Evidence for a pioneer round of mRNA translation: mRNAs subject to nonsense-mediated decay in mammalian cells are bound by CBP80 and CBP20

Cell. 2001 Sep 7;106(5):607-17. doi: 10.1016/s0092-8674(01)00475-5.

Abstract

Nonsense-mediated decay (NMD) eliminates mRNAs that prematurely terminate translation. We used antibody to the nuclear cap binding protein CBP80 or its cytoplasmic counterpart eIF4E to immunopurify RNP containing nonsense-free or nonsense-containing transcripts. Data indicate that NMD takes place in association with CBP80. We defined other components of NMD-susceptible mRNP as CBP20, PABP2, eIF4G, and the NMD factors Upf2 and Upf3. Consistent with the dependence of NMD on translation, the NMD of CBP80-bound mRNA is blocked by cycloheximide or suppressor tRNA. These findings provide evidence that translation can take place in association with CBP80. They also indicate that CBP80-bound mRNA undergoes a "pioneer" round of translation, before CBP80-CBP20 are replaced by eIF4E, and Upf2 and Upf3 proteins dissociate from upstream of exon-exon junctions.

Publication types

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

MeSH terms

  • 3T3 Cells
  • Alpha-Globulins / genetics
  • Alpha-Globulins / metabolism
  • Animals
  • COS Cells
  • Cell Nucleus / metabolism
  • Codon, Nonsense / metabolism*
  • Cross-Linking Reagents / metabolism
  • Cycloheximide / pharmacology
  • Eukaryotic Initiation Factor-4G
  • Globins / genetics
  • Globins / metabolism
  • Glutathione Peroxidase / genetics
  • Glutathione Peroxidase / metabolism
  • Humans
  • Immunoblotting
  • Macromolecular Substances
  • Mice
  • Models, Biological
  • Peptide Initiation Factors / genetics
  • Peptide Initiation Factors / metabolism
  • Poly(A)-Binding Proteins
  • Protein Biosynthesis*
  • Protein Synthesis Inhibitors / pharmacology
  • Proteins
  • RNA Cap-Binding Proteins
  • RNA Caps / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transfection

Substances

  • Alpha-Globulins
  • Codon, Nonsense
  • Cross-Linking Reagents
  • Eukaryotic Initiation Factor-4G
  • Macromolecular Substances
  • Peptide Initiation Factors
  • Poly(A)-Binding Proteins
  • Protein Synthesis Inhibitors
  • Proteins
  • RNA Cap-Binding Proteins
  • RNA Caps
  • RNA, Messenger
  • RNA-Binding Proteins
  • major urinary proteins
  • Globins
  • Cycloheximide
  • glutathione peroxidase GPX1
  • Glutathione Peroxidase