Figure 2.

Comparison of the induced tyrosine kinase activity of PFR1, -3, and -4. PC12 cells expressing the chimeric receptors were incubated at 37°C for 10 min without (−) or with (+) PDGF (30 ng/ml). Lysates (2 mg) were immunoprecipitated with anti-PDGFR and immunoblotted with anti-phosphotyrosine (αPY). (A) Upper, high-molecular-weight region of the anti-phosphotyrosine blot; Lower, the same blot stripped and reprobed with monoclonal anti-PDGFR. The arrows indicate the two forms (mature and incompletely glycosylated) of the chimeric receptors. (B) Upper, longer exposure of the same (full) antiphosphotyrosine blot shown in A. Tyrosine-phosphorylated proteins of 145, 89, and 43 kDa are indicated by arrows; Lower, the same blot stripped and reprobed with anti-PLCγ. Molecular mass standards (kDa) are shown.