Eukaryotic elongation factor 1delta is hyperphosphorylated by the protein kinase encoded by the U(L)13 gene of herpes simplex virus 1

J Virol. 1998 Mar;72(3):1731-6. doi: 10.1128/JVI.72.3.1731-1736.1998.

Abstract

The translation elongation factor 1delta (EF-1delta) consists of two forms, a hypophosphorylated form (apparent Mr, 38,000) and a hyperphosphorylated form (apparent Mr, 40,000). Earlier Y. Kawaguchi, R. Bruni, and B. Roizman (J. Virol. 71:1019-1024, 1997) reported that whereas mock-infected cells accumulate the hypophosphorylated form, the hyperphosphorylated form of EF-1delta accumulates in cells infected with herpes simplex virus 1. We now report that the accumulation of the hyperphosphorylated EF-1delta is due to phosphorylation by U(L)13 protein kinase based on the following observations. (i) The relative amounts of hypo- and hyperphosphorylated EF-1delta in Vero cells infected with mutant virus lacking the U(L)13 gene could not be differentiated from those of mock-infected cells. In contrast, the hyperphosphorylated EF-1delta was the predominant form in Vero cells infected with wild-type viruses, a recombinant virus in which the deleted U(L)13 sequences were restored, or with a virus lacking the U(S)3 gene, which also encodes a protein kinase. (ii) The absence of the hyperphosphorylated EF-1delta in cells infected with the U(L)13 deletion mutant was not due to failure of posttranslational modification of infected-cell protein 22 (ICP22)/U(S)1.5 or of interaction with ICP0, inasmuch as preferential accumulation of hyperphosphorylated EF-1delta was observed in cells infected with viruses from which the genes encoding ICP22/U(S)1.5 or ICP0 had been deleted. (iii) Both forms of EF-1delta were labeled by 32Pi in vivo, but the prevalence of the hyperphosphorylated EF-1delta was dependent on the presence of the U(L)13 protein. (iv) EF-1delta immunoprecipitated from uninfected Vero cells was phosphorylated by U(L)13 precipitated by the anti-U(L)13 antibody from lysates of wild-type virus-infected cells, but not by complexes formed by the interaction of the U(L)13 antibody with lysates of cells infected with a mutant lacking the U(L)13 gene. This is the first evidence that a viral protein kinase targets a cellular protein. Together with evidence that ICP0 also interacts with EF-1delta reported in the paper cited above, these data indicate that herpes simplex virus 1 has evolved a complex strategy for optimization of infected-cell protein synthesis.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Chlorocebus aethiops
  • Eukaryotic Cells
  • Herpesvirus 1, Human / metabolism*
  • Humans
  • Immediate-Early Proteins / genetics
  • Immediate-Early Proteins / metabolism
  • Peptide Elongation Factor 1
  • Peptide Elongation Factors / metabolism*
  • Phosphorylation
  • Precipitin Tests
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein Processing, Post-Translational
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Rabbits
  • Ubiquitin-Protein Ligases
  • Vero Cells
  • Viral Proteins*
  • Viral Regulatory and Accessory Proteins

Substances

  • ICP22 protein, human herpesvirus 1
  • Immediate-Early Proteins
  • Peptide Elongation Factor 1
  • Peptide Elongation Factors
  • Viral Proteins
  • Viral Regulatory and Accessory Proteins
  • EUS1 protein, Equine herpesvirus 1
  • Ubiquitin-Protein Ligases
  • Vmw110 protein, Human herpesvirus 1
  • Protein Kinases
  • UL13 protein, Simplexvirus
  • Protein Serine-Threonine Kinases
  • US3 protein, Human herpesvirus 1