title: Mre11 and Exo1 contribute to the initiation and processivity of resection at meiotic double-strand breaks made independently of Spo11.
abstract: During meiosis DNA double-strand breaks (DSBs) are induced and repaired by homologous recombination to create gene conversion and crossover products. Mostly these DSBs are made by Spo11, which covalently binds to the DSB ends. More rarely in Saccharomyces cerevisiae, other meiotic DSBs are formed by self-homing endonucleases such as VDE, which is site specific and does not covalently bind to the DSB ends. We have used experimentally located VDE-DSB sites to analyse an intermediate step in homologous recombination, resection of the single-strand ending 5' at the DSB site. Analysis of strains with different mutant alleles of MRE11 (mre11-58S and mre11-H125N) and deleted for EXO1 indicated that these two nucleases make significant contributions to repair of VDE-DSBs. Physical analysis of single-stranded repair intermediates indicates that efficient initiation and processivity of resection at VDE-DSBs require both Mre11 and Exo1, with loss of function for either protein causing severe delay in resection. We propose that these experiments model what happens at Spo11-DSBs after removal of the covalently bound protein, and that Mre11 and Exo1 are the major nucleases involved in creating resection tracts of widely varying lengths typical of meiotic recombination.
authors.affiliation: Department of Molecular Biology & Biotechnology, Krebs Institute, The University of Sheffield, Sheffield, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Hodgson
authors.forename: Yaroslav
authors.initials: Y
authors.lastname: Terentyev
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Johnson
authors.forename: Anna
authors.initials: A
authors.lastname: Bishop-Bailey
authors.forename: Thibaut
authors.initials: T
authors.lastname: Angevin
authors.forename: Adam
authors.initials: A
authors.lastname: Croucher
authors.forename: Alastair S H
authors.initials: AS
authors.lastname: Goldman
mesh_terms: D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000502:physiology*; D005785:Gene Conversion; D008540:Meiosis; D009154:Mutation; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000502:physiology; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology*; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D004277:DNA, Single-Stranded; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D006180:Proton-Translocating ATPases; D029701:Saccharomyces cerevisiae Proteins; D000099257:Meiotic Recombination Protein SPO11; C094191:MRE11 protein, S cerevisiae; C028450:exodeoxyribonuclease I; C081687:VMA1 protein, S cerevisiae