SCF-induced tyrosine phosphorylation of PTP-RO in COS-7 cells transfected with c-Kit and PTP-RO cDNAs. Serum-starved COS-7 cells expressing exogenous c-Kit and PTP-RO-cFlag were incubated with 500 ng/mL SCF for the indicated times. Cells were lysed with the modified RIPA buffer and immunoprecipitated with 5 μg of anti-Flag antibody (Zymed). The immunoprecipitates were used for Western blotting using the antiphosphotyrosine antibody, PY20 (1:800; A). The immunoblot was stripped and reprobed with anti-Flag antibody (M2; 1:2,000; B), anti–PTP-RO antibodies (R5702; 7 μg/mL; C), and anti-PTPλ antibodies (D), sequentially.