Molecular Basis Of Transgenerational Epigenetic Inheritance In Mammals
Funder
National Health and Medical Research Council
Funding Amount
$477,965.00
Summary
While it has long been recognised that it is not just DNA, but chromosomes, that are passed from the gametes to the embryo, the non-DNA component was thought to carry no information with respect to the offspring's ultimate phenotype. However, there is now evidence that the non-DNA component, the epigenetic component, can play a role in the inheritance of phenotype in mammals. This study will attempt to determine the molecular nature of this phenomenon.
Regulation Of Tissue-type Plasminogen Activator Gene Expression In Endothelial Cells And In Transgenic Mice
Funder
National Health and Medical Research Council
Funding Amount
$244,009.00
Summary
Tissue-type plasminogen activator (t-PA) is an enzyme which plays an important role in the removal of blood clots from the circulation. One of the major sites of production of t-PA are endothelial cells which line the blood vessel wall. The rate of t-PA production is greatly influenced by factors released from other cells. One of these factors is tumour necrosis factor (TNF). The t-PA gene is switched off in endothelial cells exposed to TNF. One of the aims of this project is to understand how t ....Tissue-type plasminogen activator (t-PA) is an enzyme which plays an important role in the removal of blood clots from the circulation. One of the major sites of production of t-PA are endothelial cells which line the blood vessel wall. The rate of t-PA production is greatly influenced by factors released from other cells. One of these factors is tumour necrosis factor (TNF). The t-PA gene is switched off in endothelial cells exposed to TNF. One of the aims of this project is to understand how the t-PA gene is suppressed by TNF in human endothelial cells and in transgenic mice. The transgenic mice we have available express the regulatory region of the t-PA gene (called the gene promoter) connected to a reporter gene called LacZ. We will use these animals to visualise the expression pattern of LacZ expression under normal conditions and in mice treated with TNF. The results of these experiments will provide new information as to how the t-PA gene is controlled in cells and in the body.Read moreRead less
Epigenetic Silencing Of Retroelements In Mammalian Stem Cells: A Role For RNA Interference?
Funder
National Health and Medical Research Council
Funding Amount
$296,980.00
Summary
Now that the human genome has been sequenced, all the genes which encode the bricks and mortar of our cells have been defined. A major question remains: how are all these genes controlled and co-ordinated? What turns them on or off at precisely the right time? In this project we wish to test whether a newly-discovered mechanism of turning genes off in plants and flies also works in mammals. If we demonstrate this mechanism then it may help us to improve gene therapy - a novel form of medical tre ....Now that the human genome has been sequenced, all the genes which encode the bricks and mortar of our cells have been defined. A major question remains: how are all these genes controlled and co-ordinated? What turns them on or off at precisely the right time? In this project we wish to test whether a newly-discovered mechanism of turning genes off in plants and flies also works in mammals. If we demonstrate this mechanism then it may help us to improve gene therapy - a novel form of medical treatment in which healthy genes are used to replace defective genes in cells. Both inherited diseases, like hemophilia, and acquired diseases, like cancer, have been considered appropriate targets for gene therapies. Surprisingly, however, the promises of gene therapy have not kept up with expectations. In attempting to achieve clinically relevant results, viruses (masters of forcing infected cells to do their bidding) have been harnessed to deliver healthy genes into diseased cells. A major problem has been that the modified, safe viruses used clinically have not been efficient at achieving sustained production of healthy gene products. In examining the question of what turns gene off, we will attack the problem of sustainability of gene therapy by defining the mechanisms involved in switching gene therapy viruses off. If we can understand what switches viral genes off in cells, then we should be able to devise means to avoid the 'off switch' and thereby provide durable treatments for many types of cancer. In the studies described , we will attack this problem using a number of different, but complementary approaches.Read moreRead less
Translational Control Of Gene Expression And The Choice Between Cell Death And Proliferation
Funder
National Health and Medical Research Council
Funding Amount
$378,000.00
Summary
