title: The 19S regulatory particle of the proteasome is required for efficient transcription elongation by RNA polymerase II.
abstract: It is generally thought that the primary or even sole activity of the 19S regulatory particle of the 26S proteasome is to facilitate the degradation of polyubiquitinated proteins by the 20S-core subunit. However, we present evidence that the 19S complex is required for efficient elongation of RNA polymerase II (RNAP II) in vitro and in vivo. First, yeast strains carrying alleles of SUG1 and SUG2, encoding 19S components, exhibit phenotypes indicative of elongation defects. Second, in vitro transcription is inhibited by antibodies raised against Sug1, or by heat-inactivating temperature-sensitive Sug1 mutants with restoration of elongation by addition of immunopurified 19S complex. Finally, Cdc68, a known elongation factor, coimmunoprecipitates with the 19S complex, indicating a physical interaction. Inhibition of the 20S proteolytic core of the proteasome has no effect on elongation. This work defines a nonproteolytic role for the 19S complex in RNAP II transcription.
authors.affiliation: Departments of Internal Medicine and Biochemistry, Ryburn Center for Molecular Cardiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX7 5390-8573, USA.
authors.forename: A
authors.initials: A
authors.lastname: Ferdous
authors.forename: F
authors.initials: F
authors.lastname: Gonzalez
authors.forename: L
authors.initials: L
authors.lastname: Sun
authors.forename: T
authors.initials: T
authors.lastname: Kodadek
authors.forename: S A
authors.initials: SA
authors.lastname: Johnston
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D000483:Alleles; D018797:Cell Cycle Proteins / Q000378:metabolism; D010450:Endopeptidases; D005656:Fungal Proteins / Q000235:genetics / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D011233:Precipitin Tests; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D021122:Protein Subunits; D012319:RNA Polymerase II / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects* / Q000235:genetics; D035602:Transcriptional Elongation Factors
chemical_list: D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D021122:Protein Subunits; D012097:Repressor Proteins; C071238:SPT16 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D012319:RNA Polymerase II; D010450:Endopeptidases; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; C119011:26S proteasome non-ATPase regulatory subunit 13; D000251:Adenosine Triphosphatases; C069670:RPT6 protein, S cerevisiae