Fig. 3.

The AP-1 adaptor is a crucial regulator of polarized lysosome exocytosis. (A) LAMP2 on the surface of wild-type MDCK cells or cells lacking μ1A (μ1AKD) or μ1B (μ1BKD) after ionomycin (Iono) treatment. (B) Quantification of surface LAMP2 fluorescence (expressed as a percentage of total fluorescence) in each confocal slice, numbered starting from the top of the monolayer. The gray bar indicates slices where ZO-1 is found and demarcates the apical and basolateral domains. (C) β-hex release from wild-type (wt), μ1AKD, μ1BKD or μ1ABKD double knockdown cells. *P<0.001, compared with corresponding apical values. (D) β-hex release from wild-type, μ1BKD and μ1BKD cells with reconstituted μ1B.