Fig. 3. Inhibitors of Src family kinases blocked collagen-I-induced SHIP2 tyrosine phosphorylation. (A) IPs were carried out from HeLa cells that were detached (D) or freshly re-plated (RP) on collagen-I-coated dishes (6 µg/cm²) in the presence of vehicle dimethyl sulfoxide (DMSO; —) or Src-kinase-selective Pyrido (2,3-d) pyrimidine tyrosine kinase inhibitors PD173956 (#56), PD173958 (#58) and PD180970 (#70) at 1 µM for 60 minutes. Anti-SHIP2 or pre-immune IPs were immunoblotted with anti-phosphotyrosine (-PY) or anti-SHIP2 antibodies. (B) As described above except HeLa cells were re-plated in the presence of DMSO (-) or increasing concentrations (0.05-1.0 µM) of PD173956 (similar results were obtained with PD180970). The arrows point to tyrosine-phosphorylated SHIP2.