Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that human placental estradiol-17 beta dehydrogenase (EC 1.1.1.62; 17 beta-EDH) catalyzes the conversion of estradiol-17 beta to estrone and stereospecifically reduces NAD+ to [4-pro-S]NADH, [( 4-B]NADH). Subsequently, this enzyme was found to reduce the ketone function at C-20 of progesterone, and evidence indicates that both activities reside at the same active site. This study was done to further elucidate spatial arrangements of cofactor and the 21-carbon substrate as they bind at the active site. The cofactor, [4B-3H]NADPH, was generated with homogeneous 17 beta-EDH from term human placenta, utilizing [17 alpha-3H]estradiol-17 beta and NADP+. The resulting [4B-3H]NADPH was then purified by ion exchange chromatography and was separately incubated (24.4 microM) with a large molar excess of progesterone (150 microM) as substrate in the presence of the enzyme. Following incubation, the steroid reactants and products were extracted, separated by high-performance liquid chromatography and quantitated as to mass and tritium content. Oxidized and reduced cofactor were separated by ion-exchange chromatography and similarly quantitated. In all incubations, equimolar amounts of 20 alpha-hydroxy-4-pregnen-3-one (20 alpha-OHP) and NADP+ were obtained. Radioactivity was stoichiometrically transferred from [4B-3H]NADPH to the steroid product [( 3H]20 alpha-OHP). These results further substantiate a single active site for both 17 beta- and 20 alpha-dehydrogenation enzyme activities. In addition, the enzyme is B-side specific, catalyzing the transfer of the 4B-hydrogen from the dihydronicotinamide moiety of the cofactor, for both C-18 and C-21 steroid substrates. Since the 20 alpha-dehydrogenation by other enzyme sources has always been demonstrated to be an A-side specific reaction, this observation represents an important exception to the Alworth-Bentley rules of enzyme stereospecificity.
J Steroid Biochem Mol Biol 1990 Sep
PMID:Stereospecificity of hydrogen transfer between progesterone and cofactor by human placental estradiol-17 beta dehydrogenase. 214 72

The cDNA of porcine 17 beta-estradiol dehydrogenase codes for a polypeptide of 737 amino acids. The dehydrogenase activity of the 80 kDa translation product is located in its N-terminal 32 kDa fragment, which is the major form isolated from endometrial epithelium. beta-Actin co-purifies with some of the 32 kDa enzyme, which contains actin-binding motifs and is homologous to hydratase-dehydrogenase-epimerase of Candida tropicalis. The microbody-targeting signal AKI and sequences resembling sterol carrier protein 2 are present in the C-terminal part of the 80 kDa protein. The N- and C-terminal parts are connected by a sequence containing the putative protease recognition signal AAP.
Mol Cell Endocrinol 1994 Sep
PMID:The sequence of porcine 80 kDa 17 beta-estradiol dehydrogenase reveals similarities to the short chain alcohol dehydrogenase family, to actin binding motifs and to sterol carrier protein 2. 798 41

Porcine 17 beta-estradiol dehydrogenase (EDH) was recently purified and cloned. It catalyzes the NAD(+)-dependent oxidation of estradiol to estrone 360-fold more efficiently than the back reaction with NADPH. The 32 kDa EDH is cut from an 80 kDa primary translation product with a multidomain structure unknown for other hydroxysteroid dehydrogenases. The highest EDH activities and strongest immunoreactions are found in liver (hepatocytes) and kidney (proximal tubuli) followed by uterus (luminal and glandular epithelium), lung (bronchial epithelium). Progesterone treatment of ovariectomized gilts stimulates oxidative EDH activity in uterus, anterior pituitary, skeletal muscle (diaphragm) and kidney. Constitutive levels of EDH activity were seen in the adrenals, the lung and the liver.
J Steroid Biochem Mol Biol 1995 Dec
PMID:The tissue distribution of porcine 17 beta-estradiol dehydrogenase and its induction by progesterone. 854 79

