Splicing of U12-type introns deposits an exon junction complex competent to induce nonsense-mediated mRNA decay

Proc Natl Acad Sci U S A. 2004 Dec 28;101(52):17976-81. doi: 10.1073/pnas.0408435102. Epub 2004 Dec 17.

Abstract

Metazoan cells have two pathways for intron removal involving the U2- and U12-type spliceosomes, which contain mostly nonoverlapping sets of small nuclear ribonucleoproteins. We show that in vitro splicing of a U12-type intron assembles an exon junction complex (EJC) that is comparably positioned and contains many of the same components as that deposited by the U2-type spliceosome. The presence of a U12-type intron downstream of a premature termination codon within an open reading frame (ORF) induces nonsense-mediated decay of the mRNA in vivo. These findings suggest a common pathway for EJC assembly by the two spliceosomes and highlight the evolutionary age of the EJC and its downstream functions in gene expression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Line
  • Cell Nucleus / metabolism
  • Codon, Nonsense
  • DNA, Complementary / metabolism
  • Evolution, Molecular
  • Exons
  • Gene Expression Regulation
  • HeLa Cells
  • Humans
  • Immunoprecipitation
  • Introns*
  • Mutagenesis, Site-Directed
  • Open Reading Frames
  • Plasmids / metabolism
  • RNA / chemistry
  • RNA / metabolism
  • RNA Precursors / metabolism
  • RNA Splicing*
  • RNA, Messenger / metabolism*
  • RNA, Small Nuclear / genetics*
  • RNA, Small Nuclear / metabolism
  • Ribonuclease H / chemistry
  • Ribonucleoproteins, Small Nuclear / metabolism
  • Spliceosomes / metabolism
  • Time Factors
  • Transfection

Substances

  • Codon, Nonsense
  • DNA, Complementary
  • RNA Precursors
  • RNA, Messenger
  • RNA, Small Nuclear
  • Ribonucleoproteins, Small Nuclear
  • U12 small nuclear RNA
  • RNA
  • Ribonuclease H