Saccharomyces_cerevisiaeFamily: Smg4_UPF3 Number of Genes: 1
Ensembl IDSymbolEntrez IDRBD RBPome PRIExpresion PathwayPhenotype ParalogOrthologGO



This family contains proteins that are involved in nonsense mediated mRNA decay. A process that is triggered by premature stop codons in mRNA. The family includes Smg-4 [1] and UPF3.


Nonsense-mediated mRNA decay (NMD) is a surveillance mechanism by which eukaryotic cells detect and degrade transcripts containing premature termination codons. Three 'up-frameshift' proteins, UPF1, UPF2 and UPF3, are essential for this process in organisms ranging from yeast, human to plants [PUBMED:11368911]. Exon junction complexes (EJCs) are deposited ~24 nucleotides upstream of exon-exon junctions after splicing. Translation causes displacement of the EJCs, however, premature translation termination upstream of one or more EJCs triggers the recruitment of UPF1, UPF2 and UPF3 and activates the NMD pathway [PUBMED:12718880, PUBMED:15048104].


  1. Aronoff R, Baran R, Hodgkin J; , Gene 2001;268:153-164.: Molecular identification of smg-4, required for mRNA surveillance in C. elegans. PUBMED:11368911 EPMC:11368911.