Inside our cells is a complex traffic system. The vehicles are vesicles that come in different shapes and sizes and travel to specific destinations in the cell to deliver cargo such as: surface growth factor receptors that are to have their signalling terminated, proteins and lipids destined for the cell wall for growth or development (like neurite outgrowth) and proteins and hormones destined for secretion (like neurotransmitter release). More than 100 human genetic disorders map to defects in ....Inside our cells is a complex traffic system. The vehicles are vesicles that come in different shapes and sizes and travel to specific destinations in the cell to deliver cargo such as: surface growth factor receptors that are to have their signalling terminated, proteins and lipids destined for the cell wall for growth or development (like neurite outgrowth) and proteins and hormones destined for secretion (like neurotransmitter release). More than 100 human genetic disorders map to defects in one of the components of this system. Proteins called small GTPases provide order for this traffic and allow specific cargo to reach specific destinations. They regulate cell functions by acting as switches, turning biochemical processes on and off inside the cell. Ral is a small GTPase enzyme found in brain and broadly distributed in other cells. We have discovered that Ral is part of a large signalling complex. When activated Ral stimulates effectors, either the exocyst or RalBP1. In turn, mild oxidative stress controls a Ral inhibitor protein called ERp57. The research proposed aims to establish the functional role for the Ral signalling complex in cells. We will determine with which vesicle trafficking events Ral is associated, which effector it utilises in that pathway, and how that effector directs the traffic. We will also map the steps that may lead to inactivation of Ral via ERp57 in cells, and propose that this is mediated by mild oxidative stress. Techniques of molecular biology, biochemistry, molecular biology, proteomics and microscopy will be used to establish these functions. The research will lead to increased knowledge of the significance of this protein to cellular and particularly neuronal cell function. This forms the basis for understanding normal cell function and for identification of further factors causing diseases of vesicle transport. In time, such research aids in the development of specific therapies for sufferers of such diseases.Read moreRead less
Regulators Of G Protein Signalling On The Golgi Complex
Funder
National Health and Medical Research Council
Funding Amount
$666,116.00
Summary
The secretion of proteins from cells involves a host of regulatory and signalling proteins. G proteins, signal transducers, located on the Golgi membranes, participate in the budding of transport vesicles in the secretory pathway. A newly-discovered family of Regulators of G Protein Signalling (RGS) proteins perform the critical function of turning off signals generated by G proteins. RGS proteins are powerful, but as yet, ill-defined regulatory molecules. In this study we will identify and char ....The secretion of proteins from cells involves a host of regulatory and signalling proteins. G proteins, signal transducers, located on the Golgi membranes, participate in the budding of transport vesicles in the secretory pathway. A newly-discovered family of Regulators of G Protein Signalling (RGS) proteins perform the critical function of turning off signals generated by G proteins. RGS proteins are powerful, but as yet, ill-defined regulatory molecules. In this study we will identify and characterize RGS proteins in macrophages that are located on Golgi membranes and help to regulate cytokine secretion and other immune functions. More detailed studies on selected RGS proteins will include mutational analysis of functional domains within the proteins and identification of other proteins that interact with RGS proteins. Overall these studies will lead us to understand how specific RGS proteins interact with G proteins and other molecules to regulate signalling in the secretory pathway. Anomalies in cell signalling have severe consequences in a variety of diseases and can cause cancer. Similarly, abnormal secretion in cells contributes to inflammation, diabetes and other disease processes. Information forthcoming from our studies on RGS proteins will have wide-reaching implications and the potential to reveal new targets for therapeutics in these diseases.Read moreRead less
Characterization Of Novel Regulators Of Erythropoiesis
Funder
National Health and Medical Research Council
Funding Amount
$437,545.00
Summary
Mature red and white blood cells develop from hemopoietic stem cells in the adult bone marrow. The production of red blood cells is primarily controlled by the hormone erythropoietin (epo). The availability of this hormone in a recombinant form has aided in the treatment of numerous forms of anaemia resulting from kidney failure, malignancies, and AIDS. Previously we had identified that the protein Lyn must be present inside primitive red blood cells for epo to stimulate them to become mature fu ....Mature red and white blood cells develop from hemopoietic stem cells in the adult bone marrow. The production of red blood cells is primarily controlled by the hormone erythropoietin (epo). The availability of this hormone in a recombinant form has aided in the treatment of numerous forms of anaemia resulting from kidney failure, malignancies, and AIDS. Previously we had identified that the protein Lyn must be present inside primitive red blood cells for epo to stimulate them to become mature functional cells. We have identified six molecules which interact with Lyn in red blood cells. We have shown that amolecule called HS1 is important for epo function in individual red blood cells and now we plan to investigate its functions in whole animals, including mice that lack the HS1 gene. We have also shown that a molecule called Trip1 is important for red blood cell development. Interestingly, this molecule also interacts with the thyroid hormone receptor and can influence the effects of epo and thyroid hormone on red blood cell development. The interplay between these two hormones will be looked at in more detail both at the cell and whole animal levels in normal mice and those lacking the thyroid hormone receptor gene. The third Lyn binding molecule we isolated is a novel gene-we have named it ankyrin repeat protein in line with the molecules it is related to. This gene is expressed in red blood cells and we aim to investigate what role it plays in the development of these cells. The fourth gene is also novel and is closely related to another called AFAP-110, which can exert effects on the structure of a cell. Its role in red blood cell structure will also be investigated. Finally, the last two molecule we have identified are both novel and are unrelated to any other known proteins. As above, the effects of these two molecules on red blood cell development will be investigated.Read moreRead less
