Sandbox TYRP1: Difference between revisions
Emma Charles (talk | contribs) No edit summary |
Emma Charles (talk | contribs) No edit summary |
||
| Line 10: | Line 10: | ||
== Function == | == Function == | ||
=== Role in melanocytes | === Role in melanocytes === | ||
First, TYRP1 has a role in melanin biosynthesis. Indeed, this enzyme has a catalytic function in the melanin biosynthetic pathway. In mouse, when a Cu2+ cation is bound, the protein catalyzes the oxidation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA) into indole-5,6-quinone-2-carboxylic acid. This protein is also able to catalyze the oxidation of 5,6-dihydroxyindole (DHI) into indole-5,6-quinone. Both products will allow to obtain eu-melanin, while pheo-melanin is obtain thanks to [https://www.uniprot.org/uniprot/P40126 TYRP2] activity. The activity of the TYRP1 enzyme increase when the serine residues in position 505 and 509 are phosphorylated <ref>PMID:11441007 </ref>. However, this mechanism does not happens in Humans because Human TYRP1 does not have the DHCIA activity. This can be explain by the fact that the nature of ions in the active site is different. Indeed, a Zn2+ ion bounds the active site of the TYRP1 enzyme instead of a Cu2+, which is responsible for a different activity. To conclude, the exact role of TYRP1 in pigmentation remains still unclear. Moreover, no gene polymorphism has been observed among caucasian population, despite the variation of hair and skin colors. | First, TYRP1 has a role in melanin biosynthesis. Indeed, this enzyme has a catalytic function in the melanin biosynthetic pathway. In mouse, when a Cu2+ cation is bound, the protein catalyzes the oxidation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA) into indole-5,6-quinone-2-carboxylic acid. This protein is also able to catalyze the oxidation of 5,6-dihydroxyindole (DHI) into indole-5,6-quinone. Both products will allow to obtain eu-melanin, while pheo-melanin is obtain thanks to [https://www.uniprot.org/uniprot/P40126 TYRP2] activity. The activity of the TYRP1 enzyme increase when the serine residues in position 505 and 509 are phosphorylated <ref>PMID:11441007 </ref>. However, this mechanism does not happens in Humans because Human TYRP1 does not have the DHCIA activity. This can be explain by the fact that the nature of ions in the active site is different. Indeed, a Zn2+ ion bounds the active site of the TYRP1 enzyme instead of a Cu2+, which is responsible for a different activity. To conclude, the exact role of TYRP1 in pigmentation remains still unclear. Moreover, no gene polymorphism has been observed among caucasian population, despite the variation of hair and skin colors. | ||
In addition, the [https://www.uniprot.org/uniprot/P07147 mouse homolog of the TYRP1] is involved in melanocytes differenciation too. Therefore, it could be used as a differentiation marker. In humans, the exact role of TYRP1 in differentiation of melanocyte is unclear. However, it is supposed that the protein is involved in the mechanism, as it is involved in pigmentation. | In addition, the [https://www.uniprot.org/uniprot/P07147 mouse homolog of the TYRP1] is involved in melanocytes differenciation too. Therefore, it could be used as a differentiation marker. In humans, the exact role of TYRP1 in differentiation of melanocyte is unclear. However, it is supposed that the protein is involved in the mechanism, as it is involved in pigmentation. | ||
=== Role in melanoma | === Role in melanoma === | ||
TYRP1 also have a role in progression of melanoma. In fact, as TYRP1 is involved in the proliferation and differentiation of melanocytes, a mutation of the protein is associated with a higher risk for melanoma. Therefore, the level of expression of TYRP1 mRNA is prognostic marker. | TYRP1 also have a role in progression of melanoma. In fact, as TYRP1 is involved in the proliferation and differentiation of melanocytes, a mutation of the protein is associated with a higher risk for melanoma. Therefore, the level of expression of TYRP1 mRNA is prognostic marker. | ||