A quality-control pathway that destroys mRNAs with premature stop codons.
During splicing, exon junction complexes are deposited; if a stop codon lies more than about 50 nt upstream of the last junction, the mRNA is flagged and degraded. It prevents truncated proteins and also regulates normal genes.
A quality-control pathway that destroys mRNAs with premature stop codons.
Nonsense-Mediated Decay is one of the 52 topics in Molecular Biology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Non-Homologous End Joining, Enhancers and Silencers, Alternative Splicing.
Many mutations producing premature stop codons cause recessive rather than dominant disease thanks to NMD.
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Nonsense-Mediated Decay. Advanced topics assume the Intermediate vocabulary.
The closest topics to Nonsense-Mediated Decay are Non-Homologous End Joining, Enhancers and Silencers, Alternative Splicing, Codon. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Nonsense-Mediated Decay. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
Nonsense-Mediated Decay: A quality-control pathway that destroys mRNAs with premature stop codons. Non-Homologous End Joining: An error-prone repair pathway that directly ligates broken DNA ends. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Non-Homologous End Joining and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
An error-prone repair pathway that directly ligates broken DNA ends.
🧫 Molecular BiologyDistant regulatory DNA elements that increase or decrease transcription via looping to the promoter.
🧫 Molecular BiologyDifferent exon combinations from one gene yield several protein variants.
🧫 Molecular BiologyA triplet of mRNA bases that codes for one amino acid or a stop signal.
🧫 Molecular Biology