title: Dual regulation of Dmc1-driven DNA strand exchange by Swi5-Sfr1 activation and Rad22 inhibition.
abstract: Both ubiquitously expressed Rad51 and meiosis-specific Dmc1 are required for crossover production during meiotic recombination. The budding yeast Rad52 and its fission yeast ortholog, Rad22, are "mediators;" i.e., they help load Rad51 onto ssDNA coated with replication protein A (RPA). Here we show that the Swi5-Sfr1 complex from fission yeast is both a mediator that loads Dmc1 onto ssDNA and a direct "activator" of DNA strand exchange by Dmc1. In stark contrast, Rad22 inhibits Dmc1 action by competing for its binding to RPA-coated ssDNA. Thus, Rad22 plays dual roles in regulating meiotic recombination: activating Rad51 and inhibiting Dmc1.
authors.affiliation: Department of Biological Sciences, School and Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa 226-8501, Japan;
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Murayama
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kurokawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tsutsui
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwasaki
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D003434:Crossing Over, Genetic / Q000235:genetics; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000235:genetics; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D059765:Homologous Recombination; D008540:Meiosis; D011485:Protein Binding; D055550:Protein Stability; D051721:Rad52 DNA Repair and Recombination Protein / Q000378:metabolism; D045522:Recombinases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C514358:Dmc1 protein, S pombe; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D045522:Recombinases; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C514357:Sfr1 protein, S pombe; C483769:Swi5 protein, S pombe; C085412:rad52 protein, S pombe; D000255:Adenosine Triphosphate
keywords: Dmc1; Rad52 mediator; crossover; homologous recombination; meiosis; negative regulation