Genomic DNA is constantly exposed to assaults, which if not dealt with, can lead to genomic instability and carcinogenesis. In response to stress including either Ionising Radiation (IR) or replication stress, ATM and ATR promote the activation of cell cycle checkpoints and initiate repair of DNA damage. Recent studies have revealed that ATM signalling can activate LATS1 via a cascade through RASSF1A and MST2. LATS1 is a tumour suppressor, which forms a barrier to carcinogenesis restricting cell proliferation and promoting apoptosis by stabilising a YAP/p73 transcriptional complex, hence upregulating p73 responsive genes. LATS1 is inactivated through promoter hypermethylation in a number of cancer types including breast cancer and soft tissue sarcoma. This research project seeks to define the mechanism through which LATS1 is involved in IR-induced DNA damage signalling. The data presented in this thesis shows that LATS1 controls CDK2 and regulates phosphorylation of S3291 on BRCA2. Cells lacking LATS1 exhibited enhanced accumulation of damage-induced Rad51 foci leading to cell cycle arrest at the G<sub>2</sub>/M checkpoint. Furthermore, the data presented here suggests that LATS1 may not be required for homologous recombination. This work supports the hypothesis that LATS1 inhibits CDK2-dependent phosphorylation of BRCA2 at S3291, hence protecting stalled replication forks from nucleolytic degradation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:589598 |
| Date | January 2012 |
| Creators | Latusek, Robert |
| Contributors | O'Neill, Eric ; Helleday, Thomas |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:7f21ecaf-20a6-45a9-8403-c8255955920e |
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