Proteins carry out most enzymatic and structural functions in a cell. Thus, the kinds of protein molecules that are found in a given cell determine its characteristics and cells respond to changes in their environment by adjusting the abundance of some or many proteins in their collection. The instructions for the assembly of proteins are encoded in the genes and this information is expressed via intermediary molecules called messenger (m)RNA. Both, transcription of the genes into mRNA molecules ....Proteins carry out most enzymatic and structural functions in a cell. Thus, the kinds of protein molecules that are found in a given cell determine its characteristics and cells respond to changes in their environment by adjusting the abundance of some or many proteins in their collection. The instructions for the assembly of proteins are encoded in the genes and this information is expressed via intermediary molecules called messenger (m)RNA. Both, transcription of the genes into mRNA molecules and their subsequent translation by the ribosomes into protein are tightly controlled steps in the gene expression pathway. Erroneous gene expression is a major factor in human disease and dysregulation of translation is linked to a growing spectrum of illnesses such as cancer and cardiovascular disease, viral infection, and less frequent hereditary syndromes. The project proposed here is prompted by emerging evidence for a role of translational regulation in controlling the balance between cell death and survival. Tipping this balance has disastrous consequences for an organism as evidenced by its involvement in many major disorders (e. g. stroke, heart failure, neurodegeneration, AIDS, cancer, autoimmunity). Our aim is to test the hypothesis that a putative translational regulator termed p97-DAP5-NAT1, and a specialised mechanism of translation initiation by internal ribosome entry are important for the maintenance of this balance. To investigate this, we will employ DNA chips, a novel tool from Genomics research that allows the measurement of the levels of thousands of mRNA molecules in a single experiment. It is conceivable that knowledge of these special mechanisms of translation will lead to novel targets for therapeutic intervention, and this work will contribute some of the experimental tools to explore these avenues in the future.Read moreRead less
Molecular And Cellular Studies Of The Copper-transporting ATPases Affected In Menkes And Wilson Diseases
Funder
National Health and Medical Research Council
Funding Amount
$558,300.00
Summary
Copper is an element that is essential for life but is highly toxic in excess. Because of this, the regulation of copper uptake, distribution in the body and excretion of excess is a very tightly regulated process. Until recently little was known about the molecular basis of this process. Two genetic disorders that show these two aspects of copper are Menkes disease (deficiency) and Wilson disease (toxicity). Both diseases are caused by mutations in similar copper pumping proteins. Our research ....Copper is an element that is essential for life but is highly toxic in excess. Because of this, the regulation of copper uptake, distribution in the body and excretion of excess is a very tightly regulated process. Until recently little was known about the molecular basis of this process. Two genetic disorders that show these two aspects of copper are Menkes disease (deficiency) and Wilson disease (toxicity). Both diseases are caused by mutations in similar copper pumping proteins. Our research is trying to establish the molecular mechanisms used in the body to control copper metabolism. We made a major breakthrough in 1993 with the isolation of the gene affected in Menkes disease, and we continue to be one of the leading groups in the world in studying the molecular mechanisms that handle copper, and the importance of these mechanisms in health and disease. Research into the biology of copper has become much more important following the recent discoveries of the involvement of the metal in such important neurodegenerative conditions such as Alzheimer's, Mad Cow, and Parkinson's diseases. Health effects from the lack of copper may be widespread also, copper deficiency is suspected to contribute to some common diseases, such as cardiovascular problems and osteoporosis. Our research is providing information about copper transport mechanisms that are necessary for the understanding of, and may lead to better treatment and diagnosis of common and important diseases. In this grant we propose to continue our studies into the molecular signals that control the copper pumps, that make the regulation of copper metabolism possible. We also will use various test systems for studying the effect of mutations on the activity of these proteins and relate these effects to the type of disease produced in patients.Read moreRead less