The activities of estrogen sulfotransferase, estrogen sulfatase and estradiol 17beta-dehydrogenase change considerably in the guinea pig uterine compartment during gestation. This study was undertaken to inquire if the chorion membrane could influence the pattern of estrogen resulting when substrates were applied to the fetal surface of the chorion while it was attached, late in gestation, to the uterine wall. This tissue system resulted in a differential handling of estrone and estradiol. Estrone was largely excluded from the tissue, remaining mainly in free steroidal form. Estradiol was considerably converted to its 3-sulfate which was mainly retained by the chorion. Parallel experiments with chorion and uterus separately failed to discriminate between the two substrates. Hydrolysis of estrone sulfate and estradiol 3-sulfate was similar in all three tissue systems. It appears that the interaction of chorion with uterus late in gestation causes a difference in tissue action towards the two steroid substrates of closely related structure. The results suggest a limitation in tissue uptake of estrone compared with estradiol, or a much greater sulfotransferase activity towards estradiol. Whole cytosols of late gestational chorion catalyzed sulfation of estradiol at about double the velocity of estrone. This may only partly account for the difference in the intact chorion-uterine tissue system.
J Steroid Biochem Mol Biol 1996 Dec
PMID:Sulfation by guinea pig chorion and uterus: differential action towards estrone and estradiol. 901 Mar 53

In human placenta the cytochrome P450 side-chain cleavage (P450scc) and 3 beta-hydroxysteroid dehydrogenase type 1 (3 beta-HSD-1) convert cholesterol and pregnenolone producing progesterone, whereas 17 beta-hydroxysteroid dehydrogenase type 1 (17 beta-HSD-1) mediates the interconversion of estrone and estradiol. We have examined the effects of calcium on phorbol ester- and cAMP-induced P450scc, 3 beta-HSD-1 and 17 beta-HSD-1 mRNAs in human JEG-3 cells. A23187 increased in a dose-dependent fashion in the 1.3 kb 17 beta-HSD-1 mRNA whereas a weaker increase followed by a gradual depletion effect of A23187 was observed on 3 beta-HSD-1 mRNA. No significant effect of A23187 on P450scc mRNA was observed. Using 0.50 microM of A23187 the induction of 3 beta-HSD-1 and 17 beta-HSD-1 mRNAs was maximum within about 6 h whereas P450scc mRNA levels stayed unaffected throughout the time-course period. The action of A23187 was synergistic on cAMP-stimulated 17 beta-HSD-1 mRNA levels, while in a dose-dependent manner A23187 progressively depleted 3 beta-HSD-1 and P450scc mRNA abundance probably by activation of a calcium-/calmodulin-dependent phosphodiesterase. On the phorbol 12-myristate, 13-acetate (PMA)-stimulated 3 beta-HSD-1, 17beta-HSD-1 and P450scc mRNA levels only the lowest concentration of A23187 potentialized the PMA effect on the 17 beta-HSD-1 mRNA levels. Using thapsigargin (TG), a cell-permeable sesquiterpene lactone that releases calcium by inhibiting sarco/endoplasmic reticular calcium-ATPase, our data indicated the presence in JEG-3 cells of TG-sensitive and TG-insensitive calcium-ATPases regulating 3 beta-HSD-1 and 17 beta-HSD-1 mRNA levels. These results emphasized the complexity of calcium contribution with the protein kinase A and C pathways in the regulation of P450scc, 3 beta-HSD-1 and 17 beta-HSD-1 mRNA levels. In addition, the different sensitivity of these genes to calcium suggest they could be activated by different subclasses of PKCs.
Mol Cell Endocrinol 1997 Sep 30
PMID:Regulation of cytochrome P450 cholesterol side-chain cleavage, 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase type 1 and estradiol-17 beta-hydroxysteroid dehydrogenase mRNA levels by calcium in human choriocarcinoma JEG-3 cells. 935 73

