Coupling transcription, splicing and mRNA export.

Previous studies have led to the view that mRNAs are transported from the nucleus to the cytoplasm by machinery that is conserved from yeast to humans. Moreover, this machinery is coupled both physically and functionally to the pre-mRNA splicing machinery. During the past year, important new insights into the mechanisms behind this coupling have been made. In addition, recent advances have revealed mechanisms for the co-transcriptional loading of the export machinery on to mRNAs. Finally, a newly identified link between the nuclear exosome and the machineries required for transcription, 3'-end formation and mRNA export suggests that proper mRNP formation is co-transcriptionally monitored.