title: Modulation of transcription affects mRNP quality.
abstract: Cotranscriptional loading of proteins onto nascent transcripts contributes to the formation of messenger ribonucleoprotein particles (mRNPs) competent for nuclear export. The transcription machinery is believed to play a pivotal role in mRNP assembly, which is at least partially linked to the function of the THO/TREX complex and the mRNA termination/polyadenylation apparatus. Here we demonstrate a prominent role for the rate of transcription in the production of export-competent mRNPs. We show that a transcription-defective allele of the Rad3p helicase, a component of the TFIIH transcription initiation factor, suppresses several phenotypes associated with defective mRNA processing and export. Strikingly, the effects of compromised Rad3p activity can be phenocopied by a transcription elongation drug as well as by other mutations affecting transcription. Our results suggest that efficient mRNP assembly is under a kinetic control that is influenced by the rate of transcription.
authors.affiliation: Department of Molecular Biology, Aarhus University, C.F. Møllers Alle, Building 130, 8000 Aarhus C, Denmark. thj@mb.au.dk
authors.forename: Torben Heick
authors.initials: TH
authors.lastname: Jensen
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Boulay
authors.forename: Jens Raabjerg
authors.initials: JR
authors.lastname: Olesen
authors.forename: Jessie
authors.initials: J
authors.lastname: Colin
authors.forename: Michael
authors.initials: M
authors.lastname: Weyler
authors.forename: Domenico
authors.initials: D
authors.lastname: Libri
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D009154:Mutation; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D012261:Ribonucleoproteins / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D014158:Transcription, Genetic / Q000502:physiology*; D015003:Yeasts / Q000235:genetics / Q000502:physiology
chemical_list: D012333:RNA, Messenger; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C026452:messenger ribonucleoprotein; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases