4EHP and GIGYF1/2 Mediate Translation-Coupled Messenger RNA Decay

Area of Science:

• Molecular Biology
• Gene Expression Regulation
• Cellular mRNA Turnover

Background:

• mRNA degradation is known to be coupled with translation in the cytoplasm.
• The precise molecular mechanisms coordinating ribosome activity and mRNA decay pathways remain incompletely understood.

Purpose of the Study:

• To investigate the role of 4EHP-GIGYF1/2 complexes in co-translational mRNA decay.
• To elucidate how ribosome transit is coordinated with mRNA decay machinery.

Main Methods:

• Analysis of mRNA accumulation and ribosome pausing in human cells lacking 4EHP-GIGYF1/2 proteins.
• Investigation of 4EHP-GIGYF1/2 complex interactions with mRNA cap structures, DDX6, and ZNF598.
• Assessment of mRNA decay rates in the presence or absence of ribosome stalling and specific protein interactions.

Main Results:

• Human cells deficient in 4EHP-GIGYF1/2 exhibit accumulation of mRNAs with significant ribosome pausing.
• These affected transcripts include those for secretory/membrane proteins and tubulin subunits.
• 4EHP-GIGYF1/2 complex function in mRNA decay is dependent on ribosome stalling and interactions with the cap structure, DDX6, and ZNF598.

Conclusions:

• 4EHP-GIGYF1/2 complexes actively trigger co-translational mRNA decay by targeting mRNAs with perturbed elongation.
• This pathway serves to minimize protein output from specific transcripts, including those implicated in neurological disorders.
• The findings reveal a novel mechanism linking ribosome dynamics to mRNA decay for fine-tuning gene expression.