A study of the nongenomic action of Vitamin D: proposed role of the nuclear VDR and downstream signalling molecules. Vitamin D (1,25D) activates genes in the nucleus through the vitamin D receptor (VDR). 1,25D can also elicit rapid responses at the plasma membrane. This action is critical to the activation of nuclear genes. We hypothesise that a proportion of the nuclear VDR is located at the plasma membrane where it stimulates downstream signalling molecules eg Ras, ERK1/2 and ERK5. We plan to ....A study of the nongenomic action of Vitamin D: proposed role of the nuclear VDR and downstream signalling molecules. Vitamin D (1,25D) activates genes in the nucleus through the vitamin D receptor (VDR). 1,25D can also elicit rapid responses at the plasma membrane. This action is critical to the activation of nuclear genes. We hypothesise that a proportion of the nuclear VDR is located at the plasma membrane where it stimulates downstream signalling molecules eg Ras, ERK1/2 and ERK5. We plan to explore this hypothesis and to identify the signalling molecules. We will also investigate our novel finding that a specific Ras isoform is involved in ERK5 activation. The work will provide new information on signalling pathways.Read moreRead less
Regulatory mechanisms for calcium release-activated calcium channels. Store-operated calcium channels play a central role in the functions of all animal cells. They participate in generating the cellular responses to hormones, growth factors and other physiological stimuli. The aims of this project are to elucidate the mechanisms that regulate the activity of store-operated channels and how their properties can be modulated by different pharmacological agents. Using chiefly the techniques of ele ....Regulatory mechanisms for calcium release-activated calcium channels. Store-operated calcium channels play a central role in the functions of all animal cells. They participate in generating the cellular responses to hormones, growth factors and other physiological stimuli. The aims of this project are to elucidate the mechanisms that regulate the activity of store-operated channels and how their properties can be modulated by different pharmacological agents. Using chiefly the techniques of electrophysiology and molecular biology we expect to learn the fundamental mechanisms that modulate the opening and closing of store-operated calcium channels and to gain an important information that can be used for determining the molecular structure of these channelsRead moreRead less
Second messenger-activated calcium channels in liver cells. This project concerns second messenger-activated calcium channels, part of the family of hormone-activated calcium channels which are essential to the functions of all animal cells. The aims are to elucidate the properties of a novel "large conductance" Ca2+ channel (using maitotoxin as an artificial activator), an inositol 1,4,5-trisphosphate-activated calcium channel, and the calcium channel formed by the transient receptor potential ....Second messenger-activated calcium channels in liver cells. This project concerns second messenger-activated calcium channels, part of the family of hormone-activated calcium channels which are essential to the functions of all animal cells. The aims are to elucidate the properties of a novel "large conductance" Ca2+ channel (using maitotoxin as an artificial activator), an inositol 1,4,5-trisphosphate-activated calcium channel, and the calcium channel formed by the transient receptor potential-1 (TRP-1) protein in hepatocytes. The electrophysiological properties, mechanisms of activation and intracellular trafficking of the channels will be investigated. It is anticipated the results will provide basic information on the physiological functions of second messenger-activated calcium channels. This will benefit the understanding of liver function, hepatotoxicity in animals, animal production and the development of pharmaceuticals in animal husbandary.Read moreRead less
The bHLH.PAS transcription factors: Determinants of dimerization specificity and high affinity DNA binding. This program of fundamental research will advance our knowledge of the way essential proteins act to correctly regulate critical biological processes. A detailed understanding of these processes at the molecular level has the potential to contribute to the design of pharmaceutical compounds to assist in the treatment of diseases such as ischaemia, myocardial infarction and tumour progress ....The bHLH.PAS transcription factors: Determinants of dimerization specificity and high affinity DNA binding. This program of fundamental research will advance our knowledge of the way essential proteins act to correctly regulate critical biological processes. A detailed understanding of these processes at the molecular level has the potential to contribute to the design of pharmaceutical compounds to assist in the treatment of diseases such as ischaemia, myocardial infarction and tumour progression. The work will contribute to the training of one or more graduate students in a technologically advancing and internationally competitive field.Read moreRead less
Genetic dissection of a regulatory deubiquitlyation network. The potential impact of this work is widespread, because although it is known that ubiquitlyation has regulatory consequences in multicellular eukaryotes, individual networks have not been completely described in higher eukaryotes. Knowledge gained about fundamental processes in the A. nidulans model system is directly applicable to fungi used in biotechnology in the food, beverage, enzyme and pharmaceutical production industries, and ....Genetic dissection of a regulatory deubiquitlyation network. The potential impact of this work is widespread, because although it is known that ubiquitlyation has regulatory consequences in multicellular eukaryotes, individual networks have not been completely described in higher eukaryotes. Knowledge gained about fundamental processes in the A. nidulans model system is directly applicable to fungi used in biotechnology in the food, beverage, enzyme and pharmaceutical production industries, and to fungal pathogens. Since the fungal genes that form the basis of this project are conserved in higher eukaryotes including humans, the knowledge will be transferable to these systems. A further benefit that cannot be overstated is the research education and training opportunities provided.
