Select paramyxoviral V proteins inhibit IRF3 activation by acting as alternative substrates for inhibitor of κB kinase ε (IKKe)/TBK1

Lenette L. Lu, Mamta Puri, Curt M. Horvath, Ganes C. Sen

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77 Scopus citations


V accessory proteins from Paramyxoviruses are important in viral evasion of the innate immune response. Here, using a cell survival assay that identifies both inhibitors and activators of interferon regulatory factor 3 (IRF3)-mediated gene induction, we identified select paramyxoviral V proteins that inhibited double-stranded RNA-mediated signaling; these are encoded by mumps virus (MuV), human parainfluenza virus 2 (hPIV2), and parainfluenza virus 5 (PIV5), all members of the genus Rubulavirus. We showed that interaction between V and the IRF3/7 kinases, TRAF family member-associated NFκB activator (TANK)-binding kinase 1 (TBK1)/inhibitor of κB kinase ε (IKKe), was essential for this inhibition. Indeed, V proteins were phosphorylated directly by TBK1/IKKe, and this, intriguingly, resulted in lowering of the cellular level of V. Thus, it appears that V mimics IRF3 in both its phosphorylation by TBK1/IKKe and its subsequent degradation. Finally, a PIV5 mutant encoding a V protein that could not inhibit IKKe was much more susceptible to the antiviral effects of double-stranded RNA than the wild-type virus. Because many innate immune response signaling pathways, including those initiated by TLR3, TLR4, RIG-I, MDA5, and DNA-dependent activator of IRFs (DAI), use TBK1/IKKe as the terminal kinases to activate IRFs, rubulaviral V proteins have the potential to inhibit all of them.

Original languageEnglish (US)
Pages (from-to)14269-14276
Number of pages8
JournalJournal of Biological Chemistry
Issue number21
Publication statusPublished - May 23 2008
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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