TRP-2 mediates coat color pigmentation in sheep skin

Tyrosinase-related protein 2 (TRP-2) is one of the most important members of the tyrosinase family, and is a key enzyme involved in melanin biosynthesis. In the present study, a skin transcriptome profile, immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction were used to investigate TRP-2 expression in sheep with different coat colors, namely, black, white and black-white. TRP-2 was overexpressed in melanocytes in order to study the effect of TRP-2 on melanin production. Results revealed differing TRP-2 levels in sheep of different coat colors and in various parts of the coat with different colors in the same sheep. TRP-2 expression levels in dark-colored areas were significantly increased compared with light-colored areas in piebald sheep. TRP-2 overexpression may regulate melanogenesis and significantly increase melanogenesis associated transcription factor expression in vitro. Therefore, TRP-2 may affect melanin production in sheep, and different expression levels determine coat color. The results may provide novel approaches for developing therapeutic strategies for skin diseases associated with pigmentation disorders.