Qin K N, New M I, Cheng K C
Department of Pediatrics, Cornell University Medical College, New York, NY 10021.
J Steroid Biochem Mol Biol. 1993 Dec;46(6):673-9. doi: 10.1016/0960-0760(93)90308-j.
Rat liver 3 alpha-hydroxysteroid dehydrogenase cDNA was previously cloned by us. In this study, we used the rat cDNA as the probe to screen a human liver lambda gt11 cDNA library. A total of four different cDNAs were identified and sequenced. The sequence of one of the cDNAs is identical to that of the human chlordecone reductase cDNA except that our clone contains a much longer 5'-coding sequence than previously reported. The other three cDNAs display high degrees of sequence homology to those of both rat 3 alpha-hydroxysteroid dehydrogenase and human chlordecone reductase. Because 3 alpha-hydroxysteroid dehydrogenase and human chlordecone reductase belong to the aldo-keto reductase superfamily, we named these human clones HAKRa to HAKRd. Northern blot analysis showed that the liver expresses the highest levels of all four clones. Expression of all four clones was also detected in the brain, kidney, lung, and testis, whereas the placenta expressed only the messenger RNA for HAKRb. Genomic blot analysis using HAKRb as the probe detected multiple DNA fragments hybridized to the probe and a high degree of restriction fragment length polymorphism, suggesting the complexity of this supergene family.
大鼠肝脏3α-羟基类固醇脱氢酶cDNA先前已由我们克隆。在本研究中，我们使用大鼠cDNA作为探针筛选人肝脏λgt11 cDNA文库。共鉴定并测序了四个不同的cDNA。其中一个cDNA的序列与人类十氯酮还原酶cDNA的序列相同，只是我们的克隆包含比先前报道长得多的5'编码序列。另外三个cDNA与大鼠3α-羟基类固醇脱氢酶和人类十氯酮还原酶的cDNA具有高度的序列同源性。由于3α-羟基类固醇脱氢酶和人类十氯酮还原酶属于醛酮还原酶超家族，我们将这些人类克隆命名为HAKR a至HAKR d。Northern印迹分析表明，肝脏中所有四个克隆的表达水平最高。在脑、肾、肺和睾丸中也检测到了所有四个克隆的表达，而胎盘中仅表达HAKR b的信使RNA。以HAKR b为探针的基因组印迹分析检测到多个与探针杂交的DNA片段以及高度的限制性片段长度多态性，表明该超基因家族的复杂性。
