Defining The Requirement For The Inhibition Of Bak To The Pathogenesis Of Cytomegalovirus Infection
Funder
National Health and Medical Research Council
Funding Amount
$592,661.00
Summary
Apoptosis, or programmed cell death is a powerful defence mechanism against viral infection. Thus, to replicate efficiently viruses have evolved means to inhibit apoptosis. The central aim of this work is to understand how cytomegalovirus prevents cell death protein during infection. The proposed studies will improve our understanding of the mechanisms that regulate viral replication and will contribute insights into the normal processes that control cell survival.
Targeting To Mitochondria Of Tail-Anchored Proteins. Defining The Molecular Apparatus Of Targeting.
Funder
National Health and Medical Research Council
Funding Amount
$254,751.00
Summary
The cells of the body have an intricate and dynamic internal architecture, with the components (proteins, lipids, and nucleic acids) of the cell carefully arranged. It is widely viewed that just how each component finds its place in the cell, the cellular adressing system, is of critical importance. This was recognized this year by the award of the Nobel Prize in Medicine to Dr. Gunter Blobel for his work on the signals that direct different proteins to their correct destination. One such destin ....The cells of the body have an intricate and dynamic internal architecture, with the components (proteins, lipids, and nucleic acids) of the cell carefully arranged. It is widely viewed that just how each component finds its place in the cell, the cellular adressing system, is of critical importance. This was recognized this year by the award of the Nobel Prize in Medicine to Dr. Gunter Blobel for his work on the signals that direct different proteins to their correct destination. One such destination is the mitochnondria, the particles in the cell that produce chemical energy. The work in this proposal is designed to define precisely the molecular apparatus that targets a group of proteins to mitochondria. This group, proteins that are inserted into the mitochondria at one end of the protein, includes a variety of critical proteins, including those that determine the life or death of a cell. We will define both the address contained within those proteins, and the machinery on the mitochondria that recognizes that address, and ensures that those proteins will become part of the mitochondria. This research has two applications. By understanding the address, we will be able to decode the vast amount genomic data that is being produced, to predict exactly which proteins are delivered to mitochondria. Secondly, by understanding the targeting machinery, we may begin to design molecules that can inhibit its function, and thus manipulate the delivery of those proteins that affect cell life and death.Read moreRead less
Dissection Of The Mechanisms Of Action Of Evolutionarily Conserved Apoptotic Pathway Components
Funder
National Health and Medical Research Council
Funding Amount
$253,500.00
Summary
Animals eliminate unwanted cells through a highly controlled process termed apoptosis. Defects in apoptosis can contribute to cancer or autoimmune disease. Conversely, diseases such as stroke and Alzheimer's disease have been linked to excessive cell death. To develop drugs that promote apoptosis when it fails to occur, or prevent inappropriate cell death, it is necessary to elucidate the molecular mechanisms controlling apoptosis. The first recognised component of the mammalian cell death machi ....Animals eliminate unwanted cells through a highly controlled process termed apoptosis. Defects in apoptosis can contribute to cancer or autoimmune disease. Conversely, diseases such as stroke and Alzheimer's disease have been linked to excessive cell death. To develop drugs that promote apoptosis when it fails to occur, or prevent inappropriate cell death, it is necessary to elucidate the molecular mechanisms controlling apoptosis. The first recognised component of the mammalian cell death machinery was Bcl-2; a protein associated with development of cancer. Despite much research since then, the way in which Bcl-2 and related proteins function is still unknown. This project capitalises on previous genetic and biochemical studies in a model genetic organism (the roundworm) to address this important issue. Animal cell death pathway components can be introduced into yeast such that activation of the introduced pathways leads to yeast death and its inhibition promotes yeast survival. We have used this approach to reconstitute the worm cell death pathway and a major mammalian apoptosis pathway in yeast. Yeast strains bearing these reconstituted pathways will be used to test functional equivalence of candidate mammalian proteins and their putative roundworm counterparts. The system will also be exploited to identify and characterise novel proteins that regulate cell death in mammals and worms. Understanding the way in which key molecules regulate apoptosis will assist in the development of diagnostic and therapeutic reagents for many diseases in which cell death regulation is perturbed. This project capitalises on the evolutionary conservation of apoptosis to characterise the mechanisms of action of important mammalian apoptotic regulators and to seek novel mammalian apoptotic pathway components. Proteins identified in this way are likely to be important apoptotic regulators, as our approach ensures that their functions are evolutionarily conserved.Read moreRead less
Structural Basis For Restraint And Activation Of Pro-apoptotic Bax And Bak
Funder
National Health and Medical Research Council
Funding Amount
$246,478.00
Summary
The aim of this project is to understand how cell death is controlled. Defects in the cell death machinery occur in many cancers, making that machinery an attractive target for cancer therapeutics. My experiments will yield atomic resolution pictures of the functional machinery, illustrating for the first time how the molecular brakes are applied to prevent cells dying. Understanding these structures will aid the discovery of drugs that can activate the cell death machinery in cancer cells.
