Analyses of c-Abl activation on RKO/neo and β4-transfected cells.

(A) Total cell lysates (500 μg) from RKO/neo (lane 1) and RKO/β4 (lane 2) cells were immunoprecipitated with anti–β4 monoclonal antibody. The immunoprecipitated β4 proteins were analyzed by SDS-PAGE and probed with an antibody direct to the β4 integrin subunit. (B) Equal amounts of cell lysates from RKO/neo cells (lane 1) and RKO/β4 cells (lanes 2) were immunoprecipitated with anti–Abl monoclonal antibody. The immunoprecipitated Abl proteins were analyzed by SDS-PAGE and probed with antiphosphotyrosine monoclonal antibody (upper panel B). The nitrocellulose was stripped and probed again with the anti–Abl polyclonal antibody (lower panel B). (C) Equal amounts of cell lysates from RKO/neo cells (lane 1) and RKO/β4 cells (lanes 2) were immunoprecipitated with anti–p73 polyclonal antibody and probed with anti–cAbl antibody (upper panel C). The nitrocellulose was stripped and probed again with the anti–p73 antibody (lower panel C).