Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.3 (HSD)
 3,464 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Complementary DNA clones encoding 3 alpha-hydroxysteroid dehydrogenase (3 alpha HSD) were isolated from a rat liver cDNA lambda gt11 expression library using monoclonal antibodies as probes. The sizes of the cDNA inserts ranged from 1.3-2.3 kilobases. Sequence analysis indicated that variation in the DNA size was due to heterogeneity in the length of 3' noncoding sequences. A full-length cDNA clone of 1286 basepairs contained an open reading frame encoding a protein of 322 amino acids with an estimated mol wt of 37 kDa. When expressed in E. coli, the encoded protein migrated to the same position on sodium dodecyl sulfate-polyacrylamide gels as the enzyme purified from rat liver cytosols. The protein expressed in bacteria was highly active in androsterone reduction in the presence of NAD as cofactor, and this activity was inhibited by indomethacin, a potent inhibitor of 3 alpha HSD. The predicted amino acid sequence of 3 alpha HSD was related to sequences of several other enzymes, including bovine prostaglandin F synthase, human chlordecone reductase, human aldose reductase, human aldehyde reductase, and frog lens epsilon-crystalline, suggesting that these proteins belong to the same gene family.
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PMID:Molecular cloning and expression of rat liver 3 alpha-hydroxysteroid dehydrogenase. 192 97

20 alpha-Hydroxysteroid dehydrogenase (20 alpha-HSD, EC 1.1.1.149) catalyses the conversion of progesterone into 20 alpha-dihydroprogesterone (20 alpha-OHP). Previously, we purified the enzyme (37 kDa) from rat ovary and determined its N-terminal amino acid sequence. In the present study we succeeded in cloning a full-length 20 alpha-HSD cDNA. mRNA was extracted from immature rat ovaries after successive treatment with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). A cDNA library was constructed in lambda ZAP. For screening, a 576 bp probe was amplified by the PCR using mixed primers based on the N-terminal sequence of 20 alpha-HSD, and labelled with [32P]dCTP. Eight positive clones were isolated from 1.2 x 10(4) recombinants. Analysis of the nucleotide sequence revealed that one clone of 1.2 kbp cDNA (pHSD12-07) contained a polyadenylation site and an open reading frame encoding 323 amino acids with the N-terminal sequence of 20 alpha-HSD. The fusion protein of pHSD12-07 produced by Escherichia coli reacted with a specific polyclonal antibody generated against rat ovarian 20 alpha-HSD. In addition, the in vitro transcription-translation product produced by Xenopus oocytes showed 20 alpha-HSD activity and Northern-blotting analysis revealed that the ovaries from normal adult rats contained a 1.2 kb mRNA. Thus we succeeded in isolating a clone encoding the full length of rat ovarian 20 alpha-HSD. The sequence showed high similarity with those of rat liver 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD), bovine lung prostaglandin F synthase (PGFS), human liver chlordecone reductase (CDR), frog lens rho-crystallin and aldose reductases, indicating that 20 alpha-HSD belongs to the aldo-keto reductase family.
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PMID:Molecular cloning of cDNA for rat ovarian 20 alpha-hydroxysteroid dehydrogenase (HSD1). 817 18

We have previously reported that an abundant 37,000 mol wt protein with a pI of 6.15 (37K) is expressed specifically in the corpus luteum and is markedly inhibited by PRL. To identify the 37K, amino acid sequence analysis of the protein was performed. The 37K protein showed sequence similarity with rabbit 20 alpha-hydroxysteroid dehydrogenase (20 alpha HSD), chlordecone reductase, prostaglandin synthase, and 3 alpha-hydroxysteroid dehydrogenase, which are members of the aldo-keto reductase group of enzymes that catalyze the NADPH-dependent reduction of carbonyl compounds. Comparison of 20 alpha HSD activity with the level of 37K in the corpus luteum throughout pregnancy demonstrated a close correlation between enzyme activity and luteal levels of the protein. Both protein and enzyme activity were low early in pregnancy, reached a nadir between days 5-19, and reappeared abruptly between days 19-21 of pregnancy. To establish that the enzyme activity is intrinsic to the 37K, the protein was purified from sodium dodecyl sulfate-polyacrylamide electrophoresis gels (SDS-PAGE), renatured, and assayed for 20 alpha HSD activity. The renatured protein exhibited substantial 20 alpha HSD activity. As 20 alpha HSD is known to play a major role in the termination of pregnancy in the rat, it was of interest to examine whether the rapid appearance of the 37 K protein at the end of pregnancy is accompanied by the induction of 20 alpha HSD gene expression. Northern blot analysis using a rabbit cDNA for 20 alpha HSD indicated that the pattern of 20 alpha HSD mRNA expression in the corpus luteum closely paralleled the ontogeny of 20 alpha HSD enzyme activity as well as 37K protein levels. Our studies demonstrated that 20 alpha HSD protein and mRNA levels are coordinately regulated, and that the profound inhibitory effect of PRL on 20 alpha HSD activity is apparently due to inhibition of 20 alpha HSD gene expression, leading to the disappearance of the protein from the corpus luteum.
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PMID:Identification of a major prolactin-regulated protein as 20 alpha-hydroxysteroid dehydrogenase: coordinate regulation of its activity, protein content, and messenger ribonucleic acid expression. 819 72

