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Symbol OCA2 contributors: mct/npt - updated : 15-11-2018
HGNC name oculocutaneous albinism II
HGNC id 8101
Corresponding disease
AS Angelman syndrome
HECD skin, hair and eye pigmentation variations
OCA2 oculocutaneous albinism, type 2
PWS Prader-Willi syndrome
Location 15q13.1      Physical location : 28.000.024 - 28.344.458
Synonym name
  • melanosomal membrane protein (110kD)
  • pink-eyed dilution,homolog of mouse p locus
  • oculocutaneous albinism II (pink-eye dilution homolog, mouse)
  • P protein
  • melanocyte-specific transporter protein
  • eye color 2 (central brown)
  • eye color 3 (brown)
  • total brown iris pigmentation
  • Synonym symbol(s) D15S12, PEDH, BOCA, P, PED, EYCL3, EYCL2, BEY2, EYCL, BEY, BEY1, SHEP1
    TYPE functioning gene
    STRUCTURE 380.33 kb     24 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    MAPPING cloned Y linked N status confirmed
    Physical map
    X102 15q11.2 X102 protein IPW 15q11.2-q12 imprinted in Prader-Willi syndrome PAR1 15q11-q13 imprinted in Prader-Willi syndrome HBII-52 15q11.2 HBII-52 snoRNA PAR4 15q11.2 PAR4 gene HBII-438B 15q11.2 HBII-438B C/D box snoRNA UBE3A 15q11-q12 ubiquitin protein ligase E3A (human papilloma virus E6-associated protein, Angelman syndrome) ATP10A 15q11-q13 ATPase, Class V, type 10A MRPS18CP5 15q11.2 mitochondrial ribosomal protein S18C pseudogene 5 GABRB3 15q11.2-q12 gamma-aminobutyric acid (GABA) A receptor, beta 3 GABRA5 15q11.2-q12 gamma-aminobutyric acid (GABA) A receptor, alpha 5 LOC390550 15 LOC390550 GABRG3 15q11.2-q12 gamma-aminobutyric acid (GABA) A receptor, gamma 3 OCA2 15q11.2-q12 oculocutaneous albinism II (pink-eye dilution homolog, mouse) LOC388091 15 LOC388091 HERC2 15q13 hect domain and RLD 2 RPL41P2 15q11-q13 ribosomal protein L41, pseudogene 2 LOC390551 15 similar to hect domain and RLD 2 LOC390552 15 similar to hypothetical protein FLJ36144 LOC388092 15 similar to hypothetical protein LOC342156 15q12 similar to ATP-binding cassette, sub-family B, member 10, mitochondrial precursor (ATP-binding cassette transporter 10) (ABC transporter 10 protein) (Mitochondrial ATP-binding cassette 2) (M-ABC2) LOC388093 15 similar to hypothetical protein MGC5244 LOC390553 15 hypothetical gene supported by NM_012089 LOC388094 15 similar to hypothetical protein LOC390554 15 similar to hypothetical protein FLJ36144 LOC388095 15 hypothetical gene supported by NM_004667 LOC342179 15q12 similar to KIAA0855 protein LOC390555 15 similar to Mothers against decapentaplegic homolog interacting protein (Madh-interacting protein) (Smad anchor for receptor activation) (Receptor activation anchor) (hSARA) (Novel serine protease) (NSP) LOC388096 15 LOC388096 LOC219392 15q12 similar to HP95 APBA2 15q14 amyloid beta (A4) precursor protein-binding, family A, member 2 (X11-like) NDNL2 15q11-q13 necdin-like 2 LOC390556 15 similar to tubulin, beta 5 LOC283697 15q13.1 hypothetical protein LOC283697 TJP1 15q13 tight junction protein 1 (zona occludens 1) LOC390557 15 similar to chromosome condensation protein G LOC283698 15q13.1 similar to synaptogyrin 2; cellugyrin LOC283717 15q13.1 similar to hypothetical protein FLJ35785 LOC390558 15 similar to Dynamin-1 (D100) (Dynamin, brain) (B-dynamin) LOC388097 15 similar to hyperpolarization activated cyclic nucleotide-gated potassium channel 2; brain cyclic nucleotide gated channel 2
    regionally located included in PWS/AS critical region
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    24 - 3154 - 838 - 2017 28456133
    23 - 3082 - 814 - 2017 28456133
    Type restricted
       expressed in (based on citations)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Nervousnervecranial nerve   
    Respiratoryrespiratory tractlarynx  highly
    Skin/Tegumentskin   highly
    cell lineage
    cell lines
    at STAGE
  • N-terminal cytoplasmic domain of human OCA2 contains three consensus aLL motifs termed LL1, LL2, and LL3
  • twelve transmembrane spanning segments (12TM)
  • a conserved consensus acidic dileucine-based sorting motif within the cytoplasmic N-terminal region
  • a second dileucine signal within this region confers steady-state lysosomal localization in melanocytes, suggesting that OCA2 might traverse multiple sequential or parallel trafficking routes (Sitaram 2009)
    interspecies homolog to murine p locus
  • citM transporter family
  • CATEGORY transport carrier
    SUBCELLULAR LOCALIZATION     plasma membrane
    intracellular,cytoplasm,organelle,endoplasmic reticulum
    text targeted to and functions within melanosomes but that residence within melanosomes may be regulated by secondary or alternative targeting to lysosomes (Sitaram 2009)
    basic FUNCTION
  • involved in small molecule transport, specifically tyrosine - a precursor of melanin
  • involved in melanogenesis
  • may serve as a key control point at which ethnic skin color variation is determined
  • plays a critical role in melanin synthesis in melanocytes and retinal pigment epithelium cells
    text tyrosine into melanosomes (sodium sulfate symporter)
    signaling sensory transduction/vision
    a component
  • protein constituent of membrane
    small molecule
  • MC1R (interactive effect on melanoma risk)
  • significant interactions of a redundant character between the HERC2 and OCA2 genes affecting determination of hazel eye colour
  • distinct roles of AP1B1 and AP3B1 in OCA2 transport to melanosomes, indicating that BLOC1S1 can cooperate with either adaptor during cargo sorting to lysosome-related organelles (LROs)
  • TBX2 acts as regulator of melanogenesis by repressing the expression of the gene encoding the melanosomal protein OCA2
  • cell & other
    Other modified by MC1R
    corresponding disease(s) OCA2 , PWS , AS , HECD
    related resource AlbinismDatabase
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional germinal mutation      
    associated with mutation of OCA2 in oculocutaneous albinism with red hair
    constitutional       loss of function
    can significantly change the melanosomal morphology, types and their respective numbers, and provided a novel strategy for the control of melanin synthesis
    constitutional     --low  
    disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes
  • to skin cancer (melanoma), in addition to MC1R
  • to blue/nonblue eye color
  • to variation of skin pigmentation
  • Variant & Polymorphism SNP
  • polymorphisms Arg305Trp and Arg419Gln associated with nonblue eyes and the TGT haplotype within the intron 1 of with blue eye color
  • variant located within the gene OCA2 (rs1800414) is associated with skin pigmentation in two samples of East Asian ancestry (Edwards 2010)
  • Candidate gene for fair complexion in Deleted PWS and AS patients
    Therapy target