Article open access publication

H3K23me2 is a new heterochromatic mark in Caenorhabditis elegans

Nucleic Acids Research, Oxford University Press (OUP), ISSN 0305-1048

Volume 43, 20, 2015

DOI:10.1093/nar/gkv1063, Dimensions: pub.1059932046, PMC: PMC4787770, PMID: 26476455,



  1. (1) University of Copenhagen, grid.5254.6, KU
  2. (2) University of Southern Denmark, grid.10825.3e, SDU






Genome-wide analyses in Caenorhabditis elegans show that post-translational modifications (PTMs) of histones are evolutionary conserved and distributed along functionally distinct genomic domains. However, a global profile of PTMs and their co-occurrence on the same histone tail has not been described in this organism. We used mass spectrometry based middle-down proteomics to analyze histone H3 N-terminal tails from C. elegans embryos for the presence, the relative abundance and the potential cross-talk of co-existing PTMs. This analysis highlighted that the lysine 23 of histone H3 (H3K23) is extensively modified by methylation and that tri-methylated H3K9 (H3K9me3) is exclusively detected on histone tails with di-methylated H3K23 (H3K23me2). Chromatin immunoprecipitation approaches revealed a positive correlation between H3K23me2 and repressive marks. By immunofluorescence analyses, H3K23me2 appears differentially regulated in germ and somatic cells, in part by the action of the histone demethylase JMJD-1.2. H3K23me2 is enriched in heterochromatic regions, localizing in H3K9me3 and heterochromatin protein like-1 (HPL-1)-positive foci. Biochemical analyses indicated that HPL-1 binds to H3K23me2 and interacts with a conserved CoREST repressive complex. Thus, our study suggests that H3K23me2 defines repressive domains and contributes to organizing the genome in distinct heterochromatic regions during embryogenesis.

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Times Cited: 20

Field Citation Ratio (FCR): 2.79

Relative Citation ratio (RCR): 0.58

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