Counter-regulatory effects of phosphatidic acid on protein kinase C activity in the presence of calcium and diolein.

ABSTRACT

Phosphatidic acid can replace phosphatidylserine in the activation of protein kinase C. However, in the presence of diolein, the addition of Ca2+ results in the inhibition of the enzyme. This phenomenon could lead to a negative feedback regulation of protein kinase C activity as a result of stimulation of the cycling of phosphatidylinositol.