TYR

Case study 1: Chen Hong, 2024

Epimedin B (EB) is one of the main flavonoid ingredients present in Epimedium brevicornum Maxim., a traditional herb widely used in China. The researchers's previous study showed that EB was a stronger inducer of melanogenesis and an activator of tyrosinase (TYR). However, the role of EB in melanogenesis and the mechanism underlying the regulation remain unclear.

Herein, as an extension to the previous investigation, they provide comprehensive evidence of EB-induced pigmentation in vivo and in vitro and elucidate the melanogenesis mechanism by assessing its effects on the TYR family of proteins (TYRs) in terms of expression, activity, and stability. The results showed that EB increased TYRs expression through microphthalmia-associated transcription factor-mediated p-Akt (referred to as protein kinase B (PKB))/glycogen synthase kinase 3β (GSK3β)/β-catenin, p-p70 S6 kinase cascades, and protein 38 (p38)/mitogen-activated protein (MAP) kinase (MAPK) and extracellular regulated protein kinases (ERK)/MAPK pathways. Furthermore, EB exerted repigmentation by stimulating TYR activity in hydroquinone- and N-phenylthiourea-induced TYR inhibitive models, including melanoma cells, zebrafish, and mice. Finally, EB ameliorated monobenzone-induced depigmentation in vitro and in vivo through the enhancement of TYRs stability by inhibiting TYR misfolding, TYR-related protein 1 formation, and retention in the endoplasmic reticulum and then by downregulating the ubiquitination and proteolysis processes.

Fig1. The protein expression levels of p-MITF, MITF, TYR, TYR-related protein 1 (TYRP1), dopachrome tautomerase (DCT), and melanoma antigen (Melan-A) (72 h on B16F10 cells).

Fig2. The protein expression levels of protein kinase A (PKA), phosphoinositide 3-kinase (PI3K), p-AKT, AKT, GSK-3β, β-catenin, p-p70 S6, p70 S6, p-c-Jun N-terminal kinase (JNK), JNK, p-p38, p38, p-ERK, and ERK (24 h on B16F10 cells).

Case study 2: Zi-Yi Xia, 2024

Resina Draconis is a traditional Chinese medicine, with the in-depth research, its medicinal value in anti-tumor has been revealed. Loureirin A is extracted from Resina Draconis, however, research on the anti-tumor efficacy of Loureirin A is rare.

This research demonstrated that Loureirin A inhibited the proliferation of and caused G0/G1 cell cycle arrest in melanoma cells in a concentration-dependent manner. Further study showed that the melanin content and tyrosinase activity was enhanced after Loureirin A treatment, demonstrated that Loureirin A promoted melanoma cell differentiation. The activity and the expression of tyrosinase was measured. Taken together, this study demonstrated for the first time the anti-tumor effects of Loureirin A in melanoma cells, which provided a novel therapeutic strategy against melanoma.

Fig3. Loureirin A promotes the differentiation of B16 cells. The tyrosinase activity in B16 cells.

Fig4. The protein levels of Tyrosinase, TRP1, TRP2, and MITF in B16 cells were measured by western blot.

Fig1. Impact of antioxidants on melanogenesis, melanosome transfer, melanocyte proliferation, inflammation, chemokine production, and minimal erythema dose (MED). (Reinhart Speeckaert, 2023)

Fig2. Role of Tyrosinase in melanin synthesis: Conversion of L-tyrosine to L-DOPA is the rate-limiting step in melanin synthesis, and this step is catalyzed by the enzyme Tyrosinase. (Rajan Logesh, 2023)

TYR involved in several pathways and played different roles in them. We selected most pathways TYR participated on our site, such as Tyrosine metabolism, Riboflavin metabolism, Metabolic pathways, which may be useful for your reference. Also, other proteins which involved in the same pathway with TYR were listed below. Creative BioMart supplied nearly all the proteins listed, you can search them on our site.

TYR has several biochemical functions, for example, copper ion binding, monooxygenase activity, monophenol monooxygenase activity. Some of the functions are cooperated with other proteins, some of the functions could acted by TYR itself. We selected most functions TYR had, and list some proteins which have the same functions with TYR. You can find most of the proteins on our site.

TYR has direct interactions with proteins and molecules. Those interactions were detected by several methods such as yeast two hybrid, co-IP, pull-down and so on. We selected proteins and molecules interacted with TYR here. Most of them are supplied by our site. Hope this information will be useful for your research of TYR.