Analysis Of The Plasmodium Falciparum M18 Aspartyl Aminopeptidase
Funder
National Health and Medical Research Council
Funding Amount
$613,683.00
Summary
Malaria remains a major cause of death and disease in many parts of the world. There is widespread resistance to all currently used drugs and an urgent need for new treatmants. We have identified the malaria enzyme, aspartyl aminopeptidase as a new drug target. This proposal will investigate the biological role of this enzyme and has the potential to identify new compounds which may be effective antimalarial drugs.
Regulation Of Protein Kinases And Their Substrates
Funder
National Health and Medical Research Council
Funding Amount
$553,197.00
Summary
Our research is concerned with the control of the body's energy metabolism via an enzyme called AMPK. This enzyme is at the hub of metabolic control in response to diet and exercise. AMPK controls energy expenditure in response to demand as well as appetite. It is well recognized that diet and sedentary life-styles are major contributors to obesity and cardiovascular disease. We are testing how a new drug activates AMPKand how energy expenditure can be increased.
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
Analysis Of The Interaction Of The T-cell Oncoproteins Scl And Lmo2 In T Cell Acute Lymphoblastic Leukaemia
Funder
National Health and Medical Research Council
Funding Amount
$179,149.00
Summary
Leukaemic cells frequently contain alterations to the chromosomes which contribute to the generation of the leukaemia by causing the expression of cancer-promoting genes. In the case of T cell acute lymphoblastic leukaemia (T-ALL), the most frequent target of chromosomal alterations is the Stem Cell Leukaemia gene, or SCL. In leukaemic cells, the SCL protein is found to be associated with another protein, called Lmo2, the gene for which is also activated due to chromosomal alterations in T-ALL. ....Leukaemic cells frequently contain alterations to the chromosomes which contribute to the generation of the leukaemia by causing the expression of cancer-promoting genes. In the case of T cell acute lymphoblastic leukaemia (T-ALL), the most frequent target of chromosomal alterations is the Stem Cell Leukaemia gene, or SCL. In leukaemic cells, the SCL protein is found to be associated with another protein, called Lmo2, the gene for which is also activated due to chromosomal alterations in T-ALL. It is thought that these two proteins must bind each other to cause leukaemia, but this has never been proven. This project aims to test whether removal of SCL and Lmo2 is able to stop the progress of leukaemias which they initiate. We will do this by overexpressing SCL and Lmo2 to establish leukaemia in mice, then removing these genes to see if the leukaemia is cured. We will then test whether removal of the endogenous SCL protein is able to stop the onset and progress of leukaemias initiated by Lmo2. We will do this by removing SCL in mice which overexpress Lmo2. Lastly we will generate mutant SCL proteins which are unable to interact with Lmo2, and co-express these along with Lmo2 in mice to assess whether they are able to co-operate with Lmo2 in causing leukaemia. We predict these mutants which are unable to bind to Lmo2 will be unable to co-operate with it in causing leukaemia. This will identify regions of these proteins which can be used as targets for anti-leukaemia drug development.Read moreRead less
Interaction Of New Kinase Inhibitor Drugs With Multi-drug Resistance (MDR) Transporter Proteins.
