title: Rad52 sumoylation and its involvement in the efficient induction of homologous recombination.
abstract: The protein Rad52 is a key player in various types of homologous recombination and is essential to maintenance of genomic integrity. Although evidence indicates that Rad52 is modified by SUMO, the physiological relevance of this sumoylation remains unclear. Here, we identify the conditions under which Rad52 sumoylation is induced, and clarify the role of this modification in homologous recombination. Oligomerization of Rad52 was a prerequisite for sumoylation, and the modification occurred in the cell proceeding S phase being exposed to the DNA-damaging agent methyl methanesulfonate (MMS). Following exposure to MMS, sumoylated Rad52 accumulated in rad51 cells, but not in the recombination-related gene mutants, rad54, rad55, rad59, sgs1, or srs2. The accumulation of sumoylated Rad52 was suppressed in rad51 cells expressing Rad51-K191R, an ATPase-defective protein presumed to be recruited to ssDNA. Although the sumoylation defective mutant rad52-3KR (K10R/K11R/K220R) showed no defect in mating-type switching, which did not lead to Rad52 sumoylation in wild-type cells, the mutant did demonstrate a partial defect in MMS-induced interchromosomal homologous recombination.
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohuchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Seki
authors.forename: Dana
authors.initials: D
authors.lastname: Branzei
authors.forename: Daisuke
authors.initials: D
authors.lastname: Maeda
authors.forename: Ayako
authors.initials: A
authors.lastname: Ui
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ogiwara
authors.forename: Shusuke
authors.initials: S
authors.lastname: Tada
authors.forename: Takemi
authors.initials: T
authors.lastname: Enomoto
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000187:drug effects; D017931:DNA Primers; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D051721:Rad52 DNA Repair and Recombination Protein / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*
chemical_list: D017931:DNA Primers; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D004247:DNA; D008741:Methyl Methanesulfonate