A Functional Proteomics Approach To The Study Of Inducible Gene Transcription In A Chromatin Context.
Funder
National Health and Medical Research Council
Funding Amount
$452,310.00
Summary
Cells of the immune system detect assaults on the body such as infection, inflammatory or allergy-causing agents. Using a complex set of signaling pathways, the cells translate this information into a change in the pattern of expressed genes in those cells. These changes in gene expression occur rapidly and are generally transient. The changes that occur in gene expression pattern leads to functional changes in the cell that in turn are critical for the downstream events of the immune response. ....Cells of the immune system detect assaults on the body such as infection, inflammatory or allergy-causing agents. Using a complex set of signaling pathways, the cells translate this information into a change in the pattern of expressed genes in those cells. These changes in gene expression occur rapidly and are generally transient. The changes that occur in gene expression pattern leads to functional changes in the cell that in turn are critical for the downstream events of the immune response. One set of genes that is rapidly and transiently switched on in response to immune stimuli in T cells (one important immune cell type) are those that encode proteins known as cytokines. These cytokines function to send messages between cells thus activating downstream events of the immune response. Thus understanding the mechanism of how these genes are switched on and off is critical in understanding an immune response and in developing potential novel therapeutics based on gene transcription. Genes exist in the nucleus of the cell in the context of a complex structure known as chromatin. The process of RNA transcription from these genes, therefore, takes place in the context of this complex structure. While there have been many studies defining the molecular mechanisms that control the expression of cytokine genes, little attention has been paid to the role of chromatin in the inducible and transient nature of this gene transcription. This proposal addresses the molecular mechanisms by which inducible cytokine gene transcription occurs in a chromatin context. We will use both in vitro and in vivo approaches to probe the structure of chromatin that overlies these genes and the mechanism by which this structure is altered to allow the genes to be expressed.Read moreRead less
Regulation Of A Novel Target Gene, Aldehyde Dehydrogenase 1, By HOX11 In Childhood Leukaemia
Funder
National Health and Medical Research Council
Funding Amount
$382,027.00
Summary
Leukaemia is the most common cancer of childhood. Patients with the T-cell form of this disease (T-ALL), often carry specific chromosomal abnormalities that result in the activation of genes specifying transcription factors (TF's). TF's determine which genes are expressed in any given cell type, but when present in the wrong cell type at the wrong time may initiate cancer due to the combined activity of target genes under their control. The identification of target genes involved in cancer is th ....Leukaemia is the most common cancer of childhood. Patients with the T-cell form of this disease (T-ALL), often carry specific chromosomal abnormalities that result in the activation of genes specifying transcription factors (TF's). TF's determine which genes are expressed in any given cell type, but when present in the wrong cell type at the wrong time may initiate cancer due to the combined activity of target genes under their control. The identification of target genes involved in cancer is therefore essential in order to understand the mechanisms by which TF oncogenes induce tumour growth. However, very few target genes of TF's implicated in T-ALL have been discovered. HOX11 is one example of a TF aberrently expressed in childhood T-ALL. Recently we have shown that a gene called ALDH1 is under the control of HOX11 in a model cell system and also during normal development. The proper control of ALDH1 expression is important to the cell because it functions in the conversion of vitamin A to retinoic acid, a signalling molecule that critically affects cell growth and development. A related gene called RALDH2, that is also involved in retinoic acid synthesis, has very recently been shown to be under the control of other TF's implicated in T-ALL. These two discoveries therefore suggest that this disease may occur via a common pathway involving altered retinoic acid signalling. This project seeks to find out whether ALDH1 is also a target of HOX11 in T-ALL and if so, what effects it has on the cell. It also aims to determine how HOX11 influences the expression of ALDH1 and whether there are any other genes controlled by HOX11 that may be involved in tumour development. HOX11 provides an ideal model system to study the events leading to cancer that occur as a result of abnormal control of gene expression. Ultimately, such studies may lead to a better understanding of our normal biology as well as provide the basis for the design of improved cancer therapies.Read moreRead less
