title: A novel role for Cet1p mRNA 5'-triphosphatase in promoter proximal accumulation of RNA polymerase II in Saccharomyces cerevisiase.
abstract: Yeast mRNA 5'-triphosphatase, Cet1p, recognizes phosphorylated-RNA polymerase II as a component of capping machinery via Ceg1p for cotranscriptional formation of mRNA cap structure that recruits cap-binding complex (CBC) and protects mRNA from exonucleases. Here, we show that the accumulation of RNA polymerase II at the promoter proximal site of ADH1 is significantly enhanced in the absence of Cet1p. Similar results are also found at other genes. Cet1p is recruited to the 5' end of the coding sequence, and its absence impairs mRNA capping, and hence CBC recruitment. However, such an impaired recruitment of CBC does not enhance promoter proximal accumulation of RNA polymerase II. Thus, Cet1p specifically lowers the accumulation of RNA polymerase II at the promoter proximal site independently of mRNA cap structure or CBC. Further, we show that Cet1p's N-terminal domain, which is not involved in mRNA capping, decreases promoter proximal accumulation of RNA polymerase II. An accumulation of RNA polymerase II at the promoter proximal site in the absence of Cet1p's N-terminal domain is correlated with reduced transcription. Collectively, our results demonstrate a novel role of Cet1p in regulation of promoter proximal accumulation of RNA polymerase II independently of mRNA capping activity, and hence transcription in vivo.
authors.affiliation: Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901.
authors.forename: Shweta
authors.initials: S
authors.lastname: Lahudkar
authors.forename: Geetha
authors.initials: G
authors.lastname: Durairaj
authors.forename: Bhawana
authors.initials: B
authors.lastname: Uprety
authors.forename: Sukesh R
authors.initials: SR
authors.lastname: Bhaumik
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000235:genetics*; D000426:Alcohol Dehydrogenase / Q000235:genetics*; D001665:Binding Sites / Q000235:genetics; D051417:Focal Adhesion Kinase 1 / Q000235:genetics; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary / Q000235:genetics; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps / Q000096:biosynthesis*; D012319:RNA Polymerase II / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D061805:Transcription Elongation, Genetic; D061785:Transcription Initiation, Genetic; D014158:Transcription, Genetic
chemical_list: D039381:RNA Cap-Binding Proteins; D012315:RNA Caps; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C516801:ADH1 protein, S cerevisiae; D000426:Alcohol Dehydrogenase; D051417:Focal Adhesion Kinase 1; D012319:RNA Polymerase II; D017766:Acid Anhydride Hydrolases; C023090:RNA triphosphatase
keywords: CBC; Ceg1p; Cet1p; RNA polymerase II; transcription