Fig. 7. Src-kinase activity is necessary for fibronectin-induced PLC-1 phosphorylation. Null+ cells were allowed to adhere to fibronectin-coated dishes (10 µg ml^-1) in serum-free medium containing 50 µM sodium pervanadate and in the presence of (A) EGF-receptor tyrosine-kinase inhibitor AG1478 or (B) Src-kinase inhibitor PP2. Then, the cells were lysed and each lysate was precipitated with anti-PLC-1 antibodies followed by blotting with antibodies against tyrosine-783-phosphorylated PLC-1 or PLC-1 as indicated. In each experiment, 25 ng ml^-1 EGF was added for comparative purposes.