C-Jun N-terminal Kinase Actions In The Response To Stress
Funder
National Health and Medical Research Council
Funding Amount
$480,127.00
Summary
All cells in our body sense and respond to stressful changes in our environment. We are focused on enzymes called JNKs that relay this information, and so form part of the key response pathways. JNKs are now being evaluated as new drug targets for the treatment of diseases including diabetes and stroke, but we know very little about how JNKs work in stressed cells. We will define new partners for the JNKs and in so doing reveal new information on the stress-activated events they regulate.
Identification And Characterisation Of Novel Copper Homeostasis Genes And Proteins
Funder
National Health and Medical Research Council
Funding Amount
$70,307.00
Summary
Copper is an essential nutrient that is also toxic when in excess. Specific mechanisms exist to regulate copper levels and these are conserved across many species. Disrupted copper regulation contributes to many diseases including: cardiovascular disease, osteoporosis and Alzheimer’s. I aim to identify and characterise novel copper regulatory proteins using the model organism Drosophila (vinegar fly) together with human cultured cells as a foundation for work to prevent or treat these diseases.
Investigation Of The Role Of The ATM Protein In Peroxisome Function And Biogenesis.
Funder
National Health and Medical Research Council
Funding Amount
$250,756.00
Summary
Ataxia-telangiectasia (A-T) is a complex multisystem disease characterized by extreme sensitivity to ionizing radiation (X-rays) and susceptibility to cancer, however the most debilitating symptoms are neurodegeneration and susceptibility to bronchial infections. The gene (atm) which is mutated in this disease has recently been cloned and current research is focussed on the function of the protein (termed ATM) that this gene encodes. We have localized the ATM protein to the nucleus, where it pla ....Ataxia-telangiectasia (A-T) is a complex multisystem disease characterized by extreme sensitivity to ionizing radiation (X-rays) and susceptibility to cancer, however the most debilitating symptoms are neurodegeneration and susceptibility to bronchial infections. The gene (atm) which is mutated in this disease has recently been cloned and current research is focussed on the function of the protein (termed ATM) that this gene encodes. We have localized the ATM protein to the nucleus, where it plays a role in monitoring DNA damage, and also to vesicles in the cytoplasm of the cell. We have demonstrated that some of these vesicles are peroxisomes, vital cellular organelles involved in a wide range of metabolic functions. The importance of peroxisomes is evidenced by the severe abnormalities in patients with disorders of peroxisome formation and function. Interestingly many of the neurological features of these patients overlap with those displayed by A-T patients. We propose that abnormalities in peroxisomal function in A-T may contribute to the development of neurological symptoms and we plan to examine the function of peroxisomes in cells from A-T patients, and in tissues from A-T mutant mice. This work may help design new treatments to ameliorate the most debilitating aspects of this disease.Read moreRead less
MITOCHONDRIA, OXIDATIVE STRESS AND NEURONAL APOPTOSIS: BIOCHEMICAL, CELLULAR AND PHARMACOLOGICAL APPROACHES
Funder
National Health and Medical Research Council
Funding Amount
$145,880.00
Summary
Our goal is to understand the detailed process whereby nerve cells die after various stresses and injury. We aim also to develop novel ways of protecting cells against such death. The death of nerve cells plays an important role in a series of neurodegenerative diseases, such as Parkinson's, Huntington's and Motor Neurone Diseases. One prevalent cause of cell death arises from the action of transmitters that normally signal between nerve cells but which, under conditions of stress and injury, ca ....Our goal is to understand the detailed process whereby nerve cells die after various stresses and injury. We aim also to develop novel ways of protecting cells against such death. The death of nerve cells plays an important role in a series of neurodegenerative diseases, such as Parkinson's, Huntington's and Motor Neurone Diseases. One prevalent cause of cell death arises from the action of transmitters that normally signal between nerve cells but which, under conditions of stress and injury, cause overstimulation of the nerve cells leading to death (excitotoxicity). Mitochondria are component of cells normally providing energy for the cell to carry out its various functions; but under stress conditions mitochondria act as controllers in cellular decision-making processes leading to cell death. Moreover, mitochondria are known to play an important role in neurodegenerative diseases, as they are a source of damaging oxygen derivatives called free radicals that cause cell injury. Mitochondria are also involved in death resulting from excitotoxicity. In order to understand the detailed mechanism of the nerve cell death process, we will use cultured nerve cells from the brains of laboratory mice, including both normal mice and those that are models of neurodegenerative disease. Injury leading to death will be induced by analogues of the transmitters that cause excitotoxicity. We will concentrate the those aspects of the death process that involve mitochondria, as this will enable us to test a range of antioxidants that can be expected to lead to new drug treatments for neuronal cell injury. Included in these compounds are novel antioxidants that are targeted to mitochondria. This project brings together the expertise in neuroscience and pharmacology of Professor Beart with the skills in biochemistry of Professor Nagley, particularly in mitochondrial and cell death research, to address this important medical research problem in a multidisciplinary manner.Read moreRead less
Structure-function Inter-relationships Of Small Heat-shock Chaperone Proteins
Funder
National Health and Medical Research Council
Funding Amount
$240,990.00
Summary
