Abstract
Centromeres are heterochromatic in many organisms, but the mitotic function of this silent chromatin remains unknown. During cell division, newly replicated sister chromatids must cohere until anaphase when Scc1/Rad21-mediated cohesion is destroyed. In metazoans, chromosome arm cohesins dissociate during prophase, leaving centromeres as the only linkage before anaphase. It is not known what distinguishes centromere cohesion from arm cohesion. Fission yeast Swi6 (a Heterochromatin protein 1 counterpart) is a component of silent heterochromatin. Here we show that this heterochromatin is specifically required for cohesion between sister centromeres. Swi6 is required for association of Rad21-cohesin with centromeres but not along chromosome arms and, thus, acts to distinguish centromere from arm cohesion. Therefore, one function of centromeric heterochromatin is to attract cohesin, thereby ensuring sister centromere cohesion and proper chromosome segregation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cell Cycle Proteins*
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Centromere / metabolism*
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Centromere / physiology
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Chromatids / metabolism
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Chromosomal Proteins, Non-Histone
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Chromosome Segregation
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Chromosomes, Fungal / metabolism
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Cohesins
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Fungal Proteins / genetics
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Fungal Proteins / metabolism*
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Heterochromatin / metabolism*
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In Situ Hybridization, Fluorescence
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Metaphase
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Nuclear Proteins / metabolism*
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Phosphoproteins / metabolism*
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Saccharomyces cerevisiae Proteins*
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Schizosaccharomyces / genetics
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Schizosaccharomyces / physiology*
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Schizosaccharomyces pombe Proteins / genetics
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Schizosaccharomyces pombe Proteins / metabolism*
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Transcription, Genetic
Substances
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Cell Cycle Proteins
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Chromosomal Proteins, Non-Histone
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Fungal Proteins
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Heterochromatin
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MCD1 protein, S cerevisiae
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Nuclear Proteins
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Phosphoproteins
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Rad21 protein, S pombe
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SWI6 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Schizosaccharomyces pombe Proteins
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Transcription Factors
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psm1 protein, S pombe
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ura4 protein, S pombe