Genetic polymorphism in the human UGT1A6 (planar phenol) UDP-glucuronosyltransferase: pharmacological implications
Genetic polymorphism in the human UGT1A6 (planar phenol) UDP-glucuronosyltransferase: pharmacological implications
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DOI：
10.1097/00008571-199712000-00007
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发表时间：
1997-12-01
期刊：
影响因子：
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通讯作者：
Owens, IS
中科院分区：
文献类型：
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作者：
Ciotti, M;Marrone, A;Owens, IS
在编码人类酚代谢udp -葡萄糖醛基转移酶的UGT1A6 (HLUG P1) cDNA中发现了两个错义突变。从自定义合成的人肝脏lambda Zap cDNA文库中分离到突变型和野生型UGT1A6 cDNA。在UGT1位点的UGT1A6 （UGT1F）基因外显子1上发生了核苷酸541 （T181 A）和核苷酸552 （R184S）的A到C翻转。在一个等位基因上的两个突变产生了杂合基因型。以供体肝脏基因组DNA为模板，对pcr生成的DNA进行核酸内切酶处理，分别在T181 A和R184S位点上新创建了BsmI和BsoFI位点。核酸内切酶筛选结果显示，33/98的DNA样本是杂合的，在一个等位基因上发生两个突变。另一个个体在第二个等位基因上也携带R184S突变。野生型UGT1A6对某些实验酚类在pH 5.0 ~ pH 8.0范围内产生了广泛的活性平台，而在pH 6.4条件下的活性是其他实验酚类在pH 7.2条件下的1.3 ~ 2.5倍。UGT1A6*2 （181 A+和184S+）对4-硝基酚、4-叔丁基酚、3-乙基酚/4-乙基酚、4-羟基香豆素、丁基羟基苯甲醚和丁基羟基甲苯的代谢率仅为野生型同工酶的27-75%，pH为6.4优先，而对1-萘酚、3-碘酚、7-羟基香豆素和7-羟基-4-甲基香豆素的代谢率基本为正常水平。此外，UGT1A6*2代谢3- o -甲基多巴和水杨酸甲酯的水平为野生型的41-74%，一系列β受体阻滞剂的代谢水平为正常水平的28-69%。这表明UGT1A6酶的活性受到不同氨基酸的影响，这取决于底物的选择。
Two missense mutations were uncovered in the UGT1A6 (HLUG P1) cDNA which codes for a human phenol-metabolizing UDP-glucuronosyltransferase. The mutant and a wild-type UGT1A6 cDNAs were isolated from a custom synthesized human liver lambda Zap cDNA library. Both an A to G transition at nucleotide 541 (T181 A) and an A to C transversion at nucleotide 552 (R184S) occurred in exon 1 of the UGT1A6 (UGT1F) gene at the UGT1 locus. The two mutations on a single allele created a heterozygous genotype. Newly created BsmI and BsoFI sites at the T181 A and R184S locations, respectively, were confirmed by endonuclease treatment of PCR-generated DNA using the donor-liver genomic DNA as template. Screens with endonuclease treatment showed that 33/98 DNA samples were heterozygous with both mutations on one allele. One other individual also carried the R184S mutation on the second allele. Wild-type UGT1A6 generated a broad plateau of activity from pH 5.0 to pH 8.0 with certain experimental phenols, while activity was 1.3-2.5-fold higher at pH 6.4 than at pH 7.2 for others. UGT1A6*2 (181 A+ and 184S+) metabolized 4-nitrophenol, 4-tert-butylphenol, 3-ethylphenol/4-ethylphenol, 4-hydroxycoumarin, butylated hydroxy anisole and butylated hydroxy toluene, with the pH 6.4 preference, at only 27-75% of the rate of the wild-type isozyme whereas 1-naphthol, 3-iodophenol, 7-hydroxycoumarin, and 7-hydroxy-4-methylcoumarin were metabolized at essentially the normal level. Furthermore, UGT1A6*2 metabolized 3-O-methyl-dopa and methyl salicylate at 41-74% of that of the wild-type, and a series of beta-blockers at 28-69% of the normal level. This evidence suggests that the UGT1A6 enzyme activity is affected by different amino acids depending upon the substrate selection.