Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

1.14.18.1

Official Name

monophenol monooxygenase

Name from literature

Tyrosinase

Pathway from literature

melanin synthesis

Pathway from KEGG

Metabolism of Cofactors and Vitamins; Riboflavin metabolism; map00740

Biosynthesis of Secondary Metabolites; Alkaloid biosynthesis I; map00950

Cellular Processes; Endocrine System; Melanogenesis; map04916

Amino Acid Metabolism; Tyrosine metabolism; map00350

Organisms

Human (9606)

Genome localization

11q14-q21[7299 ],

Comments

A group of copper proteins that also catalyse the reaction of EC 1.10.3.1 catechol oxidase, if only 1,2-benzenediols are available as substrate.

Rate-limiting Description

"To distinguish these two possibilities, the present study examined the effects of latanoprost on tyrosinase activity (the rate-limiting step for melanin synthesis) and mitotic index of cultured melanoma lines." (10870514)

"Tyrosinase is a copper containing enzyme and is responsible for catalyzing the rate limiting step in melanin biosynthesis, the hydroxylation of tyrosine to dopaquinone." (10671066)

Regulatory Information

Upstream transcription factor

5092;4286;5925;6927

Regulatory type

Detail

key enzyme;

"Tyrosinase (EC 1.14.18.1) is the key enzyme of melanin pigment formation and it is unclear whether it is synthesized in human postnatal retinal pigment epithelium (RPE). " (17318568)

transcriptional factor;DCoH(5092)/HNF-1(6927)

"Data reveal DCoH/HNF-1 alpha expression and transcriptional activity in human epidermal melanocytes in vitro and in situ and identified tyrosinase, the key enzyme for pigmentation, as a new transcriptional target." (12565907)

phosphorylation;PKC

"These results suggest that phosphorylation of tyrosinase by PKC-beta induces a complex formation between tyrosinase and TRP-1." (14623273)

inhibitor;

"data show that chloride ion inhibited tyrosinase in a competitive manner" (17718595)

phosphorylation;

P14679

transcriptional factor;MITF(4286)

"These results indicate that MITF is a cell-type-specific factor that is capable of activating transcription of the tyrosinase gene." (7969144)

transcriptional factor;RB1(5925)

"Mitf cooperates with Rb1 and activates p21Cip1 expression to regulate cell cycle progression." (15716956)

Gene ontology

Gene ontology

GO:0006726 (P) eye pigment biosynthetic process [P14679 ];
GO:0007601 (P) visual perception [P14679 ];
GO:0042803 (F) protein homodimerization activity [P14679 ];
GO:0033162 (C) melanosome membrane [P14679 ];
GO:0046982 (F) protein heterodimerization activity [P14679 ];
GO:0007605 (P) sensory perception of sound [P14679 ];
GO:0005798 (C) Golgi-associated vesicle [P14679 ];
GO:0006583 (P) melanin biosynthetic process from tyrosine [P14679 ];
GO:0048471 (C) perinuclear region of cytoplasm [P14679 ];
GO:0016021 (C) integral to membrane [P14679 ];
GO:0005507 (F) copper ion binding [P14679 ];
GO:0005764 (C) lysosome [P14679 ];
GO:0004503 (F) monophenol monooxygenase activity [P14679 ];
GO:0055114 (P) oxidation reduction [P14679 ];

Subcellular localization

Localization

cell membrane [P14679 ];

cytoplasm [P14679 ];

Disease relevance

Disease

Defects in TYR are the cause of oculocutaneous albinism type I temperature-sensitive (OCA-ITS) [MIM:606952]. OCA-ITS patients have white axillary and scalp hair and pigmented arm and leg hair [P14679 ];

Defects in TYR are the cause of oculocutaneous albinism type IB (OCA-IB) [MIM:606952];
also known as albinism yellow mutant type. OCA-IB patients have white hair at birth that rapidly turns yellow or blond. They manifest the development of minimal-to-moderate amounts of cutaneous and ocular pigment [P14679 ];

Defects in TYR are the cause of oculocutaneous albinism type IA (OCA-IA) [MIM:203100]. OCA-I, also known as tyrosinase negative oculocutaneous albinism, is an autosomal recessive disorder characterized by absence of pigment in hair, skin and eyes. OCA-I is divided into 2 types: type IA, characterized by complete lack of tyrosinase activity due to production of an inactive enzyme, and type IB characterized by reduced activity of tyrosinase. OCA-IA patients presents with the life-long absence of melanin pigment after birth and manifest increased sensitivity to ultraviolet radiation and to predisposition to skin cancer [P14679 ];

Links

SwissProt

P14679

Entrez Gene

7299

HPRD

06086



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  Last Modified: 2009-03-24  
  Design by Zhao Min