Fig. 7. Effect of 480-Cbl expression on PDGF-mediated activation of Rac. Wild-type, c-Cbl- and 480-Cbl-expressing NIH 3T3 cells were lysed following serum starvation or after 1 and 5 minutes of treatment with PDGF. (A) Aliquots of the lysates were either directly subjected to SDS-PAGE and western blotting with anti-Rac antibodies or incubated with sepharose-bound GST-PAK-CD and bound proteins subjected to SDS-PAGE and western blotting with anti-Rac antibodies as indicated. (B) Densitometric scans for anti-Rac blots of GST-PAK-CD bound proteins obtained from five experiments were averaged and plotted. Error bars represent the standard deviations. (C) Aliquots of serum starved and PDGF treated wild-type, c-Cbl and 480-Cbl expressing NIH 3T3 cells were subjected to SDS-PAGE and Western blotting with anti-phospho-p38 MAPK (Thr180/Tyr182) and anti-p38 MAPK specific antibodies, as indicated.