A basic way to tan
Darker-skinned individuals have more melanin in their skin and a lower risk for skin cancer than fairer-skinned individuals. The production of melanin occurs in organelles called melanosomes and is regulated by melanosome pH. Zhou et al. found that cAMP generated by soluble adenylyl cyclase (sAC) resulted in decreases in melanosome pH and in the activity of tyrosinase, the rate-limiting enzyme in melanin synthesis. sAC deficiency or inhibitors increased melanosome pH and pigmentation in mice. These results define a mechanism of rapidly regulating melanin synthesis that could be exploited to reduce skin cancer risk for fair-skinned individuals.