Figure 3.

PDGF-AA treatment results in the differential phosphorylation of several Akt targets in primary MEPM cells. (A) PDGF-AA-dependent Akt and Erk1/2 phosphorylation time course in E13.5 primary MEPM lysates. Following serum starvation, low-passage MEPM cells were stimulated with 10 ng/mL PDGF-AA ligand for 2 min to 2 h. Western blot analysis of whole-cell lysates revealed peaks of both Akt and Erk1/2 phosphorylation 15 min after ligand treatment. (B) PDGF-AA-dependent Akt target phosphorylation in E13.5 primary MEPM lysates. Immunoprecipitation of Akt targets from lysates of primary MEPM cells that were untreated or treated for 15 min with 10 ng/mL PDGF-AA ligand with an anti-Akt phosphosubstrate antibody followed by Western blotting with the same antibody revealed 14 protein bands (arrowheads) that increased in intensity upon ligand stimulation. Large bands at ∼50 kDa correspond to the heavy chain of IgG. (WB) Western blot; (WCL) whole-cell lysate; (IP) immunoprecipitation.