title: Ccr4-Not and TFIIS Function Cooperatively To Rescue Arrested RNA Polymerase II.
abstract: Expression of the genome requires RNA polymerase II (RNAPII) to transcribe across many natural and unnatural barriers, and this transcription across barriers is facilitated by protein complexes called elongation factors (EFs). Genetic studies in Saccharomyces cerevisiae yeast suggest that multiple EFs collaborate to assist RNAPII in completing the transcription of genes, but the molecular mechanisms of how they cooperate to promote elongation are not well understood. The Ccr4-Not complex participates in multiple steps of mRNA metabolism and has recently been shown to be an EF. Here we describe how Ccr4-Not and TFIIS cooperate to stimulate elongation. We find that Ccr4-Not and TFIIS mutations show synthetically enhanced phenotypes, and biochemical analyses indicate that Ccr4-Not and TFIIS work synergistically to reactivate arrested RNAPII. Ccr4-Not increases the recruitment of TFIIS into elongation complexes and enhances the cleavage of the displaced transcript in backtracked RNAPII. This is mediated by an interaction between Ccr4-Not and the N terminus of TFIIS. In addition to revealing insights into how these two elongation factors cooperate to promote RNAPII elongation, our study extends the growing body of evidence suggesting that the N terminus of TFIIS acts as a docking/interacting site that allows it to synergize with other EFs to promote RNAPII transcription.
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Arnob
authors.initials: A
authors.lastname: Dutta
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Vinod
authors.initials: V
authors.lastname: Babbarwal
authors.affiliation: Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Fu
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Brunke-Reese
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Libert
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Willis
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Eukaryotic Gene Regulation, Pennsylvania State University, University Park, Pennsylvania, USA Jcr8@psu.edu.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Reese
mesh_terms: D010445:Peptide Elongation Factors / Q000235:genetics; D012319:RNA Polymerase II / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D012260:Ribonucleases / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics; D035602:Transcriptional Elongation Factors / Q000235:genetics*
chemical_list: D010445:Peptide Elongation Factors; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D012319:RNA Polymerase II; C078657:CCR4 protein, S cerevisiae; D012260:Ribonucleases