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In Vitro Analysis of Myd88-mediated Cellular Immune Response to West Nile Virus Mutant Strain Infection
10:39

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Published on: November 27, 2014

West Nile virus capsid protein interaction with importin and HDM2 protein is regulated by protein kinase C-mediated

Raghavan Bhuvanakantham1, Yuen Kuen Cheong, Mah-Lee Ng

  • 1Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.

Microbes and Infection
|April 27, 2010
PubMed

Insights

West Nile virus capsid protein phosphorylation by protein kinase C regulates nuclear entry and apoptosis. This post-translational modification is key to viral protein function.

Area of Science:

  • Virology
  • Molecular Biology
  • Cellular Biology

Background:

  • West Nile virus (WNV) capsid (C) protein nuclear import and apoptosis induction mechanisms are not fully understood.
  • Nuclear trafficking and apoptosis are critical for WNV pathogenesis.

Purpose of the Study:

  • To elucidate the regulatory mechanisms of WNV C protein nuclear import and apoptosis induction.
  • To investigate the role of post-translational modifications, specifically phosphorylation, in WNV C protein function.

Main Methods:

  • Bio-informatics analysis
  • Site-directed mutagenesis
  • Co-immunoprecipitation assays
  • Immuno-fluorescence microscopy
  • Mammalian two-hybrid analysis

Main Results:

  • Protein kinase C (PKC) phosphorylates WNV C protein.
  • PKC-mediated phosphorylation enhances C protein binding to importin-alpha, facilitating nuclear import.
  • Phosphorylation sites (Ser83, Ser99, Thr100) near/within the nuclear localization motif are crucial for importin-alpha interaction.
  • Phosphorylated WNV C protein binds to HDM2, leading to p53-dependent apoptosis.

Conclusions:

  • Phosphorylation is a critical post-translational modification regulating WNV C protein nuclear trafficking and function.
  • PKC-mediated phosphorylation of WNV C protein is essential for importin-alpha binding, nuclear import, and subsequent induction of apoptosis.
  • This study reveals a novel regulatory pathway for WNV C protein, impacting viral pathogenesis.

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