title: Polycomb protein Ezh1 promotes RNA polymerase II elongation.
abstract: Polycomb group (PcG) proteins initiate the formation of repressed chromatin domains and regulate developmental gene expression. A mammalian PcG protein, enhancer of zeste homolog 2 (Ezh2), triggers transcriptional repression by catalyzing the addition of methyl groups onto lysine 27 of histone H3 (H3K27me2/3). This action facilitates the binding of other PcG proteins to chromatin for purposes of transcriptional silencing. Interestingly, there exists a paralog of Ezh2, termed Ezh1, whose primary function remains unclear. Here, we provide evidence for genome-wide association of Ezh1 complex with active epigenetic mark (H3K4me3), RNA polymerase II (Pol II), and mRNA production. Ezh1 depletion reduced global Pol II occupancy within gene bodies and resulted in delayed transcriptional activation during differentiation of skeletal muscle cells. Conversely, overexpression of wild-type Ezh1 led to premature gene activation and rescued Pol II occupancy defects in Ezh1-depleted cells. Collectively, these findings reveal a role for a PcG complex in promoting mRNA transcription.
authors.affiliation: Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20852, USA.
authors.forename: Kambiz
authors.initials: K
authors.lastname: Mousavi
authors.forename: Hossein
authors.initials: H
authors.lastname: Zare
authors.forename: A Hongjun
authors.initials: AH
authors.lastname: Wang
authors.forename: Vittorio
authors.initials: V
authors.lastname: Sartorelli
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D044127:Epigenesis, Genetic; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006657:Histones / Q000378:metabolism; D008745:Methylation; D051379:Mice; D024510:Muscle Development; D010441:Peptide Chain Elongation, Translational / Q000502:physiology*; D063151:Polycomb Repressive Complex 2; D034622:RNA Interference; D012319:RNA Polymerase II / Q000378:metabolism / Q000502:physiology*; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D006657:Histones; D012097:Repressor Proteins; C494163:Suz12 protein, mouse; D014157:Transcription Factors; C498408:Ezh1 protein, mouse; D011495:Histone-Lysine N-Methyltransferase; D063151:Polycomb Repressive Complex 2; D012319:RNA Polymerase II