Activation of phospholipase [C.sub.epsilon] by free fatty acids and cross talk with phospholipase D and phospholipase [A.sub.2]

Phospholiphase [C.sub.epsilon] is used as a model to demonstrate that lipids can act as ligands to bind to specific motifs and regulate protein activity via allosteric effects. It is shown that phospholipids such as phosphatidic acid and free fatty acids such as arachidonate are potent activators of [C.sub.epsilon], increasing the rate of Phosphatidylinositol hydrolysis by 8-fold and 50-fold, respectively.