title: Chromatin loading of Smc5/6 is induced by DNA replication but not by DNA double-strand breaks.
abstract: Smc6, a member of the structural maintenance of chromosomes (SMC) family of proteins, forms a complex with related Smc5. Genetic analyses of yeast have demonstrated the involvement of Smc6 in DNA repair and checkpoint responses. In this study, we investigated the role of the Smc5/6 complex in higher eukaryotes by analyzing its behavior in Xenopus laevis egg extracts. Smc5/6 was loaded onto chromatin during DNA replication in a manner dependent on the initiation of DNA synthesis, and it dissociated from chromatin during mitosis. Moreover, the induction of DNA double-strand breaks following replication did not significantly affect the amount of chromatin-associated Smc6. These findings suggest that the Smc5/6 complex is regulated during the cell cycle, presumably in anticipation of DNA damage that may arise during replication.
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuyama
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Inou
authors.forename: Masayuki
authors.initials: M
authors.lastname: Seki
authors.forename: Takahiko
authors.initials: T
authors.lastname: Seki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kumata
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Keiji
authors.initials: K
authors.lastname: Kimura
authors.forename: Fumio
authors.initials: F
authors.lastname: Hanaoka
authors.forename: Takemi
authors.initials: T
authors.lastname: Enomoto
authors.forename: Shusuke
authors.initials: S
authors.lastname: Tada
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004249:DNA Damage; D004261:DNA Replication; D016195:G2 Phase; D008938:Mitosis; D016196:S Phase; D029867:Xenopus Proteins / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C516333:Smc5 protein, Xenopus; D029867:Xenopus Proteins; C516334:smc6.1 protein, Xenopus