Exonucleolysis is required for nuclear mRNA quality control in yeast THO mutants.
Production of aberrant messenger ribonucleoprotein particles (mRNPs) is subject to quality control (QC). In yeast strains carrying mutations of the THO complex, transcription induction triggers a number of interconnected QC phenotypes: (1) rapid degradation of several mRNAs; (2) retention of a fraction of THO-dependent mRNAs in transcription site-associated foci; and (3) formation of a high molecular weight DNA/protein complex in the 3'-ends of THO target genes. Here, we demonstrate that the 3'-5' exonucleolytic domain of the nuclear exosome factor Rrp6p is necessary for establishing all QC phenotypes associated with THO mutations. The N terminus of Rrp6p is also important presumably through its binding to the Rrp6p co-factor Rrp47p. Interestingly, the 3'-5' exonucleolytic activity of Dis3p, the only other active exonuclease of the nuclear exosome, can also contribute to RNA QC in THO mutants, while other nuclear 3'-5' exonucleases cannot. Our data show that exonucleolytic attack by the nuclear exosome is needed both for provoking mRNP QC and for its ensuing elimination of faulty RNA.
Assenholt
Jannie
J
Centre for mRNP Biogenesis and Metabolism, Department of Molecular Biology, The Faculty of Science, Aarhus University, DK-8000 Aarhus C, Denmark.
Mouaikel
John
J
Andersen
Kasper R
KR
Brodersen
Ditlev E
DE
Libri
Domenico
D
Jensen
Torben Heick
TH
D004268:DNA-Binding Proteins; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism*; D063326:Exosome Multienzyme Ribonuclease Complex; D005656:Fungal Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C494789:LRP1 protein, S cerevisiae; D009687:Nuclear Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C026452:messenger ribonucleoprotein; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C542283:DIS3 protein, S cerevisiae; C112610:RRP6 protein, S cerevisiae