Use Of Novel Transfection Protocols To Study Protein Trafficking In Malaria-infected Erythrocytes
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
Malaria kills between 1 and 3 million children each year. In addition, the disease debilitates the adult population in malaria-endemic areas, thereby contributing to the cycle of poverty in many third world countries. As resistance to existing antimalarial drugs increases, there is an urgent need to understand the workings of the parasite at a molecular level to enable the development of alternative antimalarial strategies. During part of its life cycle, the malaria parasite infects the erythroc ....Malaria kills between 1 and 3 million children each year. In addition, the disease debilitates the adult population in malaria-endemic areas, thereby contributing to the cycle of poverty in many third world countries. As resistance to existing antimalarial drugs increases, there is an urgent need to understand the workings of the parasite at a molecular level to enable the development of alternative antimalarial strategies. During part of its life cycle, the malaria parasite infects the erythrocytes of its human host. The parasite transports proteins to the erythrocyte membrane so as to modify the properties of its adopted cellular residence. The parasite proteins that are deposited at or in the erythrocyte membrane increase the leakiness and the stickiness of the parasitised erythrocytes. This allows more efficient uptake of nutrients and allows the parasitised erythrocytes to adhere to blood vessel walls, thereby avoiding passage through the spleen. Adherence of parasitised erythrocytes to capillaries in the brain is thought to lead to the development of the complication known as cerebral malaria. This complication is responsible for most of the deaths due to malaria. In order to traffic the adherence proteins to the erythrocyte surface, the parasite establishes a novel transport pathway for moving proteins across the erythrocyte cytoplasm. As the uninfected erythrocyte has no means, nor requirement, for moving proteins, this novel transport mechanism may represent a target for drugs that kill the malaria parasite without being toxic to humans. The pathways for the movement of proteins around the infected erythrocyte are largely unknown. We propose to use techniques to introduce foreign genes into malaria-infected erythrocytes to unravel the details of the molecular machinery and the ticketing system that the parasite uses to traffic proteins to their correct destinations in its adopted home.Read moreRead less
Protein Trafficking In Malaria Parasite-infected Erythrocytes
Funder
National Health and Medical Research Council
Funding Amount
$417,750.00
Summary
Malaria kills between 1 and 3 million children each year. In addition, the disease debilitates the adult population in malaria-endemic areas, thereby contributing to the cycle of poverty in many third world countries. As resistance to existing antimalarial drugs increases, there is an urgent need to understand the workings of the parasite at a molecular level to enable the development of alternative antimalarial strategies. During part of its life cycle, the malaria parasite infects the erythroc ....Malaria kills between 1 and 3 million children each year. In addition, the disease debilitates the adult population in malaria-endemic areas, thereby contributing to the cycle of poverty in many third world countries. As resistance to existing antimalarial drugs increases, there is an urgent need to understand the workings of the parasite at a molecular level to enable the development of alternative antimalarial strategies. During part of its life cycle, the malaria parasite infects the erythrocytes of its human host. The parasite transports proteins to the erythrocyte membrane so as to modify the properties of its adopted cellular residence. The parasite proteins that are deposited at or in the erythrocyte membrane increase the leakiness and the stickiness of the parasitised erythrocytes. This allows more efficient uptake of nutrients and allows the parasitised erythrocytes to adhere to blood vessel walls, thereby avoiding passage through the spleen. Adherence of parasitised erythrocytes to capillaries in the brain is thought to lead to the development of the complication known as cerebral malaria. This complication is responsible for most of the deaths due to malaria. In order to traffic the adherence proteins to the erythrocyte surface, the parasite establishes novel transport pathways for moving proteins across the erythrocyte cytoplasm. As the uninfected erythrocyte has no means, nor requirement, for moving proteins, this novel transport mechanism may represent a target for drugs that kill the malaria parasite without being toxic to humans. The pathways for the movement of proteins around the infected erythrocyte are largely unknown. We propose to use cell biology techniques and techniques to introduce foreign genes into malaria-infected erythrocytes to unravel the details of the molecular machinery and the ticketing system that the parasite uses to traffic proteins to their correct destinations in its adopted home.Read moreRead less
