[Nonsense-mediated mRNA decay (NMD)--on guard of mRNA quality].

Nonsense-mediated mRNA decay (NMD) is a surveillance pathway that protects cells from potentially harmful effects of truncated proteins that would otherwise be translated from mRNAs bearing premature termination codons (PTC). NMD targets not only aberrant mRNAs possessing PTCs resulting from mutations, transcription errors or abnormal splicing but is also thought to be involved in regulating the expression of several wild-type transcripts (approximately 10% of the transcriptome). NMD is a conserved pathway present in all eukaryotic organisms studied so far (yeast, nematoda, flies, mammals and plants). The key players involved in NMD are also conserved among these species. However, details of NMD mechanism vary among eukaryotic organisms studied so far.