Inhibition of brain protein kinase C subtypes by lead.

Academic Article

Abstract

  • Protein kinase C (PKC) is an important enzyme in mediating cellular signal transduction and neuronal plasticity. Extremely low concentrations (picomolar range) of Pb++ have been reported to activate partially purified PKC from rat brain (Markovac and Goldstein, 1988). However, the lead activation of PKC at such low concentrations is still a matter of discussion (Simons, 1989). To clarify this point, we have examined the lead effect on highly purified PKC subtypes. Pb++ was found to be a potent inhibitor for all three PKC subtypes (types I, II and III) with IC50 of 2 to 10 microM. Characterization of this lead inhibition of PKC suggests that 1) the inhibition is not due to the competition with Ca++, 2) the site of action of lead is on the catalytic domain of PKC, 3) the inhibition is not dependent on the mode of activation (phosphatidylserine/diacylglycerol vs. cis-unsaturated fatty acid) and 4) the inhibition is totally reversible.
  • Authors

    Keywords

  • Animals, Brain, Calcium, In Vitro Techniques, Lead, Male, Protein Kinase C, Rats, Rats, Sprague-Dawley
  • Author List

  • Murakami K; Feng G; Chen SG
  • Start Page

  • 757
  • End Page

  • 761
  • Volume

  • 264
  • Issue

  • 2