Melanosomes are specialized lysosomes that store pigments for eventual release by exocytosis. Various cells such as skin and hair cells then take up the pigment, which accounts for their characteristic pigmentation. Mouse mutants that have defective melanosomes often have pale or unusual coat colors. One such light-colored mouse, the Mocha mouse (Figure Q13–3), has a defect in the gene for one of the subunits of the adaptor protein complex AP3, which is associated with coated vesicles budding from the trans Golgi network. How might the loss of AP3 cause a defect in melanosomes?

Figure Q13-3

Transcribed Image Text:

normal mouse Mocha mouse