ID:P_HUMAN DESCRIPTION: RecName: Full=P protein; AltName: Full=Melanocyte-specific transporter protein; AltName: Full=Pink-eyed dilution protein homolog; FUNCTION: Could be involved in the transport of tyrosine, the precursor to melanin synthesis, within the melanocyte. Regulates the pH of melanosome and the melanosome maturation. One of the components of the mammalian pigmentary system. Seems to regulate the post-translational processing of tyrosinase, which catalyzes the limiting reaction in melanin synthesis. May serve as a key control point at which ethnic skin color variation is determined. Major determinant of brown and/or blue eye color. SUBCELLULAR LOCATION: Melanosome membrane; Multi-pass membrane protein. INDUCTION: Expression inhibited by a regulatory element found within an intron of the HERC2 gene. POLYMORPHISM: Genetic variants in OCA2 define the skin/hair/eye pigmentation variation locus 1 (SHEP1) [MIM:227220]; also known as skin/hair/eye pigmentation type 1, blue/nonblue eyes or skin/hair/eye pigmentation type 1, blue/brown eyes or skin/hair/eye pigmentation type 1, blond/brown hair or eye color, brown/blue or eye color, blue/nonblue or eye color type 3 (EYCL3) or brown eye color type 2 (BEY2) or hair color type 3 (HCL3). 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. OCA2 polymorphisms may act as a penetrance modifier of the risk of malignant melanoma. DISEASE: Defects in OCA2 are the cause of albinism oculocutaneous type 2 (OCA2) [MIM:203200]. An autosomal recessive disorder in which the biosynthesis of melanin pigment is reduced in skin, hair, and eyes. Although affected infants may appear at birth to have complete absence of melanin pigment, most patients acquire small amounts of pigment with age. Visual anomalies include decreased acuity and nystagmus. The phenotype is highly variable. The hair of affected individuals may turn darker with age, and pigmented nevi or freckles may be seen. African and African American individuals may have yellow hair and blue-gray or hazel irides. One phenotypic variant, 'brown OCA,' has been described in African and African American populations and is characterized by light brown hair and skin color and gray to tan irides. SIMILARITY: Belongs to the CitM (TC 2.A.11) transporter family. WEB RESOURCE: Name=Mutations of the P gene; Note=Retina International's Scientific Newsletter; URL="http://www.retina-international.org/files/sci-news/pgenemut.htm"; WEB RESOURCE: Name=Albinism database (ADB); Note=P mutations; URL="http://albinismdb.med.umn.edu/oca2mut.html"; WEB RESOURCE: Name=Protein Spotlight; Note=Questioning colour - Issue 54 of January 2005; URL="http://web.expasy.org/spotlight/back_issues/sptlt054.shtml"; WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/OCA2";
Protein Domain and Structure Information
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Other Names for This Gene
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Methods, Credits, and Use Restrictions
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