Protein SMG9, Protein smg-9 homolog, SMG9, C19orf61
C19orf61 is component of the SMG1C complex, a mRNA surveillance complex that recognizes and degrades mRNAs containing premature translation termination codons (PTCs) via the nonsense-mediated mRNA decay (NMD). The complex probably acts by associating with ribosomes during tranlation termination on mRNPs. If an exon junction complex (EJC) is located 50-55 or more nucleotides downstream from the termination codon, SMG1 phosphorylates UPF1/RENT1, triggering nonsense-mediated mRNA decay (NMD). In the SMG1C complex, it is required for the efficient association between SMG1 and SMG8.