title: Propagation of Polycomb-repressed chromatin requires sequence-specific recruitment to DNA.
abstract: Epigenetic inheritance models posit that during Polycomb repression, Polycomb repressive complex 2 (PRC2) propagates histone H3 lysine 27 trimethylation (H3K27me3) independently of DNA sequence. We show that insertion of Polycomb response element (PRE) DNA into theDrosophilagenome creates extended domains of H3K27me3-modified nucleosomes in the flanking chromatin and causes repression of a linked reporter gene. After excision of PRE DNA, H3K27me3 nucleosomes become diluted with each round of DNA replication, and reporter gene repression is lost. After excision in replication-stalled cells, H3K27me3 levels stay high and repression persists. H3K27me3-marked nucleosomes therefore provide a memory of repression that is transmitted in a sequence-independent manner to daughter strand DNA during replication. In contrast, propagation of H3K27 trimethylation to newly incorporated nucleosomes requires sequence-specific targeting of PRC2 to PRE DNA.
authors.affiliation: Laboratory of Chromatin Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Friederike
authors.identifier: 0000-0002-6219-7609
authors.initials: F
authors.lastname: Laprell
authors.affiliation: Laboratory of Chromatin Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Finkl
authors.affiliation: Laboratory of Chromatin Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany. muellerj@biochem.mpg.de.
authors.forename: Jürg
authors.identifier: 0000-0003-2391-4641
authors.initials: J
authors.lastname: Müller
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D017930:Genes, Reporter; D006657:Histones / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D008745:Methylation; D009707:Nucleosomes / Q000378:metabolism; D063151:Polycomb Repressive Complex 2 / Q000378:metabolism*; D020218:Response Elements
chemical_list: D002843:Chromatin; D029721:Drosophila Proteins; D006657:Histones; D009707:Nucleosomes; D004247:DNA; D063151:Polycomb Repressive Complex 2; D008239:Lysine