Abstract
Genetic studies in yeast indicate that RNA transcripts facilitate homology-directed DNA repair in a manner that is dependent on RAD52. The molecular basis for so-called RNA−DNA repair, however, remains unknown. Using reconstitution assays, we demonstrate that RAD52 directly cooperates with RNA as a sequence-directed ribonucleoprotein complex to promote two related modes of RNA−DNA repair. In a RNA-bridging mechanism, RAD52 assembles recombinant RNA−DNA hybrids that coordinate synapsis and ligation of homologous DNA breaks. In an RNA-templated mechanism, RAD52-mediated RNA−DNA hybrids enable reverse transcription-dependent RNA-to-DNA sequence transfer at DNA breaks that licenses subsequent DNA recombination. Notably, we show that both mechanisms of RNA−DNA repair are promoted by transcription of a homologous DNA template in trans. In summary, these data elucidate how RNA transcripts cooperate with RAD52 to coordinate homology-directed DNA recombination and repair in the absence of a DNA donor, and demonstrate a direct role for transcription in RNA−DNA repair.
Highlights
Genetic studies in yeast indicate that RNA transcripts facilitate homology-directed DNA repair in a manner that is dependent on RAD52
Mammalian RAD52 was shown to be preferentially recruited to double-strand break (DSB) in a transcription-dependent manner during G0 and G1 cell-cycle stages[4], and multiple reports demonstrate that RAD52 associates with RNA polymerase II and RNA transcripts in mammalian cells[5,6]
Our data demonstrate that RAD52 cooperates with RNA as a homology-directed ribonucleoprotein complex to facilitate both mechanisms of RNA −DNA repair
Summary
Genetic studies in yeast indicate that RNA transcripts facilitate homology-directed DNA repair in a manner that is dependent on RAD52. Spliced RNA transcripts were implicated in serving as templates for DNA repair synthesis at homologous DSBs either in cis or in trans of the transcription site[3] This form of RNA transcript-dependent DNA recombinational repair (RNA−DNA repair) was shown to be promoted by RAD52 and putative reverse transcriptase (RT) activity, while being suppressed by RNase H3. Mammalian RAD52 was shown to be preferentially recruited to DSBs in a transcription-dependent manner during G0 and G1 cell-cycle stages[4], and multiple reports demonstrate that RAD52 associates with RNA polymerase II and RNA transcripts in mammalian cells[5,6] It is unknown how RAD52 promotes RNA−DNA repair, we envisaged the following two models based in part on yeast genetics[3]. We further show that these modes of RNA−DNA a RNA-bridging DSB repair
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
