Further Genetic and Molecular studies of an Important Prokaryotic Regulator Protein TyrR. Genomes encode many functions whose expression varies dramatically depending on particular cellular environments. Special proteins called Regulator Proteins act as sensors to detect subtle changes in the environment and, in response, to influence the expression of certain genes either dampening them down or stimulating their activity. We are working with the TyrR regulator protein of the simple bacterium E ....Further Genetic and Molecular studies of an Important Prokaryotic Regulator Protein TyrR. Genomes encode many functions whose expression varies dramatically depending on particular cellular environments. Special proteins called Regulator Proteins act as sensors to detect subtle changes in the environment and, in response, to influence the expression of certain genes either dampening them down or stimulating their activity. We are working with the TyrR regulator protein of the simple bacterium Escherichia coli to elucidate the molecular strategies used in these controls. Because this protein controls the expression of a number of genes with diverse functions, evolution has selected equally diverse mechanisms to achieve appropriate transcriptional responses. The detailed knowledge of the E.coli genome and of the various genes regulated by TyrR make it an excellent system for such fundamental studies.Read moreRead less
The host specificity of bacterial pathogens. The vast majority of microorganisms that cause diseases in animals are host specific. In other words, they cause disease exclusively in a particular animal species, but are harmless for others. Despite considerable recent advances in our understanding of the mechanisms used by microorganisms in general to cause disease, in most cases the underlying basis of host-specificity is not known. In this project, we will use two animal pathogens, rabbit-spe ....The host specificity of bacterial pathogens. The vast majority of microorganisms that cause diseases in animals are host specific. In other words, they cause disease exclusively in a particular animal species, but are harmless for others. Despite considerable recent advances in our understanding of the mechanisms used by microorganisms in general to cause disease, in most cases the underlying basis of host-specificity is not known. In this project, we will use two animal pathogens, rabbit-specific enteropathogenic E. coli and the closely related bacterium, Citrobacter rodentium, which specifically infect rabbits and mice respectively, to investigate the molecular basis of host specificity.Read moreRead less
How does Clostridium perfringens carry multiple closely related plasmids? The project aims to determine how bacteria are able to replicate and maintain multiple copies of very closely related extrachromosomal elements or plasmids in the same cell. These plasmids are important as they encode toxin genes and antibiotic resistance genes. The project proposes to examine two fundamental hypotheses that are postulated to explain this novel phenomenon. The anticipated outcome of the project is the adva ....How does Clostridium perfringens carry multiple closely related plasmids? The project aims to determine how bacteria are able to replicate and maintain multiple copies of very closely related extrachromosomal elements or plasmids in the same cell. These plasmids are important as they encode toxin genes and antibiotic resistance genes. The project proposes to examine two fundamental hypotheses that are postulated to explain this novel phenomenon. The anticipated outcome of the project is the advancement of fundamental knowledge of how bacteria that cause disease in food-production animals can maintain the genetic elements that enable them to cause these diseases. This would contribute to our understanding of the epidemiology of these economically significant animal pathogens and may support the development of new methods of prevention or treatment.Read moreRead less
Biology and evolution of intracellular parasitism. This project will investigate the development of intracellular parasitism in environmental amoebae. The outcomes of this work will help to understand the mechanisms by which bacteria have evolved to survive inside cells and in some cases cause disease.
