FIGURE 2:

Rac signaling regulates junctional WAVE2. (A, B) Rac and Cdc42 coaccumulate with WAVE2 at the zonula adherens. Caco-2 cells were immunostained for WAVE2 and either Rac (A) or Cdc42 (B) and imaged by confocal microscopy. (C–E) Junctional WAVE2 requires Rac signaling. Caco-2 cells transiently expressing dominant-negative (DN) Rac or DN Cdc42 mutants were immunostained for WAVE2 and the epitope tag (not shown). Asterisks mark cells positive for DN-Rac or DN-Cdc42 expression, and arrows indicate contacts between transgene-expressing cells. Junctional WAVE2 was reduced at contacts between cells expressing DN-Rac but not at contacts between cells expressing DN-Cdc42 (D, E; n = 30 contacts from three independent experiments each; data are means ± SEM, normalized to control. ****p < 0.0001; n.s. not significant; AU, arbitrary units). (F, G) WAVE regulatory complex components are junctional proteins. Confluent Caco-2 monolayers were costained for E-cadherin and either Sra1 (F) or Nap1 (G) and imaged at the ZA. Scale bars, 10 μm.