Figure 4.

PAE cell density does not alter PDGFR-α activation. PAE cells expressing PDGFR-α were cultured in the confluent or sparse condition, serum starved overnight, and then stimulated with PDGF-AA (40 ng/ml) for 5 min. Cells were lysed and immunoprecipitated with an PDGFR-α antibody and immunoblotted with an anti-phosphotyrosine (pY) antibody (A). The same membrane was reprobed with PDGFR-α antibody (B).