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Tyrosine 78 of premembrane protein is essential for assembly of West Nile virus

Terence T T Tan1, Raghavan Bhuvanakantham1, Jun Li1

  • 1Flavivirology Laboratory, Department of Microbiology, Yong Loo Lin School of Medicine, 5 Science Drive 2, National University of Singapore, Singapore 117597.

The Journal of General Virology
|March 7, 2009
PubMed

Insights

Researchers identified a critical amino acid, tyrosine 78, on the flavivirus premembrane (prM) protein. This discovery is vital for understanding flavivirus assembly and developing antiviral strategies.

Area of Science:

  • Virology
  • Molecular Biology
  • Structural Biology

Background:

  • The flavivirus premembrane (prM) protein is crucial for envelope (E) protein folding and preventing premature fusion.
  • Key molecular determinants on the prM ectodomain regulating flavivirus assembly remain poorly understood.

Purpose of the Study:

  • To identify and characterize molecular determinants on the flavivirus prM protein ectodomain essential for virus assembly.
  • To elucidate the specific role of conserved residues in flavivirus prM ectodomain function.

Main Methods:

  • Bioinformatics analysis to identify conserved residues in flavivirus prM ectodomains.
  • Alanine scanning mutagenesis and site-directed mutagenesis of West Nile virus (WNV) prM protein.
  • Transmission electron microscopy and trans complementation studies to assess virus assembly and infectivity.

Main Results:

  • An amino acid triplet (Val76, Tyr78, Gly79) was found to be conserved in flavivirus prM ectodomains.
  • Mutations in this triplet, particularly at tyrosine 78, abrogated WNV infectivity and virus particle formation.
  • Tyrosine 78 mutation did not impact prM and E protein folding, modification, or trafficking, indicating a specific role in assembly.

Conclusions:

  • Tyrosine 78 is a novel, critical determinant on the flavivirus prM protein ectodomain required for efficient virus assembly.
  • Understanding the function of tyrosine 78 provides crucial insights into the mechanisms of flavivirus particle formation.
  • This research contributes to the fundamental knowledge needed for developing targeted antiviral therapies against flaviviruses.

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