Characterization of a cDNA encoding a new member of the glucocorticoid-responsive cytochromes P450 in human liver.
Characterization of a cDNA encoding a new member of the glucocorticoid-responsive cytochromes P450 in human liver.
复制标题
编码人肝脏中糖皮质激素反应性细胞色素 P450 新成员的 cDNA 的表征。
DOI：
10.1016/0003-9861(89)90449-9
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发表时间：
1989
影响因子：
3.9
通讯作者：
Guzelian,PS
中科院分区：
文献类型：
--
作者：
Schuetz,JD;Molowa,DT;Guzelian,PS
成人肝脏含有一种称为HLp的细胞色素P450，其结构、功能和调节类似于大鼠肝脏中糖皮质激素诱导的细胞色素P450 p，并催化环孢菌素、硝苯地平、红霉素和咪达唑仑等临床重要底物的氧化。然而，最近的证据表明，HLp可能代表两种或更多种密切相关的细胞色素P450形式，其中一种被称为P450 nf。为了寻找人类III类亚家族的其他成员的HLp相关基因，我们筛选了一个人肝cDNA文库，该文库克隆在噬菌体载体λ gt 11中，具有与HLp相关的寡核苷酸和cDNA片段。我们分离了全长cDNA（1709个核苷酸）编码一种新形式的人类细胞色素P450称为HLp 2。HLp 2cDNA分析预测了502个氨基酸的蛋白质，重57，294 Da，与HLp相似83%。通过克隆人基因的部分序列分析和Southern印迹杂交，在不同严格性条件下，与HLpcDNA的3′部分和HLp 2特异性寡核苷酸杂交，判断HLp 2似乎代表一个不同的基因。北方印迹分析显示，在所有未用HLp诱导剂治疗的成人患者的肝mRNA中存在HLp/P450 nf，而HLp 2 mRNA在超过三分之二的患者中检测不到。人胎肝RNA含有与HLp 2寡核苷酸杂交的2.1和1.9kb的mRNA种类。我们的结论是HLp 2代表第三类糖皮质激素反应基因家族的成员，在胎儿和成人肝脏中表达，并可能占多态性的临床重要药物的代谢。
Adult human liver contains a form of cytochrome P450, termed HLp, that resembles the glucocorticoid-inducible cytochrome P450p in rat liver in its structure, function, and regulation and catalyzes the oxidation of such clinically important substrates as cyclosporin, nifedipine, erythromycin, and midazolam. Recent evidence, however, suggests that HLp may represent two or more closely related forms of cytochromes P450, one of which is termed P450nf. To search for additional members of the Class III human subfamily of HLp related genes, we screened a human liver cDNA library cloned in phage vector λgt11 with oligonucleotides and with a cDNA fragment related to HLp. We isolated a full-length cDNA (1709 nucleotides) encoding a new form of human cytochrome P450 termed HLp2. Analysis of HLp2 cDNA predicted a protein of 502 amino acids, weighing 57,294 Da 83% similar to HLp. HLp2 appears to represent a distinct gene as judged by partial sequence analysis of a cloned human gene and by hybridizations of Southern blots, under conditions of varying stringency, with a 3′-portion of HLp cDNA and with an oligonucleotide specific for HLp2. Northern blot analysis revealed that HLp/ P450nf was present in all samples of liver mRNA from adult patients not treated with inducers of HLp, whereas HLp2 mRNA was undetectable in more than two-thirds. Human fetal liver RNA contained mRNA species 2.1 and 1.9 kb which hybridized with an HLp2 oligonucleotide. We conclude that HLp2 represents a third member of the Class III glucocorticoid-responsive gene family that is expressed in both fetal and adult human liver and may account for polymorphism in metabolism of clinically important drugs.