Figure 4.

Inhibition of actin polymerization and phosphatase activity block R-Ras–dependent cell adhesion. Mouse 32D cells were cotransfected with empty pCGN control vector, pCGN NΔ87L R-Ras, pCGN Q87L R-Ras, or pCGN S43N R-Ras plus pGL-3 and assayed for cell adhesion as described in Figure 2A. Cells were pretreated with the indicated concentrations of latrunculin B (LB), cytochalasin D (CD), calyculin A (CA), or 0.1% DMSO control for 30 min at 37°C before adhesion to vitronectin. Data represent triplicate means of a representative experiment from four independent trials.