Figure 3.
Effect of altered intracellular cAMP levels on UV irradiation–induced JNK activation. (A) Effect of 8-cpt-cAMP on UV irradiation–induced JNK phosphorylation. (B) Effect of forskolin on UV irradiation–induced JNK phosphorylation. (C) Effect of Rp-cpt-cAMP on UV irradiation–induced JNK phosphorylation. Intracellular cMAP levels were altered by exposure of HCE cells to 8-cpt-cAMP, forskolin or Rp-cpt-cAMP at indicated concentrations in the absence and presence of 5 mM caffeine 30 minutes before UV irradiation. HCE cells were harvested 15 minutes after UV irradiation for Western blot analysis.