Identification Of Kinases Involved In The Regulation Of Homologous Recombination Mediated DNA Repair

DNA repair is an essential process in the maintenance of genomic stability. The regulation of DNA repair requires a series of highly coordinated events. Deregulation of DNA repair can lead to multiple diseases including cancer. One DNA repair mechanism, homologous recombination, plays a pivotal role in the repair of highly toxic DNA damage lesions known as DNA double strand breaks. Despite numerous studies that elucidate mechanisms of homologous recombination, our understanding of the regulation of the mechanism remains incomplete. In this study, I propose to elucidate novel mechanisms for the regulation of homologous recombination, focusing on protein phosphorylation as one such potential regulatory mechanism. I hypothesize that there are unidentified kinases involved in the regulation of homologous recombination. I have conducted a high-throughput RNAi screen of the human kinome following DNA damage, using RAD51 foci formation as readout. Using this unbiased approach, I have identified twenty candidate kinases as possible regulators of homologous recombination. This study aims at identifying the role played by these kinases through a series of functional assays, including: analysis of cell cycle distribution, cellular sensitivity to DNA damaging agents, and efficiency of homologous recombination. The kinases NEK8, PAK4, and DGKD have been identified as candidates. This study is the first comprehensive analysis of the role of the human kinome in the DNA damage response, and serves to identify novel kinases that regulate homologous recombination-mediated DNA repair. It will also serve to understand the role of DNA repair in cancer therapy and possibly identify novel chemotherapeutic targets.