Figure 5.

PKCε induces phosphorylation of Elk-1. (A) In HeLa cells, a doxycycline-inducible constitutively active PKCε²⁷ leads to phosphorylation of Elk-1. The cells were left untreated or induced with doxycycline (2 μg/mL) for 24 h. Additional stimulation with TPA (50 nM) was performed for 10 min. Phosphorylation of Elk-1 was detected with a phospho-specific antibody against the Ser383 residue of Elk-1. GAPDH was used as loading control. (B) Densitometric analysis of Western blots. Elk-1 phosphorylation was normalized to the GAPDH loading control, and data are expressed relative to untreated cells (control). Bar graphs represent quantitation of three independent experiments (±SD). Dox = doxycycline. Fold of control is calculated from Dox and TPA. (C) Compound 8 inhibits the phosphorylation of Elk-1 in PathDetect HeLa-HLR cells. Luciferase activity following activation of Elk-1 is shown. Data shown are the mean values (±SD) of three independent experiments. Because the relative light units vary from experiment to experiment, the data were normalized to the controls. Therefore, the standard deviation for the control is 0.