This is a copper-containing oxidase that functions in the formation of pigments such as melanins and other polyphenolic compounds (By similarity). Catalyzes the initial and rate limiting step in the cascade of reactions leading to melanin production from tyrosine (By similarity). In addition to hydroxylating tyrosine to DOPA (3,4-dihydroxyphenylalanine), also catalyzes the oxidation of DOPA to DOPA-quinone, and possibly the oxidation of DHI (5,6-dihydroxyindole) to indole-5,6 quinone (By similarity). 2 L-dopa + O2 = 2 H2O + 2 L-dopaquinone L-tyrosine + O2 = H2O + L-dopaquinone Binds 2 copper ions per subunit. Forms an OPN3-dependent complex with DCT in response to blue light in melanocytes. Proper trafficking to melanosome is regulated by SGSM2, ANKRD27, RAB9A, RAB32 and RAB38. Increased expression after UVB irradiation. Glycosylated. Genetic variants in TYR define the skin/hair/eye pigmentation variation locus 3 (SHEP3) [MIM:601800]. Hair, eye and skin pigmentation are among the most visible examples of human phenotypic variation, with a broad normal range that is subject to substantial geographic stratification. In the case of skin, individuals tend to have lighter pigmentation with increasing distance from the equator. By contrast, the majority of variation in human eye and hair color is found among individuals of European ancestry, with most other human populations fixed for brown eyes and black hair. Compound heterozygosity for the R402Q polymorphism and a mutant allele of TYR is a common cause of autosomal recessive ocular albinism. The R402Q polymorphism is also found in Waardenburg syndrome type II with ocular albinism in association with a deletion in the MITF gene. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the tyrosinase family. Retina International's Scientific Newsletter TYR mutations Snowy stardom - Issue 49 of August 2004 Tyrosinase entry