Simian virus 40 large-T bypasses the translational block imposed by the phosphorylation of elF-2 alpha

Virology. 1996 May 1;219(1):321-3. doi: 10.1006/viro.1996.0255.

Abstract

One of the cellular defense mechanisms against virus infection is mediated by activating the interferon-induced, double-stranded-RNA-activated protein kinase, PKR. Upon activation, PKR phosphorylates and thereby inactivates the protein synthesis initiation factor, elF-2, leading to cessation of protein synthesis. Viruses have evolved diverse strategies to counteract this cellular antiviral response. A majority of these strategies target PKR to prevent its activation. Recently, we showed that simian virus 40 (SV40) large-T antigen reverses PKR-mediated translational inhibition at a step downstream of PKR activation (Rajan et al., J. Virol. 69, 785--795, 1995). In this paper, we present evidence showing that SV40 can restore efficient translation in cells despite the elevated levels of phosphorylated elF-2 alpha resulting from PKR activation. Thus, SV40 large-T-mediated translational rescue occurs at a step downstream of elF-2 alpha phosphorylation.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens, Polyomavirus Transforming / metabolism*
  • Cell Line
  • Chlorocebus aethiops
  • Eukaryotic Initiation Factor-2 / antagonists & inhibitors
  • Eukaryotic Initiation Factor-2 / metabolism*
  • Gene Expression Regulation, Viral
  • Phosphorylation
  • Protein Biosynthesis
  • Protein Serine-Threonine Kinases / metabolism
  • Signal Transduction
  • eIF-2 Kinase

Substances

  • Antigens, Polyomavirus Transforming
  • Eukaryotic Initiation Factor-2
  • Protein Serine-Threonine Kinases
  • eIF-2 Kinase