Poliovirus switches to an eIF2-independent mode of translation during infection

J Virol. 2011 Sep;85(17):8884-93. doi: 10.1128/JVI.00792-11. Epub 2011 Jun 22.

Abstract

Inhibition of translation is an integral component of the innate antiviral response and is largely accomplished via interferon-activated phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF2α). To successfully infect a host, a virus must overcome this blockage by either controlling eIF2α phosphorylation or by utilizing a noncanonical mode of translation initiation. Here we show that enterovirus RNA is sensitive to translation inhibition resulting from eIF2α phosphorylation, but it becomes resistant as infection progresses. Further, we show that the cleavage of initiation factor eIF5B during enteroviral infection, along with the viral internal ribosome entry site, plays a role in mediating viral translation under conditions that are nonpermissive for host cell translation. Together, these results provide a mechanism by which enteroviruses evade the antiviral response and provide insight into a noncanonical mechanism of translation initiation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Eukaryotic Initiation Factor-2 / metabolism*
  • Eukaryotic Initiation Factors / metabolism*
  • HeLa Cells
  • Host-Pathogen Interactions*
  • Humans
  • Poliovirus / physiology*
  • Protein Biosynthesis*
  • Viral Proteins / biosynthesis*

Substances

  • Eukaryotic Initiation Factor-2
  • Eukaryotic Initiation Factors
  • Viral Proteins
  • eukaryotic initiation factor-5B