Bone is an estradiol-responsive tissue. Estrogen withdrawal during the menopause causes loss of bone mass and clinically relevant osteoporosis in a third of all women. Sufficient or impaired local production, as well as degradation of estradiol in cells present in the bone microenvironment might be an important mechanism of rescue or might contribute to the development of osteoporosis, respectively. We therefore investigated aromatase and 17beta-hydroxysteroid dehydrogenase type IV (17beta-HSD IV) expression in osteoblast- and osteoclast-like cells. Aromatase mRNA was increasingly expressed in myeloid THP 1 cells differentiated along the monocyte/phagocyte pathway exploiting vitamin D and either granulocyte-macrophage-stimulating factor (GMCSF) or macrophage-stimulating factor (MCSF). In long-term cultures, when sequentially exposed to vitamin D (days 0-21) and GMCSF (days 5-10) and plated on collagen, the amount of expression of aromatase mRNA steadily increased along with the increasing expression of osteopontin mRNA, alpha(v) integrin mRNA, c-fms (MCSF-receptor) mRNA and multinucleated cells developing. The conversion of estradiol from testosterone (10(-7) M/l) in the supernatants of dishes mirrored changes in aromatase mRNA expression and by day 21 rose to 30,000 ng/10(7) cells/24 h. 17Beta-HSD IV mRNA expression was abundant in undifferentiated THP 1 cells and was decreased to approximately 50% by day 21. Unstimulated SV-40 immortalized fetal osteoblasts did not express aromatase mRNA, but the expression was stimulated by the addition of the phorbol ester phorbol myristate acetate (PMA). Unstimulated osteoblasts from primary cultures did not express aromatase mRNA. Osteoblast-like osteosarcoma cells MG 63 expressed faint levels of aromatase mRNA in contrast to the osteosarcoma cell line HOS 58. 17Beta-HSD IV mRNA was expressed in fetal osteoblasts as well as in osteoblasts from primary culture, MG 63 and HOS 58 cells. In summary, we can show the expression of estradiol metabolizing enzymes in cells which are present in the bone microenvironment. Impaired aromatase expression and/or enhanced expression of 17beta-HSD IV may contribute to the pathogenesis of osteoporosis.
J Steroid Biochem Mol Biol 1997 Apr
PMID:Local estradiol metabolism in osteoblast- and osteoclast-like cells. 936 87

This study investigated the mechanisms underlying 2-hydroxyestradiol (2-OHE2) effect on luteal steroidogenesis using serum-free cultures of mixed luteal cells from day 8 pseudopregnant rats. Initially, interactions between 2-OHE2 and LH or dibutyryl (db)cAMP on progesterone production were investigated. LH (250 ng/ml) and 2-OHE2 (2.5 microg/ml) had comparable effects on progesterone accumulation, while dbcAMP (5 mM) was more stimulatory. When applied together, 2-OHE2 did not synergize with LH or dbcAMP to further enhance progesterone accumulation. Furthermore, in time course experiments, the dose-dependent effect of 2-OHE2 was to reduce and eventually abolish the time-dependent increase in cAMP accumulation. In contrast LH stimulated cAMP accumulation at all times. Experiments in which cells were co-treated with 2-OHE2, 22-OH-cholesterol and cyanoketone, or with 2-OHE2 and 22-OH-cholesterol or pregnenolone indicated that 2-OHE2 not only had a stimulatory effect on the cholesterol side-chain cleavage and 3beta-hydroxysteroid dehydrogenase enzymes, but it also appeared to inhibit the 20alpha-hydroxysteroid dehydrogenase leading to a relative increase in progesterone accumulation. Experiments with hormone antagonists suggested that the actions of 2-OHE2 were not mediated by the estrogen, alpha- or beta-adrenergic receptors. The results of this study support the concept of a physiological role for catecholestrogens in rat luteal steroidogenesis.
Mol Cell Endocrinol 1994 May
PMID:Catecholestrogen modulation of steroid production by rat luteal cells: mechanism of action. 939 36

