Modulation of transcription affects mRNP quality.
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.
Jensen
Torben Heick
TH
Department of Molecular Biology, Aarhus University, C.F. Møllers Alle, Building 130, 8000 Aarhus C, Denmark. thj@mb.au.dk
Boulay
Jocelyne
J
Olesen
Jens Raabjerg
JR
Colin
Jessie
J
Weyler
Michael
M
Libri
Domenico
D
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
D012333:RNA, Messenger; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C026452:messenger ribonucleoprotein; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases