Comparison of the roles of the C1a and C1b domains of protein kinase C alpha in ligand induced translocation in NIH 3T3 cells

To explore the relative roles of the two C1 domains of protein kinase C alp ha (PKC alpha) in the response to phorbol esters and related analogs, we mu tated the individual C1 domains, expressed the mutated PKC alpha in NIH 3T3 cells, and then examined the ability of ligands to induce its translocatio n to the membrane, The C1a and C1b domains play equivalent roles for transl ocation in response to phorbol 12-myristate 13-acetate, mezerein, and (-)oc tylindolactam V, These results contrast with those previously reported for PKC delta, suggesting that the domains play different roles in different PK C isoforms, (C) 1999 Federation of European Biochemical Societies.