title: Sub1 contacts the RNA polymerase II stalk to modulate mRNA synthesis.
abstract: Biogenesis of messenger RNA is critically influenced by the phosphorylation state of the carboxy-terminal domain (CTD) in the largest RNA polymerase II (RNAPII) subunit. Several kinases and phosphatases are required to maintain proper CTD phosphorylation levels and, additionally, several other proteins modulate them, including Rpb4/7 and Sub1. The Rpb4/7 heterodimer, constituting the RNAPII stalk, promote phosphatase functions and Sub1 globally influences CTD phosphorylation, though its mechanism remains mostly unknown. Here, we show that Sub1 physically interacts with the RNAPII stalk domain, Rpb4/7, likely through its C-terminal region, and associates with Fcp1. While Rpb4 is not required for Sub1 interaction with RNAPII complex, a fully functional heterodimer is required for Sub1 association to promoters. We also demonstrate that a complete CTD is necessary for proper association of Sub1 to chromatin and to the RNAPII. Finally, genetic data show a functional relationship between Sub1 and the RNAPII clamp domain. Altogether, our results indicate that Sub1, Rpb4/7 and Fcp1 interaction modulates CTD phosphorylation. In addition, Sub1 interaction with Rpb4/7 can also modulate transcription start site selection and transcription elongation rate likely by influencing the clamp function.
authors.affiliation: Instituto de Biología Funcional y Genómica. CSIC/Universidad de Salamanca, C/ Zacarías González 2, Salamanca 37007, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Garavís
authors.affiliation: Instituto de Biología Funcional y Genómica. CSIC/Universidad de Salamanca, C/ Zacarías González 2, Salamanca 37007, Spain.
authors.forename: Noelia
authors.initials: N
authors.lastname: González-Polo
authors.affiliation: Instituto de Biología Funcional y Genómica. CSIC/Universidad de Salamanca, C/ Zacarías González 2, Salamanca 37007, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Allepuz-Fuster
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Jaime Alegrio
authors.initials: JA
authors.lastname: Louro
authors.affiliation: Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-Tornero
authors.affiliation: Instituto de Biología Funcional y Genómica. CSIC/Universidad de Salamanca, C/ Zacarías González 2, Salamanca 37007, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Calvo
mesh_terms: D000483:Alleles; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D055503:Protein Multimerization; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D021122:Protein Subunits; D012333:RNA, Messenger; C101206:SUB1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012319:RNA Polymerase II; D010749:Phosphoprotein Phosphatases; C116022:carboxy-terminal domain phosphatase