Ago2/miRISC-mediated inhibition of CBP80/20-dependent translation and thereby abrogation of nonsense-mediated mRNA decay require the cap-associating activity of Ago2

FEBS Lett. 2011 Sep 2;585(17):2682-7. doi: 10.1016/j.febslet.2011.07.047. Epub 2011 Aug 10.

Abstract

Nuclear cap-binding protein (CBP) 80/20-dependent translation (CT) is one of the targets for miRNA-mediated gene silencing. Here, we provide evidence that human argonaute 2 (Ago2) competes with CBP80/20 for cap-association, inhibiting CT and thus nonsense-mediated mRNA decay (NMD), which is tightly coupled to CT. Tethering of Ago2, but not of Ago2F2V2 which lacks cap-association activity, to the 3'UTR of PTC-containing mRNA abrogates NMD. Immunoprecipitation using CBP80 antibody reveals that Ago2, but not Ago2F2V2, inhibits the binding of CBP80/20 to cap structure. Our observations provide molecular insight into the cross-talk between miRNA-mediated gene silencing, CT, and NMD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Animals
  • Argonaute Proteins
  • Blotting, Western
  • COS Cells
  • Chlorocebus aethiops
  • Eukaryotic Initiation Factor-2 / genetics
  • Eukaryotic Initiation Factor-2 / metabolism*
  • Eukaryotic Initiation Factor-4E / genetics
  • Eukaryotic Initiation Factor-4E / metabolism
  • HeLa Cells
  • Humans
  • Immunoprecipitation
  • MicroRNAs / genetics
  • Nuclear Cap-Binding Protein Complex / genetics
  • Nuclear Cap-Binding Protein Complex / metabolism*
  • Protein Binding
  • Protein Biosynthesis
  • RNA Stability / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • 3' Untranslated Regions
  • AGO2 protein, human
  • Argonaute Proteins
  • Eukaryotic Initiation Factor-2
  • Eukaryotic Initiation Factor-4E
  • MicroRNAs
  • Nuclear Cap-Binding Protein Complex