Following a meal glucose circulates in the blood and is taken up into cells via movement of an intracellular glucose transporter from the inside of the cell to fuse with the cell membrane and subsequent transfer of the glucose into the cell. This process is triggered by insulin. One of the commonest diseases resulting from a failure of this cellular process is diabetes. A common form of diabetes which occurs in many adults in Australia results from insulin resistance, whereby the effects of insu ....Following a meal glucose circulates in the blood and is taken up into cells via movement of an intracellular glucose transporter from the inside of the cell to fuse with the cell membrane and subsequent transfer of the glucose into the cell. This process is triggered by insulin. One of the commonest diseases resulting from a failure of this cellular process is diabetes. A common form of diabetes which occurs in many adults in Australia results from insulin resistance, whereby the effects of insulin are diminished and cells become increasingly unable to uptake glucose. Recent studies have demonstrated that a novel enzyme known as SHIP-2 may play a role in regulating insulin action in cells. Deletion of SHIP-2 in mice results in these animals have increased sensitivity to insulin, low blood glucose levels, and a greatly enhanced ability to take up glucose in cells in response to low dose insulin. Our laboratory has been working on the cellular mechanisms regulating SHIP-2 function. We have recently revealed the intracellular location of SHIP-2 and also demonstrated how SHIP-2 is localized in the cell. These studies have shown that SHIP-2, via interactions with other proteins, regulates the actin cytoskeleton immediately beneath the cell membrane and this may be a mechanism for facilitating cellular glucose uptake. This research proposal aims to determine how SHIP-2 facilitates glucose uptake into cells. We will make cell lines and transgenic animals which express high levels of this enzyme and determine the functional consequences on insulin stimulated glucose uptake. Collectively these studies in the long term may facilitate better treatment strategies for diabetic patients.Read moreRead less
Structural Studies Of The Jak And Abl Kinases: A Prerequisite For Drug Design
Funder
National Health and Medical Research Council
Funding Amount
$360,965.00
Summary
Protein tyrosine kinases (PTK) are a large, pivotal family of signalling molecules implicated in diseases such as cancer and immune related disorders. This fellowship aims to develop more potent kinase inhibitors of a number of PTKs using Cytopia’s drug discovery capability coupled with the X-ray crystallography expertise within Monash University. This innovative approach will permit a rational structure-based drug discovery platform to be established and will lead to the creation of a portfolio ....Protein tyrosine kinases (PTK) are a large, pivotal family of signalling molecules implicated in diseases such as cancer and immune related disorders. This fellowship aims to develop more potent kinase inhibitors of a number of PTKs using Cytopia’s drug discovery capability coupled with the X-ray crystallography expertise within Monash University. This innovative approach will permit a rational structure-based drug discovery platform to be established and will lead to the creation of a portfolio of phase I therapeutics, which will be of substantial benefit in the medical health area.Read moreRead less
Identification Of Insulin Specific Signal Transduction Pathways In Adipocytes
Funder
National Health and Medical Research Council
Funding Amount
$451,980.00
Summary
Insulin resistance, which represents an inability of insulin to regulate metabolism in appropriate target tissues such as muscle and adipose tissue, contributes to a number of diseases including diabetes and obesity. A key metabolic step in these tissues is the uptake of glucose from the blood stream. This step is accelerated by insulin thus allowing efficient clearance of glucose from the bloodstream after a meal. Our laboratory has played a major role in showing that insulin regulates glucose ....Insulin resistance, which represents an inability of insulin to regulate metabolism in appropriate target tissues such as muscle and adipose tissue, contributes to a number of diseases including diabetes and obesity. A key metabolic step in these tissues is the uptake of glucose from the blood stream. This step is accelerated by insulin thus allowing efficient clearance of glucose from the bloodstream after a meal. Our laboratory has played a major role in showing that insulin regulates glucose uptake into muscle and adipose tissue by stimulating the movement of a glucose transport protein from inside the cell to the cell surface (see http:--www.imb.uq.edu.au-groups-james-glut4 for an animated description of this process). In the present proposal we will pursue a number of strategies to dissect the signal transduction pathways that connect the insulin receptor to the movement of this glucose transporter. Identification of these molecules will provide the missing pieces to this important puzzle. Once solved we will have at our disposal a novel set of targets for designing drugs that will combat insulin resistant diseases.Read moreRead less
Development Of BRET Detection Systems: Tools For Functional Proteomics And Drug Discovery
Funder
National Health and Medical Research Council
Funding Amount
$376,320.00
Summary
