S-Palmitoylation of Tyrosinase at Cysteine500 Regulates Melanogenesis
S-Palmitoylation of Tyrosinase at Cysteine500 Regulates Melanogenesis
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DOI：
10.1016/j.jid.2022.08.040
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发表时间：
2023-01-19
影响因子：
6.5
通讯作者：
Ueyama, Takehiko
中科院分区：
文献类型：
--
作者：
Niki, Yoko;Adachi, Naoko;Ueyama, Takehiko
棕榈酰化是一种脂质修饰，涉及棕榈酸与半胱氨酸残基的连接，从而影响蛋白质功能。我们研究了棕榈酰化酪氨酸酶，在黑色素合成的限速酶，使用人类三维皮肤模型系统和黑素细胞培养的效果。棕榈酰化抑制剂2-溴棕榈酸酯通过抑制酪氨酸酶降解增加黑色素生成细胞中的黑色素含量和酪氨酸酶蛋白水平。棕榈酰化位点是酪氨酸酶C端胞质尾区的半胱氨酸500。的nonpalmitoylatable突变体，酪氨酸酶（C500 A），缓慢降解和泛素化比野生型酪氨酸酶。筛选Asp-His-His-Cys（DHHC）家族的酪氨酸酶棕榈酰化蛋白表明DHHC 2、3、7和15参与酪氨酸酶棕榈酰化。DHHC 2、3或15的敲低增加酪氨酸酶蛋白水平和黑色素含量。它们在原代黑素细胞中的亚细胞定位的测定显示DHHC 2、3和15定位于内质网、高尔基体和/或黑素体中，而只有DHHC 2定位于黑素体中。免疫沉淀显示DHHC 2和DHHC 3主要分别与成熟和未成熟的酪氨酸酶结合。总之，酪氨酸酶在半胱氨酸500处被DHHC 2、3和/或15棕榈酰化，特别是反式高尔基体和黑素体中的DHHC 2和内质网和顺式高尔基体中的DHHC 3，通过调节酪氨酸酶蛋白水平来调节黑素生成。
Palmitoylation is a lipid modification involving the attachment of palmitic acid to a cysteine residue, thereby affecting protein function. We investigated the effect of palmitoylation of tyrosinase, the rate-limiting enzyme in melanin synthesis, using a human three-dimensional skin model system and melanocyte culture. The pal-mitoylation inhibitor, 2-bromopalmitate, increased melanin content and tyrosinase protein levels in melano-genic cells by suppressing tyrosinase degradation. The palmitoylation site was Cysteine500 in the C-terminal cytoplasmic tail of tyrosinase. The nonpalmitoylatable mutant, tyrosinase (C500A), was slowly degraded and less ubiquitinated than wild-type tyrosinase. Screening for the Asp-His-His-Cys (DHHC) family of proteins for tyrosinase palmitoylation suggested that DHHC2, 3, 7, and 15 are involved in tyrosinase palmitoylation. Knockdown of DHHC2, 3, or 15 increased tyrosinase protein levels and melanin content. Determination of their subcellular localization in primary melanocytes revealed that DHHC2, 3, and 15 were localized in the endo-plasmic reticulum, Golgi apparatus, and/or melanosomes, whereas only DHHC2 was localized in the melano-somes. Immunoprecipitation showed that DHHC2 and DHHC3 predominantly bind to mature and immature tyrosinase, respectively. Taken together, tyrosinase palmitoylation at Cysteine500 by DHHC2, 3, and/or 15, especially DHHC2 in trans-Golgi apparatus and melanosomes and DHHC3 in the endoplasmic reticulum and cis-Golgi apparatus, regulate melanogenesis by modulating tyrosinase protein levels.