title: Cotranscriptional recruitment of the mRNA export factor Yra1 by direct interaction with the 3' end processing factor Pcf11.
abstract: We investigated recruitment of the yeast mRNA export factor Yra1 to the transcription elongation complex (TEC). Previously, the Sub2 helicase subunit of TREX was proposed to recruit Yra1. We report that Sub2 is dispensable for Yra1 recruitment, but the cleavage/polyadenylation factor, CF1A, is required. Yra1 binds directly to the Zn finger/Clp1 region of Pcf11, the pol II CTD-binding subunit of CF1A, and this interaction is conserved between their human homologs. Tethering of Pcf11 to nascent mRNA is sufficient to enhance Yra1 recruitment. Interaction with Pcf11 can therefore explain Yra1 binding to the TEC independently of Sub2. We propose that after initially binding to Pcf11, Yra1 is transferred to Sub2. Consistent with this idea, Pcf11 binds the same regions of Yra1 that also contact Sub2, indicating a mutually exclusive interaction. These results suggest a mechanism for cotranscriptional assembly of the export competent mRNP and for coordinating export with 3' end processing.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
authors.forename: Sara Ann
authors.initials: SA
authors.lastname: Johnson
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Cubberley
authors.forename: David L
authors.initials: DL
authors.lastname: Bentley
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D008954:Models, Biological; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D026721:RNA 3' End Processing / Q000235:genetics*; D034443:RNA Transport; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; C512637:PCF11 protein, S cerevisiae; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C105887:YRA1 protein, S cerevisiae; D039221:mRNA Cleavage and Polyadenylation Factors; C026452:messenger ribonucleoprotein; D000251:Adenosine Triphosphatases; C027900:RNA-dependent ATPase