Identifying Novel Biosynthetic Pathways in Mycobacteria using DNA Microarray Technology. DNA microarrays are a powerful new bioinformatics-based technology and an ideal tool for characterising complex biosynthetic pathways since the expression of all genes in the bacterial genome can be monitored in a single experiment. In this project we aim to construct and use a DNA microarray to identify novel biosynthetic pathways in mycobacteria. Of particular interest are pathways used to create compone ....Identifying Novel Biosynthetic Pathways in Mycobacteria using DNA Microarray Technology. DNA microarrays are a powerful new bioinformatics-based technology and an ideal tool for characterising complex biosynthetic pathways since the expression of all genes in the bacterial genome can be monitored in a single experiment. In this project we aim to construct and use a DNA microarray to identify novel biosynthetic pathways in mycobacteria. Of particular interest are pathways used to create components of the highly complex and poorly characterised cell wall. Since this structure is unique in the bacterial world, we expect to identify and characterise pathways that are unique to mycobacteria.Read moreRead less
The role of dysregulated signalling by TORC1 in mitochondrial disease. The mitochondria are tiny subcellular compartments responsible for producing over 90 per cent of the cell's energy. Mitochondrial defects feature both in genetic diseases that directly affect the mitochondria and in most neurodegenerative diseases. These incurable diseases are expected to eclipse cancer as the second major cause of death worldwide by 2040. Using a simple model organism, Dictyostelium, previous research showed ....The role of dysregulated signalling by TORC1 in mitochondrial disease. The mitochondria are tiny subcellular compartments responsible for producing over 90 per cent of the cell's energy. Mitochondrial defects feature both in genetic diseases that directly affect the mitochondria and in most neurodegenerative diseases. These incurable diseases are expected to eclipse cancer as the second major cause of death worldwide by 2040. Using a simple model organism, Dictyostelium, previous research showed that dysregulated intracellular signalling by a cellular energy-sensing alarm protein is responsible for diverse cellular pathologies in mitochondrially diseased cells. This project will determine the role in these pathways of a second cellular stress-sensing protein complex, TORC1. New treatment possibilities may emerge.Read moreRead less
Genomic and molecular characterisation of a novel Australian leishmania pathogen. Leishmaniasis is the second most serious protozoal disease after malaria. This project will help characterise the first Leishmania species identified in Australia providing molecular tools to monitor the pathogen and a detailed assessment of any potential risk to human health. Comparative analysis with more pathogenic species will help identify genes and mechanisms that determine the progression of human disease le ....Genomic and molecular characterisation of a novel Australian leishmania pathogen. Leishmaniasis is the second most serious protozoal disease after malaria. This project will help characterise the first Leishmania species identified in Australia providing molecular tools to monitor the pathogen and a detailed assessment of any potential risk to human health. Comparative analysis with more pathogenic species will help identify genes and mechanisms that determine the progression of human disease leading to the potential identification of new drug and vaccine targets. The methodologies and expertise developed will be used will be available to other research groups working on infectious diseases.Read moreRead less
Molecular genetic analysis of genes controlling morphogenesis: Dimorphic switching in the fungus Penicillium marneffei. Fungi exist in two predominant growth forms; unicellular yeast and multicellular mould (filamentous hyphae). Some fungi can alternate between these two forms in response to environmental stimuli, a process known as dimorphic switching. The cells of these two forms have distinctive shapes and physiological capacities established by genome-wide expression patterns that are trigge ....Molecular genetic analysis of genes controlling morphogenesis: Dimorphic switching in the fungus Penicillium marneffei. Fungi exist in two predominant growth forms; unicellular yeast and multicellular mould (filamentous hyphae). Some fungi can alternate between these two forms in response to environmental stimuli, a process known as dimorphic switching. The cells of these two forms have distinctive shapes and physiological capacities established by genome-wide expression patterns that are triggered by signalling pathways. This research aims to understand the fundamental mechanisms controlling dimorphic switching using Penicillium marneffei, a model system. P. marneffei switches between yeast and filamentous forms in response to temperature. Uncovering the molecular mechanisms that control dimorphic switching has important implications for biotechnology and medicine.Read moreRead less
Regulation of nuclear localisation of the AreA transcription factor in Aspergillus nidulans. An understanding of the means by which the expression of genes is regulated is of fundamental significance. Changes in gene expression are central to the development, growth and viability of all cells and their response to environmental changes/stresses. This study uses the fungus Aspergillus nidulans as an excellent molecular genetic tool to investigate how a key regulatory protein controls gene expres ....Regulation of nuclear localisation of the AreA transcription factor in Aspergillus nidulans. An understanding of the means by which the expression of genes is regulated is of fundamental significance. Changes in gene expression are central to the development, growth and viability of all cells and their response to environmental changes/stresses. This study uses the fungus Aspergillus nidulans as an excellent molecular genetic tool to investigate how a key regulatory protein controls gene expression in response to nitrogen starvation stress. Our understanding of these dynamic processes informs our approaches to the development of cancer therapies, to commercial biotechnology application and to control of human, plant and animal pathogens in which the infectious process is triggered by environmental stress. Read moreRead less
Host cell targets of bacterial virulence effectors. The research described in this proposal will result in a better understanding of the cell biology of host-pathogen interactions. We are in a unique position to analyze the importance of protein/protein interactions between bacterial virulence determinants and host cell proteins using a range of cell biology techniques to address the fundamental, molecular basis of the host-pathogen interaction. In addition we will construct a new genetic tool ....Host cell targets of bacterial virulence effectors. The research described in this proposal will result in a better understanding of the cell biology of host-pathogen interactions. We are in a unique position to analyze the importance of protein/protein interactions between bacterial virulence determinants and host cell proteins using a range of cell biology techniques to address the fundamental, molecular basis of the host-pathogen interaction. In addition we will construct a new genetic tool to identify novel bacterial virulence determinants. We anticipate that a greater knowledge of the factors that contribute to the host-pathogen interaction will provide new insights into the subversion of host cell processes by bacterial pathogens of animals, plants and humans.
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