Figure 5.

Paxillin does not stably associate with c-Crk proteins in NMuMG cells. NMuMG cells were treated or untreated with 2 ng/ml TGF-β for 3 days and then solubilized in 1% Nonidet P-40 buffer (27). Anti-Crk-I/Crk-II or anti-Crk-L immunoprecipitants were prepared from each 500 μg of 1% Nonidet P-40 cell lysates, separated by SDS/PAGE (8% gel), and subjected to sequential immunoblotting analysis by using antibodies as indicated. NMuMG cells expressed both Crk-I and Crk-II proteins (not shown). Total cell lysates (20 μg each) were also included (Total). Arrowheads indicate crossreaction of the secondary antibody with the heavy chain of anti-Crk antibodies used for immunoprecipitation.