Figure 5.

Effect of vanadate pretreatment on platelet-derived growth factor-R phosphorylation state after platelet-derived growth factor/insulin stimulation. Cells (1 × 10⁶) were serum starved for 24 h pretreated for 1 min with 0.1 mM vanadate and then stimulated with 30 ng/ml platelet-derived growth factor and 10 nM insulin either separately or in combination. At the indicated times, cells were lysed in RIPA buffer, immunoprecipitated with anti-platelet–derived growth factor-R antibodies. Immunoblots were first probed with anti-phosphotyrosine antibodies and then the blot was stripped and reprobed with anti-platelet–derived growth factor-R antibodies. The result is representative of three independent experiments with similar results.