Eukaryotic mRNAs containing nonsense codons are degraded by nonsense-mediated mRNA decay (NMD). In humans, NMD was proposed to act exclusively on newly synthesized mRNA during a 'pioneer round' of translation, when mRNA is associated with the nuclear cap-binding complex (CBC). Two reports now challenge this view, revealing that NMD is independent of whether CBC or the cytoplasmic cap-binding protein (eIF4E) promotes translation and can occur later in an mRNA's life.
- Matthias W Hentze
- Elisa Izaurralde
