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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
a) tyrosine to DOPA
b) DOPA to DOPA-quinone
c) 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
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
Pathology:
- defects in TYR are the cause of oculocutaneous albinism type 1
Related
5,6-dihydroxyindole-2-carboxylic acid oxidase; DHICA oxidase; tyrosinase-related protein 1; TYRP1, catalase B; glycoprotein-75; gp75; brown [b] locus protein homolog; CAS2 protein; melanoma antigen gp75; monophenol monooxygenase homolog (TYRP1, CAS2, TYRP, TYRRP)
L-dopachrome tautomerase; DCT; DT; L-dopachrome delta-isomerase; tyrosinase-related protein 2; TRP-2; TRP2 (DCT, TYRP2)
General
glycoprotein
hydroxylase; monooxygenase
membrane protein
Properties
SIZE: entity length = 529 aa
MW = 60 kD
COMPARTMENT: cellular membrane
MOTIF: signal sequence {1-18}
N-glycosylation site {N86}
N-glycosylation site {N111}
N-glycosylation site {N161}
copper [Cu]-binding site
SITE: 180-180
MOTIF: histidine residue (3)
copper [Cu]-binding site
SITE: 202-202
MOTIF: histidine residue (3)
copper [Cu]-binding site
SITE: 211-211
MOTIF: histidine residue (3)
N-glycosylation site {N230}
N-glycosylation site {N337}
copper [Cu]-binding site
SITE: 363-363
MOTIF: histidine residue (3)
copper [Cu]-binding site
SITE: 367-367
MOTIF: histidine residue (3)
N-glycosylation site {N371}
copper [Cu]-binding site
SITE: 390-390
MOTIF: histidine residue (3)
transmembrane domain {477-497}
Database Correlations
OMIM correlations
MORBIDMAP 606933
UniProt P14679
Pfam PF00264
Kegg hsa:7299
ENZYME 1.14.18.1
References
- UniProt :accession P14679
- OMIM :accession 203100
- Mutations of the TYR gene;
Retina International's Scientific newsletter
http://www.retina-international.com/sci-news/tyrmut.htm
- Albinism database (ADB); Note: TYR mutations
http://albinismdb.med.umn.edu/oca1mut.html
- GeneReviews
https://www.genecards.org/cgi-bin/carddisp.pl?gene=TYR
- Protein Spotlight; Note: Snowy stardom
- Issue 49 of August 2004
http://www.expasy.org/spotlight/back_issues/sptlt049.shtml
- Wikipedia; Note: Tyrosinase entry
http://en.wikipedia.org/wiki/Tyrosinase