Enhancing Host Defence Against Intracellular Pathogens By Preventing INOS Interaction With A Negative Regulator, SSB-2
Funder
National Health and Medical Research Council
Funding Amount
$448,881.00
Summary
Secretion of nitric oxide (NO) gas by immune cells is a critical defence mechanism for the killing of intracellular pathogens. Production of NO within cells is regulated by the enzyme iNOS. We propose that preventing iNOS from interacting with its natural inhibitor protein (SSB-2) would allow enhanced and prolonged iNOS expression leading to increased NO and increased killing of pathogens such as the mycobacterium tuberculosis and the Leishmania parasite.
Regulation Of Gene Expression: Biomolecular Interactions In Cellular Development And Disease
Funder
National Health and Medical Research Council
Funding Amount
$2,998,713.00
Summary
This team consists of three of Australia�s younger researchers Merlin Crossley, Joel Mackay and Jacqui Matthews (as Chief Investigators), who are recognized as authorities in the areas of gene regulation and the structural and functional analysis of proteins. They are joined by Mitchell Weiss, a world authority on blood development and clinical disorders,and Alexis Verger, a molecular and cell biologist recruited from France, both as Principal Investigators. Crossley, Mackay and Matthews have wo ....This team consists of three of Australia�s younger researchers Merlin Crossley, Joel Mackay and Jacqui Matthews (as Chief Investigators), who are recognized as authorities in the areas of gene regulation and the structural and functional analysis of proteins. They are joined by Mitchell Weiss, a world authority on blood development and clinical disorders,and Alexis Verger, a molecular and cell biologist recruited from France, both as Principal Investigators. Crossley, Mackay and Matthews have worked as a team for around six years to date, have published together in high-quality international journals, and have received anumber of accolades for their contributions to Australian science. For example, Crossley has won a number of national awards, including the Gottschalk Medal of the Australian Academy of Science; Mackay was recently awarded the Prime Minister�s Prize for Life Scientist of the Year, and Matthews won the only Charles and Sylvia Viertel Medical Research Fellowship to be awarded in 2003. The members of this team have collaborated extensively on the world stage and Crossley, Mackay and Matthews have also taken leadership roles in the Australian scientific community. Mitchell Weiss has been an important collaborator, exchanging reagents and advice, since he and Crossley trained together as postdocs in Stu Orkin�s lab at Harvard in the early 90s. Most recently Weiss, in collaboration with Mackay, has made important discoveries on a-globin production, which has led to several highly significant publications including a seminal paper in Cell in 2004.The program of research put forward in this proposal centres around understanding the mechanisms through which genes are switched on and off, using blood development as a model system, that is also fundamental to human life. The regulation of gene output is essential both during the development of an organism and throughout the course of its life. Problems with this regulation can result in many different disease states, most notably cancer, which includes the many different types of leukemias. At one level, gene output is controlled by networks of specific proteins known as transcription factors that interact both with each other and with DNA. Currently, however, the details surrounding which complexes regulate which genes and the processes that control the making and breaking up of the complexes are not well understood. Knowledge of how these interactions take place will put us in a position to control the output of chosen genes for therapeutic purposes. We propose to use a combination of cell biological, biochemical, and structural approaches to firstly shed light on these complexes and secondly develop reagents that can be used to manipulate the activity of specific genes.Read moreRead less
Protein / Protein Interactions Important For AMP-activated Protein Kinase Regulation
Funder
National Health and Medical Research Council
Funding Amount
$242,545.00
Summary
The AMP-activated protein kinase (AMPK) is an enzyme that monitors the energy levels of the body. When oxygen and nutrient levels decrease, the energy levels of a cell also decrease leading to activation of the AMPK. This results in activation of energy-producing pathways and inhibition of energy-consuming pathways, allowing cells to match supply with demand to ensure their survival. The AMPK comprises of three proteins that together form a functional enzyme. In this application I aim to obtain ....The AMP-activated protein kinase (AMPK) is an enzyme that monitors the energy levels of the body. When oxygen and nutrient levels decrease, the energy levels of a cell also decrease leading to activation of the AMPK. This results in activation of energy-producing pathways and inhibition of energy-consuming pathways, allowing cells to match supply with demand to ensure their survival. The AMPK comprises of three proteins that together form a functional enzyme. In this application I aim to obtain a thorough understanding of the molecular basis of how the AMPK functions. I will determine how and where the three proteins interact with each other and determine where in a cell at any given time the AMPK can be found. This is an important question to answer because many proteins are inactive within the cytoplasm but when they are bound to the plasma membrane they are active. I have previously found the AMPK to be localized to the cytoplasm, membrane and nuclear compartments of the cell, but little is known about the AMPK s function in these different locations. Activation of the AMPK is known to depend on another protein that is also activated when cellular energy levels decrease. This protein has remained elusive to many researchers over the past few years. I plan to identify this protein using new bioinformatics together with the vast amount of information provided by the sequencing of the human genome. Exercise and reduced caloric intake activate the AMPK, these are associated with health benefits and reduce the risk of cardiovascular and neurodegenerative diseases, diabetes and obesity. For these reasons information on the role of the AMPK may improve our understanding of the reasons these diseases develop.Read moreRead less
