title: Ybp2 associates with the central kinetochore of Saccharomyces cerevisiae and mediates proper mitotic progression.
abstract: The spindle checkpoint ensures the accurate segregation of chromosomes by monitoring the status of kinetochore attachment to microtubules. Simultaneous mutations in one of several kinetochore and cohesion genes and a spindle checkpoint gene cause a synthetic-lethal or synthetic-sick phenotype. A synthetic genetic array (SGA) analysis using a mad2Delta query mutant strain of yeast identified YBP2, a gene whose product shares sequence similarity with the product of YBP1, which is required for H(2)O(2)-induced oxidation of the transcription factor Yap1. ybp2Delta was sensitive to benomyl and accumulated at the mitotic stage of the cell cycle. Ybp2 physically associates with proteins of the COMA complex (Ctf19, Okp1, Mcm21, and Ame1) and 3 components of the Ndc80 complex (Ndc80, Nuf2, and Spc25 but not Spc24) in the central kinetochore and with Cse4 (the centromeric histone and CENP-A homolog). Chromatin-immunoprecipitation analyses revealed that Ybp2 associates specifically with CEN DNA. Furthermore, ybp2Delta showed synthetic-sick interactions with mutants of the genes that encode the COMA complex components. Ybp2 seems to be part of a macromolecular kinetochore complex and appears to contribute to the proper associations among the central kinetochore subcomplexes and the kinetochore-specific nucleosome.
authors.affiliation: Department of Molecular Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ohkuni
authors.forename: Rashid
authors.initials: R
authors.lastname: Abdulle
authors.forename: Amy Hin Yan
authors.initials: AH
authors.lastname: Tong
authors.forename: Charles
authors.initials: C
authors.lastname: Boone
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kitagawa
mesh_terms: D002503:Centromere; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins; D018386:Kinetochores / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules; D008938:Mitosis; D046912:Multiprotein Complexes; D009154:Mutation; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008941:Spindle Apparatus
chemical_list: D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; C493834:YBP2 protein, S cerevisiae; D004247:DNA