Tyrosinase-Related Protein-1 Novocastra
Tyrosinase-related protein-1 (TRP-1) is a member of a family of proteins which are involved in melanin biosynthesis. The catalytic function of TRP-1 has not been fully resolved but the enzyme appears to be important in the oxidation of 5,6-dihydroxyindole-2-carboxylic acid to form a high molecular weight pigmented biopolymer. In mammals, there are two basic types of melanin, the brown-black eumelanin and the reddish-yellow phaeomelanin. The concentrations of each are variable and are not related to skin type. In skin exposed to suberythemal doses of UVB, an increase in the number of melanocytes expressing TRP-1 and TRP-2 is reported with no increase in the number of tyrosinase-expressing melanocytes. In normal, untreated skin the number of melanocytes that express either TRP-1, TRP-2 or tyrosinase are similar irrespective of skin type. TRP-1 is also reported to be expressed in more than 50 percent of choroidal melanocytes in the adult eye.