title: The resistance of DMC1 D-loops to dissociation may account for the DMC1 requirement in meiosis.
abstract: The ubiquitously expressed Rad51 recombinase and the meiosis-specific Dmc1 recombinase promote the formation of strand-invasion products (D-loops) between homologous molecules. Strand-invasion products are processed by either the double-strand break repair (DSBR) or synthesis-dependent strand annealing (SDSA) pathway. D-loops destined to be processed by SDSA need to dissociate, producing non-crossovers, and those destined for DSBR should resist dissociation to generate crossovers. The mechanism that channels recombination intermediates into different homologous-recombination pathways is unknown. Here we show that D-loops in a human DMC1-driven reaction are substantially more resistant to dissociation by branch-migration proteins such as RAD54 than those formed by RAD51. We propose that the intrinsic resistance to dissociation of DMC1 strand-invasion intermediates may account for why DMC1 is essential to ensure the proper segregation of chromosomes in meiosis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Bugreev
authors.forename: Roberto J
authors.initials: RJ
authors.lastname: Pezza
authors.forename: Olga M
authors.initials: OM
authors.lastname: Mazina
authors.forename: Oleg N
authors.initials: ON
authors.lastname: Voloshin
authors.forename: R Daniel
authors.initials: RD
authors.lastname: Camerini-Otero
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Mazin
mesh_terms: D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D020090:Chromosome Segregation; D004265:DNA Helicases; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008540:Meiosis; D008957:Models, Genetic; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D017434:Protein Structure, Tertiary; D051135:Rad51 Recombinase / Q000737:chemistry / Q000378:metabolism; D011995:Recombination, Genetic; D015534:Trans-Activators / Q000737:chemistry / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C510357:MND1 protein, human; D009687:Nuclear Proteins; C443678:PSMC3IP protein, human; D015534:Trans-Activators; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C074556:DMC1 protein, human; D004265:DNA Helicases; C103532:RAD54L protein, human