Phosphorylation of elongation factor 2 by EF-2 kinase affects rate of translation

Nature. 1988 Jul 14;334(6178):170-3. doi: 10.1038/334170a0.


A new Ca2+/calmodulin-dependent protein kinase has been recently discovered in mammalian cells. The major substrate of this kinase, a protein of relative molecular mass (Mr) approximately equal to 100,000 (100K), has been identified as elongation factor 2 (EF-2), which participates in protein synthesis. The in vivo activity of the EF-2 kinase depends upon growth factors and other agents affecting the level of Ca2+ and cAMP. Its effect on EF-2 activity, however, remained obscure. This work shows that the phosphorylation of EF-2 by the EF-2 kinase results in a drastic inhibition of polyphenylalanine synthesis in poly(U)-directed translation. Phosphorylated EF-2 is completely inactive in translation and, moreover, inhibits the activity of non-phosphorylated EF-2. Dephosphorylation of EF-2 by phosphatase restores its activity. Hence, the phosphorylation of EF-2 directly affects the elongation stage of translation and thus represents a novel mechanism of translational control.

MeSH terms

  • Animals
  • Calcium-Calmodulin-Dependent Protein Kinases*
  • Cell-Free System
  • Elongation Factor 2 Kinase
  • Gene Expression Regulation
  • In Vitro Techniques
  • Peptide Elongation Factor 2
  • Peptide Elongation Factors / physiology*
  • Phosphoproteins / physiology
  • Phosphorylation
  • Protein Biosynthesis*
  • Protein Kinases / metabolism*
  • Protein Kinases / physiology*
  • Rabbits


  • Peptide Elongation Factor 2
  • Peptide Elongation Factors
  • Phosphoproteins
  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Elongation Factor 2 Kinase