RAD52 resolves replication-transcription collisions to mitigate R-loop induced genome instability

Collisions of transcription and replication machinery on the same DNA strand can pose a significant threat to genomic stability. These collision occur in part due to of RNA-DNA hybrids termed R-loops, in which a newly synthesized RNA molecule hybridizes with the DNA template strand. This study investigated the novel role of RAD52, a known DNA repair factor, in preventing collisions by managing R-loop formation and resolution. We show that RAD52 deficiency increases R-loop accumulation, exacerbating collisions and resulting in elevated DNA damage. Further, RAD52's ability to interact with the transcription machinery, coupled with its capacity to facilitate R-loop dissolution, highlights its role in preventing collisions. Lastly, we provide the first evidence of an increased mutational burden at conserved R-loop sites in human tumor samples. In summary, this study underscores the importance of RAD52 in orchestrating the delicate balance between replication and transcription processes to prevent collisions and maintain genome stability. In HeLa cells: ChIP-seq of RNA Pol II (Rpb1), gH2AX and S9.6 in untreated (siNT) andd RAD52-depleted (si52) cells; ChIP-seq of RAD52 in untreated (siNT) cells.