The balance between cell division and programmed cell death is crucial for normal development, maintenance of homeostasis, and immune system function. Inappropriately regulated cell death contributes to the pathogenesis of a wide variety of human diseases including neurodegenerative disorders, autoimmune syndromes and several forms of cancer. Death receptors such as Fas and TNFR1 are cell-surface sensors that trigger cellular destruction by apoptosis in response to specific extracellular death s ....The balance between cell division and programmed cell death is crucial for normal development, maintenance of homeostasis, and immune system function. Inappropriately regulated cell death contributes to the pathogenesis of a wide variety of human diseases including neurodegenerative disorders, autoimmune syndromes and several forms of cancer. Death receptors such as Fas and TNFR1 are cell-surface sensors that trigger cellular destruction by apoptosis in response to specific extracellular death signals. Recent studies have demonstrated that the mechanisms of signal transduction through Fas and TNFR1 differ significantly, however, they both require the adaptor protein FADD to induce apoptosis. In this study we will elucidate the molecular basis of the interactions between FADD and its binding partners using biochemical and biophysical studies. This research will improve our understanding of death receptor-induced apoptosis and the differences in signalling mechanisms. A detailed knowledge of these aspects of death receptor signalling is of significance because they represent critical regulatory steps that could be useful for targeted interventions.Read moreRead less
Structure And Function Of The Alternative Splicing Factor ZNF265
Funder
National Health and Medical Research Council
Funding Amount
$509,017.00
Summary
Now that the human genome has been sequenced, we can see that a human being is defined bye approximately 30000 genes. One of the biggest surprises to come from this work was that the number of genes was significantly smaller than many predicted. Similar surprise was registered at the discovery that the genome of the fruit fly actually contained fewer genes than that of the model worm, Caenorhabditis elegans. Part of the explanation for these apparent discrepencies lies in the phenomenon known as ....Now that the human genome has been sequenced, we can see that a human being is defined bye approximately 30000 genes. One of the biggest surprises to come from this work was that the number of genes was significantly smaller than many predicted. Similar surprise was registered at the discovery that the genome of the fruit fly actually contained fewer genes than that of the model worm, Caenorhabditis elegans. Part of the explanation for these apparent discrepencies lies in the phenomenon known as gene splicing, whereby one gene can actually give rise to many different isoforms of the same protein. These different isoforms can have different structures and-or functions, and dramatically increase the complexity that it is possible for an organism to achieve with a given number of genes. The process of splicing is very intricate, requiring precise control to allow an organism to develop normally. Many human genetic diseases are known to arise from problems with splicing. However, our understanding of the mechanisms of splicing is rather incomplete. This proposal aims to improve our understanding of the splicing process through a range of biophysical and molecular biological approaches. This information should prove useful in understanding human development and disease.Read moreRead less
Deciphering The Molecular Basis Of SM Regulation Of Exocytosis
Funder
National Health and Medical Research Council
Funding Amount
$515,564.00
Summary
Diabetes, obesity, heart disease and physical inactivity are major and escalating health problems within western societies. These problems are all linked to, or aggravate, the condition known as insulin resistance. Insulin resistance occurs when normal levels of insulin are insufficient to remove glucose from the blood. In the normal situation, insulin regulates glucose uptake into muscle and fat cells by stimulating the movement of a glucose transport protein from inside the cell to the cell su ....Diabetes, obesity, heart disease and physical inactivity are major and escalating health problems within western societies. These problems are all linked to, or aggravate, the condition known as insulin resistance. Insulin resistance occurs when normal levels of insulin are insufficient to remove glucose from the blood. In the normal situation, insulin regulates glucose uptake into muscle and fat cells by stimulating the movement of a glucose transport protein from inside the cell to the cell surface. The trafficking of this protein is somehow disrupted in insulin resistance. The purpose of this research is to follow up our exciting preliminary results on this system to shed light on the molecular processes that regulate the trafficking of the glucose transporter. Information resulting from our studies will lead to a better understanding of insulin-stimulated glucose transport and may also unravel the details of a related cellular secretion system that regulates neurotransmission. Our hope is that by understanding at the molecular level how cells regulate secretion, we can in the future develop therapeutics to counteract many of today s major health problems.Read moreRead less
