Chromatin assembly factor I and Hir proteins contribute to building functional kinetochores in S. cerevisiae.
Budding yeast centromeres are comprised of approximately 125-bp DNA sequences that direct formation of the kinetochore, a specialized chromatin structure that mediates spindle attachment to chromosomes. We report here a novel role for the histone deposition complex chromatin assembly factor I (CAF-I) in building centromeric chromatin. The contribution of CAF-I to kinetochore function overlaps that of the Hir proteins, which have also been implicated in nucleosome formation and heterochromatic gene silencing. cacDelta hirDelta double mutant cells lacking both CAF-I and Hir proteins are delayed in anaphase entry in a spindle assembly checkpoint-dependent manner. Further, cacDelta and hirDelta deletions together cause increased rates of chromosome missegregation, genetic synergies with mutations in kinetochore protein genes, and alterations in centromeric chromatin structure. Finally, CAF-I subunits and Hir1 are enriched at centromeres, indicating that these proteins make a direct contribution to centromeric chromatin structures.
Sharp
Judith A
JA
Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Franco
Alexa A
AA
Osley
Mary Ann
MA
Kaufman
Paul D
PD
D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D020090:Chromosome Segregation; D004268:DNA-Binding Proteins / Q000502:physiology*; D018386:Kinetochores / Q000502:physiology*; D008938:Mitosis / Q000502:physiology; D009154:Mutation; D009687:Nuclear Proteins / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000502:physiology* / Q000648:ultrastructure
D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins