Endonucleolytic cleavage of eukaryotic mRNAs with stalls in translation elongation

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Eukaryotic mRNA biogenesis relies on quality control mechanisms to eliminate non-functional transcripts.
• Nonsense-mediated decay and non-stop decay rapidly degrade mRNAs with premature or failed translation termination.

Purpose of the Study:

• To investigate the cellular response to stalled translation elongation in eukaryotic mRNAs.
• To identify the molecular mechanisms responsible for recognizing and degrading mRNAs with elongation stalls.

Main Methods:

• Utilized yeast as a model organism to study mRNA decay pathways.
• Investigated the role of specific proteins, Dom34p and Hbs1p, in the degradation process.
• Analyzed the dependency of the decay mechanism on active translation.

Main Results:

• Identified a novel mRNA degradation pathway termed 'no-go decay' that targets mRNAs with stalled translation elongation.
• Demonstrated that no-go decay is a translation-dependent process.
• Showed that Dom34p and Hbs1p are essential for no-go decay, suggesting their role in recognizing stalled ribosomes.

Conclusions:

• No-go decay provides a crucial mechanism for clearing stalled translation elongation complexes in yeast.
• This pathway contributes to maintaining cellular homeostasis by removing potentially harmful stalled complexes.
• Dom34p and Hbs1p likely function as key sensors of translation stalls, initiating mRNA degradation.