UPF1

Regulator of nonsense transcripts 1 (or Up-frameshift suppressor 1 homolog) is a protein that in humans is encoded by the UPF1 gene.

Function

This gene encodes a protein that is part of a post-splicing multiprotein complex, the exon junction complex, involved in both mRNA nuclear export and mRNA surveillance. mRNA surveillance detects exported mRNAs with truncated open reading frames and initiates nonsense-mediated mRNA decay (NMD). When translation ends upstream from the last exon-exon junction, this triggers NMD to degrade mRNAs containing premature stop codons. This protein is located in both the cytoplasm and nucleus. When translation ends, it interacts with the functional homolog of yeast Upf2p to trigger mRNA decapping. Use of multiple polyadenylation sites has been noted for this gene.

Interactions

UPF1 interacts with:

• DCP1A,
• DCP2,
• SMG1,
• UPF2,
• UPF3A, and
• UPF3B.

Further reading