Fig. 3. Requirement for SHP-2 binding sites in the SHPS-1 ligand-induced inhibition of cell migration. (A) Lysates prepared from CHO-IR cells expressing rat wild-type SHPS-1 or from CHO-IR cells expressing the rat SHPS-1-4F mutant were subjected to immunoblot analysis with pAbs to SHPS-1. The position of the recombinant SHPS-1 proteins is indicated. (B) Migration assays were performed for 16 h with parental CHO-IR cells, CHO-IR-rSHPS-1-WT cells, or CHO-IR-rSHPS-1-4F cells that had been preincubated for 30 min at 37°C with normal mouse IgG (5 µg/ml) (open columns) or with mAb 2F34 to rat SHPS-1 (5 µg/ml; solid columns). Insulin (100 nM) was included in the lower chambers of the Transwell apparatus. Data are means ± SE of triplicates from an experiment that was repeated a total of three times with similar results. *P < 0.05 for the indicated comparisons; NS, not significant (Student’s t-test).