title: Transient RNA-DNA Hybrids Are Required for Efficient Double-Strand Break Repair.
abstract: RNA-DNA hybrids are a major internal cause of DNA damage within cells, and their degradation by RNase H enzymes is important for maintaining genomic stability. Here, we identified an unexpected role for RNA-DNA hybrids and RNase H enzymes in DNA repair. Using a site-specific DNA double-strand break (DSB) system in Schizosaccharomyces pombe, we showed that RNA-DNA hybrids form as part of the homologous-recombination (HR)-mediated DSB repair process and that RNase H enzymes are essential for their degradation and efficient completion of DNA repair. Deleting RNase H stabilizes RNA-DNA hybrids around DSB sites and strongly impairs recruitment of the ssDNA-binding RPA complex. In contrast, overexpressing RNase H1 destabilizes these hybrids, leading to excessive strand resection and RPA recruitment and to severe loss of repeat regions around DSBs. Our study challenges the existing model of HR-mediated DSB repair and reveals a surprising role for RNA-DNA hybrids in maintaining genomic stability.
authors.affiliation: Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Corina
authors.initials: C
authors.lastname: Ohle
authors.affiliation: Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Rafael
authors.initials: R
authors.lastname: Tesorero
authors.affiliation: Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Géza
authors.initials: G
authors.lastname: Schermann
authors.affiliation: Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Dobrev
authors.affiliation: Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
authors.forename: Irmgard
authors.initials: I
authors.lastname: Sinning
authors.affiliation: Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany; The John Curtin School of Medical Research, The Australian National University, Canberra ACT 2601, Australia. Electronic address: tamas.fischer@anu.edu.au.
authors.forename: Tamás
authors.initials: T
authors.lastname: Fischer
mesh_terms: D004247:DNA / Q000378:metabolism; D004249:DNA Damage; D015870:Gene Expression; D042822:Genomic Instability; D012313:RNA / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D059767:Recombinational DNA Repair; D016914:Ribonuclease H / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*
chemical_list: D012313:RNA; D004247:DNA; D012319:RNA Polymerase II; C091139:ribonuclease HII; D016914:Ribonuclease H; C078856:ribonuclease HI
keywords: DNA repair; DSB repair; R loops; RNA-DNA hybrids; RNase H; RPA; genome stability; homologous recombination