The Role Of The Microphthalmia Transcription Factor Family In Macrophage Differentiation.
Funder
National Health and Medical Research Council
Funding Amount
$367,193.00
Summary
Macrophages are large white blood cells that are also found in all the tissues of the body. They are a major part of the front line defence against infection and malignancy, but they also cause much of the pathology of many diseases particularly those in which there is chronic inflammation. Macrophages, like all the cells of the blood, are produced from the bone marrow. In the process of macrophage production a suite of genes must be switched on so that the mature macrophage can carry out its fu ....Macrophages are large white blood cells that are also found in all the tissues of the body. They are a major part of the front line defence against infection and malignancy, but they also cause much of the pathology of many diseases particularly those in which there is chronic inflammation. Macrophages, like all the cells of the blood, are produced from the bone marrow. In the process of macrophage production a suite of genes must be switched on so that the mature macrophage can carry out its functions. This project aims to understand the process of selective gene expression in macrophages. It is based upon the identification of four members of a gene family, called the microphthalmia gene family, as candidate master genes that control the overall process of macrophage production. We seek to understand how the products of genes interact.Read moreRead less
Functional Characterisation Of Regulators Of Human Globin Gene Switching
Funder
National Health and Medical Research Council
Funding Amount
$232,131.00
Summary
Red blood cells produce haemoglobin, a tetramer of two alpha globin chains and two beta-globin chains. Haemoglobin reversibly interacts with oxygen in such a way that it efficiently shuttles oxygen between the lungs and the rest of the body. Integrity of the hemoglobin molecule, and red cells which carry it, is essential for life of all organisms with blood. The alpha-globin and beta-globin chains that make up haemoglobin are prodcued by red cell precursors in the bone marrow according to the ge ....Red blood cells produce haemoglobin, a tetramer of two alpha globin chains and two beta-globin chains. Haemoglobin reversibly interacts with oxygen in such a way that it efficiently shuttles oxygen between the lungs and the rest of the body. Integrity of the hemoglobin molecule, and red cells which carry it, is essential for life of all organisms with blood. The alpha-globin and beta-globin chains that make up haemoglobin are prodcued by red cell precursors in the bone marrow according to the genetic blueprint (genes) that are inherited. Genetic disorders resulting from defects in the beta-globin gene are the most common inherited disorders of man. Children who fail to make beta-globin have a disease known as beta-thalassaemia. They are transfusion dependent from ~ 6 months of age and need intensive chelation therapy (infusions) to avoid the serious consequnces of iron overload. The average life expectancy in Western cultures is ~ 30 years. There is no cure. In third world countries where a reliable blood supply is unavailable, death occurs earlier. Patients are aften infected with blood born viruses such as hepatitis B, hepatitis C and the AIDS virus, HIV. Sickle cell anaemia is also a very common disease. It is due to a single DNA base mutation at in the beta-globin gene that results in production of normal amounts of a defective beta-globin molecule (HbS). In low oxygen, HbS molecules polymerize in red cells and irreversibly damage them. These red cells get trapped in small blood capillaries throughout the circulation causing small infarcts which results in severe pain and organ damage. The life expectancy is <2 years in the thrid world and ~20-30 years in the west. The irony of these two diseases is that there is a perfectly normal fetal globin gene that has been silenced during fetal life. This grant aims to understand the mechanism of the switch from fetal to adult globin gene usage so it can be reversed in adults with b-thalassemia and sickle cell diseaseRead moreRead less
Functional Analysis Of The P160 Myb-binding Protein - A Regulator Of Multiple Transcription Factors?
