title: BRG1 helps RNA polymerase II to overcome a nucleosomal barrier during elongation, in vivo.
abstract: RNA polymerase II (RNAPII) transcribes genes in a chromatin context. We have designed a system to investigate the role of chromatin remodelling during elongation in vivo, which involves inserting a strong nucleosome-positioning sequence between a promoter and a reporter gene. Our data indicate that a nucleosome positioned in the body of a transcription unit impairs RNAPII progression, provokes RNAPII accumulation upstream to the positioned nucleosome and reduces transcription. By using this system, we show that BRG1, the enzymatic motor of the SWI-SNF chromatin-remodelling complex, is recruited to the positioned nucleosome in a transcription elongation-dependent manner and facilitates traversal of the nucleosome by RNAPII.
authors.affiliation: Centro Andaluz de Biología Molecular y Medicina Regenerativa Consejo Superior de Investigaciones Científicas, Avenida Americo Vespucio, 41092 Seville, Spain.
authors.forename: Alicia
authors.initials: A
authors.lastname: Subtil-Rodríguez
authors.forename: José C
authors.initials: JC
authors.lastname: Reyes
mesh_terms: D002460:Cell Line; D042002:Chromatin Assembly and Disassembly; D004265:DNA Helicases / Q000378:metabolism*; D017930:Genes, Reporter; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism*; D012319:RNA Polymerase II / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D035602:Transcriptional Elongation Factors / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D009707:Nucleosomes; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D012319:RNA Polymerase II; C084108:SMARCA4 protein, human; D004265:DNA Helicases