The article reviews the evidence for functional coupling.

• Summary
• Introduction
• 5' end capping: coupling is key
• Pre-mRNA splicing: a race against transcription time?
• 3' end formation: tied up with termination
• Release of mRNPs from the transcription unit: a distinct step?
• Conclusions and perspectives
• Acknowledgements
• References

I would like to thank David Bentley, Ann Beyer, Tony Krumm, Iain Mattaj, David Stanek, Elmar Wahle and Lars Wieslander for helpful discussions and critical comments on the manuscript. Ken Howe and Manny Ares kindly shared unpublished results.