title: Global analysis of core histones reveals nucleosomal surfaces required for chromosome bi-orientation.
abstract: The attachment of sister kinetochores to microtubules from opposite spindle poles is essential for faithful chromosome segregation. Kinetochore assembly requires centromere-specific nucleosomes containing the histone H3 variant CenH3. However, the functional roles of the canonical histones (H2A, H2B, H3, and H4) in chromosome segregation remain elusive. Using a library of histone point mutants in Saccharomyces cerevisiae, 24 histone residues that conferred sensitivity to the microtubule-depolymerizing drugs thiabendazole (TBZ) and benomyl were identified. Twenty-three of these mutations were clustered at three spatially separated nucleosomal regions designated TBS-I, -II, and -III (TBZ/benomyl-sensitive regions I-III). Elevation of mono-polar attachment induced by prior nocodazole treatment was observed in H2A-I112A (TBS-I), H2A-E57A (TBS-II), and H4-L97A (TBS-III) cells. Severe impairment of the centromere localization of Sgo1, a key modulator of chromosome bi-orientation, occurred in H2A-I112A and H2A-E57A cells. In addition, the pericentromeric localization of Htz1, the histone H2A variant, was impaired in H4-L97A cells. These results suggest that the spatially separated nucleosomal regions, TBS-I and -II, are necessary for Sgo1-mediated chromosome bi-orientation and that TBS-III is required for Htz1 function.
authors.affiliation: Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawashima
authors.forename: Yu
authors.initials: Y
authors.lastname: Nakabayashi
authors.forename: Kazuko
authors.initials: K
authors.lastname: Matsubara
authors.forename: Norihiko
authors.initials: N
authors.lastname: Sano
authors.forename: Takemi
authors.initials: T
authors.lastname: Enomoto
authors.forename: Kozo
authors.initials: K
authors.lastname: Tanaka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Seki
authors.forename: Masami
authors.initials: M
authors.lastname: Horikoshi
mesh_terms: D000595:Amino Acid Sequence; D001542:Benomyl / Q000494:pharmacology; D002503:Centromere / Q000378:metabolism / Q000648:ultrastructure; D043171:Chromosomal Instability; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000502:physiology*; D025141:Drug Resistance, Fungal / Q000235:genetics; D006657:Histones / Q000235:genetics / Q000502:physiology*; D008870:Microtubules / Q000187:drug effects; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015739:Nocodazole / Q000494:pharmacology; D009687:Nuclear Proteins / Q000502:physiology; D009707:Nucleosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D017354:Point Mutation; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D008941:Spindle Apparatus / Q000378:metabolism / Q000648:ultrastructure; D013827:Thiabendazole / Q000494:pharmacology; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D006657:Histones; C493530:Htz1 protein, S cerevisiae; D009687:Nuclear Proteins; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; C482640:Sgo1 protein, S cerevisiae; D050257:Tubulin Modulators; D013827:Thiabendazole; D015739:Nocodazole; D001542:Benomyl