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Investigation of the fundamental roles of class Ib MHC (major histocompatibility complex) molecules in immunity. The proposed research program, using laboratory-based and synchrotron-based radiation, will provide insight into the roles of a poorly understood class of immune molecules. This will improve our understanding of the regulation of immunity, and the knowledge gained will increase Australia's international research profile.
Structural studies of the interactions of actinin-4 and intracellular signalling proteins. The intracellular signalling cascade plays important roles in cellular processes such as growth and differentiation by exerting changes in gene expression or remodelling of the intracellular protein framework. The actin-based cytoskeleton is one such network of proteins responsible for a number of processes including cell division, migration and adhesion to other cells and tissues. This proposal aims to un ....Structural studies of the interactions of actinin-4 and intracellular signalling proteins. The intracellular signalling cascade plays important roles in cellular processes such as growth and differentiation by exerting changes in gene expression or remodelling of the intracellular protein framework. The actin-based cytoskeleton is one such network of proteins responsible for a number of processes including cell division, migration and adhesion to other cells and tissues. This proposal aims to understand how actinin-4, a component of the actin cytoskeleton in non-muscle tissues, interacts with and is stimulated by proteins of the intracellular signalling cascade.Read moreRead less
Development and regulation of thermogenesis in thermoregulating flowers. Flowers of certain primitive plants produce enough heat to raise their temperatures up to 40 C above the air, and regulate it at a nearly constant level. Like warm-blooded mammals, the flowers increase heat production as environmental temperature falls. However, they thermoregulate on a cellular level, unlike mammals with their complex nervous system. We aim to elucidate the mechanisms involved in regulation of heat-prod ....Development and regulation of thermogenesis in thermoregulating flowers. Flowers of certain primitive plants produce enough heat to raise their temperatures up to 40 C above the air, and regulate it at a nearly constant level. Like warm-blooded mammals, the flowers increase heat production as environmental temperature falls. However, they thermoregulate on a cellular level, unlike mammals with their complex nervous system. We aim to elucidate the mechanisms involved in regulation of heat-production, with molecular, biochemical and stable isotope techniques. We will investigate spatial and temporal patterns of gene expression and activity of putative regulatory enzymes. The results will have implications for human physiology and agriculture.Read moreRead less
Enhancement of monopartite geminivirus pathogenicity by satellite DNA beta encoded betaC1 protein: the role of host factors. Australian incursions of geminiviruses are uncontrollable due to their unique mode of spread by whiteflies. The first incursion in Darwin in 1970 has spread to Far Northern Queensland. The second in SE Queensland in 2006 is estimated to cause $500 million loss to horticulture. Our $2 billion cotton industry is threatened by cotton leaf curl diseases from South Asia, where ....Enhancement of monopartite geminivirus pathogenicity by satellite DNA beta encoded betaC1 protein: the role of host factors. Australian incursions of geminiviruses are uncontrollable due to their unique mode of spread by whiteflies. The first incursion in Darwin in 1970 has spread to Far Northern Queensland. The second in SE Queensland in 2006 is estimated to cause $500 million loss to horticulture. Our $2 billion cotton industry is threatened by cotton leaf curl diseases from South Asia, where DNA beta enhances virus replication and disease severity. DNA beta has the potential to enter Australia with several different geminiviruses and to spread into others by co-infection, which requires research on detection and pathogenesis of DNA beta.Read moreRead less
Small is beautiful: Did gene-rich regions of mammal chromosomes evolve from microchromosomes? Most birds and reptile genomes feature many tiny microchromosomes. These are not junk, as previously thought, but contain most of the genes. Mammals lack microchromosomes, but contain gene-rich regions with similar attributes. We suggest that microchromosomes originated by genome duplication, and evolved into the gene-rich regions of mammalian chromosomes. We will test this hypothesis by comparing seque ....Small is beautiful: Did gene-rich regions of mammal chromosomes evolve from microchromosomes? Most birds and reptile genomes feature many tiny microchromosomes. These are not junk, as previously thought, but contain most of the genes. Mammals lack microchromosomes, but contain gene-rich regions with similar attributes. We suggest that microchromosomes originated by genome duplication, and evolved into the gene-rich regions of mammalian chromosomes. We will test this hypothesis by comparing sequences and genes in microchromosomes of birds, reptiles and monotremes. This will clarify the origin and evolution of the ?microgenome?, establish its suitability as a model for vertebrate genome organisation, and demonstrate whether microchromosomes are the ancestors of the gene-rich regions of mammalian chromosomes.Read moreRead less