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eIF5A promotes +1 programmed ribosomal frameshifting in Euplotes octocarinatus
Yu Xiao1, Jia Li1, Ruanlin Wang1
1Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China.
International Journal of Biological Macromolecules
|January 30, 2024
Summary
Scientists discovered that eIF5A regulates programmed ribosomal frameshifting (+1 PRF) in Euplotes. This finding reveals a conserved role for eIF5A in eukaryotic gene expression, impacting translational control.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Programmed ribosomal frameshifting (PRF) is a key translational control mechanism across life.
- Euplotes, a single-celled eukaryote, exhibits high PRF frequencies, but its regulation is poorly understood.
- eIF5A proteins are known regulators of translation, but their specific role in Euplotes PRF is uncharacterized.
Purpose of the Study:
- To identify and characterize novel eIF5A genes in Euplotes octocarinatus.
- To investigate the role of these eIF5A genes in regulating programmed ribosomal frameshifting.
- To determine if Euplotes eIF5A can functionally substitute for yeast eIF5A.
Main Methods:
- Gene identification and characterization of two novel eIF5A genes (eIF5A1 and eIF5A2) in Euplotes octocarinatus.
- Functional analysis using knockdown experiments to assess the impact on PRF.
- In vitro reconstituted translation systems to study the activity of hypusinated eIF5A (Eo-eIF5AH).
Main Results:
- Two novel eIF5A genes, Eo-eIF5A1 and Eo-eIF5A2, were identified in Euplotes octocarinatus.
- Eo-eIF5A2 requires a -1 PRF for full-length protein production.
- Knockdown of Eo-eIF5A inhibited +1 PRF of the η-tubulin gene, and hypusinated Eo-eIF5A promoted +1 PRF in vitro.
- Neither Euplotes eIF5A could functionally replace yeast eIF5A.
Conclusions:
- eIF5A acts as a novel trans-regulator of programmed ribosomal frameshifting in Euplotes.
- This finding highlights an evolutionarily conserved role for eIF5A in regulating +1 PRF in eukaryotes.
- The study elucidates a specific molecular mechanism for translational control in Euplotes.
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