Biochemical, Genomic and Phenomic Analysis of Gastric Parietal Cells from Wildtype and Mutant Mice. The interface between the cell and its environment is the cell membrane. Signals, nutrients, and ions all have to cross this barrier. In addition, the cells contain many specialized intracellular membranous compartments. We know little about the signals that direct the synthesis of these structures and determine their final composition and shape. This grant will utilize acid secretory cells in the ....Biochemical, Genomic and Phenomic Analysis of Gastric Parietal Cells from Wildtype and Mutant Mice. The interface between the cell and its environment is the cell membrane. Signals, nutrients, and ions all have to cross this barrier. In addition, the cells contain many specialized intracellular membranous compartments. We know little about the signals that direct the synthesis of these structures and determine their final composition and shape. This grant will utilize acid secretory cells in the stomach to examine these questions because they contain a very extensive membrane system. We will use a state-of-the-art genetic and cell biological technologies to manipulate and analyse these cells in a whole animal setting.Read 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
Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will cap ....Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will capitalize on our progress in describing the functional genetics of this process and aims to elucidate the mechanism of active CO2 uptake and the way that cells sense the ambient CO2 concentration. The information gained is likely to be useful for designing improved crops.Read moreRead less
The role of mechanosensitive (MS) ion channels in magnetoreception. The magnetic field of the Earth has for long been known to influence the behaviour and orientation of a variety of organisms. Experimental study of the magnetic sense has however, been impaired by the lack of a plausible cellular and/or molecular mechanism providing meaningful explanation for detection of magnetic fields by living organisms. Recently, mechanosensitive (MS) ion channels have been implied to play a role in magneto ....The role of mechanosensitive (MS) ion channels in magnetoreception. The magnetic field of the Earth has for long been known to influence the behaviour and orientation of a variety of organisms. Experimental study of the magnetic sense has however, been impaired by the lack of a plausible cellular and/or molecular mechanism providing meaningful explanation for detection of magnetic fields by living organisms. Recently, mechanosensitive (MS) ion channels have been implied to play a role in magnetoreception. Based on our preliminary investigations, which suggest that the activity of bacterial MS channels may be affected by magnetic fields, we propose to study effects of magnetic fields on MS ion channels in Gram-negative bacteria Escherichia coli and Magnetospirillum magnetotacticum. The project promises also to contribute towards better understanding of adverse effects of electromagnetic radiation on human health and towards understanding the mechanisms behind remote magnetic-nanoparticle mediated activation of MS ion channels.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.
A study of the nongenomic action of Vitamin D: proposed role of the nuclear VDR and downstream signalling molecules. Vitamin D (1,25D) activates genes in the nucleus through the vitamin D receptor (VDR). 1,25D can also elicit rapid responses at the plasma membrane. This action is critical to the activation of nuclear genes. We hypothesise that a proportion of the nuclear VDR is located at the plasma membrane where it stimulates downstream signalling molecules eg Ras, ERK1/2 and ERK5. We plan to ....A study of the nongenomic action of Vitamin D: proposed role of the nuclear VDR and downstream signalling molecules. Vitamin D (1,25D) activates genes in the nucleus through the vitamin D receptor (VDR). 1,25D can also elicit rapid responses at the plasma membrane. This action is critical to the activation of nuclear genes. We hypothesise that a proportion of the nuclear VDR is located at the plasma membrane where it stimulates downstream signalling molecules eg Ras, ERK1/2 and ERK5. We plan to explore this hypothesis and to identify the signalling molecules. We will also investigate our novel finding that a specific Ras isoform is involved in ERK5 activation. The work will provide new information on signalling pathways.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
Ribonucleic acid (RNA)-binding proteins regulate protein targeting and organelle biosynthesis. We will investigate a new paradigm in biology: the coordination of protein expression in space and time. Detailed knowledge will be gained about proteins that perform important roles in ensuring the proliferative potential of cells an essential aspect of stem cell biology, regenerative medicine and development of cancer. The study combines skills in several aspects of genetics, biochemistry and molecul ....Ribonucleic acid (RNA)-binding proteins regulate protein targeting and organelle biosynthesis. We will investigate a new paradigm in biology: the coordination of protein expression in space and time. Detailed knowledge will be gained about proteins that perform important roles in ensuring the proliferative potential of cells an essential aspect of stem cell biology, regenerative medicine and development of cancer. The study combines skills in several aspects of genetics, biochemistry and molecular cell biology and will therefore provide excellent training opportunities for PhD students and postdoctoral fellows in an internationally highly competitive field of research.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.
Expression and characterisation of nutrient transporters from the intracellular malaria parasite, Plasmodium falciparum. The malaria parasite invades the red blood cells of its host and this provides it with a safe haven in which to grow and replicate. Within the red blood cell, the parasite takes up nutrients and excretes metabolic wastes via specialised membrane transport proteins which are, as yet, very poorly understood. The sequencing of the malaria parasite genome has enabled us to ident ....Expression and characterisation of nutrient transporters from the intracellular malaria parasite, Plasmodium falciparum. The malaria parasite invades the red blood cells of its host and this provides it with a safe haven in which to grow and replicate. Within the red blood cell, the parasite takes up nutrients and excretes metabolic wastes via specialised membrane transport proteins which are, as yet, very poorly understood. The sequencing of the malaria parasite genome has enabled us to identify candidates for a wide variety of these proteins. The aim of this project is to establish systems in which the functional properties of these transporter proteins may be characterised in detail.Read moreRead less