Molecular Cloning and Characterization of Mouse Estradiol 17β-Dehydrogenase (A-Specific), a Member of the Aldoketoreductase Family

Abstract

Several mammalian livers contain monomeric 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) with A-stereospecificity in hydrogen transfer, which differs from the B-specific dimeric enzyme of human placenta in its ability to catalyze the oxidoreduction of xenobiotic trans-dihydrodiols of aromatic hydrocarbons and carbonyl compounds. Here, we report the isolation and characterization of a mouse cDNA clone encoding monomeric 17 beta-HSD of the liver. This clone had an entire coding region for a protein of 323 amino acid residues with a molecular weight of 37,055. The deduced sequence of the protein aligned with a high degree of identity with rat and rabbit 20 alpha-HSDs, rat and human 3 alpha-HSD/dihydrodiol dehydrogenases, and bovine prostaglandin F synthase, which are members of the aldoketoreductase family, but was distinct from human 17 beta-HSD and carbonyl reductase, members of the short chain dehydrogenases. The expression of the cDNA in Escherichia coli resulted in synthesis of a protein that was active toward androgens, estrogens, and xenobiotic substrates. The recombinant and mouse liver 17 beta-HSDs also exhibited low 20 alpha-HSD activity toward progestins, which is similar to bifunctional activity of human placental 17 beta-HSD. Therefore, the mouse enzyme was given the designation of estradiol 17 beta-dehydrogenase (A-specific). Northern analysis of mouse tissues revealed the existence of a single 1.7-kilobase 17 beta-HSD mRNA species in the liver, kidney, testis, and stomach. The liver mRNA content was considerably more abundant than those found in the other tissues, as 17 beta-HSD protein was mainly detected in the liver by Western analysis.

In vivo and in vitro expression of steroid-converting enzymes in human breast tumours: associations with interleukin-6

“…Type IV 17-HSD is similar to the type II isoform in that it is NAD + -dependent and is principally involved in the oxidation and therefore inactivation of oestrogens and androgens (Adamski et al, 1992). 17-HSD type V belongs to the aldoketoreductase family (Jornvall et al, 1995) while the sixth isoform is a member of the short-chain alcohol reductase family (Deyashiki et al, 1995). A seventh murine isoform of 17-HSD, present in corpus luteum and which possesses reductive activity has recently been described (Nokelainen et al, 1998).…”

Insights into the transcriptome of oenocytes from Aedes aegypti pupae

“…The 17β-hydroxysteroid dehydrogenases are a group of enzymes that are involved in the interconversion of active and inactive forms of androgens and estrogens in the human liver (Deyashiki et al 1995).…”

Cloning and sequencing of the cDNA species for mammalian dimeric dihydrodiol dehydrogenases

“…DNA sequencing confirmed that no unintended base substitution had been incorporated in the coding regions of the expression plasmids. Transformation of the plasmid into E. coli JM109, expression of the recombinant protein and preparation of E. coli cell extract were performed as described [9]. The recombinant enzyme was purified from the cell extract by the method described for the enzyme of Japanese monkey kidney [12].…”

“…The enzyme exists in multiple forms in mammalian tissues. Most of the enzymes purified from various mammalian tissues are monomeric and have been shown to be identical with 3α-, 17β-and 20α-hydroxysteroid dehydrogenases, aldehyde reductase and\or aldose reductase [5][6][7][8][9][10], which are members of the aldo-keto reductase superfamily [11]. In addition to the monomeric enzymes, dimeric DDs composed of 39 kDa subunits have been isolated from rabbit lens [10], monkey kidney [12,13], pig tissues [14] and dog liver [15].…”