Figure 7.

Rab11 mutants mistarget hEcad and transform polarized MDCK cells. Confluent monolayers of MDCK cells were fixed and labeled, and confocal imaging was performed to generate XZ and XY sections. Single expression of hEcad (A) or ΔS1-Ecad (B) shows their basolateral or apical distribution, respectively (red labeling), relative to nuclear staining (DAPI, blue). In cells coexpressing Rab11SN-GFP (green), hEcad (red) is dramatically shifted to the apical surface (C). Coexpression of Rab11SN-GFP (green) does not alter the apical delivery of ΔS1-Ecad (red; D). The expression of Rab11SN-GFP notably transforms the cells initially causing enhanced spreading and invasive protrusion at the basal cell surface, as seen in basal XY sections (C and D). This phenotypic change was even more striking after expression of Rab11QL-GFP as seen in a 3D reconstruction of cells cotransfected with Rab11QL-GFP (green) and hEcad (red; E). 3D rendered animations of confocal sections pertaining to each panel are available in the supplementary material (Supplementary Movies 5–9) Scale bars, 10 μm.