Characterization of the Zebrafish Ugt Repertoire Reveals a New Class of Drug-Metabolizing UDP Glucuronosyltransferases
Characterization of the Zebrafish Ugt Repertoire Reveals a New Class of Drug-Metabolizing UDP Glucuronosyltransferases
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斑马鱼 Ugt 库的表征揭示了一类新的药物代谢 UDP 葡萄糖醛酸基转移酶
DOI：
10.1124/mol.113.091462
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发表时间：
2014-07-01
影响因子：
3.6
通讯作者：
Wu, Qiang
中科院分区：
文献类型：
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作者：
Wang, Yuanming;Huang, Haiyan;Wu, Qiang
斑马鱼基因组包含一个由40个Ugt基因组成的基因超家族，可分为Ugt 1、Ugt 2和Ugt 5家族。由于编码的斑马鱼UDP葡萄糖醛酸基转移酶（UGT）蛋白不显示任何哺乳动物和鸟类UGT酶的分子同源性的关系，很难预测其底物特异性。在这里，我们绘制了它们的组织特异性表达模式。我们发现斑马鱼UGT酶可以被糖基化。我们确定了它们对不同糖苷配基底物的底物特异性和催化活性。具体而言，我们测量了11个成年组织中40个斑马鱼Ugt基因的mRNA水平，发现它们以组织特异性方式表达。此外，与UDP葡萄糖醛酸（UDPGA）的40斑马鱼UGT蛋白的每一个捐助者的功能分析显示其对10个重要的糖苷配基的底物特异性。特别是，UGT 1A 1、UGT 1A 7和UGT 1B 1对大多数酚苷元（4-甲基伞形酮、4-硝基苯酚、1-萘酚、双酚A和霉酚酸）和两种羧酸（胆红素和双氯芬酸）显示出良好的葡萄糖醛酸化活性。重要的是，最近发现的一个新的UGT家族UGT 5的一些成员能够用UDPGA的供体辅因子使多种糖苷配基葡萄糖醛酸化。特别是，UGT 5A 5、UGT 5 B2和UGT 5E 1葡萄糖醛酸酯酚和类固醇对雌二醇和睾酮的类固醇激素和雌激素烷基酚4-叔辛基酚具有高度特异性。这些结果揭示了鱼类通过葡萄糖醛酸结合防御大量外源性物质的机制，并可能有助于建立斑马鱼作为毒理学，发育和病理学研究的模型脊椎动物。
The zebrafish genome contains a gene superfamily of 40 Ugt genes that can be divided into Ugt1, Ugt2, and Ugt5 families. Because the encoded zebrafish UDP glucuronosyltransferase (UGT) proteins do not display orthologous relationships to any of the mammalian and avian UGT enzymes based on molecular phylogeny, it is difficult to predict their substrate specificity. Here, we mapped their tissue-specific expression patterns. We showed that the zebrafish UGT enzymes can be glycosylated. We determined their substrate specificity and catalytic activity toward diverse aglycone substrates. Specifically, we measured mRNA levels of each of the 40 zebrafish Ugt genes in 11 adult tissues and found that they are expressed in a tissue-specific manner. Moreover, functional analyses with the donor of UDP glucuronic acid (UDPGA) for each of the 40 zebrafish UGT proteins revealed their substrate specificity toward 10 important aglycones. In particular, UGT1A1, UGT1A7, and UGT1B1 displayed good glucuronidation activities toward most phenolic aglycones (4-methylumbelliferone, 4-nitrophenol, 1-naphthol, bisphenol A, and mycophenolic acid) and the two carboxylic acids (bilirubin and diclofenac). Importantly, some members of the UGT5, a novel UGT family identified recently, are capable of glucuronidating multiple aglycones with the donor cofactor of UDPGA. In particular, UGT5A5, UGT5B2, and UGT5E1 glucuronidate phenols and steroids with high specificity toward steroid hormones of estradiol and testosterone and estrogenic alkylphenols 4-tert-octylphenol. These results shed new insights into the mechanisms by which fish species defend themselves against vast numbers of xenobiotics via glucuronidation conjugations and may facilitate the establishment of zebrafish as a model vertebrate in toxicological, developmental, and pathologic studies.