TYRP1 oxidises DHICA to IQCA

Stable Identifier
Reaction [transition]
Homo sapiens
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5,6-dihydroxyindole-2-carboxylic acid oxidase (TYRP1, aka gp75, CAS2, TRP-1) is an abundant protein in the melanosome membrane which, amongst other functions, can oxidise 5,6-dihydroxyindole-2-carboxylic acid (DHICA) into the corresponding 5,6-indolequinone-2-carboxylic acid (IQCA), thus promoting the incorporation of DHICA units into eumelanin (Olivares et al. 2001). Oculocutaneous albinism (OCA) is an autosomal recessive disorder caused by either complete lack of or a reduction of melanin biosynthesis in melanocytes. Mutations in TYRP1 cause OCA3, aka Rufous oculocutaneous albinism. Tyrosinase activity is normal and patients have only a moderate reduction of melanin. Darker-skinned sufferers have bright copper-red colouration of the skin and hair (Kamaraj & Purohit 2014, Rooryck et al. 2006).

Literature References
PubMed ID Title Journal Year
16704458 Oculocutaneous albinism with TYRP1 gene mutations in a Caucasian patient

Müsebeck, J, Rooryck, C, Arveiler, B, Roudaut, C, Robine, E

Pigment Cell Res. 2006
25093188 Mutational analysis of oculocutaneous albinism: a compact review

Kamaraj, B, Purohit, R

Biomed Res Int 2014
11171088 The 5,6-dihydroxyindole-2-carboxylic acid (DHICA) oxidase activity of human tyrosinase

Olivares, C, Jiménez-Cervantes, C, Lozano, JA, Solano, F, García-Borrón, JC

Biochem. J. 2001
Catalyst Activity

oxidoreductase activity of TYRP1 [melanosome membrane]

Orthologous Events
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