Nonsense-mediated mRNA decay uses complementary mechanisms to suppress mRNA and protein accumulation

Life Sci Alliance. 2021 Dec 8;5(3):e202101217. doi: 10.26508/lsa.202101217. Print 2022 Mar.


Nonsense-mediated mRNA decay (NMD) is an essential, highly conserved quality control pathway that detects and degrades mRNAs containing premature termination codons. Although the essentiality of NMD is frequently ascribed to its prevention of truncated protein accumulation, the extent to which NMD actually suppresses proteins encoded by NMD-sensitive transcripts is less well-understood than NMD-mediated suppression of mRNA. Here, we describe a reporter system that permits accurate quantification of both mRNA and protein levels via stable integration of paired reporters encoding NMD-sensitive and NMD-insensitive transcripts into the AAVS1 safe harbor loci in human cells. We use this system to demonstrate that NMD suppresses proteins encoded by NMD-sensitive transcripts by up to eightfold more than the mRNA itself. Our data indicate that NMD limits the accumulation of proteins encoded by NMD substrates by mechanisms beyond mRNA degradation, such that even when NMD-sensitive mRNAs escape destruction, their encoded proteins are still effectively suppressed.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Gene Expression
  • Gene Expression Regulation*
  • Gene Order
  • Genes, Reporter
  • Humans
  • Nonsense Mediated mRNA Decay*
  • Plasmids / genetics
  • RNA Interference
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / metabolism*
  • Transfection


  • RNA, Messenger
  • RNA-Binding Proteins