PKP2 is required for long-range transport of Dsc2 but not Dsg2. (A) Scc9 cells were treated with control or siPKP2 oligos mixed with siGLO (positive transfection indicator) and imaged 3 d after transfection. First frames show areas (boxes) analyzed in control or PKP2-deficient cells, and the three magnified columns show selected vesicles (colored arrows) at three time points. Vesicle trajectories taken from the analyzed area are shown on the right, where colored tracks represent the movement of selected vesicles. Bars, 20 µm. (B) Bar graphs show quantification of distribution of particle movements (equal to instantaneous velocity; for each set of bars **, P < 0.01) and the ratio of rapid movements to the average amount of analyzed particles (10–15 particles per cell) in each cell (three to four cells were analyzed per experiment) for Dsc2 in control and knockdown conditions. In PKP2-deficient cells, the amount of the particle movements as well as the ratio of rapid movements for Dsc2 was dramatically decreased compared with the control cells (**, P < 0.01 for the ratio of rapid movements). (C) Distribution of long vectors and the ratio of long vectors to the average amount of analyzed particles (10–15 particles in each cell) for Dsg2 in cells with PKP2 knockdown are similar to that observed in control cells (P = 0.9). (D) Immunoblot showing level of PKP2 knockdown (∼60%, n = 3; *, P < 0.05) for experiments in A and B. NT, nontargeting; Tub, tubulin.