MAP kinase-activated protein kinases 2 and 3 are required for influenza A virus propagation and act via inhibition of PKR

FASEB J. 2010 Oct;24(10):4068-77. doi: 10.1096/fj.10-158766. Epub 2010 May 19.

Abstract

Influenza viruses have to overcome the type I interferon induced antiviral response to successfully propagate in target cells. A major antiviral factor induced by interferons is the protein kinase R (PKR) that is further activated by dsRNA and phosphorylates the eukaryotic initiation factor 2 (eIF2α). This results in inhibition of protein translation thereby limiting viral replication. Here we describe a novel mechanism by which influenza A viruses escape the antiviral action of PKR. We demonstrate that the mitogen-activated protein kinase-activated protein kinases (MAPKAPKs) MK2 and MK3 are activated on virus infection and, in their active form, directly interact with the repressor of the inhibitor of PKR p88(rIPK). This leads to recruitment of a tetrameric protein complex consisting of p88(rIPK), the inhibitor of PKR p58(IPK) and PKR itself, and finally results in inhibition of the kinase. The importance of MKs for influenza virus propagation was further underscored by demonstrating reduced viral progeny in cells genetically deficient in MK2 or MK3 genes as well as in highly proliferating tumor cells, in which expression of MKs was diminished by specific small interfering RNA. Accordingly, knockdown of MKs resulted in enhanced phosphorylation of PKR and its substrate eIF2α.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Line
  • DNA Primers
  • Gene Knockout Techniques
  • Humans
  • Influenza A virus / physiology*
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Polymerase Chain Reaction
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Two-Hybrid System Techniques
  • Virus Replication*
  • eIF-2 Kinase / antagonists & inhibitors*

Substances

  • DNA Primers
  • Intracellular Signaling Peptides and Proteins
  • MAP-kinase-activated kinase 2
  • MAP-kinase-activated kinase 3
  • Protein Serine-Threonine Kinases
  • eIF-2 Kinase