Human Rad52 Promotes XPG-Mediated R-loop Processing to Initiate Transcription-Associated Homologous Recombination Repair

Publication date: Available online 20 September 2018Source: CellAuthor(s): Takaaki Yasuhara, Reona Kato, Yoshihiko Hagiwara, Bunsyo Shiotani, Motohiro Yamauchi, Shinichiro Nakada, Atsushi Shibata, Kiyoshi MiyagawaSummaryGiven that genomic DNA exerts its function by being transcribed, it is critical for the maintenance of homeostasis that DNA damage, such as double-strand breaks (DSBs), within transcriptionally active regions undergoes accurate repair. However, it remains unclear how this is achieved. Here, we describe a mechanism for transcription-associated homologous recombination repair (TA-HRR) in human cells. The process is initiated by R-loops formed upon DSB induction. We identify Rad52, which is recruited to the DSB site in a DNA-RNA-hybrid-dependent manner, as playing pivotal roles in promoting XPG-mediated R-loop processing and initiating subsequent repair by HRR. Importantly, dysfunction of TA-HRR promotes DSB repair via non-homologous end joining, leading to a striking increase in genomic aberrations. Thus, our data suggest that the presence of R-loops around DSBs within transcriptionally active regions promotes accurate repair of DSBs via processing by Rad52 and XPG to protect genomic information in these critical regions from gene alterations.Graphical Abstract
Source: Cell - Category: Cytology Source Type: research