All cells in the blood are the descendants of a single cell type, the stem cell. Stem cells are found in the bone marrow and throughout life have the unique ability to generate more of themselves (termed self-renewal) as well as to produce the functional cell types of the blood, ie. red and white blood cells. This project concentrates on the processes by which these stem cells can achieve these two functions. What are the genes that enable a stem cell to have this self-renewal characteristic and ....All cells in the blood are the descendants of a single cell type, the stem cell. Stem cells are found in the bone marrow and throughout life have the unique ability to generate more of themselves (termed self-renewal) as well as to produce the functional cell types of the blood, ie. red and white blood cells. This project concentrates on the processes by which these stem cells can achieve these two functions. What are the genes that enable a stem cell to have this self-renewal characteristic and conversely what are the genes that are activated when a cell becomes committed to become, for example, a white blood cell ? We have identified a gene, Pax5, which is essential in the process whereby a stem cell commits to become a lymphocyte . Our aim is to understand the function of Pax5 as a model for understanding how the commitment process as a whole works in the blood. These studies, as well as having an underlying fundamental scientific importance, are relevant to the clinical development of a number of stem cell therapies which rely on boosting stem cell production in procedures such as bone marrow transplantation for leukaemia and immune deficiency. In addition a number of characterised human blood malignancies indicate that inappropriate lineage commitment may be a factor in cancer.Read moreRead less
Structure-function Analysis Of Nuclear Receptor And Cofactor Action: Evidence For A Role In Muscle.
Funder
National Health and Medical Research Council
Funding Amount
$692,040.00
Summary
Hormone receptors have critical roles in almost all aspects of physiology by transducing the effects of hormones into metabolic responses. There are ~45 orphan hormone receptors encoded by distinct genes in humans, since all receptors are important in the treatment of human disease, the plethora of orphan receptors has been the catalyst for the development of a new paradigm, reverse endocrinology. Reverse endocrinology is the process whereby the orphan hormone receptor is used to search for a pr ....Hormone receptors have critical roles in almost all aspects of physiology by transducing the effects of hormones into metabolic responses. There are ~45 orphan hormone receptors encoded by distinct genes in humans, since all receptors are important in the treatment of human disease, the plethora of orphan receptors has been the catalyst for the development of a new paradigm, reverse endocrinology. Reverse endocrinology is the process whereby the orphan hormone receptor is used to search for a previously unknown hormone, and metabolic pathway. We are interested in the orphan hormone receptors, Rev-erbA and RVR, orphan members of the receptor superfamily. Rev-erb alpha expression is regulated by fibrates, widely used hypolipidemic drugs, and the circadian cycle. Rev-erbs mediate the regulation of lipid metabolism and peroxisomal beta oxidation. Furthermore, Rev-erbs are acutely induced during brain seizures, postulated to regulate cerebellar plasticity, and involved in growth control. In view of these critical regulatory roles, and the success of reverse endocrinology to date, we intend to complete the structural analysis of the Rev-erb and RVR as a tool to identify the hormone that binds this receptor. Hormone receptors recruit proteins called nuclear receptor cofactors, that function as regulators of gene expression. The cofactors regulate gene expression and development. Furthermore these cofactors, when misregulated result in the onset of disease and carcinogenesis, which underscores the need for achieving a high resolution view of their function in many tissues. Along these lines, we are interested in exmining the function of these cofactors in muscle. Understanding the molecular role of the NR cofactors during muscle differentiation will be a critical step toward elucidating the dysregulation-function of these proteins in muscle diseases, such as rhabdomyosarcoma and inflammatory myopathy that have cofactor deficiency.Read moreRead less
Probing The Cellular Functions Of The Translation Factor P97
Funder
National Health and Medical Research Council
Funding Amount
$370,307.00
Summary
The protein p97 takes part in the synthesis of cellular proteins from messenger RNA, a central step in gene expression. We will characterise p97 function as cells progress through their cycle of growth and division, and during responses to stress. Cellular stress is important in many diseases, such as viral infection, diabetes, heart disease, cancer, or complications during major surgery. Knowledge of p97 function may help us to better understand and treat these diseases.