In vivo, most proteins only function over a narrow temperature or pH range. For example, if the solution containing a particular protein is heated (stressed), the protein will unfold, aggregate and potentially precipitate. The act of protein precipitation is an irreversible process that, in many cases, has deleterious consequences for cell viability. Protein precipitation is associated with a diversity of diseases, e.g. cataract and neurodegenerative diseases such as Alzheimer's, Creutzfeldt-Jak ....In vivo, most proteins only function over a narrow temperature or pH range. For example, if the solution containing a particular protein is heated (stressed), the protein will unfold, aggregate and potentially precipitate. The act of protein precipitation is an irreversible process that, in many cases, has deleterious consequences for cell viability. Protein precipitation is associated with a diversity of diseases, e.g. cataract and neurodegenerative diseases such as Alzheimer's, Creutzfeldt-Jakob and Parkinson's diseases. Nature has evolved cellular mechanisms to minimise protein misfolding, aggregation and precipitation which principally utilise a diverse group of controlling or regulatory proteins called molecular chaperones. Amongst the most important of these are the small heat-shock proteins (sHsps) which are found in all organisms. sHsps function by interacting in a very efficient manner with destabilised proteins to prevent their precipitation. Little is known, however, about the structure of sHsps nor the mechanism by which they perform their chaperone action. This proposal will address these fundamental aspects via the use of a variety of spectroscopic techniques, principally nuclear magnetic resonance (NMR) spectroscopy.Read moreRead less
The Role Of Molecular Chaperones And Proteases In Mitochondrial Function
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
Mitochondria are essential organelles providing the cell with essential molecules and being the source of oxidative energy in the cell. They are at the centre of many clinical conditions, ranging from genetic to common neurological diseases and other conditions related to ageing. We have been defining the way in which mammalian cells respond to the accumulation of unfolded proteins within the mitochondrial compartment and have found this produces what we have called the Mitochondrial Stress Resp ....Mitochondria are essential organelles providing the cell with essential molecules and being the source of oxidative energy in the cell. They are at the centre of many clinical conditions, ranging from genetic to common neurological diseases and other conditions related to ageing. We have been defining the way in which mammalian cells respond to the accumulation of unfolded proteins within the mitochondrial compartment and have found this produces what we have called the Mitochondrial Stress Response, a process that results in the selective upregulation of a suite of genes encoding mitochondrial stress proteins. This application deals with the question of the consequences to the cell of the creation of proteolytic environment. We have found that the two major proteases of the mitochondrion are upregulated and that this results in a marked increase in the rate of degradation of mitochondrial proteins. We aim to determine the specific roles of individual proteases in this process and the consequences of this proteolysis on the efflux of peptides from the mitochondria. This question has important medical implications, as one of the consequences of defects in mitochondrial function is the loss of cells from the affected tissue. We will also address the question of how mitochondrial biogenesis is regulated. We have recently found that the cytosolic molecular chaperone Hsp90 is required for protein import into mitochondria in mammalian cells. Since Hsp90 has hitherto been shown to be a key regulatory component in the steroid hormone and tyrosine kinase signalling pathways, this finding raises the possibility that protein import and thereby mitochondrial biogenesis may be regulated via the involvement of Hsp90.Read moreRead less
Biogenesis Of Respiratory Chain Complex I And Analysis Of Assembly Defects In Patients With Mitochondrial Disease
Funder
National Health and Medical Research Council
Funding Amount
$254,250.00
Summary
Complex I of the mitochondrial respiratory chain is a large assembly of protein subunits that is involved in the main production of cellular energy. Complex I is found in intracellular compartments termed mitochondria. The predicament for Complex I is that in order for it to be built, it requires 38 different proteins that are made in one place in the cell to be imported into mitochondria and then somehow joined together with the 7 other subunits that are made by mitochondria. This is clearly a ....Complex I of the mitochondrial respiratory chain is a large assembly of protein subunits that is involved in the main production of cellular energy. Complex I is found in intracellular compartments termed mitochondria. The predicament for Complex I is that in order for it to be built, it requires 38 different proteins that are made in one place in the cell to be imported into mitochondria and then somehow joined together with the 7 other subunits that are made by mitochondria. This is clearly a complicated procedure and we have little information on how its assembly is achieved. We do know however that mistakes in the assembly of Complex I do happen. In Australia, about 50 children born each year have inherited disorders of mitochondrial energy generation. The most severe disorders cause infant death, while others present later causing a range of degenerative diseases, particularly affecting brain, muscle and heart. The most common defect in these patients is a loss in the activity of Complex I. Interestingly it seems that in most cases, the defect is not due to a mutation in one or more of the Complex I subunits and so we believe that such defects arise form accessory proteins that are involved in the construction of Complex I. The aim of this proposal is to investigate how Complex I is assembled and to identify and characterise accessory proteins. We will also analyse assembly defects by studying skin fibroblasts from patients. This work will aid in our understanding of not only how protein complexes are built, but how defects in their assembly can cause disease. This will not only be informative to families of affected individuals but may aid in future diagnosis and prevention of mitochondrial disease.Read moreRead less