Quality control of spliced mRNAs requires the shuttling SR proteins Gbp2 and Hrb1.
Eukaryotic cells have to prevent the export of unspliced pre-mRNAs until intron removal is completed to avoid the expression of aberrant and potentially harmful proteins. Only mature mRNAs associate with the export receptor Mex67/TAP and enter the cytoplasm. Here we show that the two shuttling serine/arginine (SR)-proteins Gbp2 and Hrb1 are key surveillance factors for the selective export of spliced mRNAs in yeast. Their absence leads to the significant leakage of unspliced pre-mRNAs into the cytoplasm. They bind to pre-mRNAs and the spliceosome during splicing, where they are necessary for the surveillance of splicing and the stable binding of the TRAMP complex to spliceosome-bound transcripts. Faulty transcripts are marked for their degradation at the nuclear exosome. On correct mRNAs the SR proteins recruit Mex67 upon completion of splicing to allow a quality controlled nuclear export. Altogether, these data identify a role for shuttling SR proteins in mRNA surveillance and nuclear mRNA quality control.
Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany.
Alexandra
A
Hackmann
Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany.
Haijia
H
Wu
Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany.
Ulla-Maria
UM
Schneider
1] Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany [2] Institut für Genomforschung und Systembiologie, Universität Bielefeld, 33615 Bielefeld, Germany.
Katja
K
Meyer
Institut für Medizinische Statistik, Universitätsmedizin Göttingen, 37073 Göttingen, Germany.
Klaus
K
Jung
Abteilung für Molekulare Genetik, Institut für Mikrobiologie und Genetik, Göttinger Zentrum für Molekulare Biowissenschaften (GZMB), Georg-August Universität Göttingen, 37077 Göttingen, Germany.
Heike
H
Krebber
D021581:Active Transport, Cell Nucleus; D002467:Cell Nucleus / Q000378:metabolism; D017353:Gene Deletion; D008954:Models, Biological; D050505:Mutant Proteins / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism*; D039102:Poly(A)-Binding Proteins / Q000378:metabolism*; D011485:Protein Binding; D059748:Proteolysis; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D017381:Spliceosomes / Q000378:metabolism
C474034:Gbp2 protein, S cerevisiae; C089362:Hrb1 protein, S cerevisiae; D050505:Mutant Proteins; D029543:Nucleocytoplasmic Transport Proteins; D039102:Poly(A)-Binding Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins