Rules of engagement: co-transcriptional recruitment of pre-mRNA processing factors

Curr Opin Cell Biol. 2005 Jun;17(3):251-6. doi: 10.1016/


The universal pre-mRNA processing events of 5' end capping, splicing, and 3' end formation by cleavage/polyadenylation occur co-transcriptionally. As a result, the substrate for mRNA processing factors is a nascent RNA chain that is being extruded from the RNA polymerase II exit channel at 10-30 bases per second. How do processing factors find their substrate RNAs and complete most mRNA maturation before transcription is finished? Recent studies suggest that this task is facilitated by a combination of protein-RNA and protein-protein interactions within a 'mRNA factory' that comprises the elongating RNA polymerase and associated processing factors. This 'factory' undergoes dynamic changes in composition as it traverses a gene and provides the setting for regulatory interactions that couple processing to transcriptional elongation and termination.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Humans
  • Models, Biological
  • RNA Caps / genetics
  • RNA Caps / metabolism
  • RNA Polymerase II / metabolism
  • RNA Precursors / genetics
  • RNA Precursors / metabolism*
  • RNA Processing, Post-Transcriptional*
  • RNA Splicing / physiology
  • Spliceosomes / metabolism
  • Transcription, Genetic*


  • RNA Caps
  • RNA Precursors
  • RNA Polymerase II