Demonstration of a stimulatory protein for virus-specified DNA polymerase in phorbol ester-treated Epstein-Barr virus-carrying cells

Proc Natl Acad Sci U S A. 1985 Sep;82(17):5728-31. doi: 10.1073/pnas.82.17.5728.


A heat-labile Epstein-Barr virus-specific DNA polymerase stimulatory protein having a molecular mass of 45 kDa was purified from phorbol 12-myristate 13-acetate-treated P3HR-1 cells by column chromatography. The virus DNA polymerase stimulatory protein was precipitated by sera from patients with nasopharyngeal carcinoma but not by sera from healthy donors. The interaction of the stimulatory protein with DNA polymerase was stoichiometric. Furthermore, this protein stimulated Epstein-Barr virus DNA polymerase but not herpes simplex virus type 1 or type 2 or human DNA polymerase alpha. The stimulatory protein did not alter the Km value of dTTP or DNA but did increase the Vmax of DNA polymerase. Salt concentrations between 100 mM and 150 mM KCl were optimal for this protein-induced stimulation of Epstein-Barr virus DNA polymerase activity. The presence of the stimulatory protein in the reaction mixture enhanced the sensitivity of virus DNA polymerase to phosphonoformate.

Publication types

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

MeSH terms

  • Carcinoma / metabolism
  • Cell Line
  • DNA-Directed DNA Polymerase / metabolism*
  • Enzyme Activation
  • Foscarnet
  • Herpesvirus 4, Human / enzymology*
  • Hot Temperature
  • Humans
  • Kinetics
  • Nasopharyngeal Neoplasms / metabolism
  • Nucleic Acid Synthesis Inhibitors
  • Phosphonoacetic Acid / analogs & derivatives
  • Phosphonoacetic Acid / pharmacology
  • Potassium Chloride / pharmacology
  • Tetradecanoylphorbol Acetate / pharmacology
  • Viral Proteins / immunology
  • Viral Proteins / isolation & purification*


  • DNA polymerase stimulatory protein, Epstein-Barr virus
  • Nucleic Acid Synthesis Inhibitors
  • Viral Proteins
  • Foscarnet
  • Potassium Chloride
  • DNA-Directed DNA Polymerase
  • Phosphonoacetic Acid
  • Tetradecanoylphorbol Acetate