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Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE
Published on: July 29, 2014
Arenavirus nucleoprotein targets interferon regulatory factor-activating kinase IKKε
Christelle Pythoud1, W W Shanaka I Rodrigo, Giulia Pasqual
1Institute of Microbiology University Hospital Center and University of Lausanne, Lausanne, Switzerland.
Journal of Virology
|April 26, 2012
Summary
Arenaviruses block antiviral defenses by targeting IKKε, a key kinase. The viral nucleoprotein (NP) binds and inactivates IKKε, preventing interferon production and aiding viral evasion.
Area of Science:
- Virology
- Immunology
- Cellular Biology
Background:
- Arenaviruses are significant human pathogens that subvert host innate immunity.
- Type I interferons (IFNs) are crucial for antiviral defense, and their induction is a common target for viral evasion.
- The arenavirus nucleoprotein (NP) is known to interfere with interferon regulatory factor 3 (IRF3) activation.
Purpose of the Study:
- To identify cellular factors involved in innate antiviral signaling that are targeted by arenavirus NP.
- To elucidate the mechanism by which arenavirus NP disrupts the RIG-I/MAVS signaling pathway.
Main Methods:
- Coimmunoprecipitation assays to identify protein interactions.
- Confocal microscopy to visualize protein localization.
- In vitro kinase assays to assess protein activity.
Main Results:
- Lymphocytic choriomeningitis virus (LCMV) NP associates with IKKε, but not TBK-1.
- The NP-IKKε interaction is conserved across different arenavirus clades.
- LCMV NP binds the kinase domain of IKKε, inhibiting its activity and IRF3 phosphorylation.
Conclusions:
- IKKε is a novel cellular target of arenavirus NP.
- Arenavirus NP sequesters IKKε in an inactive complex, thereby blocking innate antiviral signaling.
- The NP-IKKε interaction is critical for arenavirus pathogenesis and host immune evasion.
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