title: Molecular cloning and characterization of mouse estradiol 17 beta-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.
authors.affiliation: Biochemistry Laboratory, Gifu Pharmaceutical University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Deyashiki
authors.forename: K
authors.initials: K
authors.lastname: Ohshima
authors.forename: M
authors.initials: M
authors.lastname: Nakanishi
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Matsuura
authors.forename: A
authors.initials: A
authors.lastname: Hara
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004960:Estradiol Dehydrogenases / Q000235:genetics*; D015870:Gene Expression; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D018076:DNA, Complementary; D010446:Peptide Fragments; D012333:RNA, Messenger; D004960:Estradiol Dehydrogenases