An X-ray Crystallographic Investigation Into The Structural Basis Of T-cell Allorecognition
Funder
National Health and Medical Research Council
Funding Amount
$441,000.00
Summary
X-ray crystallography is an essential tool for solving the three-dimensional (3-D) structure of proteins. Proteins control the biological processes within the cell and it is the exact shape of proteins that determines how they function. Each protein is made up like a string of beads, with the building units being amino acids. Depending on the sequence of the amino acids, the protein molecule bends and forms a distinct, complex shape. This three dimensional shape allows it to specifically interac ....X-ray crystallography is an essential tool for solving the three-dimensional (3-D) structure of proteins. Proteins control the biological processes within the cell and it is the exact shape of proteins that determines how they function. Each protein is made up like a string of beads, with the building units being amino acids. Depending on the sequence of the amino acids, the protein molecule bends and forms a distinct, complex shape. This three dimensional shape allows it to specifically interact with carbohydrates, other proteins, such as enzymes or receptors, or even with molecules like DNA, to have its effect. To determine how a protein acts, it is vital to know the precise three-dimensional shape of a protein at the atomic level. This work is focused on understanding the precise shape of proteins that control the immune system. The immune system is avital process whereby individuals can fight off disease. This work will further our understanding of the immune system.Read moreRead less
Role Of NF-kB Recruited SWI/SNF Chromatin Remodeling Complexes In Inducible Gene Expression In T Cells
Funder
National Health and Medical Research Council
Funding Amount
$243,500.00
Summary
The immune system consists of a group of cell types, including T cells, which are capable of recognising foreign agents and eradicating them from the body. T cells are activated by foreign antigen and respond by producing an array of soluble factors including cytokines, which act as communicators between cells. The correct expression of these factors is critical for the maintenance and function of the immune system, and is therefore tightly regulated. The genes encoding these factors are general ....The immune system consists of a group of cell types, including T cells, which are capable of recognising foreign agents and eradicating them from the body. T cells are activated by foreign antigen and respond by producing an array of soluble factors including cytokines, which act as communicators between cells. The correct expression of these factors is critical for the maintenance and function of the immune system, and is therefore tightly regulated. The genes encoding these factors are generally maintained in an 'inactive' state but are switched on rapidly when required. Within the cell, genes or DNA are found wrapped up in a complex protein structure called chromatin which plays an important role in regulating gene expression. Chromatin forms a barrier to active gene expression which must be overcome before the gene can be switched on. There are protein complexes within the cell that are able to alter or remodel chromatin structure from an 'inactive' to an 'active' state. We are investigating one of these chromatin remodeling complexes to determine which genes it is able to switch on and how it targets these particular genes. Aberrant gene expression within T cells contributes to a range of diseases including certain leukemias and inflammatory conditions such as asthma and rheumatoid arthritis. Understanding the events and protein complexes involved in switching on specific genes in T cells will potentially identify molecules which can be targeted in an effort to control inappropriate gene expression in these disease states.Read moreRead less
Cytoskeletal Regulation Of Adhesion Structure And Cell Movement
Funder
National Health and Medical Research Council
Funding Amount
$60,420.00
Summary
Metastatic (secondary) cancers are a frequent cause of patient mortality. Central to the development of metastasis is cell motility-movement. A key component of cell movement is the way that cells bind and release the extra-cellular matrix as they move. By understanding how the dynamics of cell interaction with the matrix are regulated, we will identify molecules that are critical to the development of metastatic cancer and thus novel targets for inhibition of metastasis.
