Figure 2.

FAK inhibition prevents adhesion-induced activation of Rab5. A549 cells were either left in suspension (Susp.) or allowed to adhere to fibronectin-coated plates (2 μg/ml) for 2 h in the presence of DMSO (Ctrl) or 1 μm PF562,271 (PF). A–D, cell extracts were prepared and used for subsequent whole-cell lysate analysis (A and B) or R5BD pulldown assays (C and D). A and C, representative Western blot images are shown for phospho-Tyr³⁹⁷–FAK (pY397-FAK), total FAK, β-actin, Rab5-GTP, and total Rab5. B and D, quantification of pTyr³⁹⁷-FAK with respect to total FAK (B) and Rab5-GTP with respect to total Rab5 (D), as obtained from scanning densitometric analysis. Data represent the average of six independent experiments (mean ± S.E.; *, p < 0.05; **, p < 0.01; ***, p < 0.001; n.s., nonsignificant).