FIG. 3.

FN- and ILK-mediated stimulation of AP-1 is dependent on PI 3-kinase. (A) FN-induced AP-1 activity is sensitive to LY294002. HEK-293 cells transfected by calcium phosphate with 50 μg of pGL3-AP-1 were plated on BSA or FN for 30 min in the presence of the indicated concentrations of LY294002, and AP-1 activity was evaluated by luciferase assay. (B) ILK-induced AP-1 activity is sensitive to PI 3-kinase inhibitors. AP-1 activity in HEK-293 cells cotransfected by Lipofectin with 0.5 μg of pGL3-AP-1 and 0.5 μg of pcDNA3.1-ILK-V5 was measured. PD98059 (25 μM), wortmannin (100 nM), LY294002 (10 μM), or dimethyl sulfoxide (DMSO) was added to the cell culture medium 30 min prior to harvesting the cells. AP-1 activity was then evaluated by a luciferase assay. ILK expression is shown by Western blotting with anti-V5 antibody.