Molecular Mechanisms Of Death In Cells With Defective Apoptotic Pathways
Funder
National Health and Medical Research Council
Funding Amount
$335,065.00
Summary
The body protects itself from cancer by killing any cell that poses a risk of becoming a tumour. The body kills these cells via a carefully orchestrated sequence (or pathway) of events, however many cancer cells have defects in cell death pathways that has permitted them to survive even though they have been told to die. In this proposal we set out a research program to investigate how to kill cancer cells that don't want to die. Various tumour cells have been shown to have increased levels of B ....The body protects itself from cancer by killing any cell that poses a risk of becoming a tumour. The body kills these cells via a carefully orchestrated sequence (or pathway) of events, however many cancer cells have defects in cell death pathways that has permitted them to survive even though they have been told to die. In this proposal we set out a research program to investigate how to kill cancer cells that don't want to die. Various tumour cells have been shown to have increased levels of Bcl-2, a proto-oncogene that blocks cell death induced by diverse stimuli. Cells that over-express Bcl-2 are also resistant to cytotoxic drugs. Understanding how to bypass Bcl-2 (or proteins that block cell death in tumours) will lead to a better understanding of cell death-cell survival and allow us to explore the possibility of tailoring treatment for patients in which specific defects in death pathways have been identified in their cancer cells. Cytotoxic lymphocytes (CL) are cells of the immune system that defend the body from cancer by specifically attacking and killing tumor cells. We have been pioneering studies of CL:tumour interactions in which we can define the morphology and kinetics of critical events in cell death and have shown that CL have the ability to kill target cells that over-express Bcl-2. Following the aims in this proposal, we will understand the mechanisms by which cytotoxic lymphocytes kill target cells that have defects in classical cell death pathways. These studies will therefore define alternative pathways to cell death in the event that a key component of the preferential pathway to cell death is inoperative. Since cytotoxic lymphocytes use a variety of ways to kill their targets and tumors may contain multiple defects in cell death pathways, we will explore which are the key defects, or the combination of multiple defects, in cell death pathways that prevent cytotoxic lymphocyte mediated cell death and permit tumour survival in vivo.Read moreRead less
Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in g ....Cell death by a special process called apoptosis is a means of deleting unwanted and harmful cells from the body. Extensive apoptosis occurs during foetal development which is required to get rid of many excess cells produced during the growth of the embryo. Selective apoptosis is also essential for the formation of different tissues and organs in developing foetus. In the adult, apoptosis is required for proper functioning of the immune system, to remove virus infected and cancer cells and in general to maintain the correct number of cells in the body. As such, misregulation of apoptosis is associated with the pathogenesis of a wide array of diseases such as autoimmune diseases, many forms of cancer and neurodegenerative disorders (such as Alzheimer's and Parkinson's diseases), heart disease, ischaemia and other conditions. To understand, manage and treat disorders that result from aberrant apoptosis, we need to know at molecular and cellular level, how apoptosis is brought about and how it is regulated. We have been studying these processes in detail for several years. Central to the apoptotic execution of cell death are a group of proteases that target many cellular proteins for specific cleavage. The activation of these proteases is the crucial step in the initiation of apoptosis and therefore each cell has developed complex ways to control this process. If we understand how these regulatory mechanisms operate, we can then formulate strategies that are targeted towards pathologies involving abnormal apoptosis. Various molecules that are involved in the execution and regulation of apoptosis are potentially excellent targets for therapeutic intervention in a number of disorders and will lead to the development of novel drugs for the treatment and prevention of many pathological conditions.Read moreRead less