title: Cut1/separase-dependent roles of multiple phosphorylation of fission yeast cohesion subunit Rad21 in post-replicative damage repair and mitosis.
abstract: Cohesin is a multiprotein complex essential for sister-chromatid cohesion. It plays a pivotal role in proper chromosome segregation and DNA damage repair. The mitotic behavior of cohesin is controlled through its phosphorylation, which possibly induces the dissociation of cohesin from chromosomes and enhances its susceptibility to separase. Here, we report using mass spectrometry and anti-phospho antibodies that the central domain of Rad21, the separase-target subunit of Schizosaccharomyces pombe cohesin, is regulated by various kinase-induced phosphorylation at nine residues, indicating the multiple roles for S. pombe cohesin. In vegetative and non-dividing G(0) cells, Rad21 is phosphorylated by unknown S/TP-consensus kinases, in mitotic and non-mitotic cells by polo/Plo1 and CDK, and in DNA-damaged cells by Rad3/ATR. While mitotic phosphorylation is implicated in the dissociation of Rad21 and its cleavage by separase in anaphase, the Rad3/ATR-dependent damage-induced phosphorylation occurs intensively at the time of repair completion, and only in post-replicative cells. This damage-induced Rad21 phosphorylation is involved in the recovery process of cells from checkpoint arrest, and needed for the removal of cohesin by separase after the completion of damage repair. These complex phospho-regulations of Rad21 indicate the functional significance of cohesin in cell adaptation to a variety of cellular conditions.
authors.affiliation: CREST Research Program, Japan Science and Technology Corporation, Graduate School of Biostudies, Kyoto University, Yoshida-Honmachi, Kyoto, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Adachi
authors.forename: Aya
authors.initials: A
authors.lastname: Kokubu
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ebe
authors.forename: Koji
authors.initials: K
authors.lastname: Nagao
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yanagida
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D004260:DNA Repair / Q000502:physiology*; D010450:Endopeptidases / Q000378:metabolism*; D007120:Immunochemistry; D013058:Mass Spectrometry; D008938:Mitosis / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D012568:Schizosaccharomyces / Q000378:metabolism / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism*; D064247:Separase
chemical_list: D018797:Cell Cycle Proteins; C103135:Cut1 protein, S pombe; D009687:Nuclear Proteins; D010750:Phosphoproteins; C092957:Rad21 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D010450:Endopeptidases; D064247:Separase