title: R-loop mediated transcription-associated recombination in trf4Δ mutants reveals new links between RNA surveillance and genome integrity.
abstract: To get further insight into the factors involved in the maintenance of genome integrity we performed a screening of Saccharomyces cerevisiae deletion strains inducing hyperrecombination. We have identified trf4, a gene encoding a non-canonical polyA-polymerase involved in RNA surveillance, as a factor that prevents recombination between DNA repeats. We show that trf4Δ confers a transcription-associated recombination phenotype that is mediated by the nascent mRNA. In addition, trf4Δ also leads to an increase in the mutation frequency. Both genetic instability phenotypes can be suppressed by overexpression of RNase H and are exacerbated by overexpression of the human cytidine deaminase AID. These results suggest that in the absence of Trf4 R-loops accumulate co-transcriptionally increasing the recombination and mutation frequencies. Altogether our data indicate that Trf4 is necessary for both mRNA surveillance and maintenance of genome integrity, serving as a link between RNA and DNA metabolism in S. cerevisiae.
authors.affiliation: Departamento de Biología Molecular, Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Seville, Spain.
authors.forename: Sandra
authors.initials: S
authors.lastname: Gavaldá
authors.forename: Mercedes
authors.initials: M
authors.lastname: Gallardo
authors.forename: Rosa
authors.initials: R
authors.lastname: Luna
authors.forename: Andrés
authors.initials: A
authors.lastname: Aguilera
mesh_terms: D000243:Adenosine Deaminase / Q000378:metabolism; D055162:Biocatalysis; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016681:Genome, Fungal / Q000235:genetics*; D042822:Genomic Instability / Q000235:genetics; D006801:Humans; D009154:Mutation / Q000235:genetics*; D009690:Nucleic Acid Conformation; D010641:Phenotype; D026723:Polyadenylation / Q000235:genetics; D017434:Protein Structure, Tertiary; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D004259:DNA-Directed DNA Polymerase; C487545:PAP2 protein, S cerevisiae; D000243:Adenosine Deaminase