Sustaining neuronal communication through bulk endocytosis. Brain activities such as learning and memory rely on the ability of neurons to communicate. This research will improve our understanding of how synaptic vesicles recycle during periods of intense synaptic activity. This is a fundamental process relevant to neuronal communication, insulin release, hormone secretion, and allergic responses in health and disease and therefore has broad significance. This work will enhance Australia's exist ....Sustaining neuronal communication through bulk endocytosis. Brain activities such as learning and memory rely on the ability of neurons to communicate. This research will improve our understanding of how synaptic vesicles recycle during periods of intense synaptic activity. This is a fundamental process relevant to neuronal communication, insulin release, hormone secretion, and allergic responses in health and disease and therefore has broad significance. This work will enhance Australia's existing strength in cell biology and neuroscience and provide high quality training for an undergraduate student and post-doctoral scientist.Read moreRead less
Membrane excitability and cellular calcium regulation in the peripheral nervous system under different (patho)-physiological conditions and in inflammatory disease. Studies of cytokine action on neurons and muscle give new insights into functional responses of the nervous system to systemic inflammation and sepsis. In some countries, sepsis is the third most frequent cause of death following heart attack. Elucidating the pathomechanisms allows to develop therapeutic strategies. Electrophysiology ....Membrane excitability and cellular calcium regulation in the peripheral nervous system under different (patho)-physiological conditions and in inflammatory disease. Studies of cytokine action on neurons and muscle give new insights into functional responses of the nervous system to systemic inflammation and sepsis. In some countries, sepsis is the third most frequent cause of death following heart attack. Elucidating the pathomechanisms allows to develop therapeutic strategies. Electrophysiology, Ca2+ regulation and optical membrane potentiometry allow us to monitor early changes in disease on a (sub)cellular level. Experiments on Ca2+ regulation and ion channel function in muscle with different cholesterol membrane contents will help to understand pathomechanisms in high cholesterol diseases, e.g. obesity, on the membrane level long before cardiovascular effects become prominent.Read moreRead less
Calcium Signalling and Sequestration at Vertebrate Motor-Nerve Terminals. A fundamental process at Synapses is the release of transmitter from nerve terminals due to the initiation of calcium signalling in the temrinals by impulses. This calcium signalling must be terminated by sequestering processes. The aim of this project is to identify these processes in a vertebrate motor-nerve terminal and to determine the means by which calcium signals the changes in efficacy of transmitter release during ....Calcium Signalling and Sequestration at Vertebrate Motor-Nerve Terminals. A fundamental process at Synapses is the release of transmitter from nerve terminals due to the initiation of calcium signalling in the temrinals by impulses. This calcium signalling must be terminated by sequestering processes. The aim of this project is to identify these processes in a vertebrate motor-nerve terminal and to determine the means by which calcium signals the changes in efficacy of transmitter release during trains of impulses. This work will give a complete description of calcium signalling in a vertebrate nerve terminal and provide the basis for ameliorating failures in transmission from nerve to muscle.Read moreRead less
Structure and function of heterodimeric amino acid transporters. Recently a new family of amino acid transporters has been identified, the members of which are involved in the delivery of amino acids between cells and tissues. All members display a rather unusual structure in that they require two subunits to be functional. The main aim of this study is to investigate the interaction between large and small subunits. The study will give insight how membrane proteins form complexes in the membran ....Structure and function of heterodimeric amino acid transporters. Recently a new family of amino acid transporters has been identified, the members of which are involved in the delivery of amino acids between cells and tissues. All members display a rather unusual structure in that they require two subunits to be functional. The main aim of this study is to investigate the interaction between large and small subunits. The study will give insight how membrane proteins form complexes in the membrane and how these interactions affect the function of a complex membrane protein.Read moreRead less
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
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
Amino acids as nutrients - the molecular basis of amino acid absorption in kidney and intestine. Nutrition is a critical factor for well being and health. This is highlighted by the increase in frequency of type II diabetes and the obesity problem that all societies with a western diet face. Most studies in nutrition focus on fat and carbohydrates because of their direct involvement in obesity and diabetes. Proteins and the resulting peptides and amino acids, however, form 10-15% of our nutritio ....Amino acids as nutrients - the molecular basis of amino acid absorption in kidney and intestine. Nutrition is a critical factor for well being and health. This is highlighted by the increase in frequency of type II diabetes and the obesity problem that all societies with a western diet face. Most studies in nutrition focus on fat and carbohydrates because of their direct involvement in obesity and diabetes. Proteins and the resulting peptides and amino acids, however, form 10-15% of our nutrition. At a time where protein-rich diets are recommended to fight obesity and diabetes, it is important to understand the basis of protein absorption and metabolism. This project investigates the mechanism and mediators of amino acid absorption in kidney and intestine. Read moreRead less