Funder
National Health and Medical Research Council
Funding Amount
$411,000.00
Summary
Multidrug transporter proteins are remarkable molecular pumps that expel a wide variety of drugs and toxins from cells. They are located at strategic sites where they eliminate harmful substances from the body or prevent them being absorbed from our diet in the first place. Multidrug transporters are also found at natural barriers within the body where they protect vulnerable tissue compartments, including the brain, cerebrospinal fluid, testes and, in preganant women, the foetus. Nevertheless, ....Multidrug transporter proteins are remarkable molecular pumps that expel a wide variety of drugs and toxins from cells. They are located at strategic sites where they eliminate harmful substances from the body or prevent them being absorbed from our diet in the first place. Multidrug transporters are also found at natural barriers within the body where they protect vulnerable tissue compartments, including the brain, cerebrospinal fluid, testes and, in preganant women, the foetus. Nevertheless, multidrug transporters sometimes interfere with drug therapy. They can prevent efficient absorption of drugs, increase the rate of drug elimination from the body, or prevent drug access to some tissues . Moreover, the activity of the transporters is quite variable, both between patients and within the same patient over time. This makes it difficult to provide optimal drug doses, particularly when treating cancer, where the drugs must be given at the maximum tolerated dose. The presence of drug transporter proteins in tumour cells can prevent entry of anticancer drugs, rendering them resistant to treatment. This is the main cause of failure in chemotherapy. This project will investigate a class of very promising new anticancer drugs, kinase inhibitors, to determine whether they are pumped by multidrug transporters, whether they alter the amounts of drug transporters in cells, and whether they alter transporter activity. We will also determine the consequences that follow from this for drug therapy. This information will help clinicians to rationally optimise therapy with the new drugs, to identify in advance both favourable (synergistic) and unfavourable (harmful) drug interactions in combination chemotherapy, to optimise drug doses and to minimise toxic side effects. The information will also add to our general understanding of drug absorption and elimination, and to the basic science of the remarkable multidrug transporter proteins.Read moreRead less
Developing Synergisers Of The Antimalarial Drug, Chloroquine, For The Treatment Of Chloroquine-resistant P. Falciparum.
Funder
National Health and Medical Research Council
Funding Amount
$243,000.00
Summary
Malaria is a debilitating parasitic disease that is responsible for the deaths of about two million children each year. As drugs, such as chloroquine, become increasingly useless due to the development of parasite resistance, there is an urgent need to understand the mode of action of and the molecular basis of resistance to existing antimalarials and to design affordable treatments that can replace chloroquine. It is known that some compounds, that have only poor antimalarial activity themselve ....Malaria is a debilitating parasitic disease that is responsible for the deaths of about two million children each year. As drugs, such as chloroquine, become increasingly useless due to the development of parasite resistance, there is an urgent need to understand the mode of action of and the molecular basis of resistance to existing antimalarials and to design affordable treatments that can replace chloroquine. It is known that some compounds, that have only poor antimalarial activity themselves, can synergise the action of chloroquine. This may involve the inhibition of the activity of proteins that directly or indirectly extrude chloroquine from its site of action in the parasite's digestive apparatus. Unfortunately, thechloroquine synergisers examined to date have been too toxic to be useful in vivo. In preliminary studies we have identified some compounds that would be suitable for use in malaria patients, including a widely used antimalarial drug, primaquine, that can synergise the activity of chloroquine against chloroquine-resistant parasites. We will attempt to understand the molecular basis of this interaction. This will allow us to define optimal combinations of chloroquine and a resistance-reversing quinoline for use treating malaria. This could extend the clinical life of this important antimalarial drug. The information obtained may also help to design novel antimalarial drugs.Read moreRead less
Novel Fluorescent Probes Of Cellular Microenvironments To Study The Mechanism Of Action Of Endoperoxide Antimalarials
Funder
National Health and Medical Research Council
Funding Amount
$983,305.00
Summary
Malaria is responsible for the deaths of about two million children each year. As current drugs become increasingly useless due to the development of parasite resistance, there is an urgent need for new antimalarials. Artemisinin, an ancient Chinese drug that is extracted from wormwood, is now a front-line antimalarial, however its mechanism of action is not clear. Information about how artemisinin works is needed to help design cheap synthetic drugs that work in the same way.
Interactions Between The Malaria Parasite's Chloroquine Resistance Transporter And Antimalarial Drugs
Funder
National Health and Medical Research Council
Funding Amount
$485,641.00
Summary
The malaria parasite is a single-celled organism which invades the red blood cells of its host. The aim of this project is to characterize the parasite protein responsible for conferring resistance to chloroquine, and to study its interaction with other antimalarial drugs. The parasite's susceptibility to chloroquine, and other drugs, is altered by small changes in this protein. This work will advance our understanding of the increasingly widespread phenomenon of antimalarial drug resistance.
Drugs are broken down in the body by the process of metabolism. Metabolism is important as both a detoxification and elimination mechanism, and determines dose rate for chronically administered drugs. Many drugs are metabolised by a reaction called glucuronidation. We will characterise the various components of the glucuronidation reaction in an integrated manner in order to understand and predict factors that influence an individual's capacity to metabolise drugs and other chemicals.