Archives of Virology

, Volume 60, Issue 3–4, pp 177–186

Activation of rotavirus RNA polymerase by calcium chelation

  • J. Cohen
  • J. Laporte
  • A. Charpilienne
  • R. Scherrer
Original Papers

Summary

Two types of particles were isolated during purification of rotavirus. Dense (D) particles have a density of 1.38 in CsCl and exhibit spontaneously a fully active endogenous transcriptase. Light (L) particles (density 1.36 in CsCl) need to be treated with chelating agents to show a polymerase activity. The activation process of L particles was studied under strictly controlled monovalent, divalent, and hydrogen ion concentrations. These experiments demonstrate that i) activation is not affected by the ionic strength ii) activation occurs only at a pH higher than 7.1 iii) a low concentration of chelating agent (40 µm EDTA) is sufficient to activate the enzyme. Treatment of particles with EGTA, which chelates selectively Ca2+, leads to unmasking even in the presence of magnesium, indicating that the concentration of free calcium ions plays a major role in the activation process. Various glycosidases, detergents, and chelating agents were tested in respect to unmasking properties. Of these compound only chelating agents turned out to be efficient. Following activation, two glycopeptides were solubilized. These glycopeptides have an apparent molecular weight of 34,000 and 31,000 daltons and react with concanavalin A.

The role of Ca2+ upon the stability of virus particles, and the activation of the endogenous transcriptasein vitro and in the infected cells is discussed.

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Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • J. Cohen
    • 1
  • J. Laporte
    • 1
  • A. Charpilienne
    • 1
  • R. Scherrer
    • 1
  1. 1.I.N.R.A. Station de Recherches de Virologie et d'ImmunologieThiverval-GrignonFrance

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