UPF1 association with the cap-binding protein, CBP80, promotes nonsense-mediated mRNA decay at two distinct steps

Jungwook Hwang, Hanae Sato, Yalan Tang, Daiki Matsuda, Lynne E. Maquat

Research output: Contribution to journalArticle

72 Scopus citations


Nonsense-mediated mRNA decay (NMD) is an mRNA surveillance mechanism that in mammals generally occurs upon recognition of a premature termination codon (PTC) during a pioneer round of translation. This round involves newly synthesized mRNA that is bound at its 5' end by the cap-binding protein (CBP) heterodimer CBP80-CBP20. Here we show that precluding the binding of the NMD factor UPF1 to CBP80 inhibits NMD at two steps: the association of SMG1 and UPF1 with the two eukaryotic release factors (eRFs) during SURF complex formation at a PTC, and the subsequent association of SMG1 and UPF1 with an exon-junction complex. We also demonstrate that UPF1 binds PTC-containing mRNA more efficiently than the corresponding PTC-free mRNA in a way that is promoted by the UPF1-CBP80 interaction. A unifying model proposes a choreographed series of protein-protein interactions occurring on an NMD target.

Original languageEnglish (US)
Pages (from-to)396-409
Number of pages14
JournalMolecular Cell
Issue number3
StatePublished - Aug 1 2010
Externally publishedYes



  • Proteins
  • RNA

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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