Ligand binding and dimerization after SLF treatment.

MO7e cells were treated with ¹²⁵I-labeled SLF at 37°C for 5 minutes. Then, cell surface proteins were cross-linked with 2 mM BS3. Cells were solubilized with lysis buffer containing 1% CHAPS and processed for immunoprecipitation with indicated antibodies. After being separated by SDS-PAGE, c-kit bound to radiolabeled SLF was detected by autoradiography (upper panel). The same membrane was immunoblotted with anti–c-kit polyclonal antibody (lower panel). Relative SLF binding rates normalized by the protein amounts in lower panel were shown at the bottom. These are the representative results from 2 separate experiments.