This domain lies at the C-terminus of the clathrin-adaptor protein complex-3 beta-1 subunit. The AP-3 complex is associated with the Golgi region of the cell as well as with more peripheral structures. The AP-3 complex may be directly involved in trafficking to lysosomes or alternatively it may be involved in another pathway, but that mis-sorting in that pathway may indirectly lead to defects in pigment granules.
Jiyao W et al.(2023). "The conserved domain database in 2023.",