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Updated: May 23, 2025
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Monitoring eIF4F Assembly by Measuring eIF4E-eIF4G Interaction in Live Cells
Published on: May 1, 2020
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Eukaryotic initiation factors eIF4F and eIF4B promote translation termination upon closed-loop formation
Ekaterina Shuvalova1,2, Alexey Shuvalov1,2, Walaa Al Sheikh1
1Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
Nucleic Acids Research
|March 11, 2025
Summary
Eukaryotic translation initiation factor 4F (eIF4F) significantly boosts translation termination. This protein complex, along with poly (A)-binding protein (PABP), facilitates the closed-loop mRNA structure essential for efficient protein synthesis termination.
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Eukaryotic translation initiation factor 4F (eIF4F) complex is crucial for mRNA binding and ribosome scanning.
- Poly (A)-binding protein (PABP) interacts with eIF4F and eukaryotic release factor 3 (eRF3), influencing translation termination.
- The closed-loop mRNA structure is implicated in regulating translation.
Purpose of the Study:
- To investigate the direct role of eIF4F in enhancing translation termination.
- To elucidate the mechanisms by which eIF4F and PABP facilitate translation termination.
Main Methods:
- Utilized a reconstituted mammalian system.
- Investigated the interactions between translation factors and ribosomal components.
- Identified key domains within eIF4G involved in termination.
Main Results:
- Demonstrated that eIF4F potently enhances translation termination.
- Showed that eIF4A and eIF4B promote eRF1 loading, while eIF4G1 stimulates eRF3 GTPase activity.
- Identified the MIF4G domain as essential for eIF4G's termination-promoting activity.
- Confirmed that eIF4G2/DAP5 also promotes termination.
Conclusions:
- The closed-loop mRNA structure, mediated by PABP and eIF4F, directly facilitates translation termination.
- eIF4F subunits play distinct roles in promoting the recruitment and dissociation of release factors.
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