The Good and Bad of RNA:DNA Hybrids in Double-Strand Break Repair

Abstract

Transcription and genome stability have somewhat of a love-hate relationship. In a recent issue of Cell, Ohle et al. (2016) demonstrate a previously unappreciated mechanism by which transcription and RNA contribute to genome stability.

Rad52 Inverse Strand Exchange Drives RNA-Templated DNA Double-Strand Break Repair

“…Our current in vitro and in vivo findings on the mechanism of RNA-templated DNA DSB repair bring a fresh perspective to the complex relationship between RNA and DNA in the context of genome stability (summarized in Plosky, 2016). Recent work revealed an important function of Rad52 in RNA-dependent DSB repair (Keskin et al, 2014).…”

Polymerase θ-helicase efficiently unwinds DNA and RNA-DNA hybrids

“…For example, R-loops have long been associated with replicative stress and genome instability, whereas more recent work indicates that RNA-DNA hybrids can also promote DNA repair by mechanisms that remain to be elucidated (23)(24)(25)(26)(27). Considering the importance of RNA-DNA structures in DNA repair and genome instability, we proceeded to examine whether Polθ-helicase unwinds RNA-DNA duplexes with similar efficiency.…”

RNA polymerase III is required for the repair of DNA double-strand breaks by homologous recombination

“…Furthermore, it has also been reported that DDX1 RNA helicase, as well as RNase H1/2 and noncoding RNA (ncRNA)-processing RNases, are required for efficient DSB repair by HR and may be involved in removing the RNA strands at DSBs (Francia et al, 2012;Li et al, 2016;Ohle et al, 2016;Wei et al, 2012). However, regarding the RNA-DNA hybrids at DSBs, several critical questions remain, as remarked by Aguilera and Go ´mez-Gonzalez (2017) and Plosky (2016). First, is the RNA strand at DSB just a transcript at actively transcribed region where DSB happens to occur?…”