title: Nucleolar association of pEg7 and XCAP-E, two members of Xenopus laevis condensin complex in interphase cells.
abstract: Cell cycle dynamics and localization of condensins--multiprotein complexes involved in late stages of mitotic chromosome condensation--were studied in Xenopus laevis XL2 cell line. Western blot analysis of synchronized cells showed that the ratio of levels of both pEg7 and XCAP-E to beta-tubulin levels remains almost constant from G1 to M phase. pEg7 and XCAP-E were localized to the mitotic chromosomes and were detected in interphase nuclei. Immunostaining for condensins and nucleolar proteins UBF, fibrillarin and B23 revealed that both XCAP-E and pEg7 are localized in the granular component of the nucleolus. Nucleolar labeling of both proteins is preserved in segregated nucleoli after 6 hours of incubation with actinomycin D (5 mg/ml), but the size of the labeled zone was significantly smaller. The data suggest a novel interphase function of condensin subunits in spatial organization of the nucleolus and/or ribosome biogenesis.
authors.affiliation: Groupe Structure Dynamique de la Chromatine, CNRS, UMR 6061, Faculte de Medicine, 35043 Rennes, France.
authors.forename: Rustem
authors.initials: R
authors.lastname: Uzbekov
authors.forename: Elmira
authors.initials: E
authors.lastname: Timirbulatova
authors.forename: Erwan
authors.initials: E
authors.lastname: Watrin
authors.forename: Fabien
authors.initials: F
authors.lastname: Cubizolles
authors.forename: David
authors.initials: D
authors.lastname: Ogereau
authors.forename: Pavel
authors.initials: P
authors.lastname: Gulak
authors.forename: Vincent
authors.initials: V
authors.lastname: Legagneux
authors.forename: Vladimir Ju
authors.initials: VJ
authors.lastname: Polyakov
authors.forename: Katherine
authors.initials: K
authors.lastname: Le Guellec
authors.forename: Igor
authors.initials: I
authors.lastname: Kireev
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D004527:Egg Proteins / Q000737:chemistry / Q000378:metabolism*; D007399:Interphase / Q000502:physiology*; D046911:Macromolecular Substances; D016253:Microscopy, Immunoelectron; D046912:Multiprotein Complexes; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D029867:Xenopus Proteins; D014982:Xenopus laevis
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C116601:Eg7 protein, Xenopus; D004527:Egg Proteins; D046911:Macromolecular Substances; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; D012335:RNA, Ribosomal; C090453:XCAP-E protein, Xenopus; D029867:Xenopus Proteins; C108312:condensin complexes; D000251:Adenosine Triphosphatases