Nuclear mRNA Binding Proteins Couple Pre-mRNA Splicing and Post-splicing Events

New information about the pathway of eukaryotic gene expression indicates that many of the steps in this pathway are functionally interconnected. An important link has recently emerged between pre-mRNA splicing and the post-splicing events such as mRNA export and mRNA decay. Recent results reveal that the coupling is mediated by a novel group of nuclear mRNA-binding proteins that are recruited to the mRNAs by spiceosome. These proteins, including Y14, Aly/REF, RNPS1, SRm160, and DEK, are assembled into a stable complex near exon-exon junctions of spliced mRNAs. Several of them persist in their attachment to mRNAs in the cytoplasm thus communicating the history of splicing to the downstream events. The detailed mechanism of coupling and the factors that mediate these processes remain to be determined in the coming years.