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Evidence for phosphorylation of human parainfluenza virus type 3 C protein: mutant C proteins exhibit variable

Achut G Malur1, Greg Wells, Almedia McCoy

  • 1Department of Microbiology and Immunology, Brody School of Medicine, Biotech 124, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA. malurac@ecu.edu

Virus Research
|May 5, 2009
PubMed

Insights

Phosphorylation of human parainfluenza virus type 3 C protein differentially regulates viral RNA synthesis. Specific phosphorylation sites impact viral RNA levels during transcription and replication.

Area of Science:

  • Virology
  • Molecular Biology
  • Immunology

Background:

  • Human parainfluenza virus type 3 (HPIV-3) C protein regulates viral RNA synthesis and host interferon response.
  • The C protein's precise regulatory mechanisms are not fully understood.

Purpose of the Study:

  • To investigate the role of C protein phosphorylation in regulating HPIV-3 RNA synthesis.
  • To identify specific phosphorylation sites on the C protein.

Main Methods:

  • Mass spectrometry and deletion mapping to identify phosphorylation sites.
  • HPIV-3 minigenome replication assays.
  • Real-time RT-PCR to quantify viral RNA levels.

Main Results:

  • Identified S7, S22, S47T48, and S81 as C protein phosphorylation sites.
  • Mutants S7A and S81A showed reduced RNA levels during transcription.
  • Mutant 5A (lacking all sites) and S81A showed increased RNA levels during replication.

Conclusions:

  • Phosphorylation of HPIV-3 C protein plays a critical role in regulating viral RNA synthesis.
  • Specific phosphorylation sites differentially modulate the C protein's inhibitory activity.

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