Figure 2.

Actin depolymerization induces caveolae-mediated occludin endocytosis. Three-dimensional projections of monolayers labeled for occludin (red) and caveolin-1 (green), a marker of caveolae, are shown. Rather than the ordered appearance of occludin encircling the apical portion of the cell with few intracellular occludin-continuing vesicles in control epithelia (A), abundant intracellular occludin-continuing vesicles are evident after actin depolymerization (B). Many of these newly formed vesicles also contain caveolin-1, as apparent from the yellow colocalization signal. Bar = 5 μm.