Chromosomes are structures that carry genes in all our cells. Every human cell has 46 chromosomes. In the nucleus of eukaryotic cells, DNA is highly folded and compacted with specific proteins into a dynamic polymer called chromatin. Gene expression, chromosome division, DNA replication, and repair all act, not on DNA alone, but on this chromatin template. The discovery that enzymes can (re)organise chromatin into accessible and inaccessible configurations revealed mechanisms that considerably e ....Chromosomes are structures that carry genes in all our cells. Every human cell has 46 chromosomes. In the nucleus of eukaryotic cells, DNA is highly folded and compacted with specific proteins into a dynamic polymer called chromatin. Gene expression, chromosome division, DNA replication, and repair all act, not on DNA alone, but on this chromatin template. The discovery that enzymes can (re)organise chromatin into accessible and inaccessible configurations revealed mechanisms that considerably extend the information potential of the genetic code. In addition, it is now established that chromatin structural features can influence gene expression. In vitro studies support a model in which chromatin functions as a barrier for the access to DNA. Therefore this organization has to be tighly regulated and dynamic to allow the protein-DNA interactions critical for nuclear functions. Importantly genome organisation provides in addition to genetic information another layer of information, so called epigenetic, which by definition means that it is stably inherited throughout cellular divisions, yet it is not encoded genetically. Thus each cell type will display a specific epigenome. We have recently constructed small human minichromosomes, which are much easier to study than the much larger normal chromosomes. The present project proposes to define the epigenetic feature across an entire human chromosome using our minichhromosomes as working models. The outcome will be a significant gain in our knowledge on the processes underlying epigenetic regulation, the organisation of specialised chromatin domain, and behaviour of the chromosomes.Read moreRead less
Mechanisms By Which Chromatin Modulates Gene Expression.
Funder
National Health and Medical Research Council
Funding Amount
$267,750.00
Summary
Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important ....Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important function of chromatin is to tightly regulate gene expression which is essential to allow an organism to develop properly. When gene expression is not accurately controlled by chromatin developmental defects or cancer can result from the production of incorrect proteins. To control correct gene expression, highly specific mechanisms must operate in the cell to remove, or modify, nucleosomes at certain genes at a precise time during development. One mechanism that we believe to be important is changing the make-up of a nucleosome. This can be achieved in the cell by the replacement of histones with different specialized forms of these histones (variants). We believe that these histone variants can specifically generate chromosomal domains which could in some cases expose or in other cases hide certain genes and thereby turn them on or off. Employing a new approach, we will study one of these histone variants to discover the role it plays in determining the type of chromosomal domain made and the role of this domain has in turning genes on or off at precise times in early development during the formation of different specialized cell types. This new information may define targets for the prevention of incorrect gene expression during cancer progression or abnormal development.Read moreRead less
The Interactions Of Dengue Virus RNA Dependent RNA Polymerase (NS5) With Other Viral And Host Factors.
Funder
National Health and Medical Research Council
Funding Amount
$170,165.00
Summary
Dengue fever is a mosquito-borne disease that is prevalent in tropical countries. It is estimated that 40% of the global population is at risk of dengue infection. Classical dengue fever is not life threatening. However, the more serious disease, dengue haemorrhagic fever-shock syndrome requires intensive medical attention to prevent fatality. A significant number of deaths are recorded each year especially in the underdeveloped countries. Dengue is periodically also a problem in northern Austra ....Dengue fever is a mosquito-borne disease that is prevalent in tropical countries. It is estimated that 40% of the global population is at risk of dengue infection. Classical dengue fever is not life threatening. However, the more serious disease, dengue haemorrhagic fever-shock syndrome requires intensive medical attention to prevent fatality. A significant number of deaths are recorded each year especially in the underdeveloped countries. Dengue is periodically also a problem in northern Australia. There is no cure for dengue fever. The present research aims to use a knowledge-based approach to develop novel antiviral strategies based on preventing the critical protein interactions required for the normal virus life cycle. Two of the most important proteins involved in dengue virus replication are called the NS3 and NS5 proteins. The protein-protein interaction (contact) that occurs between NS5 and NS3 is crucial for the replication of the virus. Little is known about this interaction at present, and the studies we propose will directly address this issue. We have previously shown that a 37 amino acid in the middle of NS5 contains a nuclear localisation signal that can target the normally cytoplasmic protein to the nucleus of the infected cell. What the function of this protein is in the nucleus is not known. We will use a technique called the yeast two-hybrid test to address the question of dengue virus protein interactions in the common bakers yeast. This method is very sensitive and powerful and will provide important insights that will contribute to the development of a rapid high-throughput test to screen the extensive extract collection from Australia's marine biodiversity, held by the Australian Institute of Marine Sciences, to discover suitable inhibitors of NS3-NS5 interaction.Read moreRead less