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Giant DNA viruses encode a hallmark translation initiation complex of eukaryotic life
J Maximilian Fels1, Aidan B Hill2, Richard Han3
1Department of Cell Biology, Harvard Medical School, Boston, MA, USA; Department of Microbiology, Harvard Medical School, Boston, MA, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA, USA.
Cell
|February 19, 2026
Summary
Giant viruses possess their own translation initiation complex (IF4F), enabling them to synthesize proteins independently. This discovery blurs the lines between cellular and acellular life, revealing viral evolutionary innovations.
Area of Science:
- Virology
- Molecular Biology
- Cellular Biology
Background:
- Viruses were traditionally considered to lack protein synthesis machinery.
- Viruses rely on host cell factors for translating viral genetic material.
Purpose of the Study:
- To investigate the protein synthesis capabilities of giant DNA viruses.
- To identify the molecular mechanisms viruses use for translation.
Main Methods:
- Structural dissection of viral IF4F complex.
- Analysis of viral and host mRNA interactions.
- Investigating the role of viral IF4F during infection.
Main Results:
- Giant DNA viruses encode a functional IF4F translation-initiation complex.
- Viral IF4F replaces host IF4F during infection, controlling viral translation.
- The mRNA cap-binding subunit of viral IF4F selectively binds viral mRNAs.
Conclusions:
- Viruses can possess their own eukaryotic translation machinery.
- This finding redefines our understanding of viral biology and evolution.
- Viral IF4F acts as a molecular switch, prioritizing viral protein synthesis.
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