title: Functional and physical interaction of yeast Mgs1 with PCNA: impact on RAD6-dependent DNA damage tolerance.
abstract: Proliferating cell nuclear antigen (PCNA), a sliding clamp required for processive DNA synthesis, provides attachment sites for various other proteins that function in DNA replication, DNA repair, cell cycle progression and chromatin assembly. It has been shown that differential posttranslational modifications of PCNA by ubiquitin or SUMO play a pivotal role in controlling the choice of pathway for rescuing stalled replication forks. Here, we explored the roles of Mgs1 and PCNA in replication fork rescue. We provide evidence that Mgs1 physically associates with PCNA and that Mgs1 helps suppress the RAD6 DNA damage tolerance pathway in the absence of exogenous DNA damage. We also show that PCNA sumoylation inhibits the growth of mgs1 rad18 double mutants, in which PCNA sumoylation and the Srs2 DNA helicase coordinately prevent RAD52-dependent homologous recombination. The proposed roles for Mgs1, Srs2, and modified PCNA during replication arrest highlight the importance of modulating the RAD6 and RAD52 pathways to avoid genome instability.
authors.affiliation: Genome Dynamics Group, Research Institute for Microbial Diseases, Osaka University, Yamadaoka 3-1, Suita, Osaka 565-0871, Japan. hishida@biken.osaka-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Hishida
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ohya
authors.forename: Yoshino
authors.initials: Y
authors.lastname: Kubota
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kamada
authors.forename: Hideo
authors.initials: H
authors.lastname: Shinagawa
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D042822:Genomic Instability; D008239:Lysine / Q000737:chemistry; D009154:Mutation; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D018809:Proliferating Cell Nuclear Antigen; C063607:RAD18 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; C061376:SRS2 protein, S cerevisiae; C471606:RAD6 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D000251:Adenosine Triphosphatases; C506739:MGS1 protein, S cerevisiae; D004265:DNA Helicases; D008239:Lysine