title: Identification of a novel non-structural maintenance of chromosomes (SMC) component of the SMC5-SMC6 complex involved in DNA repair.
abstract: Structural maintenance of chromosomes (SMC) proteins play central roles in chromosome organization and dynamics. They have been classified into six subtypes, termed SMC1 to SMC6, and function as heterodimer components of large protein complexes that also include several non-SMC proteins. The SMC2-SMC4 and SMC1-SMC3 complexes are also known as condensin and cohesin, respectively, but the recently identified SMC5 and SMC6 complex is less well characterized. Here, we report that NSE1 from Saccharomyces cerevisiae encodes a novel non-SMC component of the SMC5(Yol034wp)-SMC6(Rhc18p) complex corresponding to the 2-3-MDa molecular mass. Nse1p is essential for cell proliferation and localizes primarily in the nucleus. nse1 mutants are highly sensitive to DNA-damaging treatments and exhibit abnormal cellular morphologies, suggesting aberrant mitosis as a terminal morphological phenotype. These results are consistent with the reported features of the Schizosaccharomyces pombe SMC6 gene, rad18, which is thought to be involved in recombinational DNA repair. We conclude that Nse1p and the SMC5-SMC6 heterodimer together form a high molecular mass complex that is conserved in eukaryotes and required for both DNA repair and proliferation.
authors.affiliation: Research and Education Center for Genetic Information, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Fujioka
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kimata
authors.forename: Koji
authors.initials: K
authors.lastname: Nomaguchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Kohno
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D002850:Chromatography, Gel; D002875:Chromosomes / Q000737:chemistry* / Q000648:ultrastructure*; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics*; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics*; D012568:Schizosaccharomyces / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D014466:Ultraviolet Rays
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C460369:NSE1 protein, S cerevisiae; D009687:Nuclear Proteins; C063607:RAD18 protein, S cerevisiae; C486627:SMC5 protein, S cerevisiae; C486631:SMC6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C486628:Smc5 protein, S pombe; C486630:smc6 protein, S pombe