure of mammalian cells to stresses and cytokines. However, their biological role has remained controversial. We believe that this problem reflects the lack of a generally applicable and specific JNK MAPK inhibitor. In this project we continue our characterisation of a small peptide inhibitor developed in our laboratori ....Probing JNK MAPK function with peptide inhibitors. It has generally been accepted that the JNK MAPK family of protein kinases is rapidly and potently activated following the exposure of mammalian cells to stresses and cytokines. However, their biological role has remained controversial. We believe that this problem reflects the lack of a generally applicable and specific JNK MAPK inhibitor. In this project we continue our characterisation of a small peptide inhibitor developed in our laboratories. We aim to determine its mechanism of inhibition, the specificity of interaction, and to evolve more effective inhibitors. With these new inhibitors, we can effectively address the biological roles of these kinases.Read moreRead less