Figure 8.

Inhibition of clathrin-mediated endocytosis blocks internalization of junctional proteins in calcium-depleted cells. T84 cells were preincubated for 60 min in either hypertonic (0.4 M sucrose) or acidic (pH 5.5) T84 media or with POA (20 μM) followed by a 120-min incubation in hypertonic or acidic or POA-containing S-MEM. Control monolayers were incubated in complete T84 medium and S-MEM. Localization of E-cadherin and occludin was determined by immunofluorescence labeling and confocal microscopy. All three inhibitors, which are known to prevent the formation of clathrin-coated pits, effectively block internalization of junctional proteins.