Assessing the physiological roles of ubiquitination in regulating neuronal ion channels, receptors and transporters. Significant alterations in the activity neuronal transporters and receptors occur during tissue injury and regeneration as well as in many neurodegenerative disease states. Modulation of the pathways that control these transporters is an emerging therapeutic target, however, the molecular basis of these control mechanisms remain poorly understood. The outcome of this project will ....Assessing the physiological roles of ubiquitination in regulating neuronal ion channels, receptors and transporters. Significant alterations in the activity neuronal transporters and receptors occur during tissue injury and regeneration as well as in many neurodegenerative disease states. Modulation of the pathways that control these transporters is an emerging therapeutic target, however, the molecular basis of these control mechanisms remain poorly understood. The outcome of this project will be a thorough characterisation of a novel regulatory paradigm in neurons that is likely to be crucial for neuronal development and regeneration, and will potentially provide novel therapeutic targets for various neuronal diseases.Read moreRead less
Molecular structure and function of the glycine receptor. This proposal will employ a cutting edge approach to reveal fundamental new insights into the ways that ligand-gated ion channels, and proteins in general, work. The new knowledge and technology developed here will broaden and strengthen Australia's research expertise across a number of basic scientific disciplines. The results will also have relevance to human health. Glycine receptors have an essential role in brain function and are ....Molecular structure and function of the glycine receptor. This proposal will employ a cutting edge approach to reveal fundamental new insights into the ways that ligand-gated ion channels, and proteins in general, work. The new knowledge and technology developed here will broaden and strengthen Australia's research expertise across a number of basic scientific disciplines. The results will also have relevance to human health. Glycine receptors have an essential role in brain function and are targets for anaesthetics and drugs of abuse. GlyRs are also important in modulating pain sensation by the brain. New insights into how natural agonists and drugs affect ion channel structure and function may lead to novel therapeutic opportunities and improved drug structure predictions.Read moreRead less
G-protein coupled receptor-mediated calcium signalling in parasympathetic neurons. External chemical stimuli act on specific cell-surface receptors of neurons resulting in an increase in the intracellular calcium ion concentration which acts as a second messenger to alter neuronal excitability. There are, however, many receptors acting through a number of closely related proteins involving complex intracellular signalling pathways which remain poorly understood. This project uses molecular, elec ....G-protein coupled receptor-mediated calcium signalling in parasympathetic neurons. External chemical stimuli act on specific cell-surface receptors of neurons resulting in an increase in the intracellular calcium ion concentration which acts as a second messenger to alter neuronal excitability. There are, however, many receptors acting through a number of closely related proteins involving complex intracellular signalling pathways which remain poorly understood. This project uses molecular, electrical and fluorescence techniques to elucidate the molecular basis for these interactions by identifying the roles individual proteins play in integrating diverse extracellular stimuli and neuronal excitablility in the peripheral nervous system.Read moreRead less
Functional ubiquitination of neuronal voltage-gated sodium channels. Alterations in the electrical properties of excitable cells occur during tissue injury and regeneration as well as many disease states. Preventing or controlling these changes is a key strategic therapeutic aim. It is, however, only through a comprehensive understanding of the molecular mechanisms that regulate cellular excitability that we can identify these therapeutic targets. The major outcome of this project will be a thor ....Functional ubiquitination of neuronal voltage-gated sodium channels. Alterations in the electrical properties of excitable cells occur during tissue injury and regeneration as well as many disease states. Preventing or controlling these changes is a key strategic therapeutic aim. It is, however, only through a comprehensive understanding of the molecular mechanisms that regulate cellular excitability that we can identify these therapeutic targets. The major outcome of this project will be a thorough characterisation of a novel pathway that is potentially crucial in the development, homeostasis and regeneration of the nervous system. Disruption of normal function of this system may underlie the hyperexcitability observed in mannu neurodegenerative conditions.Read moreRead less
Glycerotoxin, a unique tool to investigate the dynamic interactions between N-type Ca2+ channels and the exo-endocytic machinery. Communication between neurons relies on exocytosis, a process in which synaptic vesicles containing a neurotransmitter release their content in the extracellular synaptic cleft. We have recently discovered a unique neurotoxin called glycerotoxin (GLTx), which selectively activates Ca2+ channels (Cav2.2), linked with the exocytic machinery in the Central Nervous System ....Glycerotoxin, a unique tool to investigate the dynamic interactions between N-type Ca2+ channels and the exo-endocytic machinery. Communication between neurons relies on exocytosis, a process in which synaptic vesicles containing a neurotransmitter release their content in the extracellular synaptic cleft. We have recently discovered a unique neurotoxin called glycerotoxin (GLTx), which selectively activates Ca2+ channels (Cav2.2), linked with the exocytic machinery in the Central Nervous System. GLTx provide a new tool to further dissect the role of Cav2.2 in controlling neurotransmitter release. GLTx also greatly facilitates synaptic vesicle recycling, suggesting an unexpected link between Cav2.2 activation and the compensatory endocytic machinery. Our goal is to investigate functional coupling between Cav2.2 and the exo- and endocytic machineries using GLTx.Read moreRead less
