Molecular cloning and characterization of 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase cDNAs from Japanese eel ovary
Molecular cloning and characterization of 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase cDNAs from Japanese eel ovary
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DOI：
10.1016/s0960-0760(03)00138-9
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发表时间：
2003-05-01
影响因子：
4.1
通讯作者：
Yamauchi, K
中科院分区：
文献类型：
--
作者：
Kazeto, Y;Ijiri, S;Yamauchi, K
3 β-羟基类固醇脱氢酶/δ（5）-δ（4）异构酶（3 β-HSD）是一种重要的类固醇生成酶，催化所有类别类固醇激素生物合成中的重要步骤。本研究克隆了日本鳗鲡卵巢I型和II型3 β-HSD基因的两个同源基因。这两个cDNA均编码375个氨基酸残基，与虹鳟鱼（71%）和哺乳动物（约45-50%）3 β-HSD具有高度的序列同源性。I型和II型3 β-HSD在COS-7细胞中的瞬时表达表明，这两种蛋白质都具有3 β-羟基类固醇脱氢酶以及对双烯醇酮和脱氢表雄酮的Delta（5）-Delta（4）异构酶活性，双烯醇酮优先于脱氢表雄酮作为底物，尽管I型蛋白质比II型蛋白质更有活性。通过北方印迹分析，在卵巢组织中观察到长度约为1.5 kb的3 β-HSD转录物的单一条带，并且在富含促性腺激素的鲑鱼垂体匀浆人工诱导的整个卵巢发育过程中，这两种3 β-HSD的总转录物丰度保持恒定。卵巢发育过程中3 β-HSD转录丰度的变化缺乏与先前报道的其酶活性的波动无关，这可能表明卵巢发育过程中3 β-HSD活性的变化可能部分是在日本鳗鱼卵巢中转录后调节的。(C)2003爱思唯尔科技有限公司版权所有。
3beta-Hydroxysteroid dehydrogenase/Delta(5)-Delta(4) isomerase (3beta-HSD) is a crucial steroidogenic enzyme which catalyzes an essential step in the biosynthesis of all classes of steroid hormones. Two closely related cDNAs, encoding Japanese eel ovarian types I and II 3beta-HSD, were cloned and characterized. Both cDNAs putatively encoded 375 amino acid residues sharing high sequence homology with those of rainbow trout (71%) and mammalian (approximately 45-50%) 3beta-HSD. Transient expression of types I and II 3beta-HSD in COS-7 cells revealed that both proteins possess 3beta-hydroxysteroid dehydrogenase as well as Delta(5)-Delta(4) isomerase activity for both pregnenolone and dehydroepiandrosterone, with the preference of pregnenolone over dehydroepiandrosterone as substrate, although the type I protein is more active than the type II. By northern blot analysis, a single band of the 3beta-HSD transcript of approximately 1.5 kb in length was observed in ovarian tissue and the total transcript abundance of both 3beta-HSDs remained constant throughout ovarian development artificially induced by gonadotropin-rich salmon pituitary homogenate. This lack of change in 3beta-HSD transcript abundance during ovarian development did not correlate with the fluctuation of its enzymatic activity reported previously, which may suggest that changes in 3beta-HSD activity during ovarian development may be, in part, post-transcriptionally regulated in the Japanese eel ovary. (C) 2003 Elsevier Science Ltd. All rights reserved.