Cells must regulate the flow of ions and water across their membranes in order to survive and function normally. The balance of ions and water is controlled by ion channels - proteins that control the permeability of the cell membrane. Of the ion channels, chloride channels are the most abundant in cells. They are central to the functioning of normal cells as well as playing a key role in many disease states. Our group was the first to identify and characterise a new class of chloride channel wh ....Cells must regulate the flow of ions and water across their membranes in order to survive and function normally. The balance of ions and water is controlled by ion channels - proteins that control the permeability of the cell membrane. Of the ion channels, chloride channels are the most abundant in cells. They are central to the functioning of normal cells as well as playing a key role in many disease states. Our group was the first to identify and characterise a new class of chloride channel which plays a key roles in the regulation of the immune system. These channels are unusual in that they can move between two states: a soluble state and a state that resides in the cell membrane. We have determined the first structures of this class of channel in both the soluble state and what is believed to be the membrane docking state. This has given us the first atomic picture of how this channel protein can alter its structure so as to carry out its function. In this project, we will determine: how the protein completes the transition into the membrane state; the structures of other key members of this class of channel protein; complexes between channel proteins and other cellular proteins; and the structure of the protein in the membrane state. We will also determine how several drugs control the activity of this channel. The results of our work will have specific implications for our channel and will serve as a paradigm other members of this new class of chloride channel. Understanding how this channel functions and how the current drugs control it will lead to the development of a new class of therapeutic agents that will control these channels by preventing the transition from the soluble to the membrane state.Read moreRead less
Structural Characterisation Of A Natural Inhibitor Of Sporulation Bound To Its Histidine Kinase Target
Funder
National Health and Medical Research Council
Funding Amount
$261,000.00
Summary
Many bacteria, including some which are virulent pathogens such as anthrax (Bacillus anthracis), are able to enter a dormant state by forming spores (sporulation). These spores are extremely robust and may persist in the environment buried in the soil for example for hundreds of years. The initiation of sporulation occurs in response to changes in the cellular and environmental conditions which threaten the free replicating existence of the bacterium. The process of sporulation is controlled at ....Many bacteria, including some which are virulent pathogens such as anthrax (Bacillus anthracis), are able to enter a dormant state by forming spores (sporulation). These spores are extremely robust and may persist in the environment buried in the soil for example for hundreds of years. The initiation of sporulation occurs in response to changes in the cellular and environmental conditions which threaten the free replicating existence of the bacterium. The process of sporulation is controlled at the molecular level by a complex signaling relay. It is of course vital for the existence of the organism that control of sporulation is tightly regulated - preventing the onset of spore-formation in any but the desired circumstances. We aim to determine the three-dimensional structures of the molecules involved in this regulated process and how, by interacting with each other, they can pass on the signal to the bacterium to either start or stop the spore forming process. Ultimately, the results of this work might lead to antibacterial agents which could be used to control particularly dangerous strains of bacteria.Read moreRead less
Structural And Drug Discovery Studies Of Oxidative Stress Regulator, Thioredoxin-interacting Protein
Funder
National Health and Medical Research Council
Funding Amount
$288,210.00
Summary
