Periodic Reporting for period 2 - CHROMREP (Dissecting the chromatin response to DNA damage in silenced heterochromatin regions)
Berichtszeitraum: 2021-06-01 bis 2022-05-31
Cells are continuously exposed to insults that can break or chemically modify their DNA. To protect the DNA, cells have acquired an arsenal of repair mechanisms. Proper repair of DNA damage is essential for organismal viability and disease prevention. What is often overlooked is the fact that the eukaryotic nucleus contains many different chromatin domains that can each influence the dynamic response to DNA damage. Chromatin domains are specified by different levels of DNA packaging by a variety of DNA-bound proteins, with euchromatin being more open and less compact, and heterochromatin being more densely packaged. The main objective of this project is to understand how diverse chromatin domains, and in particular the dense heterochromatin environment, shape the response to DNA damage.
We developed a variety of DNA damage systems in fruit fly tissue that allow for in-depth analysis of heterochromatin domain-specific repair responses. We are currently combining these systems with chromatin analyses and high-resolution live imaging to dissect the DNA damage-associated heterochromatin changes and determine their function in DNA damage repair.
Deciphering the processes that regulate DNA damage repair in heterochromatin will have broad conceptual implications for understanding the role of these dynamics in other essential nuclear processes, such as replication and transcription. More importantly, understanding how repair is regulated in heterochromatin could be important in determining how cancer-associated changes in these repair processes impact tumour -development and -treatment in the long run.
We developed a variety of DNA damage systems in fruit fly tissue that allow for in-depth analysis of heterochromatin domain-specific repair responses. We are currently combining these systems with chromatin analyses and high-resolution live imaging to dissect the DNA damage-associated heterochromatin changes and determine their function in DNA damage repair.
Deciphering the processes that regulate DNA damage repair in heterochromatin will have broad conceptual implications for understanding the role of these dynamics in other essential nuclear processes, such as replication and transcription. More importantly, understanding how repair is regulated in heterochromatin could be important in determining how cancer-associated changes in these repair processes impact tumour -development and -treatment in the long run.
We developed a variety of DNA damage systems in fruit fly tissue that allow for in-depth analysis of heterochromatin domain-specific repair responses. We are currently combining these systems with chromatin analyses and high-resolution live imaging to dissect the DNA damage-associated heterochromatin changes and determine their function in DNA damage repair. In addition to the systems in fruit flies, we have also developed a new, in vitro (test-tube) approach to be able to identify new proteins involved in repair of DNA damage in heterochromatin. Using these systems, we have already identified a number of DNA damage responses specific to heterochromatin regions and we are currently analysing these processes in more detail.
By developing several new DNA damage systems, we are in the unique position to determine how heterochromatin is responding to DNA damage using both high resolution live imaging of larval tissues as well as chromatin analyses at the site of DNA damage. We expect that by the end of this project, we will have identified a variety of DNA damage responses specific to densely packaged heterochromatin regions. More specifically, we expect to have find the processes involved in the repair of facultative heterochromatin genes (genes important for organismal development), as well as the repair of repetitive sequences within constitutive heterochromatin. Finally, we will have assessed the role of these processes in the maintenance of genome stability in the eukaryotic nucleus by analysing chromosome structure and the accumulation of DNA mutations in the absence of these processes.