Figure 7. Notch potentiates PKC activity in S2 cells.

A. S2-Notch cells express higher levels of Pkc98E. The high level in S2-Notch cells is reduced at high concentrations of the PKC activating drug phorbol ester (12-tetradecanoyl phorbol-13 acetate, TPA), which is expected because a high level of PKC activation is known to automatically trigger its down-regulation. B. P-Cactus level in S2-Notch cells increased at a lower concentration of TPA but decreased at high concentrations. The decrease was expected due to negative regulation of PKC at high concentrations of TPA. The same number of cells was used for each sample and the same amount of the sample was loaded in lane of the blot. The Pkc98E experiment was repeated twice and the Cactus/Dorsal experiment was repeated three times.