Extended Data Fig. 12: Model of the role of DR-loops in HR.
From: RNA transcripts stimulate homologous recombination by forming DR-loops
The formation of DSBs in transcribed regions triggers the recruitment of both RAD51 and RAD51AP1. RAD51AP1 may associate with RNA transcripts through direct RNA binding. In S and G2 cells, RAD51AP1 promotes the invasion of RNA transcripts into donor DNA on sister chromatids. The presence of R-loops and RAD51AP1 in donor DNA may facilitate the invasion of RAD51 filaments, stabilize invaded ssDNA, help RAD51 find homologous sequences and promote the extension of ssDNA ends in DR-loops. It is also possible that RNA transcripts anneal with the displaced ssDNA in D-loops, helping to stabilize invaded ssDNA and extend ssDNA ends in DR-loops. The DNA–RNA hybrids in DR-loops are probably removed in a later step to allow the completion of HR.
