小鼠 Ⅲ 型 17β-羟甾脱氢酶的序列及其表达

DNA SEQUNECING AND EXPRESSION OF 17β HYDROXYSTEROID DEHYDROGENASE TYPE 3 IN MOUSE

１７β－羟甾脱氢酶（１７β－ＨＳＤ）催化１７－酮类固醇与１７β－羟类固醇相互转换。本研究从小鼠睾丸中纯化出小鼠Ⅲ型１７β－ＨＳＤ的ｃＤＮＡ克隆，最长的ｃＤＮＡ核苷酸数为１１３１，包含一个短的５′非编码序列、９１８个核苷酸编码序列和１５５个核苷酸３′非编码序列；其起始密码子为ＡＴＧ，终止密码子为ＴＡＧ，开读框架编码为３０５个氨基酸的多肽。该研究为进一步了解１７β－ＨＳＤ的缺乏和性激素代谢的分子机理奠定了基础。

Oxidatioin reduction reactions of oestrogens and androgens at position C 17 are catalysed by 17β hydroxysteroid dehydrogenases (17β HSDs). cDNA clones for mouse 17β HSD Ⅲ were isolated from mouse testis using Race. The largest cDNA contained 1131 nucleotides, consisting of a short 5′ noncoding segment, a coding segment of 918 nucleotides begun by a ATG initiating codon and terminated by a TAG codon, and a 155 nucleotide long 3′ noncoding segment. The open reading frame encoded a polypeptide of 305 amino acid residues. 17β HSD Ⅲ mRNA was expressed specially in testis. This study provides the basis for a better understanding of the molecular mechanisms involved in 17β HSD deficiency and sex steroid metabolism.