Molecular and Functional Characterization of N-Acetyltransferases NAT1 and NAT2 in Cynomolgus Macaque.
Molecular and Functional Characterization of N-Acetyltransferases NAT1 and NAT2 in Cynomolgus Macaque.
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食蟹猴 N-乙酰转移酶 NAT1 和 NAT2 的分子和功能表征。
DOI：
10.1021/acs.chemrestox.8b00236
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Yamazaki H.
中科院分区：
文献类型：
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作者：
Uno Y;Murayama N;Yamazaki H.
芳香胺N-乙酰基转移酶（NAT）是内源性底物和外源性物质代谢所必需的药物代谢酶，其分子特征已在人类中进行了广泛研究，但在食蟹猴（对药物代谢研究很重要的非人灵长类动物）中尚未进行研究。在这项研究中，食蟹猴NAT 1和NAT 2 cDNA分离自肝脏。NAT 1和NAT 2通过分子分析和药物代谢测定来表征。食蟹猴NAT 1共发现9种转录变体，与人NAT 1相似，包含1-4个外显子，编码区与人NAT 1基本保守。食蟹猴和人类的基因组结构相似。食蟹猴NAT 1和NAT 2的氨基酸序列同源性分别为95%和89%，与人类NAT 1和NAT 2的亲缘关系较近。在分析的10种不同组织中，食蟹猴NAT 2 mRNA主要在肝脏中表达，其次是肾脏和空肠。与此相反，食蟹猴NAT 1 mRNA在肝脏、肾脏和空肠以及沿着睾丸中表现出更普遍的表达，表达相对更丰富。使用重组蛋白的代谢试验表明，食蟹猴NAT 1和NAT 2代谢人NAT底物，包括对氨基苯甲酸，磺胺二甲嘧啶，异烟肼和2-氨基芴。有趣的是，对氨基苯甲酸和异烟肼在食蟹猴和人类中分别主要由NAT 1和NAT 2代谢;磺胺二甲嘧啶，人类NAT 2底物，在食蟹猴中由两种NAT酶代谢。这些结果表明食蟹猴和人类之间的NAT 1和NAT 2的分子和酶的相似性，尽管酶的底物特异性存在一些小的差异。
ArylamineN-acetyltransferases (NATs) are drug-metabolizing enzymes essential for the metabolism of endogenous substrates and xenobiotics, and their molecular characteristics have been extensively investigated in humans, but not in cynomolgus macaques, nonhuman primate species important for drug metabolism studies. In this study, cynomolgus NAT1 and NAT2 cDNAs were isolated from livers. NAT1 and NAT2 were characterized by molecular analyses and drug-metabolizing assays. A total of 9 transcript variants were found for cynomolgus NAT1, similar to human NAT1, and contained 1–4 exons with the coding region largely conserved with human NAT1. Genomic organization was similar between cynomolgus macaques and humans. Cynomolgus NAT1 and NAT2 amino acid sequences showed high sequence homology (95% and 89%, respectively) and showed close relationships with human NAT1 and NAT2 in a phylogenetic tree. Cynomolgus NAT2 mRNA was predominantly expressed in liver among the 10 different tissues analyzed, followed by kidney and jejunum. In contrast, cynomolgus NAT1 mRNA showed more ubiquitous expression with relatively more abundant expression in liver, kidney, and jejunum, along with testis. Metabolic assays using recombinant proteins showed that cynomolgus NAT1 and NAT2 metabolized human NAT substrates, includingp-aminobenzoic acid, sulfamethazine, isoniazid, and 2-aminofluorene. Interestingly,p-aminobenzoic acid and isoniazid were largely metabolized by NAT1 and NAT2, respectively, in cynomolgus macaques and humans; sulfamethazine, a human NAT2 substrate, was metabolized by both NAT enzymes in cynomolgus macaques. These results suggest molecular and enzymatic similarities of NAT1 and NAT2 between cynomolgus macaques and humans, despite some small differences in substrate specificity of the enzymes.