Examination of tyrosine phosphorylation of CDCP1 and binding of Src and PKCδ induced by DU145 media. A, anti-Src, -PKCδ, -p-CDCP1-Y734 (performed with an antibody that detects both p-CDCP1-Y734 and p-FAK-Y861), and -CDCP1 (CST 4115) Western blot analysis of anti-CDCP1 immunoprecipitates (CST 4115) obtained from DU145 cells. B, anti-CDCP1 (CST 4115), -p-CDCP1-Y734 (performed with an antibody that detects both p-CDCP1-Y734 and p-FAK-Y861), -PKCδ, and -Src Western blot analysis of anti-Src immunoprecipitates obtained from DU145 cells. C, anti-phosphotyrosine, anti-PKCδ, anti-Src, and anti-CDCP1 (CST 4115) Western blot analysis of anti-CDCP1 immunoprecipitates obtained from 22Rv1 cells either untreated (−) or treated (+) with 3 day serum-free conditioned medium from DU145 cells for 36 h. The media was either untreated (−) or treated (+) with protease inhibitor (PI) mixture before incubation with 22Rv1 cells. Lysates from all experiments were collected in the presence (+) or absence (−) of sodium vanadate and sodium fluoride. All experiments included control immunoprecipitations performed with species matched IgG. NS, nonspecific.