Alexander C Theos, Danièle Tenza, José A Martina, Ilse Hurbain, Andrew A Peden, Elena V Sviderskaya, Abigail Stewart, Margaret S Robinson, Dorothy C Bennett, Daniel F Cutler, Juan S Bonifacino, Michael S Marks, Graça Raposo
Specialized cells exploit adaptor protein complexes for unique post-Golgi sorting events, providing a unique model system to specify adaptor function. Here, we show that AP-3 and AP-1 function independently in sorting of the melanocyte-specific protein tyrosinase from endosomes to the melanosome, a specialized lysosome-related organelle distinguishable from lysosomes. AP-3 and AP-1 localize in melanocytes primarily to clathrin-coated buds on tubular early endosomes near melanosomes. Both adaptors recognize the tyrosinase dileucine-based melanosome sorting signal, and tyrosinase largely colocalizes with each adaptor on endosomes...
November 2005: Molecular Biology of the Cell