An abundant 37-kDa protein, which comprises up to 30% of the soluble proteins of the ovary, has been found to have 20 alpha-hydroxysteroid dehydrogenase (20 alpha HSD) activity. The steroidogenic enzyme 20 alpha HSD regulates the conversion of progesterone to 20 alpha-hydroxyprogesterone in many mammalian species. Complimentary DNA clones encoding a unique and abundant 20 alpha HSD were isolated from a mature rabbit ovary library using guinea pig antisera generated to the purified 37-kDa protein and from a 5' EcoRI fragment from the initial positive clone. A full-length cDNA clone of 1217 basepairs encoding a 323-amino acid protein with an estimated mol wt of 37 kilodaltons was obtained. Amino acid sequence data indicate a similarity to human chlordecone reductase, bovine lung prostaglandin F synthase, human aldose reductase, human aldehyde reductase, and frog lens rho-crystallin, placing rabbit ovarian 20 alpha HSD in the aldo-keto reductase family of proteins. Northern blot analysis demonstrated a 1.2-kilobase mRNA in the interstitial tissue of mature rabbit ovaries and, to a lesser extent, in corpora luteal tissue. 20 alpha HSD was expressed in bacteria as a recombinant protein and was shown to possess enzymatic activity, preferring NADP as a cofactor. These studies demonstrate that an abundant ovarian protein belonging to the superfamily of NADP-dependent aldo-keto reductases has 20 alpha HSD activity. This is the first example of an abundant crystallin-related protein with known enzymatic activity in a tissue other than the lens.
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PMID:Molecular cloning and expression of an abundant rabbit ovarian protein with 20 alpha-hydroxysteroid dehydrogenase activity. 824 25

In human liver, we previously identified one isoform of dihydrodiol dehydrogenase activity that expresses high affinity bile acid binding (HBAB) with minimal 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) activity for bile acids. This protein may assist in the rapid intracellular transport of bile acids from the sinusoidal to the canalicular pole of the cell. We now report the cDNA cloning and bacterial expression of this novel, multifunctional protein. A 1252-base pair HBAB cDNA was cloned from a HepG2 lambda GT11 library using a rat hepatic bile acid binder cDNA probe. Bacterial expressed recombinant HBAB oxidized racemic trans dihydrodiol benzene (0.455 mumol NADPH/mg/min) with minimal 3 alpha-HSD activity for bile acids (< 0.003 mumol NADPH/mg/min). Lithocholic acid and chenodeoxycholic acid dissociation constants as determined by displacement of the fluorescent probe, bis-1-anilino-8 sulfonate, were higher than those previously reported for the native protein (1 microM versus 10 nM). Significant amino acid sequence homology was found with the human chlordecone reductase, bovine prostaglandin F synthetase, and rat hepatic-3 alpha-HSD suggesting, that HBAB is also a member of the recently identified, monomeric oxidoreductase gene family. Future studies will define the physiologic significance of this novel, multifunctional protein in bile acid transport and xenobiotic metabolism.
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PMID:cDNA cloning and expression of the human hepatic bile acid-binding protein. A member of the monomeric reductase gene family. 848 99

3 alpha-Hydroxysteroid dehydrogenases (3 alpha-HSDs) catalyze the conversion of 3-ketosteroids to 3 alpha-hydroxy compounds. The best known 3 alpha-HSD activity is the transformation of the most potent natural androgen, dihydrotestosterone, into 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol), a compound having much lower activity. Previous reports show that 3 alpha-HSDs are involved in the metabolism of glucocorticoids, progestins, prostaglandins, bile acid precursors, and xenobiotics. 3 alpha-HSDs could, thus, play a crucial role in the control of a series of active steroid levels in target tissues. In the human, type 1 3 alpha-HSD was first identified as human chlordecone reductase. Recently, we have isolated and characterized type 3 3 alpha-HSD that shares 81.7% identity with human type 1 3 alpha-HSD. The transfection of vectors expressing types 1 and 3 3 alpha-HSD in transformed human embryonic kidney (HEK-293) cells indicates that both enzymes efficiently catalyze the transformation of dihydrotestosterone into 3 alpha-diol in intact cells. However, when the cells are broken, the activity of type 3 3 alpha-HSD is rapidly lost, whereas the type 1 3 alpha-HSD activity remains stable. We have previously found that human type 5 17 beta-HSD which possesses 84% and 86% identity with types 1 and 3 3 alpha-HSD, respectively, is also labile, whereas rodent enzymes such as mouse type 5 17 beta-HSD and rat 3 alpha-HSD are stable after homogenization of the cells. The variable stability of different enzymatic activities in broken cell preparations renders the comparison of different enzymes difficult. RNA expression analysis indicates that human type 1 3 alpha-HSD is expressed exclusively in the liver, whereas type 3 is more widely expressed and is found in the liver, adrenal, testis, brain, prostate, and HaCaT keratinocytes. Based on enzymatic characteristics and sequence homology, it is suggested that type 1 3 alpha-HSD is an ortholog of rat 3 alpha-HSD while type 3 3 alpha-HSD, which must have diverged recently, seems unique to human and is probably more involved in intracrine activity.
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PMID:Human types 1 and 3 3 alpha-hydroxysteroid dehydrogenases: differential lability and tissue distribution. 1115 55