Ctf3p, the Mis6 budding yeast homolog, interacts with Mcm22p and Mcm16p at the yeast outer kinetochore.
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.
Measday
Vivien
V
Department of Medical Genetics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada.
Hailey
Dale W
DW
Pot
Isabelle
I
Givan
Scott A
SA
Hyland
Katherine M
KM
Cagney
Gerard
G
Fields
Stan
S
Davis
Trisha N
TN
Hieter
Philip
P
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
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