A new role for Rrm3 in repair of replication-born DNA breakage by sister chromatid recombination

PLoS Genet. 2017 May 5;13(5):e1006781. doi: 10.1371/journal.pgen.1006781. eCollection 2017 May.

Abstract

Replication forks stall at different DNA obstacles such as those originated by transcription. Fork stalling can lead to DNA double-strand breaks (DSBs) that will be preferentially repaired by homologous recombination when the sister chromatid is available. The Rrm3 helicase is a replisome component that promotes replication upon fork stalling, accumulates at highly transcribed regions and prevents not only transcription-induced replication fork stalling but also transcription-associated hyper-recombination. This led us to explore the possible role of Rrm3 in the repair of DSBs when originating at the passage of the replication fork. Using a mini-HO system that induces mainly single-stranded DNA breaks, we show that rrm3Δ cells are defective in DSB repair. The defect is clearly seen in sister chromatid recombination, the major repair pathway of replication-born DSBs. Our results indicate that Rrm3 recruitment to replication-born DSBs is crucial for viability, uncovering a new role for Rrm3 in the repair of broken replication forks.

MeSH terms

  • Chromatids / genetics
  • DNA Breaks, Double-Stranded*
  • DNA Helicases / genetics*
  • DNA Helicases / metabolism
  • DNA Repair
  • DNA Replication
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Sister Chromatid Exchange*

Substances

  • Saccharomyces cerevisiae Proteins
  • Rrm3 protein, S cerevisiae
  • DNA Helicases

Grant support

This work was supported by grants from the Spanish Ministry of Economy and Innovation (BFU2013-42918), the European Union (FEDER), the European Research Council (ERC2014 AdG669898 TARLOOP), and the Junta de Andalucía (BIO1238). SMG was funded by a predoctoral training fellowship from the Spanish National Research Council (CSIC) and BGG by a postdoctoral grant from the Scientific Foundation of the Spanish Association Against Cancer (AECC). Funding for open access charge: Grants from the Spanish Ministry of Economy and Innovation (BFU2013-42918). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.