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Updated: Aug 28, 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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eIF3 Interacts with Selenoprotein mRNAs
Hassan Hayek1,2, Gilbert Eriani1, Christine Allmang1
1Architecture et Réactivité de l'ARN, Université de Strasbourg, Centre National de la Recherche Scientifique, Institut de Biologie Moléculaire et Cellulaire, 67084 Strasbourg, France.
Biomolecules
|September 23, 2022
Summary
Eukaryotic translation initiation factor 3 (eIF3) interacts with specific selenoprotein mRNAs, particularly those with unusual cap hypermethylation. This suggests eIF3 may regulate selenoprotein expression independently of the typical translation initiation factor 4E (eIF4E).
Area of Science:
- Molecular Biology
- Gene Expression Regulation
- Protein Synthesis
Background:
- Selenoprotein synthesis relies on co-translational recoding of UGA codons.
- Selenocysteine insertion involves SECIS element and SBP2 protein interactions.
- Some selenoprotein mRNAs are translated despite lacking eIF4E recognition due to cap hypermethylation.
Purpose of the Study:
- To investigate the interaction between human eukaryotic translation initiation factor 3 (eIF3) and selenoprotein mRNAs.
- To determine if eIF3 plays a role in the specialized translation of selenoprotein mRNAs.
- To elucidate the mechanisms of selenoprotein translation regulation.
Main Methods:
- Ribonucleoprotein immunoprecipitation (RNP IP) in vivo and in vitro.
- Cross-linking experiments to identify direct interactions.
- Analysis of interactions between eIF3 subunits and specific selenoprotein mRNAs (e.g., GPx1 mRNA).
Main Results:
- eIF3 interacts with a subset of selenoprotein mRNAs.
- eIF3 preferentially binds to hypermethylated capped selenoprotein mRNAs over m7G-capped mRNAs.
- Direct contacts were identified between GPx1 mRNA and eIF3 subunits c, d, and e.
- Common interaction patterns were observed for hypermethylated capped selenoprotein mRNAs.
Conclusions:
- Differential interactions of eIF3 with selenoprotein mRNAs suggest novel translation pathways.
- eIF3 may regulate selenoprotein expression independently of eIF4E.
- eIF3 emerges as a potential key regulator in the hierarchy of selenoprotein expression.
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