Figure 1.

Rac activation does not strengthen cadherin-dependent adhesion in keratinocytes. Cells containing mature intercellular junctions were microinjected with constitutively active Rac (L61Rac, 0.5 mg/ml). Activated Rac was injected either alone (a–d), or in combination with activated H-Ras (V12Ras + L61Rac, g and h). Controls show keratinocytes injected with H-Ras alone (V12Ras, e and f). After 2 h of incubation, cells were fixed and stained for E-cadherin (b, d, f, and h). In c and d, keratinocytes were preextracted with Triton X-100 before fixation (see MATERIALS AND METHODS). Microinjected patches of cells are seen in a, c, e, and g. Arrowheads (f and h) show absence of cadherin staining at junctions. Arrows (b and d) point to similar levels of cadherin staining in microinjected cells. Bar, 50 μm.