KIF3A mediates peripheral distribution of the MT1-MMP endosome in JIP3/JIP4-depleted cells. (A) Silencing of KIF3A and JIP3/4 in MT1-MMPmCh–expressing MDA-MB-231 cells. β-Actin was used as a loading control. (B) Inverted still images from time-lapse sequences of MDA-MB-231 cells expressing MT1-MMPmCh endosomes treated with the indicated siRNAs (see Video 2). Bar, 5 µm. (C) Mean percentage distribution of MT1-MMPmCh–positive endosomes according to their cell center-to-cell periphery position ± SEM. ***, P < 0.001 (compared with siNT-treated cells). (D) Color-coded time projections of 61 consecutive time frames from time-lapse sequences of MDA-MB-231 cells expressing MT1-MMPmCh (acquired with 3-s intervals). Bar, 5 µm. (E and F) Displacement index of MT1-MMP–positive endosomes in indicated cell populations. ***, P < 0.001 (compared with siNT-treated cells in E or DMSO-treated cells in F). n, number of scored cells.