Figure 4.

OCA2 melanosomal sorting requires intact dileucine motifs.(a) Topology of human OCA2 and sequence of the cytoplasmic N terminus with putative acidic dileucine motifs indicated in magenta. (b–g) Wild-type OCA2-HA (b–d) or the triple dileucine mutant OCA2-AA123 (e–g) were expressed in pigmented melan-Ink4a melanocytes. Transfected cells are identified by anti-HA staining (b and e; colored magenta in merged images, d and g). Bright field images (c and f) were inverted and colored green in merged images (d and g). Insets, 4X magnification of boxed regions. Arrows point to regions of overlap between OCA2-HA and melanosomes (b–d). Bar, 10 μm.