How Replication Stress Activates The Mitotic Telomere DNA Damage Response To Kill Cancer Cells
Funder
National Health and Medical Research Council
Funding Amount
$486,467.00
Summary
We discovered a novel mechanism linking stress during DNA replication to difficulties with the cell division process, and identified how this turns on DNA damage response signals from the chromosome ends (i.e. “telomeres”). We have further identified that we can exploit this mechanism to kill cancer cells. In this project we will explore this newly discovered mechanism and identify how it can be targeted for therapeutic purposes.
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
Ubiquitin And SUMO DNA Damage Response Signalling At Deprotected Telomeres During The Cell Cycle
Funder
National Health and Medical Research Council
Funding Amount
$302,627.00
Summary
Following genome damage cells stop the cell division process and initiate DNA repair. We discovered that at specific times during cell division his does not happen if the damage signals originate from the chromosome ends (i.e. “telomeres”). We anticipate this is necessary to prevent genomic instability in healthy cells and may be driving genomic instability in cancer cells. Experiments described here will elucidate the molecular mechanisms and biological significance of our observation.