tyrosinase (monophenol monooxygenase, tumor rejection antigen AB, SK29-AB, LB24-AB, TYR)

Function

• copper-containing oxidase that functions in formation of pigments including melanins & other polyphenolic compounds
• catalyzes rate-limiting conversions of
  • tyrosine to DOPA
  • DOPA to DOPA-quinone
  • possibly 5,6-dihydroxyindole to indole-5,6 quinone

L-tyrosine + L-dopa + O2 <--> L-dopa + dopaquinone + H2O

Cofactor: binds 2 copper ions per subunit

Structure

belongs to the tyrosinase family

Compartment

melanosome membrane

Alternative splicing

named isoforms=2

Expression

• increased expression after UV-B radiation

Pathology

• defects in TYR are the cause of oculocutaneous albinism type 1

Polymorphism

• compound heterozygosity for the R402Q polymorphism
• mutant allele of TYR is a common cause of autosomal recessive ocular albinism
• R402Q polymorphism is also found in Waardenburg syndrome type 2 with ocular albinism (WS2-OA) in association with a deletion in the MITF gene

More general terms

• hydroxylase; monooxygenase
• glycoprotein
• membrane protein

Additional terms

• DHICA oxidase
• L-dopachrome tautomerase; DCT; DT; L-dopachrome delta-isomerase; tyrosinase-related protein 2; TRP-2; TRP2 (DCT, TYRP2)

Database

• UniProt: http://www.uniprot.org/uniprot/P14679.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:7299
• OMIM: https://mirror.omim.org/entry/103470
• OMIM: https://mirror.omim.org/entry/203100
• OMIM: https://mirror.omim.org/entry/606933
• OMIM: https://mirror.omim.org/entry/606952