FIG. 7.

Effect of 8-pCPT-cGMP on EGF-induced MAP kinase nuclear translocation. Clone C11 (A to C) or clone C21 (D to F) cells were serum starved in the presence of zinc as described in Materials and Methods. Cells were incubated without additives (A and D) or with EGF (100 ng/ml) added for the last 10 min prior to fixing (B, C, E, and F); in panels C and F, 250 μM 8-pCPT-cGMP was added 30 min before the EGF. Cells were immunostained with a MAP kinase-specific antibody followed by a fluorescamine-labeled secondary antibody and were analyzed by confocal laser microscopy as described in Materials and Methods.