Figure 3.

Increased Rac activation perturbs the stability of cadherin receptors in mature junctions. Keratinocytes grown in standard medium (mature cell-cell contacts) were microinjected with different concentrations of constitutively active Rac (L61Rac) as follows: 0.25 mg/ml (a–c), 0.5 mg/ml (d–f), 1.0 mg/ml (g–i), and 2.0 mg/ml (j–l). After a 2-h incubation in the same medium, cell were fixed and double labeled for E-cadherin (b, e, h, and k) and integrins (c, f, i, and l). Injected cells are seen in a, d, g, and j. Arrows (i and l) show integrin staining at junctions; arrowheads (h and k) show absence of cadherin receptors at junctions. Bar, 50 μm.