Calcium, potassium:sodium antiporter that transports 1 Ca(2+) and 1 K(+) to the melanosome in exchange for 4 cytoplasmic Na(+). Involved in pigmentation, possibly by participating in ion transport in melanosomes. Predominant sodium-calcium exchanger in melanocytes. Ca(2+)(out) + K(+)(out) + 4 Na(+)(in) = Ca(2+)(in) + K(+)(in) + 4 Na(+)(out) Highly expressed in melanin-producing cells such as skin and eye compared to other tissues. Strongly overexpressed in melanoma cell lines. Expressed in dental tissues. Belongs to the Ca(2+):cation antiporter (CaCA) (TC 2.A.19) family. SLC24A subfamily. Skin-deep - Issue 74 of September 2006