Tremblay Y, Ringler G E, Morel Y, Mohandas T K, Labrie F, Strauss J F, Miller W L
Department of Pediatrics, University of California, San Francisco 94143.
J Biol Chem. 1989 Dec 5;264(34):20458-62.
17-Ketosteroid reductase (17KSR), also known as 17 beta-hydroxysteroid dehydrogenase, catalyzes the reversible interconversion of estradiol to estrone and of androstenedione to testosterone. Using a recently cloned human placental 17KSR cDNA, we show that the 1.4-kilobase mRNA for this enzyme is detected only in tissues producing estrogens, and a 2.4-kilobase mRNA is detected in some estrogenic tissues and some androgenic tissues. This tissue distribution suggests that the interconversion of androstenedione and testosterone may be mediated by a different enzyme. Southern blotting studies show that the mRNA for this estrogenic 17KSR is encoded by two very similar genes localized to chromosome 17cen----q25 by analysis of DNA from mouse/human somatic hybrid cell lines. 8-Br-cAMP increases the abundance of estrogenic 17KSR mRNA as well as mRNAs for other steroidogenic enzymes in JEG-3 choriocarcinoma cells. By contrast, cAMP decreases estrogenic 17KSR mRNA in primary cultures of human cytotrophoblasts and human granulosa cells, a pattern of tropic regulation that differs from other steroidogenic enzyme mRNAs.
17-酮类固醇还原酶（17KSR），也被称为17β-羟基类固醇脱氢酶，催化雌二醇与雌酮以及雄烯二酮与睾酮之间的可逆相互转化。利用最近克隆的人胎盘17KSR互补DNA（cDNA），我们发现该酶的1.4千碱基信使核糖核酸（mRNA）仅在产生雌激素的组织中被检测到，而在一些产生雌激素的组织和一些产生雄激素的组织中检测到了2.4千碱基的mRNA。这种组织分布表明雄烯二酮和睾酮的相互转化可能由一种不同的酶介导。Southern印迹研究表明，通过对小鼠/人类体细胞杂交细胞系的DNA分析，这种雌激素性17KSR的mRNA由两个非常相似的基因编码，这些基因定位于17号染色体着丝粒至q25区域。8-溴环磷腺苷（8-Br-cAMP）增加了JEG-3绒毛膜癌细胞中雌激素性17KSR mRNA以及其他类固醇生成酶mRNA的丰度。相比之下，环磷腺苷（cAMP）降低了人细胞滋养层细胞和人颗粒细胞原代培养物中雌激素性17KSR mRNA的水平，这种调节模式与其他类固醇生成酶mRNA不同。
