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Chromatin immunoprecipitation of wild type msc1D and swr1D fission yeast to determine genome-wide distribution of H2A.Z

ABSTRACT: Eukaryotic genomes are repetitively packaged into chromatin by nucleosomes, however they are regulated by the differences between nucleosomes, which establish various chromatin states. Replication-independent histone exchange could potentially perturb chromatin status if histone exchange chaperones, such as Swr1C, loaded histone variants into wrong sites. Here we use ChIP-chip analysis of H2A.Z-myc to show that in S.pombe, like S.cerevisiae, Swr1C is required for loading H2A.Z into specific sites, including the promoters of lowly expressed genes. However S.pombe Swr1C has an extra subunit, Msc1, which is a JumonjiC-domain protein of the Lid/Jarid1 family. The absence of Msc1 does not disrupt the S.pombe Swr1C or H2A.Z distribution in euchromatin. However in the absence of either Msc1 or Swr1 H2A.Z is ectopically found in the inner centromere and in subtelomeric chromatin. Normally this subtelomeric region, which appears to be a novel chromatin domain that we term ST-chromatin, not only lacks H2A.Z but also shows uniformly lower levels of H3K4me2, H4K5 and K12K5 acetylation than euchromatin. It also disproportionately contains the most lowly expressed genes during vegetative growth, including many meiotic-specific genes. These data describe H2A.Z distribution in S.pombe and identify a new mode of chromatin surveillance and maintenance based on negative regulation of histone variant misincorporation.

ORGANISM(S): Schizosaccharomyces pombe

SUBMITTER: Luke Buchanan

PROVIDER: E-MEXP-1986 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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