Transcripts harbouring premature signals for translation termination are recognised and rapidly degraded by eukaryotic cells through a pathway known as nonsense-mediated mRNA decay. In Saccharomyces cerevisiae, three trans-acting factors (Upf1 to Upf3) are required for nonsense-mediated mRNA decay [1].

1: Novel Upf2p orthologues suggest a functional link between translation initiation and nonsense surveillance complexes. Mendell JT, Medghalchi SM, Lake RG, Noensie EN, Dietz HC; Mol Cell Biol 2000;20:8944-8957. PMID:11073994