HUMAN ARYLAMINE N-ACETYLTRANSFERASE GENES - ISOLATION, CHROMOSOMAL LOCALIZATION, AND FUNCTIONAL EXPRESSION
HUMAN ARYLAMINE N-ACETYLTRANSFERASE GENES - ISOLATION, CHROMOSOMAL LOCALIZATION, AND FUNCTIONAL EXPRESSION
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DOI：
10.1089/dna.1990.9.193
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发表时间：
1990-04-01
影响因子：
3.1
通讯作者：
MEYER, UA
中科院分区：
文献类型：
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作者：
BLUM, M;GRANT, DM;MEYER, UA
通过肝芳胺N-乙酰转移酶（NAT，EC 2.3.1.5）的N-乙酰化是许多药物和外来化学物质代谢和解毒的主要途径。NAT是人类群体中具有临床相关性的常见遗传多态性的靶标。我们用我们最近分离的兔cDNA从人白细胞DNA中克隆了三个人NAT基因。三个基因组编码序列均未被内含子中断。NAT 1和NAT 2两个基因各具有870 bp的开放阅读框。这两个基因都被分配到人类8号染色体，pter-q11。转染后，它们在猴肾COS-1细胞中瞬时表达。NAT 1和NAT 2产生功能性NAT蛋白，如通过它们与芳胺底物磺胺二甲嘧啶的NAT酶活性所判断的。蛋白质印迹与NAT特异性抗血清检测蛋白质的表观分子量为33和31 kD的NAT 1和NAT 2转染的文化，分别。NAT 2产物的表观分子量与人肝胞液中NAT的表观分子量相同。NAT 2的推导的氨基酸序列还包含6个肽序列，这些肽序列先前已从人肝脏纯化的多态性NAT的胰蛋白酶肽中确定。这些数据表明，NAT 2编码多态性NAT蛋白。第三个基因，NATP，有多个有害的突变，不编码功能NAT蛋白;它最有可能代表一个假基因。
N-Acetylation by hepatic arylamineN-acetyltransferase (NAT, EC 2.3.1.5) is a major route in the metabolism and detoxification of numerous drugs and foreign chemicals. NAT is the target of a common genetic polymorphism of clinical relevance in human populations. We have used our recently isolated rabbit cDNArnatto clone three human NAT genes from human leukocyte DNA. None of the three genomic coding sequences was interrupted by introns. Two genes, designated NATI and NAT2, each possessed open reading frames of 870 bp. Both genes have been assigned to human chromosome 8, pter-q11. Following transfection they were transiently expressed in monkey kidney COS-1 cells. NAT1 and NAT2 gave rise to functional NAT proteins, as judged by their NAT enzyme activity with the arylamine substrate sulfamethazine. Western blots with NAT-specific antisera detected proteins of apparent molecular weight of 33 and 31 kD in NAT1- and NAT2-transfected cultures, respectively. The product of NAT2 had an identical apparent molecular weight as that of NAT detected in human liver cytosol. The deduced amino acid sequence of NAT2 also contained 6 peptide sequences which had previously been determined from tryptic peptides of the polymorphic NAT purified from human liver. These data suggest that NAT2 encodes the polymorphic NAT protein. The third gene, NATP, had multiple deleterious mutations and did not encode a functional NAT protein; it most likely represents a pseudogene.