title: The spliceosome-associated protein Nrl1 suppresses homologous recombination-dependent R-loop formation in fission yeast.
abstract: The formation of RNA-DNA hybrids, referred to as R-loops, can promote genome instability and cancer development. Yet the mechanisms by which R-loops compromise genome instability are poorly understood. Here, we establish roles for the evolutionarily conserved Nrl1 protein in pre-mRNA splicing regulation, R-loop suppression and in maintaining genome stability. nrl1Δ mutants exhibit endogenous DNA damage, are sensitive to exogenous DNA damage, and have defects in homologous recombination (HR) repair. Concomitantly, nrl1Δ cells display significant changes in gene expression, similar to those induced by DNA damage in wild-type cells. Further, we find that nrl1Δ cells accumulate high levels of R-loops, which co-localize with HR repair factors and require Rad51 and Rad52 for their formation. Together, our findings support a model in which R-loop accumulation and subsequent DNA damage sequesters HR factors, thereby compromising HR repair at endogenously or exogenously induced DNA damage sites, leading to genome instability.
authors.affiliation: Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, Vienna A-1030, Austria Department of Oncology, Stanford University, Stanford 94305, USA timothy.humphrey@oncology.ox.ac.uk.
authors.forename: Lucia
authors.initials: L
authors.lastname: Aronica
authors.affiliation: CRUK/MRC Oxford Institute for Radiation Oncology, Oxford OX37DQ , UK.
authors.forename: Torben
authors.initials: T
authors.lastname: Kasparek
authors.affiliation: Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, Vienna A-1030, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Ruchman
authors.affiliation: Department of Medical Biochemistry, Max F. Perutz Laboratories,Medical University of Vienna, Vienna A-1030, Austria.
authors.forename: Yamile
authors.initials: Y
authors.lastname: Marquez
authors.affiliation: Cancer Research Institute, Slovak Academy of Sciences, Bratislava 81438, Slovakia.
authors.forename: Lubos
authors.initials: L
authors.lastname: Cipak
authors.affiliation: Cancer Research Institute, Slovak Academy of Sciences, Bratislava 81438, Slovakia.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Cipakova
authors.affiliation: Max F. Perutz Laboratories, Mass Spectrometry Facility, Vienna A-1030, Austria.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Anrather
authors.affiliation: Cancer Research Institute, Slovak Academy of Sciences, Bratislava 81438, Slovakia.
authors.forename: Barbora
authors.initials: B
authors.lastname: Mikolaskova
authors.affiliation: Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, Vienna A-1030, Austria.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Radtke
authors.affiliation: CRUK/MRC Oxford Institute for Radiation Oncology, Oxford OX37DQ , UK.
authors.forename: Sovan
authors.initials: S
authors.lastname: Sarkar
authors.affiliation: CRUK/MRC Oxford Institute for Radiation Oncology, Oxford OX37DQ , UK.
authors.forename: Chen-Chun
authors.initials: CC
authors.lastname: Pai
authors.affiliation: CRUK/MRC Oxford Institute for Radiation Oncology, Oxford OX37DQ , UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Blaikley
authors.affiliation: CRUK/MRC Oxford Institute for Radiation Oncology, Oxford OX37DQ , UK.
authors.forename: Carol
authors.initials: C
authors.lastname: Walker
authors.affiliation: University of Southern California, Los Angeles 90089-0911, USA.
authors.forename: Kuo-Fang
authors.initials: KF
authors.lastname: Shen
authors.affiliation: Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, Vienna A-1030, Austria.
authors.forename: Renee
authors.initials: R
authors.lastname: Schroeder
authors.affiliation: Department of Medical Biochemistry, Max F. Perutz Laboratories,Medical University of Vienna, Vienna A-1030, Austria.
authors.forename: Andrea
authors.initials: A
authors.lastname: Barta
authors.affiliation: University of Southern California, Los Angeles 90089-0911, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Forsburg
authors.affiliation: CRUK/MRC Oxford Institute for Radiation Oncology, Oxford OX37DQ , UK timothy.humphrey@oncology.ox.ac.uk.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Humphrey
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004260:DNA Repair / Q000235:genetics; D042822:Genomic Instability / Q000235:genetics*; D059765:Homologous Recombination / Q000235:genetics*; D012313:RNA / Q000737:chemistry / Q000235:genetics; D012322:RNA Precursors / Q000235:genetics*; D051135:Rad51 Recombinase / Q000235:genetics; D051721:Rad52 DNA Repair and Recombination Protein / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics*; D017381:Spliceosomes / Q000235:genetics / Q000378:metabolism
chemical_list: C000609220:Nrl1 protein, S pombe; C497194:RAD52 protein, human; D012322:RNA Precursors; D051721:Rad52 DNA Repair and Recombination Protein; D029702:Schizosaccharomyces pombe Proteins; D012313:RNA; D004247:DNA; D051135:Rad51 Recombinase