E-cadherin is one of the major proteins responsible for mediating cell-to-cell adhesion in the body. During development, E-cadherin is essential for establishing the cellular architecture of epithelial organs and for maintaining epithelial function in the adult. In this context, E-cadherin acts to establish and maintain the polarity of epithelial cells. E-cadherin is also a powerful tumour suppressor and the loss of E-cadherin expression or function is a primary event in metastasis and cancer in ....E-cadherin is one of the major proteins responsible for mediating cell-to-cell adhesion in the body. During development, E-cadherin is essential for establishing the cellular architecture of epithelial organs and for maintaining epithelial function in the adult. In this context, E-cadherin acts to establish and maintain the polarity of epithelial cells. E-cadherin is also a powerful tumour suppressor and the loss of E-cadherin expression or function is a primary event in metastasis and cancer invasion. Proteins at the surface of epithelial cells must be sorted and trafficked, or transported, to different membrane domains. E-cadherin, for instance, must be trafficked to the lateral domain of cells in order to function in cell-cell adhesion. We recently discovered that cell surface E-cadherin is re-internalized and recycled back to the surface via a pathway that is poised to contribute to the regulation of cell adhesion. Our proposed studies aim to reveal how newly-synthesized E-cadherin and recycling E-cadherin are trafficked, which molecules and which vesicle carriers accomplish this transport. E-cadherin has specific amino acids that act as targeting signals for its sorting and trafficking; we have recently identified one such signal and will now seek the signal responsible for its endocytosis. Using specifically engineered mutants of E-cadherin we will also study other proteins that interact with E-cadherin during its trafficking for sorting and regulation. One of these is polycystin, a protein that is mutated in a common inherited kidney disease. Insights into this disease and normal kidney epithelial function will emerge from this work. A growing understanding of E-cadherin function and regulation is essential for the health of epithelial organs and for controlling and preventing cancer.Read moreRead less
A hierarchical quantum mechanical and classical simulation of biological ion channels. I aim to develop a methodology incorporating molecular quantum
mechanics and classical Brownian mechanics in a way that can be
applied practically to large macromolecular systems, thus relating
fine structural details to experimentally measurable
properties. Specifically, I will apply this methodology to study ion
channels in which the challenge is to relate electronic and atomic
structure to the conduct ....A hierarchical quantum mechanical and classical simulation of biological ion channels. I aim to develop a methodology incorporating molecular quantum
mechanics and classical Brownian mechanics in a way that can be
applied practically to large macromolecular systems, thus relating
fine structural details to experimentally measurable
properties. Specifically, I will apply this methodology to study ion
channels in which the challenge is to relate electronic and atomic
structure to the conductance properties of the channel. Accurately
determining these relationships provides a pathway to developing cures
for many neurological, cardiac, and muscular diseases.
Read moreRead less
A fundamental study of the role of signal transduction pathways in the regulation of Chlamydia's complex developmental cycle. Chlamydia are unique organisms in the microbial world. They are among the smallest bacteria and yet have a complex two-stage developmental cycle. In addition they are major causes of disease in animals and humans with no vaccines available. We have used the recent flood of full genome sequence data to identify over 30 new cell signalling proteins. By understanding how the ....A fundamental study of the role of signal transduction pathways in the regulation of Chlamydia's complex developmental cycle. Chlamydia are unique organisms in the microbial world. They are among the smallest bacteria and yet have a complex two-stage developmental cycle. In addition they are major causes of disease in animals and humans with no vaccines available. We have used the recent flood of full genome sequence data to identify over 30 new cell signalling proteins. By understanding how these cell signaling proteins are organized into pathways and how this microorganism controls its complex growth and developmental cycle, we will be able to develop novel methods of control. We are at the fore front of international research and therefore uniquely placed to conduct this project.Read moreRead less
Targeting genes elevated in the athlete's heart to improve function of the failing heart. Cardiovascular disease affects about 3.7 million Australians and heart failure ranks as one of the major killers, representing a huge burden on our health care system and economy. This situation is likely to get worse with an increasing ageing population. Current therapeutics for heart failure patients largely delay disease progression but generally fail in significantly improving heart function and quality ....Targeting genes elevated in the athlete's heart to improve function of the failing heart. Cardiovascular disease affects about 3.7 million Australians and heart failure ranks as one of the major killers, representing a huge burden on our health care system and economy. This situation is likely to get worse with an increasing ageing population. Current therapeutics for heart failure patients largely delay disease progression but generally fail in significantly improving heart function and quality of life. The proposal has focused on targeting the protective effects of 'good' heart growth by identifying genes elevated in the heart in response to exercise. Targeting genes elevated in the athlete's heart to improve function of the failing heart represents a new strategy for the treatment of heart failure.Read moreRead less
Development and Characterization of Chemokine Receptor Mimics. The proposed research will provide important fundamental insights into the molecular events underlying inflammatory diseases and cancer metastasis. The innovative nature of the research and the significance of the results will enhance Australia's international research standing. Moreover, the insights gained from this work will contribute to the development of therapies that will ultimately enhance the quality of life for Australia ....Development and Characterization of Chemokine Receptor Mimics. The proposed research will provide important fundamental insights into the molecular events underlying inflammatory diseases and cancer metastasis. The innovative nature of the research and the significance of the results will enhance Australia's international research standing. Moreover, the insights gained from this work will contribute to the development of therapies that will ultimately enhance the quality of life for Australians.Read moreRead less
Structure, Transport And Assembly Of PorB, A Key Invasion Molecule Of Meningococcal Disease
Funder
National Health and Medical Research Council
Funding Amount
$292,639.00
Summary
When the bacteria that cause meningococcal disease invade cells, they use specialized cell surface pore proteins to hijack the human cell and maintain infection. This research will study the structure of these bacterial pore proteins to help understand how they function to subvert normal cellular processes, and this insight will be important in the development of new treatments for meningococcal disease.