title: Switching between Epigenetic States at Pericentromeric Heterochromatin.
abstract: Pericentromeric DNA represents a large fraction of the mammalian genome that is usually assembled into heterochromatin. Recent advances have revealed that the composition of pericentromeric heterochromatin is surprisingly dynamic. Indeed, high levels of histone H3 trimethylation on lysine 9 (H3K9me3) and DNA methylation normally characterize the repressive environment of this region. However, in specific tissues and in cancer cells, Polycomb proteins can occupy pericentromeric heterochromatin and act as a molecular sink for transcriptional regulators. Restoring heterochromatin methylation marks could, thus, be an important way to bring back normal gene expression programs in disease. Here, I discuss the potential mechanisms by which Polycomb complexes are recruited to pericentromeric DNA.
authors.affiliation: Biology of Repetitive Sequences, CNRS UPR1142, 141 rue de la Cardonille, 34000 Montpellier, France. Electronic address: jerome.dejardin@igh.cnrs.fr.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Déjardin
mesh_terms: D000818:Animals; D002503:Centromere / Q000378:metabolism / Q000648:ultrastructure; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D006570:Heterochromatin / Q000378:metabolism* / Q000648:ultrastructure; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism*; D063146:Polycomb-Group Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D006570:Heterochromatin; D006657:Histones; D051761:Paired Box Transcription Factors; D063146:Polycomb-Group Proteins; D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases