Senataxin, A Novel Protein Involved In The DNA Damage Response
Funder
National Health and Medical Research Council
Funding Amount
$500,460.00
Summary
The human genome is constantly exposed to agents-chemicals that cause DNA damage. Some of these are generated during normal metabolism and are referred to as reactive oxygen species while others comprise damaging sunlight, radiation and a variety of chemical agents. These agents can lead to cancer and a range of pathologies to different tissues including deterioration of brain function. This project is designed to investigate these processes using a specific genetic disorder as a model system. T ....The human genome is constantly exposed to agents-chemicals that cause DNA damage. Some of these are generated during normal metabolism and are referred to as reactive oxygen species while others comprise damaging sunlight, radiation and a variety of chemical agents. These agents can lead to cancer and a range of pathologies to different tissues including deterioration of brain function. This project is designed to investigate these processes using a specific genetic disorder as a model system. This disorder is called ataxia with oculomotor apraxia type 2 or AOA2. This condition develops in the teenage to early twenties and as the name suggests is characterised by loss of control of gait together with difficulties of eye movement. It is due to reduced function of a particular region of the brain called the cerebellum responsible for controlling movement. We have initial data suggesting that cells from these patients are very sensitive to environmental chemicals and their capacity to carry out repair of damage to DNA is compromised. We will investigate the nature of the defect at the molecular level and establish the function of the protein defective in this syndrome. This information will be important to determining specific therapies for AOA2 patients and may also have relevance to other neurodegenerative disorders.Read moreRead less
Functions Of A Novel Conserved DNA Damage Response Protein Family In Telomere Stability
Funder
National Health and Medical Research Council
Funding Amount
$282,825.00
Summary
The free DNA ends of chromosomes, termed telomeres, generally resemble broken DNA. Because broken DNA is a major contributing factor to the onset of cancer, cells try to fix broken ends. However, in case of telomeres, such repair processes have to be prevented because otherwise different chromosomes would fuse with each other. Fused chromosomes are very fragile and cannot be evenly distributed between dividing cells, and are therefore another important trigger of cancer development. Therefore, c ....The free DNA ends of chromosomes, termed telomeres, generally resemble broken DNA. Because broken DNA is a major contributing factor to the onset of cancer, cells try to fix broken ends. However, in case of telomeres, such repair processes have to be prevented because otherwise different chromosomes would fuse with each other. Fused chromosomes are very fragile and cannot be evenly distributed between dividing cells, and are therefore another important trigger of cancer development. Therefore, chromosome ends are covered by a cap, which hides them from the DNA damage response machinery. From these considerations it is clear that there are close connections between the cellular DNA damage response and chromosome ends. Moreover, recently it has become clear that DNA damage proteins are also required to stop normal cells from growing, a process termed senescence. Senescence is a consequence of shortened chromosome ends, and does not occur in cancer cells. Altogether, it is clear that DNA breaks and senescence are two of the major questions for our understanding of cancer development. We have identified a novel conserved protein family that is involved in the response to DNA damage in yeast and humans. In addition, the yeast Mdt1 protein is a very sensitive indicator of changes in the telomere cap. Absence of proteins that organise the cap leads to the addition of several phosphate groups to the Mdt1 protein. We propose that phosphate-coupled Mdt1 prevents chromosome ends from fusion with each other, or from fusing with broken DNA ends after widespread damage. As a consequence, cells that have mild cap defects die at an >1000-fold increased rate in response to DNA damage when they also lack Mdt1. As part of this application we want to find out the precise mechanism by which Mdt1 stabilises chromosome ends, and test our hypothesis that the corresponding human protein termed ASCIZ also has similar functions in protecting chromosome ends.Read moreRead less
Understanding the differentiation of the endocardium. The project aims to understand the genetic regulation of endocardial development. The heart is essential for survival, its beat the indicator of life. The endocardium, the heart’s inner lining, is required for signalling during heart development and is a major component of the valves, septa and trabeculae. Despite its indispensable role, little is known about how it forms or develops. This project integrates two complementary approaches that ....Understanding the differentiation of the endocardium. The project aims to understand the genetic regulation of endocardial development. The heart is essential for survival, its beat the indicator of life. The endocardium, the heart’s inner lining, is required for signalling during heart development and is a major component of the valves, septa and trabeculae. Despite its indispensable role, little is known about how it forms or develops. This project integrates two complementary approaches that have identified the earliest marker of endocardial differentiation and devised the method to make endocardium from stem cells. Knowledge from this work will inform future research into growing and regenerating damaged tissue.Read moreRead less
Kruppel-like factors and the methylome. This project aims to test the hypothesis that the KLF/SP family of transcription factors work in part via dynamic interactions with methylated cytosine nucleotides in DNA. This is fundamental to their function as pioneer factors in reprograming and their ability to co-ordinate differentiation and organogenesis. Conversely, dynamic changes in methylation status engage or disengage new regulatory elements in the genome via recruitment of KLF/SP family protei ....Kruppel-like factors and the methylome. This project aims to test the hypothesis that the KLF/SP family of transcription factors work in part via dynamic interactions with methylated cytosine nucleotides in DNA. This is fundamental to their function as pioneer factors in reprograming and their ability to co-ordinate differentiation and organogenesis. Conversely, dynamic changes in methylation status engage or disengage new regulatory elements in the genome via recruitment of KLF/SP family proteins as specific effectors. This project will address a new paradigm in genetics that is likely to underpin development.Read moreRead less
How do transcription factors control cell fate transitions? The aim of this project is to determine how transcription factors control cellular identity, which is relevant to many biological processes including embryogenesis, cellular reprogramming and differentiation. Innovative genomic tools will be combined with various in vitro cellular conversion systems to generate fundamental mechanistic insight into how transcription factors mediate these identity changes. The knowledge gained from this w ....How do transcription factors control cell fate transitions? The aim of this project is to determine how transcription factors control cellular identity, which is relevant to many biological processes including embryogenesis, cellular reprogramming and differentiation. Innovative genomic tools will be combined with various in vitro cellular conversion systems to generate fundamental mechanistic insight into how transcription factors mediate these identity changes. The knowledge gained from this work will allow us to answer standing fundamental questions in regards to cell fate control and the biochemistry of transcription factors, which in turn will aid in the development of novel gene regulation technologies applicable to a myriad of fields and industries.Read moreRead less
Unveiling the epigenome dynamics through the pluripotency continuum. This project aims to utilise stem cells and genomics based technologies, in combination with new computational algorithms to dissect the fundamental molecular events that drive the first steps during development. The project is expected to unveil the basic mechanisms underpinning how genes driving the developmental master plan are controlled in cells that have the capacity to give rise to the whole organism and placenta. The kn ....Unveiling the epigenome dynamics through the pluripotency continuum. This project aims to utilise stem cells and genomics based technologies, in combination with new computational algorithms to dissect the fundamental molecular events that drive the first steps during development. The project is expected to unveil the basic mechanisms underpinning how genes driving the developmental master plan are controlled in cells that have the capacity to give rise to the whole organism and placenta. The knowledge gained from this work will inform and guide future novel approaches, such as in assisted reproductive technologies or regenerative medicine.Read moreRead less