The effect of nitrogen monoxide on intracellular iron metabolism. We discovered that the crucial signalling molecule nitrogen monoxide (NO) mediates iron (Fe) and glutathione (GSH) release by the transporter MRP1 probably as an NO-Fe-GSH complex [DR(2006) PNAS USA 103:7670-5]. During our current ARC grant we have markedly extended these findings by showing that another molecule, GST Pi and MRP1 form part of a coordinated system that stores and transports NO as complexes of Fe and GSH, markedly e ....The effect of nitrogen monoxide on intracellular iron metabolism. We discovered that the crucial signalling molecule nitrogen monoxide (NO) mediates iron (Fe) and glutathione (GSH) release by the transporter MRP1 probably as an NO-Fe-GSH complex [DR(2006) PNAS USA 103:7670-5]. During our current ARC grant we have markedly extended these findings by showing that another molecule, GST Pi and MRP1 form part of a coordinated system that stores and transports NO as complexes of Fe and GSH, markedly extending NO half-life from milliseconds to hours. This has broad implications for understanding NO activity in many processes which have major vital health implications, including tumour cell killing by macrophages and blood pressure control.Read moreRead less
The Effect of Nitrogen Monoxide on Intracellular Iron Metabolism. For the first time, we discovered that nitric oxide (NO) is actively transported from cells by a protein that is known to also transport glutathione (GSH). This is important, as NO was thought to passively diffuse from cells. Active transport overcomes the problems of diffusion which is inefficient and non-targeted. Moreover, NO is released as a complex with iron and GSH which markedly increases its half-life. These findings have ....The Effect of Nitrogen Monoxide on Intracellular Iron Metabolism. For the first time, we discovered that nitric oxide (NO) is actively transported from cells by a protein that is known to also transport glutathione (GSH). This is important, as NO was thought to passively diffuse from cells. Active transport overcomes the problems of diffusion which is inefficient and non-targeted. Moreover, NO is released as a complex with iron and GSH which markedly increases its half-life. These findings have broad implications for understanding the activity of NO in many processes which have major health implications, including tumour cell killing by macrophages, blood pressure etc.Read moreRead less
The effect of nitrogen monoxide on intracellular iron metabolism. During our current ARC grant we discovered a novel relationship between energy metabolism and NO-mediated Fe efflux and showed that glutathione (GSH) is vital for this release mechanism (DR5,6). Intriguingly, this transport process is part of the cytotoxic effector machinery of activated macrophages against tumours, and requires further elucidation. We also showed that CO affects Fe metabolism by binding to Fe, and CO may modulate ....The effect of nitrogen monoxide on intracellular iron metabolism. During our current ARC grant we discovered a novel relationship between energy metabolism and NO-mediated Fe efflux and showed that glutathione (GSH) is vital for this release mechanism (DR5,6). Intriguingly, this transport process is part of the cytotoxic effector machinery of activated macrophages against tumours, and requires further elucidation. We also showed that CO affects Fe metabolism by binding to Fe, and CO may modulate NO's function. We will:-
(1) Examine if NO-mediated Fe release results in GSH efflux
(2) Identify the mechanism of NO-mediated Fe efflux.
(3) Assess the effect of inducing haem oxygenase 1 on Fe metabolism
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The Dynamics of Plant Cell Division-Discovering the Mechanisms of Organelle Inheritance. This project seeks to understand molecular mechanisms responsible for organelle partitioning in dividing plant cells. Understanding these mechanisms will contribute new knowledge relevant to plant biotechnology (eg chloroplast transformation, cytoplasmic male sterility, plant development and totipotency) and thus to Australian agriculture broadly. This project will enhance Australian research capacity in the ....The Dynamics of Plant Cell Division-Discovering the Mechanisms of Organelle Inheritance. This project seeks to understand molecular mechanisms responsible for organelle partitioning in dividing plant cells. Understanding these mechanisms will contribute new knowledge relevant to plant biotechnology (eg chloroplast transformation, cytoplasmic male sterility, plant development and totipotency) and thus to Australian agriculture broadly. This project will enhance Australian research capacity in the fields of organelle inheritance and plant cytoskeletal dynamics and thus will maintain Australia's leading reputation in these fields. In addition, the project will maintain a high quality and productive research environment capable of providing excellent research training for new scientists in this field. Read moreRead less
Regulation And Function Of The Protein Tyrosine Phosphatase TCPTP In Mitosis
Funder
National Health and Medical Research Council
Funding Amount
$455,250.00
Summary
The cell cycle is a universal process by which cells reproduce and it underlies the growth and development of all living organisms. The most important events of the cell cycle concern the replication of chromosomal DNA during S phase and the separation of replicated DNA into progeny cells at mitosis. Mitosis is morphologically the most dynamic phase of the cell cycle and involves the precise coordination of many processes that are governed by reversible protein phosphorylation. Protein phosphata ....The cell cycle is a universal process by which cells reproduce and it underlies the growth and development of all living organisms. The most important events of the cell cycle concern the replication of chromosomal DNA during S phase and the separation of replicated DNA into progeny cells at mitosis. Mitosis is morphologically the most dynamic phase of the cell cycle and involves the precise coordination of many processes that are governed by reversible protein phosphorylation. Protein phosphatases play an important role in reversible protein phosphorylation and they are essential for mitosis. This grant proposal is focused on understanding the regulation and function of protein phosphatases in mitosis. Our studies will provide novel insight into processes mediating mitosis and may lead to the development of alternative strategies for treating cancer.Read moreRead less