In androgen target tissues, 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) may regulate occupancy of the androgen receptor (AR) by catalyzing the interconversion of 5alpha-dihydrotestosterone (5alpha-DHT) (a potent androgen) and 3alpha-androstanediol (a weak androgen). In this study, a 3alpha-HSD cDNA (1170 bp) was isolated from a human prostate cDNA library. The human prostatic 3alpha-HSD cDNA encodes a 323-amino acid protein with 69.9%, 84.1%, 99.4%, and 87.9% sequence identity to rat liver 3alpha-HSD and human type 1, type 2, and type 3 3alpha-HSDs, respectively, and is a member of the aldo-keto reductase superfamily. The close homology with human type 2 3alpha-HSD suggests that it is either identical to this enzyme or a structural allele. Surprisingly, when the recombinant protein was expressed and purified from Escherichia coli, the enzyme did not oxidize androsterone when measured spectrophotometrically, an activity previously assigned to recombinant type 2 3alpha-HSD using this assay. Complete kinetic characterization of the purified protein using spectrophotometric, fluorometric, and radiometric assays showed that the catalytic efficiency favored 3alpha-androstanediol oxidation over 5alpha-DHT reduction. Using [14C]-5alpha-DHT as substrate, TLC analysis confirmed that the reaction product was [14C]-3alpha-androstanediol. However, in the reverse reaction, [3H]-3alpha-androstanediol was oxidized first to [3H]-androsterone and then to [3H]-androstanedione, revealing that the expressed protein possessed both 3alpha- and 17beta-HSD activities. The 17beta-HSD activity accounted for the higher catalytic efficiency observed with 3alpha-androstanediol. These findings indicate that, in the prostate, type 2 3alpha-HSD does not interconvert 5alpha-DHT and 3alpha-androstanediol but inactivates 5alpha-DHT through its 3-ketosteroid reductase activity. Levels of 3alpha-HSD mRNA were measured in primary cultures of human prostatic cells and were higher in epithelial cells than stromal cells. In addition, elevated levels of 3alpha-HSD mRNA were observed in epithelial cells derived from benign prostatic hyperplasia and prostate carcinoma tissues. Expression of 3alpha-HSD was not prostate specific, since high levels of mRNA were also found in liver, small intestine, colon, lung, and kidney. This study is the first complete characterization of recombinant type 2 3alpha-HSD demonstrating dual activity and cellular distribution in the human prostate.
Mol Endocrinol 1997 Dec
PMID:Expression and characterization of recombinant type 2 3 alpha-hydroxysteroid dehydrogenase (HSD) from human prostate: demonstration of bifunctional 3 alpha/17 beta-HSD activity and cellular distribution. 941 1

To characterize further the function of the intracellular vitamin D receptor (VDR), we have developed stable transfectant variants of a vitamin D-responsive cell line (U937) which express either decreased or increased numbers of VDR. In this study we have analyzed changes in gene expression associated with this variable VDR expression. Initial experiments indicated that a 50% decrease in VDR levels was associated with a 2-fold increase in cell proliferation and a similar rise in c-myc mRNA expression. Further studies were carried out using differential RNA display (DD). Sequence analysis of DD products revealed two cDNAs with identity to known gene products: the catalytic sub-unit of DNA-protein kinase (DNA-PK(CS)), and the peroxisomal enzyme 17beta-hydroxysteroid dehydrogenase type IV (17beta-HSD IV). Northern analysis confirmed that expression of both mRNAs was reduced in cells with decreased numbers of VDR. Down-regulation of 17beta-HSD IV mRNA expression was associated with enhanced estradiol inactivation by U937 cells, suggesting a link between estrogenic pathways and cell proliferation. Further Northern analyses indicated that there was no significant change in 17beta-HSD IV or DNA-PK(CS) mRNA levels following treatment with 1,25(OH)2D3, although expression of both genes varied with changes in cell proliferation. These data suggest that, in addition to its established role as a hormone-dependent trans-activator, VDR may influence gene expression by ligand-independent mechanisms.
Mol Cell Endocrinol 1998 Jul 25
PMID:Differential RNA display identifies novel genes associated with decreased vitamin D receptor expression. 978 9

Sex steroid hormones in mammals have shown to be synthesized not only in gonads but also in non-steroidogenic organs such as the brain. Steroid hormones in the brain were indicated to be involved in sex behavior and brain differentiation. In avian species, an experimental injection of androgen into the brain suggested the existence of a steroidogenic pathway. However, no studies have demonstrated the expression of genes involved in such a steroidogenic pathway in the brain, or in other non-steroidogenic organs of birds such as the liver and kidney. In this study, we have modified the RT-PCR procedure to analyze the expression of the steroidogenic genes, P-450scc, 3beta-HSD, P-450c17, 17beta-HSD and P-450arom in non-steroidogenic organs of chicken including the brain. The RT-PCR has demonstrated the presence of mRNAs from genes in non-steroidogenic as well as steroidogenic organs of chicken. The amounts of mRNAs from these genes (except for P-450c17) among the non-steroidogenic organs were found to be greatest in the brain.
J Steroid Biochem Mol Biol 1998 Oct
PMID:Determination by modified RT-PCR of transcript amounts from genes involved in sex-steroid synthesis in chicken organs including brain. 987 14


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