The melanosome is a highly specialized organelle in eukaryotic cells,which serves as the site for synthesis and storage of melanin. Melanosomes are originated from lysosomal vesicles and encapsulated by monolayer plasma membrane to form acidic and almost closed compartments,in which pH is approximately 4~5. Tyrosinase,a key rate-limiting enzyme in the melanin synthesis,is localized to the membrane of melanosomes and its optimal pH is 6.8,that means this membrane-bound enzyme is largely inactive in the acidic melanosomes. It is well established that there are many ion channels and transporters in the melanosomal membrane to regulate or maintain this slightly acidic intraluminal pH. Change of the melanogenesis in epidermal melanocytes through controlling the intramelanosomal pH paves a way for treatment of pigmentary disorders and for development of skin-lightening cosmetic products.
The Chinese Journal of Dermatovenereology