Reactome | TYRP1 oxidises DHICA to IQCA

TYRP1 oxidises DHICA to IQCA

Stable Identifier

R-HSA-8878581

Type

Reaction [transition]

Species

Homo sapiens

Compartment

melanosome membrane, melanosome lumen

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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
25093188	Mutational analysis of oculocutaneous albinism: a compact review Kamaraj, B, Purohit, R	Biomed Res Int	2014
16704458	Oculocutaneous albinism with TYRP1 gene mutations in a Caucasian patient Rooryck, C, Roudaut, C, Robine, E, Müsebeck, J, Arveiler, B	Pigment Cell Res.	2006
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