Tyrosinase-related protein 1, also known as TYRP1, is an intermembrane

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

which in humans is encoded by the ''TYRP1''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Function

Tyrp1 is a

melanocyte Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart. ...

-specific gene product involved in

melanin Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino ...

synthesis within melanosomes. Most Tyrp1 possess 5,6-dihydroxyindole-2-carboxylic acid (melanogenic intermediate) oxidase activity. The catalytic function of Tyrp1 in human melanocytes is less clear. Tyrp1 is involved in stabilizing of

tyrosinase Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper Mason pathway. Firstly, the hydroxylat ...

protein and modulating its catalytic activity. Tyrp1 is also involved in maintenance of

melanosome A melanosome is an organelle found in animal cells and is the site for synthesis, storage and transport of melanin, the most common light-absorbing pigment found in the animal kingdom. Melanosomes are responsible for color and photoprotection i ...

structure and affects melanocyte proliferation and melanocyte cell death. Melanocytes are derived from the neural crest and migrate into the overlying epidermal ectoderm of a developing organism which forms skin and hair. Therefore, Tyrp1 influences the expression of melanin notably in the skin and hair of an organism. The Tyrp1 gene also has a non-coding function which indirectly promotes melanoma tumor cell proliferation, especially when highly expressed in a cell. Tyrp1 mRNA interacts with miR-16 and affects its ability to repress genes involved in melanoma cell production.

Clinical significance

Mutations in the mouse Tyrp1 gene are associated with brown

pelage Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily #Guard hair, guard hair on top and thick #Down hair, underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as ...

and in the human TYRP1 gene with

oculocutaneous albinism Oculocutaneous albinism is a form of albinism involving the eyes ('' oculo-''), the skin (''-cutaneous''), and the hair. Overall, an estimated 1 in 20,000 people worldwide are born with oculocutaneous albinism. OCA is caused by mutations in seve ...

type 3 (OCA3). An allele of TYRP1 common in Solomon Islanders results in blond hair. Although the phenotype is similar to Northern European blond hair, this allele is not found in Europeans. More recent study, Ju et al. 2020 found TYRP1 allele was selected in European population. Norton et al. 2016 study found TYRP1 is not associated with blond hair color in Melanesians as many populations in Oceania did not carry TYRP1 alleles but still displayed blondism, study indicates that additional unknown alleles contribute to the blondism phenotype in Melanesians. Alterations of the Tyrp1 gene is responsible for some of the differing phenotypes of skin and coat appearance in various animals. In Dalmatians, black versus "liver" spot color is due to genetic variation of the TYRP1 gene. A particular deletion in the Tyrp1 gene of domestic Chinese-Tibetan swine results in a "brown coloration" of the swine's skin and hair as opposed to the wild-type "black" phenotype. In Oujiang-color carp, mutations of the Tyrp1 gene influenced the expression of "grey" or "brown" phenotypic color of scales. Elevated levels of Tyrp1 gene expression is also associated with unfavorable patient outcome of those affected by melanoma. The role of Tyrp1 in melanoma progression was determined by comparing "knockout" cell lines which have inactive Tyrp1 to cells with normal and highly expressed Tyrp1. Such studies provide insight to possible clinical usage and treatment of melanoma via regulation of Tyrp1 expression in cells.

Regulation

The expression of TYRP1 is regulated by the

microphthalmia-associated transcription factor Microphthalmia-associated transcription factor also known as class E basic helix-loop-helix protein 32 or bHLHe32 is a protein that in humans is encoded by the ''MITF'' gene. MITF is a basic helix-loop-helix leucine zipper transcription factor ...

(MITF).

Interactions

TYRP1 has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...

with

GIPC1 GIPC PDZ domain containing family, member 1 (GIPC1) is a protein that in humans is encoded by the ''GIPC1'' gene. GIPC was originally identified as it binds specifically to the C terminus of RGS-GAIP, a protein involved in the regulation of G prot ...

References

External links

* {{PDBe-KB2, P17643, 5,6-dihydroxyindole-2-carboxylic acid oxidase