Active Rab13 accumulates at the cell’s leading edge. (A) MCF10A cells expressing wild-type (WT) mCh-Rab13 were imaged live. The arrows follow a vesicle that appears to fuse with the plasma membrane. The images correspond to Videos 2 and 3. (B) MCF10A cells expressing mCh-Rab13 Q67L were imaged live. The arrows indicate a site of vesicle accumulation. The dashed lines indicate the starting position of the lagging edge. The images correspond to Video 4. (C) MCF10A cells expressing mCh-Rab13 T22N were imaged live. The arrows follow a vesicle that fails to associate with the plasma membrane. The images correspond to Video 5. Bars, 10 µm. Boxed regions are magnified on the right.