FIGURE 4.

Rab38 partially colocalizes to proteins required in the trafficking from specialized early endosomal domains to melanosomes. MNT-1 cells were fixed/permeabilized and costained with antibodies against Rab38 (A, D, G, and J) and the δ subunit of AP-3 (B), the γ subunit of AP-1 (E), the HPS6 subunit of BLOC-2 (H), or the clathrin heavy chain (K). Cells were imaged by confocal fluorescence microscopy, and Rab38 was found both on small structures and in diffuse staining distributed throughout the cells. A significant number of AP-3- (B), AP-1- (E), BLOC-2- (H), and clathrin (K)-labeled structures show colocalization with Rab38 in the merged images (C, F, I, and L). Boxed areas are shown in the magnified insets, where arrowheads indicate sites of colocalization. Scale bars indicate 10 μm.