Abstract
Heterochromatin is defined by distinct posttranslational modifications on histones, such as methylation of histone H3 at lysine 9 (H3K9), which allows heterochromatin protein 1 (HP1)-related chromodomain proteins to bind. Heterochromatin is frequently found near CENP-A chromatin, which is the key determinant of kinetochore assembly. We have discovered that the RNA interference (RNAi)-directed heterochromatin flanking the central kinetochore domain at fission yeast centromeres is required to promote CENP-A(Cnp1) and kinetochore assembly over the central domain. The H3K9 methyltransferase Clr4 (Suv39); the ribonuclease Dicer, which cleaves heterochromatic double-stranded RNA to small interfering RNA (siRNA); Chp1, a component of the RNAi effector complex (RNA-induced initiation of transcriptional gene silencing; RITS); and Swi6 (HP1) are required to establish CENP-A(Cnp1) chromatin on naïve templates. Once assembled, CENP-A(Cnp1) chromatin is propagated by epigenetic means in the absence of heterochromatin. Thus, another, potentially conserved, role for centromeric RNAi-directed heterochromatin has been identified.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cell Cycle Proteins / metabolism
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Centromere / metabolism*
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Chromatin / metabolism*
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Chromosomal Proteins, Non-Histone / genetics
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Chromosomal Proteins, Non-Histone / metabolism*
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Chromosome Segregation
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Chromosomes, Fungal / genetics
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Chromosomes, Fungal / metabolism
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DNA, Fungal / genetics
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DNA, Fungal / metabolism
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Epigenesis, Genetic
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Heterochromatin / metabolism*
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Histone-Lysine N-Methyltransferase
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Kinetochores / metabolism
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Methyltransferases / metabolism
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RNA Interference*
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RNA, Fungal / genetics
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RNA, Fungal / metabolism
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RNA, Small Interfering / genetics
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RNA, Small Interfering / metabolism
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Ribonuclease III / metabolism
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Schizosaccharomyces / genetics
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Schizosaccharomyces / metabolism*
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Schizosaccharomyces pombe Proteins / genetics
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Schizosaccharomyces pombe Proteins / metabolism*
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Transformation, Genetic
Substances
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Cell Cycle Proteins
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Chp1 protein, S pombe
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Chromatin
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Chromosomal Proteins, Non-Histone
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Cnp1 protein, S pombe
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DNA, Fungal
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Heterochromatin
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RNA, Fungal
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RNA, Small Interfering
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Schizosaccharomyces pombe Proteins
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Swi6 protein, S pombe
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Methyltransferases
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Histone-Lysine N-Methyltransferase
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clr4 protein, S pombe
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Ribonuclease III