A melanosome is a specialized, membrane-bounded organelle in which melanin is synthesized and stored. Melanocytes produce melanosomes; pigment can subsequently be transferred to neighbouring keratinocytes. The melanosome is the compartment, whereas melanin is its pigment cargo. Maturation involves changes in internal organization as well as accumulation of pigment. [ref]
Molecular Biology of the Cell, 4th edition by Bruce Alberts and others. Chapter 22, skin: melanocytes and pigment distribution
An experiment connected that organization to a particular protein. Expression of Pmel17 in nonpigmented cells produced internal striations resembling those of immature melanosomes, within multivesicular compartments. The result supported a structural role for Pmel17 in constructing a scaffold before extensive pigment deposition. It did not show that expression of one protein produces every function of a mature melanosome. [ref]
Pmel17 initiates premelanosome morphogenesis within multivesicular bodies by Joanne F. Berson and others. 2001, abstract and Pmel17 expression experiments
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