Discovery And Mechanisms Of Host Cell Factors In HIV Uncoating
Funder
National Health and Medical Research Council
Funding Amount
$635,098.00
Summary
HIV entry into the host cell involves release of its capsid, a protein shell protecting the viral genome. The capsid hijacks host proteins to cloak itself from cellular defenses while the cell has evolved sensors that can block viral infection. This proposal aims to discover proteins involved in this arms race between host and virus and decipher how they control capsid disassembly. This insight will help design new drugs against HIV infection and new ways to deliver genes for gene therapies.
Characterization Of The 72 KDa Inositol Polyphosphate 5-phosphatase
Funder
National Health and Medical Research Council
Funding Amount
$454,050.00
Summary
Cells respond to external signals and the enviroment to undergo cell growth, secretion and or other specialized functions including control of cell death and or cell size. We have identified a new enzyme (72 kDa 5-phosphatase) which resides inside the cell, which we have evidence plays a role in regulating both the movement of intracellular vesicles and also lipid signals stimulated by insulin. We have characterised the phospholipids that the enzyme cleaves and demonstrated the generation of new ....Cells respond to external signals and the enviroment to undergo cell growth, secretion and or other specialized functions including control of cell death and or cell size. We have identified a new enzyme (72 kDa 5-phosphatase) which resides inside the cell, which we have evidence plays a role in regulating both the movement of intracellular vesicles and also lipid signals stimulated by insulin. We have characterised the phospholipids that the enzyme cleaves and demonstrated the generation of new cell signals at specific subcellular localizations on intracellular membranes. We predict the generation of these specific lipid signals may play a significant role in controlling the transport of intracellular cargo to specific sites in the cell. In this grant proposal we aim to examine the regulation of specialised cargo called the glucose transporter, which is found in fat and muscle cells, and also the mannose 6-phosphate receptor, which regulates the trafficking of specific enzymes which mediate digestion of proteins. These studies include the clarification of which phospholipid signals the enzyme terminates and where in the cell this occurs. Secondly, we will examine the movement of the glucose transporter GLUT-4 in unstimulated cells and in response to insulin and furthermore how expression of the novel enzyme regulates its movement. We will also examine the movement of the mannose 6-phosphate receptor and the specific phospholipid signals which control the route the receptor traffics, using inhibitors of lipid signals and expression of lipid phosphatases and kinases. We will also examine how our novel enzyme forms complexes with other molecules in the cell and characterise these novel molecules using basic biochemical assessment of enzyme activity and function. Finally we will examine the regulation of intracellular messages by our novel enzyme following insulin stimulation, which facilitates glucose uptake into the cell.Read moreRead less
Structural Investigation Into The Regulation Of The Colony Stimulating Factor Receptor, C-FMS.
Funder
National Health and Medical Research Council
Funding Amount
$287,321.00
Summary
The colony stimulating factor receptor, c-FMS is a member of a family of protein signalling molecules expressed on the cell surface that are implicated in the development of serious diseases in humans, such as inflammatory diseases and cancer. A number of important proteins bind to and regulate c-FMS in different ways. I intend to visualise these interactions to further understand how c-FMS activity is controlled by alternative means.
Synthesis of substrate analogues for probing catalytic mechanisms and specificity of enzymes involved in the metabolism of plant polysaccharides. The project is aimed at strengthening collaborations between research groups in Adelaide and France, with the specific objective of synthesizing substrate analogues as probes of enzymatic mechanisms and substrate specificity in polysaccharide hydrolases and synthases of barley. The chemical expertise resides in France, while the enzymatic work will be ....Synthesis of substrate analogues for probing catalytic mechanisms and specificity of enzymes involved in the metabolism of plant polysaccharides. The project is aimed at strengthening collaborations between research groups in Adelaide and France, with the specific objective of synthesizing substrate analogues as probes of enzymatic mechanisms and substrate specificity in polysaccharide hydrolases and synthases of barley. The chemical expertise resides in France, while the enzymatic work will be conducted largely in Australia. Exchange of research staff, particularly at the postgraduate student and research associate levels, is considered essential to capture the benefits of the complementary expertise and to extend an existing international collaboration. The target enzymes are of central importance in cell wall metabolism during development of higher plants.Read moreRead less
Molecular mechanisms of catalysis and the basis of substrate specificity in polysaccharide hydrolases. Reaction intermediates along hydrolytic pathways and molecular determinants of substrate specificity of barley B-glucan exo- and endohydrolases will be defined using crystallographic and kinetic analyses. These enzymes are of central importance in cell wall metabolism during development of higher plants, and in plant-pathogen interactions. Realization of the project objectives will not only pro ....Molecular mechanisms of catalysis and the basis of substrate specificity in polysaccharide hydrolases. Reaction intermediates along hydrolytic pathways and molecular determinants of substrate specificity of barley B-glucan exo- and endohydrolases will be defined using crystallographic and kinetic analyses. These enzymes are of central importance in cell wall metabolism during development of higher plants, and in plant-pathogen interactions. Realization of the project objectives will not only provide fundamental information on catalytic mechanisms, but will also provide opportunities to manipulate enzyme specificity. Further, site-directed mutagenesis of the enzymes will be used to generate glycosynthases, which will be evaluated for their ability to synthesise novel oligosaccharide and polysaccharide products, some of which might show immunomodulating activity.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
A novel link between metabolism and host defence. This project aims to delineate how a protein modification that consists of the addition of a small sugar to cellular proteins, known as O-GlcNAcylation, provides a link between metabolism and complex cell functions. The model for these studies is a cell type of the immune system known as dendritic cells. Upon encountering pathogens these cells undergo metabolic changes that increase the rate of O-GlcNAcylation of proteins involved in immune respo ....A novel link between metabolism and host defence. This project aims to delineate how a protein modification that consists of the addition of a small sugar to cellular proteins, known as O-GlcNAcylation, provides a link between metabolism and complex cell functions. The model for these studies is a cell type of the immune system known as dendritic cells. Upon encountering pathogens these cells undergo metabolic changes that increase the rate of O-GlcNAcylation of proteins involved in immune responses, altering their function. This project will study how O-GlcNAcylation works and is regulated. The project expects to develop new technology and provide high-level training, increasing the competitiveness of the strategic biotechnology sector in AustraliaRead moreRead less
The role of the protease inhibitor Serpinb9 in antigen cross-presentation by dendritic cells. This project will provide fundamental new insights into antigen cross-presentation, a crucial facet of the immune system's response to viral infection or neoplastic cells. It will also provide a basis for future studies into mechanisms of immune tolerance and enhance our understanding of autoimmune disease.
Structure, Assembly, And Inhibition Of The Human Telomerase Enzyme Complex
Funder
National Health and Medical Research Council
Funding Amount
$645,359.00
Summary
In contrast to the limited growth of normal human cells, cancer cells proliferate out of control and without limit. At least 85% of all human cancers rely on the enzyme TELOMERASE to sustain their unlimited proliferation. Telomerase is absent in most normal tissues and therefore represents a potentially effective and specific target for future cancer therapy. We aim to determine the precise 3-dimensional shape of human telomerase to provide a template for rational anti-telomerase drug design.