title: Ctf3p, the Mis6 budding yeast homolog, interacts with Mcm22p and Mcm16p at the yeast outer kinetochore.
abstract: The budding yeast kinetochore is composed of an inner and outer protein complex, which binds to centromere (CEN) DNA and attaches to microtubules. We performed a genetic synthetic dosage lethality screen to identify novel kinetochore proteins in a collection of chromosome transmission fidelity mutants. Our screen identified several new kinetochore-related proteins including YLR381Wp/Ctf3p, which is a member of a conserved family of centromere-binding proteins. Ctf3p interacts with Mcm22p, Mcm16p, and the outer kinetochore protein Ctf19p. We used chromatin immunoprecipitation to demonstrate that Ctf3p, Mcm22p, and Mcm16p bind to CEN DNA in a Ctf19p-dependent manner. In addition, Ctf3p, Mcm22p, and Mcm16p have a localization pattern similar to other kinetochore proteins. The fission yeast Ctf3p homolog, Mis6, is required for loading of a CENP-A centromere specific histone, Cnp1, onto centromere DNA. We find however that Ctf3p is not required for loading of the budding yeast CENP-A homolog, Cse4p, onto CEN DNA. In contrast, Ctf3p and Ctf19p fail to bind properly to the centromere in a cse4-1 mutant strain. We conclude that the requirements for CENP-A loading onto centromere DNA differ in fission versus budding yeast.
authors.affiliation: Department of Medical Genetics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada.
authors.forename: Vivien
authors.initials: V
authors.lastname: Measday
authors.forename: Dale W
authors.initials: DW
authors.lastname: Hailey
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pot
authors.forename: Scott A
authors.initials: SA
authors.lastname: Givan
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Hyland
authors.forename: Gerard
authors.initials: G
authors.lastname: Cagney
authors.forename: Stan
authors.initials: S
authors.lastname: Fields
authors.forename: Trisha N
authors.initials: TN
authors.lastname: Davis
authors.forename: Philip
authors.initials: P
authors.lastname: Hieter
mesh_terms: D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins; D020090:Chromosome Segregation / Q000502:physiology; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000502:physiology*; D018386:Kinetochores / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid
chemical_list: D018797:Cell Cycle Proteins; C444703:Ctf3 protein, S cerevisiae; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C116308:MCM16 protein, S cerevisiae; C118345:MCM22 protein, S cerevisiae; C107314:Mis6 protein, S pombe; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins