The role of SMG-1 in nonsense-mediated mRNA decay

Biochim Biophys Acta. 2005 Dec 30;1754(1-2):305-15. doi: 10.1016/j.bbapap.2005.10.002. Epub 2005 Oct 25.


SMG-1, a member of the PIKK (phosphoinositide 3-kinase related kinases) family, plays a critical role in the mRNA quality control system termed nonsense-mediated mRNA decay (NMD). NMD protects the cells from the accumulation of aberrant mRNAs with premature termination codons (PTCs) that encode nonfunctional or potentially harmful truncated proteins. SMG-1 directly phosphorylates Upf1, another key component of NMD, and this phosphorylation occurs upon recognition of PTC on post-spliced mRNA during the initial round of translation. At present, a variety of tools are available that can specifically suppress NMD, and it is possible to examine the contribution of NMD in a variety of physiological and pathological conditions.

Publication types

  • Review

MeSH terms

  • Animals
  • Codon, Nonsense / metabolism*
  • Gene Expression Regulation
  • Humans
  • Models, Biological
  • Models, Genetic
  • Peptides / genetics
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphoinositide-3 Kinase Inhibitors
  • Phosphorylation
  • RNA Helicases
  • RNA Stability / physiology
  • RNA, Messenger / metabolism*
  • Trans-Activators / metabolism


  • Codon, Nonsense
  • Peptides
  • Phosphoinositide-3 Kinase Inhibitors
  • RNA, Messenger
  • Trans-Activators
  • RNA Helicases
  • UPF1 protein, human