title: Chromatin binding of RCC1 during mitosis is important for its nuclear localization in interphase.
abstract: RCC1, a guanine nucleotide exchange factor of the small GTPase Ran, plays various roles throughout the cell cycle. However, the functions of RCC1 in biological processes in vivo are still unclear. In particular, although RCC1 has multifunctional domains, the biological significance of each domain is unclear. To examine each domain of RCC1, we established an RCC1 conditional knockout chicken DT40 cell line and introduced various RCC1 mutants into the knockout cells. We found that nuclear reformation did not occur properly in RCC1-deficient cells and examined whether specific RCC1 mutants could rescue this phenotype. Surprisingly, we found that neither the nuclear localization signal nor the chromatin-binding domain of RCC1 is essential for its function. However, codisruption of these domains resulted in defective nuclear reformation, which was rescued by artificial nuclear localization of RCC1. Our data indicate that chromatin association of RCC1 during mitosis is crucial for its proper nuclear localization in the next interphase. Moreover, proper nuclear localization of RCC1 in interphase is essential for its function through its nucleotide exchange activity.
authors.affiliation: Department of Molecular Genetics, National Institute of Genetics, and Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Furuta
authors.affiliation: Department of Molecular Genetics, National Institute of Genetics, and Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hori
authors.affiliation: Department of Molecular Genetics, National Institute of Genetics, and Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan tfukagaw@lab.nig.ac.jp tfukagawa@fbs.osaka-u.ac.jp.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Fukagawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002645:Chickens; D002843:Chromatin / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D055786:Gene Knockout Techniques; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D007399:Interphase / Q000502:physiology*; D008938:Mitosis / Q000502:physiology*; D019913:Nuclear Localization Signals / Q000378:metabolism; D020931:ran GTP-Binding Protein / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D019913:Nuclear Localization Signals; D020931:ran GTP-Binding Protein