title: Differential expression and requirements for Schizosaccharomyces pombe RAD52 homologs in DNA repair and recombination.
abstract: In fission yeast two RAD52 homologs have been identified, rad22A(+) and rad22B(+). Two-hybrid experiments and GST pull-down assays revealed physical interaction between Rad22A and Rad22B, which is dependent on the N-terminal regions. Interaction with Rhp51 is dependent on the C-terminal parts of either protein. Both Rad22A and Rad22B also interact with RPA. The expression of rad22B(+) in mitotically dividing cells is very low in comparison with rad22A(+) but is strongly enhanced after induction of meiosis, in contrast to rad22A(+). Rad22B mutant cells are not hypersensitive to DNA-damaging agents (X-rays, UV and cisplatin) and display normal levels of recombination. In these respects the Schizosaccharomyces pombe rad22B mutant resembles the weak phenotype of vertebrate cells deficient for RAD52. Mutation of rad22A(+) leads to severe sensitivity to DNA-damaging agents and to defects in recombination. In a rad22Arad22B double mutant a further increase in sensitivity to DNA-damaging agents and additional mitotic recombination defects were observed. The data presented here indicate that Rad22A and Rad22B have overlapping roles in repair and recombination, although specialized functions for each protein cannot be excluded.
authors.affiliation: MGC Department of Radiation Genetics and Chemical Mutagenesis, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands.
authors.forename: Michael
authors.initials: M
authors.lastname: van den Bosch
authors.forename: José B M
authors.initials: JB
authors.lastname: Zonneveld
authors.forename: Kees
authors.initials: K
authors.lastname: Vreeken
authors.forename: Femke A T
authors.initials: FA
authors.lastname: de Vries
authors.forename: Paul H M
authors.initials: PH
authors.lastname: Lohman
authors.forename: Albert
authors.initials: A
authors.lastname: Pastink
mesh_terms: D004265:DNA Helicases / Q000378:metabolism; D004260:DNA Repair; D004271:DNA, Fungal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008540:Meiosis; D009154:Mutation; D010641:Phenotype; D051135:Rad51 Recombinase; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C084232:RHP51 protein, S pombe; C450139:Rad22B protein, S pombe; D051721:Rad52 DNA Repair and Recombination Protein; D029702:Schizosaccharomyces pombe Proteins; C085412:rad52 protein, S pombe; D051135:Rad51 Recombinase; D004265:DNA Helicases; C099034:Rhp54 protein, S pombe