P protein; melanocyte-specific transporter protein; pink-eyed dilution protein homolog (OCA2, D15S12, P)

Function

• role in transport of tyrosine,precursor to melanin synthesis, within melanocytes (putative)
• regulates pH of melanosomes & melanosome maturation
• component of the mammalian pigmentary system
• appears to regulate post-translational processing of tyrosinase, which catalyzes the limiting step in melanin synthesis
• may serve as a key control point at which ethnic skin color variation is determined
• major determinant of brown &/or blue eye color

Structure

• belongs to the SLC13A transporter (TC 2.A.47) family P subfamily

Compartment

melanosome membrane

Alternative splicing

named isoforms=3

Pathology

• defects in OCA2 are the cause of oculocutaneous albinism type 2
• the gene OCA2 is localized to chromosome 15 at 15q11.2-q12, a region associated with Prader-Willi & Angelman syndromes, suggesting that altered expression of the OCA2 gene may be responsible for the hypopygmentation phenotype exhibited by certain individuals with these disorders
• human pigmentation, including eye color, has been associated with skin cancer risk

Polymorphism

• genetic variations in OCA2 are associated with skin/hair/eye pigmentation variability type 1

More general terms

• transmembrane 12 protein
• carrier protein (transporter)
• glycoprotein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4948
• OMIM: https://mirror.omim.org/entry/203200
• OMIM: https://mirror.omim.org/entry/227220
• OMIM: https://mirror.omim.org/entry/611409
• UniProt: http://www.uniprot.org/uniprot/Q04671.html