SPELL - S. cerevisiae

Citation	Hackmann A, Wu H, Schneider UM, Meyer K, Jung K, Krebber H. Quality control of spliced mRNAs requires the shuttling SR proteins Gbp2 and Hrb1. Nature communications, 2014.
PubMed ID	24452287
Short Description	Quality control of spliced mRNAs requires the shuttling SR proteins Gbp2 and Hrb1.
# of Conditions	6
Full Description	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.
Tags	mRNA processing