GFP-VAMP7 exits melanosomes in STX13-independent tubules lacking TYRP1. (a–f) WT melan-Ink4a melanocytes transiently transfected with GFP-VAMP7 alone (green, a–c) or with mCh-STX13 (red, d–g) or TYRP1-mRFP (red, h–j) were analyzed 24 h later by spinning-disk confocal microscopy at ∼1 fps. (a–c) Image sequence from a cell (shown in Fig. S2 i) expressing GFP-VAMP7 relative to melanosomes visualized by BF microscopy. Arrow shows a GFP-VAMP7 tubule, and the arrowhead points to a melanosome in the BF image. Bar, 2 µm. (d) Single frame from representative cell expressing GFP-VAMP7 and mCh-STX13. Bar, 10 µm. (e–g) Single frames from boxed regions in d with single channels and merged image. Arrows show tubules labeled by GFP-VAMP7 (green), and arrowheads show tubules labeled by mCh-STX13 (red). Bar, 1 µm. Insets are magnified two times from d. (h–j) Image sequence from a cell (shown in Fig. S2 j) expressing GFP-VAMP7 (green) and TYRP1-mRFP (red). A GFP-VAMP7–labeled tubule (arrow) emerges from a TYRP1-mRFP/GFP-VAMP7–labeled melanosome (arrowhead). Elapsed time is shown in seconds (s) at the bottom. Bar, 2 µm.