The internal structure of articular cartilage is critical to its biomechanical function. Cartilage is one of the most intricate and difficult tissues to examine in-vivo. Maintenance of its functional characteristics depends heavily of the internal microstructure of the tissue, while conventional arthroscopy can only give a view of the surface and provides no information on the internal structure. Biopsy examination can also destroy the integrity of the tissue, making it impossible to concurrentl ....The internal structure of articular cartilage is critical to its biomechanical function. Cartilage is one of the most intricate and difficult tissues to examine in-vivo. Maintenance of its functional characteristics depends heavily of the internal microstructure of the tissue, while conventional arthroscopy can only give a view of the surface and provides no information on the internal structure. Biopsy examination can also destroy the integrity of the tissue, making it impossible to concurrently examine the structure and function of the tissue. The structure-function relationship is thus critical to the study and the advancement of clinical treatment techniques for cartilage disorders. Osteoarthritis is characterized by severe disruption to the cartilage matrix. The emergence of autologous chondrocyte implant (ACI) therapy as a method for repairing cartilage defects has further increased interest in clinical techniques for the examination of cartilage structure and function. The development of confocal microscopy facilitates internal examination of loaded tissue for the first time, enabling direct examination of the association between structure and function of the tissue. A prototype confocal arthroscope has been developed to facilitate clinical examination of cartilage structure. This, in turn, allows the functional characteristics of the tissue to be deduced. Cartilage exhibits little intrinsic repair making biopsies undesirable. Thus, with respect to cartilage in particular, the developed technologies promise to enable examination to a level of detail which was previously impossible. The current prototype arthroscope has demonstrated the feasibility of a genuine clinical instrument. This grant application seeks funds to conduct initial clinical trials in order to gain sufficient practical feedback to enable design and construction of a clinically ready system.Read moreRead less
Structural Studies On SNARE Proteins Involved In Insulin Action
Funder
National Health and Medical Research Council
Funding Amount
$308,263.00
Summary
Diabetes mellitus, a disease characterised by high blood glucose levels, is caused by a relative or absolute deficiency in the activity of insulin. The blood-glucose lowering action of insulin is a result of its ability to stimulate glucose uptake by fat and muscle cells. A major goal of Professor James' laboratory is to identify molecules that are involved in this insulin-regulated uptake of glucose. Professor James has identified and characterised the glucose transporter, GLUT4, a protein that ....Diabetes mellitus, a disease characterised by high blood glucose levels, is caused by a relative or absolute deficiency in the activity of insulin. The blood-glucose lowering action of insulin is a result of its ability to stimulate glucose uptake by fat and muscle cells. A major goal of Professor James' laboratory is to identify molecules that are involved in this insulin-regulated uptake of glucose. Professor James has identified and characterised the glucose transporter, GLUT4, a protein that is normally stored inside muscle and fat cells. In response to insulin stimulation, GLUT4 moves to the cell surface where it functions to transport glucose into the cell. Over the past 5 years Professor James laboratory has, in conjunction with other groups, discovered several key proteins that are involved in the insulin-regulated movement of GLUT4 within the cell. We plan to exploit the therapeutic potential of this biological system by obtaining high resolution three dimensional structures of these key proteins. The resulting structural information will allow us to develop compounds that modify the function of these key proteins. Such compounds could prove useful as novel therapeutic agents in the treatment of diabetes. The purpose of this proposal is to begin to implement this goal. By combining the knowledge and reagents coming out of the work on insulin-regulated glucose transport in Professor James' laboratory with the molecular and structural biology expertise in Dr Martin's, Dr Halliday's and Prof Craik's laboratories we are in a unique position to achieve this highly significant goal.Read moreRead less
Prof Parton is a cell biologist studying how the plasma membrane functions in health and in disease. These studies have provided new insights into potential vehicles that can be used to introduce therapeutic agents into cells.
Recent evidence suggests that the Siah proteins are involved in sensing low oxygen levels in cells, and subsequently activating processes to help the cell survive under these conditions. Low oxygen conditions occur in cancer and sites of inflammation, suggesting that inhibiting Siah may improve patient outcomes in diseases such as cancer and arthritis. We aim to perform a high throughput screen for drugs that inhibit Siah protein function and to test these in cancer cells.