Fig. 2. Kinetics of TPA-induced PKC degradation. Control empty-vector-transfected RBL cells, RBL-Syt II^- and RBL-Syt II⁺ cells were treated with TPA (50 nM) for the indicated time periods, and the cellular level of PKC was determined as described in Fig. 1. The intensities of the bands corresponding to PKC were quantified by densitometry and are presented as a percentage of the amount of enzyme present in untreated cells. Data represent the average±s.e. of three separate experiments.