Toxic oxygen molecules known as Reactive Oxygen Species (ROS) are by-product of normal metabolism. The excess of ROS is damaging and is well known to contribute to ageing process and age-related diseases such as cancer, diabetic complications, immune-system decline, and cardiovascular conditions to name a few. The human body possesses several defense systems that protect us from the excess of ROS maintaining a healthy level of ROS. A down-regulator of one of this systems, a protein called TXNIP, ....Toxic oxygen molecules known as Reactive Oxygen Species (ROS) are by-product of normal metabolism. The excess of ROS is damaging and is well known to contribute to ageing process and age-related diseases such as cancer, diabetic complications, immune-system decline, and cardiovascular conditions to name a few. The human body possesses several defense systems that protect us from the excess of ROS maintaining a healthy level of ROS. A down-regulator of one of this systems, a protein called TXNIP, has been recently discovered. The amount of TXNIP is increased in such conditions as high glucose, a first sign of diabetes, and under ischemia, a shortage of blood supply occurring during heart attack. This weakens the anti-oxidant defense systems and makes the organism more vulnerable to ROS exposure. Our team of researchers embarked on structural and functional studies of TXNIP with the purpose to identify small molecules that can interfere with the undesirable action of TXNIP. These molecules might become useful therapeutic agents to counteract weakening organism's ROS defense system caused by TXNIP in many disease conditions such as, cancer, diabetes and cardiac failure.Read moreRead less
Structure And Interactions Of The Malarial Vaccine Candidate AMA1
Funder
National Health and Medical Research Council
Funding Amount
$351,000.00
Summary
Malaria remains one the most lethal infectious diseases in the world today. It is directly responsible for 1-2 million deaths annually, many of these in children under 5 years of age. More than 300 million clinical cases are reported annually and over 40% of the global population (in excess of 2 billion people) are at risk. There is an urgent need for a vaccine against this disease, particularly because of the recent increase in forms of the parasite resistant to many of the best anti-malarial d ....Malaria remains one the most lethal infectious diseases in the world today. It is directly responsible for 1-2 million deaths annually, many of these in children under 5 years of age. More than 300 million clinical cases are reported annually and over 40% of the global population (in excess of 2 billion people) are at risk. There is an urgent need for a vaccine against this disease, particularly because of the recent increase in forms of the parasite resistant to many of the best anti-malarial drugs. AMA1 is an asexual stage antigen and a leading vaccine candidate. Little is known about the function of this protein, but it has been proposed to play a role in invasion of red blood cells. A clearer understanding of the structure of parasite antigens such as AMA1 that induce a protective response in infected individuals would provide a stimulus to research into recombinant antigens as vaccines and a deeper understanding of host-parasite interactions. The aims of this project are to determine the three-dimensional structures of the three major structural domains of AMA1 and of the complete AMA1 antigen. We shall also determine the structures, both in aqueous solution and bound to AMA1, of small peptides identified by phage display as being capable of binding to AMA1 and blocking parasite entry into red blood cells. The overall goal of this work is to determine the structure of AMA1 and define the structural basis for its interaction with small peptides capable of blocking its activity as well as the structural features necessary for AMA1 to react with protective antibodies. The structure of AMA1 will provide a molecular basis for the design of engineered antigens capable of eliciting a protective immune response against AMA1. The inhibitory peptide structures will likewise provide a molecular basis for the design of non-peptidic blockers of AMA1. Either or both of these may be useful therapeutics leads in the fight against malaria.Read moreRead less
Functional Analysis Of The Molecular Switch That Regulates ADAM10-mediated Cleavage Of RTK Ligands In Tumour Cells.
Funder
National Health and Medical Research Council
Funding Amount
$457,267.00
Summary
We have determined the structure and identified the region of the ADAM10 metalloprotease that controls its specific cleavage of ephrins. Ephrins and their receptors (Ephs) direct cell positioning during development by controlling cell-cell adhesion and repulsion. In adult tissues these proteins are present at low levels but are found at high levels in human cancers, including skin cancers, where they are thought to promote aggressive tumours. The switch to cell repulsion occurs by cleavage of th ....We have determined the structure and identified the region of the ADAM10 metalloprotease that controls its specific cleavage of ephrins. Ephrins and their receptors (Ephs) direct cell positioning during development by controlling cell-cell adhesion and repulsion. In adult tissues these proteins are present at low levels but are found at high levels in human cancers, including skin cancers, where they are thought to promote aggressive tumours. The switch to cell repulsion occurs by cleavage of the ephrin by ADAM10 which also functions in other cancer promoting events by cleaving growth factors. Our structure reveals how Eph-bound ephrin is specifically targeted by ADAM. We will now determine the relevance of this mechanism for other ADAM10 targets, and design drugs to bind this region and inhibit ADAM function, which we will test in assays measuring tumour cell movement and growth, with the aim of developing therapies to block cancer progression.Read moreRead less