Control of cleavage site selection during mRNA 3' end formation by a yeast hnRNP.
Endonucleolytic cleavage of pre-mRNAs is the first step during eukaryotic mRNA 3' end formation. It has been proposed that cleavage factors CF IA, CF IB and CF II are required for pre-mRNA 3' end cleavage in yeast. CF IB is composed of a single polypeptide, Nab4p/Hrp1p, which is related to the A/B group of metazoan heterogeneous nuclear ribonucleoproteins (hnRNPs) that function as antagonistic regulators of 5' splice site selection. Here, we provide evidence that Nab4p/Hrp1p is not required for pre-mRNA 3' end endonucleolytic cleavage. We show that CF IA and CF II devoid of Nab4p/Hrp1p are sufficient to cleave a variety of RNA substrates but that cleavage occurs at multiple sites. Addition of Nab4p/Hrp1p prevents these alternative cleavages in a concentration-dependent manner, suggesting an essential and conserved role for some hnRNPs in pre-mRNA cleavage site selection.
Minvielle-Sebastia
L
L
Department of Cell Biology, Biozentrum, University of Basel, CH-4056 Basel, Switzerland. minvielle@ubaclu.unibas.ch
Beyer
K
K
Krecic
A M
AM
Hector
R E
RE
Swanson
M S
MS
Keller
W
W
D001483:Base Sequence; D003574:Cytochrome c Group / Q000096:biosynthesis / Q000235:genetics; D045304:Cytochromes c; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011061:Poly A / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity; D039221:mRNA Cleavage and Polyadenylation Factors
C014059:CYC1 protein, S cerevisiae; D003574:Cytochrome c Group; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012322:RNA Precursors; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D011061:Poly A; D045304:Cytochromes c