Alpha-Conotoxins: Selective Probes For Nicotinic Receptor Subtype Structure And Function. Marine snails from the waters off the Australian coast produce an amazing variety of mini-proteins in their venoms called conotoxins that they use to capture prey. These conotoxins bind very specifically to receptors in our body associated with the transmission of nerve signals. We will use natural and synthetically modified conotoxins to selectively block particular types of neuronal 'receptors' to gain a ....Alpha-Conotoxins: Selective Probes For Nicotinic Receptor Subtype Structure And Function. Marine snails from the waters off the Australian coast produce an amazing variety of mini-proteins in their venoms called conotoxins that they use to capture prey. These conotoxins bind very specifically to receptors in our body associated with the transmission of nerve signals. We will use natural and synthetically modified conotoxins to selectively block particular types of neuronal 'receptors' to gain a greater understanding of how the nervous system functions. This knowledge will help in the design of new drugs to treat a variety of diseases and disorders. Essentially we will use a chemical armoury developed by the cone snail to design state-of-the-art mini-protein drugs.Read moreRead less
Conotoxins: Novel probes for ion channel structure and function. Voltage-dependent and ligand-gated ion channels are intrinsic membrane proteins that play a central role in communication in excitable cells, particularly in the nervous system. The primary goals of this project are (i) to define at a molecular level, the structural and functional determinants of ion channel/conotoxin interactions and (ii) develop new probes that advance neurophysiological research. The diversity and distribution o ....Conotoxins: Novel probes for ion channel structure and function. Voltage-dependent and ligand-gated ion channels are intrinsic membrane proteins that play a central role in communication in excitable cells, particularly in the nervous system. The primary goals of this project are (i) to define at a molecular level, the structural and functional determinants of ion channel/conotoxin interactions and (ii) develop new probes that advance neurophysiological research. The diversity and distribution of ion channel types and subtypes being uncovered through the use of molecular biology and conotoxin probes presents an exciting opportunity for the future development of novel ion channel therapeutics.Read moreRead less
New modulators of voltage-gated sodium channel subtypes from Australian Tarantula venoms. The venoms of Australian tarantula spiders provide a unique and untapped source of bioactive molecules. From a large stock of venom, and in collaboration with Australian pharmaceutical company Xenome, we will develop a comprehensive library of venom components suitable for drug screening. Potential national benefits from this work include a huge reduction in the healthcare bill deriving from a new treatmen ....New modulators of voltage-gated sodium channel subtypes from Australian Tarantula venoms. The venoms of Australian tarantula spiders provide a unique and untapped source of bioactive molecules. From a large stock of venom, and in collaboration with Australian pharmaceutical company Xenome, we will develop a comprehensive library of venom components suitable for drug screening. Potential national benefits from this work include a huge reduction in the healthcare bill deriving from a new treatment for pain, as well as substantial royalty returns from drugs sales. Discoveries from the program are also likely to lead to an enhancement in Australia's reputation in the neurosciences and to the development of new diagnostic research tools. The major community benefit will be a reduction in the suffering of chronic pain patients.Read moreRead less
Defining mechanisms of action of novel alpha-conotoxins at nicotinic receptor-channels. Marine snails from the waters off the Australian coast produce an amazing variety of mini-proteins in their venoms called conotoxins that they use to capture prey. These conotoxins bind very specifically to receptors in our body associated with the transmission of nerve signals. We will use natural and synthetically modified conotoxins to selectively block particular types of neuronal 'receptors' to gain a gr ....Defining mechanisms of action of novel alpha-conotoxins at nicotinic receptor-channels. Marine snails from the waters off the Australian coast produce an amazing variety of mini-proteins in their venoms called conotoxins that they use to capture prey. These conotoxins bind very specifically to receptors in our body associated with the transmission of nerve signals. We will use natural and synthetically modified conotoxins to selectively block particular types of neuronal 'receptors' to gain a greater understanding of how the nervous system functions. This knowledge will help in the design of new drugs to treat a variety of diseases and disorders. Essentially we will use a chemical armoury developed by the cone snail to design state-of-the-art mini-protein drugs.Read moreRead less
Role of 3'-phosphorylated phosphoinositides in neurosecretion. Neurons communicate through the release of neurotransmitter by synaptic vesicles. Minute changes underlie normal processes such as memory and modifications of neurotransmitter level contribute to a number of neurological diseases. I am interested in deciphering the role of phosphoinositides, an inner membrane-based lipid, during steps leading to the fusion of a synaptic vesicle with the plasma membrane. I have recently discovered tha ....Role of 3'-phosphorylated phosphoinositides in neurosecretion. Neurons communicate through the release of neurotransmitter by synaptic vesicles. Minute changes underlie normal processes such as memory and modifications of neurotransmitter level contribute to a number of neurological diseases. I am interested in deciphering the role of phosphoinositides, an inner membrane-based lipid, during steps leading to the fusion of a synaptic vesicle with the plasma membrane. I have recently discovered that phosphatidylinositol-3 phosphate production was critical for the vesicle to acquire the competence to fuse with the plasma membrane. This project aim to understand by which mechanism this lipid interacts with the release machinery to promote such priming step.Read moreRead less