title: The Rtf1 component of the Paf1 transcriptional elongation complex is required for ubiquitination of histone H2B.
abstract: In yeast cells, the Rtf1 and Paf1 components of the Paf1 transcriptional elongation complex are important for recruitment of Set1, the histone H3-lysine 4 (H3-Lys4) methylase, to a highly localized domain at the 5' portion of active mRNA coding regions. Here, we show that Rtf1 is essential for global methylation of H3-Lys4 and H3-Lys79, but not H3-Lys36. This role of Rtf1 resembles that of Rad6, which mediates ubiquitination of histone H2B at lysine 123. Indeed, Rtf1 is required for H2B ubiquitination, suggesting that its effects on H3-Lys4 and H3-Lys79 methylation are an indirect consequence of its effect on H2B ubiquitination. Rtf1 is important for telomeric silencing, with loss of H3-Lys4 and H3-Lys79 methylation synergistically reducing Sir2 association with telomeric DNA. Dot1, the H3-Lys79 methylase, associates with transcriptionally active genes, but unlike the association of Set1 and Set2 (the H3-Lys36 methylase), this association is largely independent of Rtf1. We suggest that Rtf1 affects genome-wide ubiquitination of H2B by a mechanism that is distinct from its function as a transcriptional elongation factor.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Huck Hui
authors.initials: HH
authors.lastname: Ng
authors.forename: Sudhanshu
authors.initials: S
authors.lastname: Dole
authors.forename: Kevin
authors.initials: K
authors.lastname: Struhl
mesh_terms: D015153:Blotting, Western; D002843:Chromatin / Q000378:metabolism; D019281:Dimerization; D004229:Dithiothreitol / Q000494:pharmacology; D017353:Gene Deletion; D020868:Gene Silencing; D006657:Histones / Q000737:chemistry* / Q000378:metabolism; D008239:Lysine / Q000737:chemistry; D008745:Methylation; D009687:Nuclear Proteins / Q000737:chemistry / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000502:physiology*; D035181:TATA-Box Binding Protein / Q000737:chemistry / Q000502:physiology*; D016615:Telomere / Q000378:metabolism / Q000648:ultrastructure; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D014158:Transcription, Genetic; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D002843:Chromatin; D006657:Histones; D009687:Nuclear Proteins; C097698:PAF1 protein, S cerevisiae; D012333:RNA, Messenger; C107273:RTF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; D025801:Ubiquitin; D008239:Lysine; D004229:Dithiothreitol