Funder
National Health and Medical Research Council
Funding Amount
$376,697.00
Summary
The c-myb gene is a key molecular regulator of normal blood cell production, but alterations to this gene can also lead to leukaemia. The protein (Myb) encode by the c-myb gene acts as a transcription factor, ie, it controls the activity of other genes. There is good evidence that interactions with other proteins can regulate the activity of Myb. Our laboratory has identified what we believe is one such protein - p160 - that binds to a part of Myb that reduces its activity, and thus that is like ....The c-myb gene is a key molecular regulator of normal blood cell production, but alterations to this gene can also lead to leukaemia. The protein (Myb) encode by the c-myb gene acts as a transcription factor, ie, it controls the activity of other genes. There is good evidence that interactions with other proteins can regulate the activity of Myb. Our laboratory has identified what we believe is one such protein - p160 - that binds to a part of Myb that reduces its activity, and thus that is likely to be responsible for regulating Myb. However, it has recently become apparent that p160 interacts with a number of other transcription factors in addition Myb. The primary aim of this project is to elucidate precisely how p160 interacts with Myb and what the consequences of this interaction are. A range of experimental approaches, which range from in vitro to genetic studies, will be employed to do this. We will test a specific role of p160 suggested by our preliminary studies - that of a transporter of transcription factors between the nucleus and the cytoplasm of the cell. Because of the wide range of transcription factors that p160 interacts with, its effects on the function of the cell are likely to be profound. For this same reason, it is difficult to specifically predict the possible medical-health implications of this work However, what we know to date is consistent with a role for p160 as a tumour suppressor gene. Moreover, parts of this project aim to generate genetic information and tools which will help in determining whether p160 does play such a role and generally, in identifying any other associations of p160 with particular diseases.Read moreRead less
Regulation Of Adult Colonic Crypt Homeostasis And Activation Of Colon Cancer Metastasis Genes By C-Myb
Funder
National Health and Medical Research Council
Funding Amount
$666,116.00
Summary
Regulation of normal colon biology and activation of genes involved colon cancer The c-myb gene is essential for the normal biology of the blood system and the colon. This gene is involved in regulating the balance between the production of new cells and their timely removal once they have completed their assigned tasks. There is a large body of evidence that supports the role of c-myb in the regulation of the blood system. We believe that the rules that govern the production of the huge number ....Regulation of normal colon biology and activation of genes involved colon cancer The c-myb gene is essential for the normal biology of the blood system and the colon. This gene is involved in regulating the balance between the production of new cells and their timely removal once they have completed their assigned tasks. There is a large body of evidence that supports the role of c-myb in the regulation of the blood system. We believe that the rules that govern the production of the huge number of cells needed to have a healthy blood system are similar if not identical to the rules used by the colon. This is because the colon also produces a massive number of cells each with special tasks and a defined life span of a few days. It is this rapid expansion of cell numbers and the programmed short life span of cells that necessitates multiple controls and very tight regulation. Furthermore if this process is hijacked by genetic changes that undermine these controls then there are numerous opportunities to initiate and potentiate malignant change or cancer. This project examines the role of the same genes in two contexts. Firstly when the genes are expressed at normal, highly regulated levels associated with the normal biology of the colon. The second context is when these genes are permitted to be over-expressed and thus drive processes for longer or in inappropriate situations leading to malignant growth.Read moreRead less
A Structural And Functional Basis For The Regulation Of Gene Expression By Nuclear Retention Of RNA
Funder
National Health and Medical Research Council
Funding Amount
$504,097.00
Summary
The nuclear retention mechanism is a novel way used by cells to control which genes are made into proteins - a fundamental process for all diseases, particularly cancers. This project will employ cutting edge structural and proteomic techniques to determine the molecular details underpinning nuclear retention. These insights will be important for the development of new tissue-restricted gene therapy applications and drugs targeting the cancers that rely on this mechanism.
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
Post-transcriptional Regulation Of Plasminogen Activator Inhibitor 2 Gene Expression
Funder
National Health and Medical Research Council
Funding Amount
$508,838.00
Summary
Plasminogen activator inhibitor type 2 (PAI-2) is a protease inhibitor that has intracellular and extracellular functions. The PAI-2 gene is highly regulated at the level of PAI-2 mRNA stability. We have identified regions within the PAI-2 transcript essential for this regulation and a number of novel proteins that engage these regions. This project is aimed at understanding how these and other proteins control PAI-2 expression at the mRNA level.
Functional Analysis Of Human MC1R Polymorphisms In Directing Melanocyte Phenotype
Funder
National Health and Medical Research Council
Funding Amount
$361,527.00
Summary
Sunsmart campaigns are a unifying element in the lives of many Australians who wish to ensure protection against the damaging effects of ultraviolet rays in sunlight. Indeed, Australians have the highest incidence of UV-induced melanoma in the world. Although it is evident that lighter skin colours are more susceptible to sun damage, the relationship between sun exposure, skin type and melanoma formation is less clear. An essential first step in understanding the complex interactions that give r ....Sunsmart campaigns are a unifying element in the lives of many Australians who wish to ensure protection against the damaging effects of ultraviolet rays in sunlight. Indeed, Australians have the highest incidence of UV-induced melanoma in the world. Although it is evident that lighter skin colours are more susceptible to sun damage, the relationship between sun exposure, skin type and melanoma formation is less clear. An essential first step in understanding the complex interactions that give rise to melanoma, and in identifying individuals that have a high susceptibility, is to reduce phenotypic analyses to genotypic classifications. As pigmentation phenotype is a factor of central importance in determining an individuals risk for melanoma, characterisation of the genes underlying the physical qualities of human eye, hair and skin colour will give a more direct and accurate genotypic assessment of risk. Results from an epidemiology study of melanoma patients in Queensland have identified a number of genetic changes within the melanocyte stimulating hormone receptor (MC1R) gene that associate with skin, hair and eye colour as well as with incidence of melanoma. Further investigation of MC1R gene alleles which segregate with skin and hair colours will provide the beginning for a whole new genotype-based classification of skin colour and melanoma risk, and will significantly contribute to our understanding of what makes some individuals highly susceptible to melanoma while others are not. Indeed, MC1R polymorphisms may numerically be the most important melanoma predisposition gene yet identified, exerting its effects as one of those common genes of small effect which may account for much more of the case load in melanoma than rarer genes of large effect. Studies such as this will enable powerful genotyping methods to be employed in identification of those individuals at highest risk for melanoma and other skin cancers.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