A conformational rearrangement in the spliceosome sets the stage for Prp22-dependent mRNA release

Mol Cell. 2008 Jun 20;30(6):743-54. doi: 10.1016/j.molcel.2008.05.003.


An essential step in pre-mRNA splicing is the release of the mRNA product from the spliceosome. The DEAH box RNA helicase Prp22 catalyzes mRNA release by remodeling contacts within the spliceosome that involve the U5 snRNP. Spliceosome disassembly requires a segment of more than 13 ribonucleotides downstream of the 3' splice site. I show here by site-specific crosslinking and RNase H protection that Prp22 interacts with the mRNA downstream of the exon-exon junction prior to mRNA release. The findings support a model for Prp22-catalyzed mRNA release from the spliceosome wherein a rearrangement that accompanies the second transesterification step deposits Prp22 on the mRNA downstream of the exon-exon junction. Bound to its target RNA, the 3'-->5' helicase acts to disrupt mRNA/U5 snRNP contacts, thereby liberating the mRNA from the spliceosome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Exons
  • Introns
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • RNA Precursors / chemistry
  • RNA Precursors / genetics
  • RNA Precursors / isolation & purification
  • RNA Precursors / metabolism
  • RNA, Fungal / chemistry
  • RNA, Fungal / genetics
  • RNA, Fungal / isolation & purification
  • RNA, Fungal / metabolism
  • RNA, Messenger / chemistry
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • Ribonucleoproteins / chemistry
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Spliceosomes / chemistry*


  • RNA Precursors
  • RNA, Fungal
  • RNA, Messenger
  • Ribonucleoproteins
  • Saccharomyces cerevisiae Proteins