Time course of PKC isozyme translocation after stimulation with PMA and the dose-response curve for PMA. In panel A, basophils were incubated with PMA (100 ng/mL) for the times indicated (n = 1) and in panel B cells were incubated with various concentrations of PMA for 15 minutes (n = 1). The membrane and cytosol fractions were prepared, analyzed by Western blotting, and the bands quantified by digital imaging. The data are expressed as the amount of membrane-associated PKC as a percentage of the summed band intensities for membrane + cytosol. PKC βI (○), βII (•), δ (▪), ε (□), and histamine (▵).