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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Dehydroepiandrosterone sulfotransferase (DHEA-ST), a
steroid sulfotransferase
(ST), has recently been purified from human liver cytosol and partially characterized. DHEA-ST has a subunit molecular mass of 35 kDa and is responsible for the majority of the sulfation of steroids and bile acids in the liver. For these studies, polyclonal antibodies to human liver DHEA-ST were raised in rabbits. The anti-human liver DHEA-ST antibodies were used to characterize the immunoreactivity of DHEA-ST in human liver and to study the relationship of human adrenal DHEA-ST to the liver form of the enzyme. Immunoblot analysis of several different human liver cytosol samples with the rabbit anti-human liver DHEA-ST antiserum detected only a single 35-kDa protein in each liver. Anti-human liver DHEA-ST antibodies also did not react with either form of phenol sulfotransferase (PST), P-PST or M-PST, present in human liver cytosol. DHEA-ST activity was purified from the 100,000 x g supernatant fraction of human adrenal tissue by DEAE-Sepharose CL-6B chromatography and 3',5'-diphosphoadenosine-agarose affinity chromatography. Human adrenal DHEA-ST was shown to have a molecular mass of 35 kDa, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunoblot analysis of human adrenal cytosol revealed that the anti-human liver DHEA-ST antibodies reacted specifically with the 35-kDa subunit of DHEA-ST. The apparent Km values for DHEA and 3'-phosphodenosine-5'-phosphosulfate obtained with human adrenal DHEA-ST were 1.0 microM and 1.6 microM, respectively. Adrenal DHEA-ST demonstrated the same pattern of reactivity towards different steroid substrates as did human liver DHEA-ST, and neither form of DHEA-ST was found to sulfate cortisol. The results of this study suggest that DHEA-ST is the major steroid ST present in human liver and adrenal tissue and that the physical, biochemical, and kinetic properties of adrenal DHEA-ST are similar if not identical to those of the liver form of the enzyme.
Mol
Pharmacol 1992 Apr
PMID:Immunological characterization of dehydroepiandrosterone sulfotransferase from human liver and adrenal. 156 19
MCF-7 human mammary carcinoma cells have been reported to possess beta-estradiol and dehydroepiandrosterone sulfotransferase activities. These
steroid sulfotransferase
activities may be important in the metabolism and activity of different steroids in these cells. This report describes and characterizes both the enzymatic activity of three cytosolic sulfotransferases found in MCF-7 cells and the corresponding immunoblot analysis of these enzymes with specific anti-sulfotransferase antibodies. Two cytosolic sulfotransferases have been purified and characterized from human tissues which are capable of sulfating estrogens. These are the phenol-sulfating form of phenol sulfotransferase (P-PST) and the hydroxysteroid sulfotransferase, dehydroepiandrosterone sulfotransferase (DHEA-ST). The results of this study show that P-PST is the major cytosolic sulfotransferase found in MCF-7 cytosol and is responsible for most of the beta-estradiol sulfation in these cells. Although DHEA-ST activity was found in MCF-7 cytosol, this activity was only about 3% of the P-PST activity. Immunoblot analysis of MCF-7 cytosol detected both P-PST and lower levels of the monoamine-sulfating form of PST; however DHEA-ST could not be detected apparently because of low levels of expression. Human liver P-PST was expressed in Cos-7 Green monkey kidney fibroblasts and the ability of the cloned enzyme to sulfate beta-estradiol was investigated. This study indicates that P-PST is the prevalent cytosolic sulfotransferase in MCF-7 cytosol and is responsible for the majority of beta-estradiol sulfation in these cells.
J Steroid Biochem
Mol
Biol 1993 Oct
PMID:Identification and characterization of cytosolic sulfotransferase activities in MCF-7 human breast carcinoma cells. 821 78
Sulfonation is a phase II conjugation reaction responsible for the biotransformation of many compounds including steroids, bile acids, and drugs. Humans are presently known to express at least five cytosolic sulfotransferase (SULT) enzymes, of which only two are hydroxysteroid SULT, SULT2A1, commonly known as
steroid sulfotransferase
, and the cholesterol sulfotransferase SULT2B1. SULT2A1 is highly expressed in the adrenal where it is responsible for the sulfation of hydroxysteroids including conversion of dehydroepiandrosterone to dehydroepiandrosterone sulfate and in the liver where it is responsible for sulfation of bile acids and circulating hydroxysteroids. Little is known concerning the transcriptional regulation of human SULT2A1 in adrenal. Herein we demonstrate the role of two transcription factors, steroidogenic factor 1 (SF1) and GATA-6, in the regulation of SULT2A1 transcription. These transcription factors were quantified by real-time RT-PCR in normal human adrenal tissue. Transient transfection assays with deleted and mutated SULT2A1 promoter constructs allowed for the determination of specific SF1 and GATA binding cis-regulatory elements necessary for transactivation of SULT2A1 promoter, and binding was confirmed by EMSA analysis. Both SF1 and GATA-6 were positive regulators of SULT2A1 promoter constructs. These data support the hypothesis that adrenal SULT2A1 expression is regulated by SF1 and GATA-6.
Mol
Endocrinol 2005 Jan
PMID:Steroid sulfotransferase 2A1 gene transcription is regulated by steroidogenic factor 1 and GATA-6 in the human adrenal. 1538 88
The skin is a well-recognized site of steroid formation and metabolism. Episkin is a cultured human epidermis. In this report, we investigate whether Episkin possesses a steroidogenic machinery able to metabolize adrenal steroid precursors into active steroids. Episkin was incubated with [14C]-dehydroepiandrosterone (DHEA) and 4-androstenedione (4-dione) and their metabolites were analyzed by liquid chromatography/mass spectrometry (LC/MS/MS). The results show that the major product of DHEA metabolism in Episkin is DHEA sulfate (DHEAS) (88% of the metabolites) while the other metabolites are 7alpha-OH-DHEA (8.2%), 4-dione (1.3%), 5-androstenediol (1.3%), dihydrotestosterone (DHT) (1.4%) and androsterone (ADT) (2.3%). When 4-dione is used as substrate, much higher levels of C19-steroids are produced with ADT representing 77% of the metabolites. These data indicate that 5alpha-reductase, 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and 3alpha-hydroxysteroid dehdyrogenase (3alpha-HSD) activities are present at moderate levels in Episkin, while 3beta-HSD activity is low and represents a rate-limiting step in the conversion of DHEA into C19-steroids. Using realtime PCR, we have measured the level of mRNAs encoding the steroidogenic enzymes in Episkin. A good agreement is found between the mRNAs expression in Episkin and the metabolic profile. High expression levels of
steroid sulfotransferase
SULT2B1B and type 3 3alpha-HSD (AKR1C2) correspond to the high levels of DHEA sulfate (DHEAS) and ADT formed from DHEA and 4-dione, respectively. 3beta-HSD is almost undetectable while the other enzymes such as type 1 5alpha-reductase, types 2, 4, 5, 7, 8, and 10 17beta-HSD and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) (AKR1C1) are highly expressed. Except for UGT-glucuronosyl transferase, similar mRNA expression profiles between Episkin and human epidermis are observed.
J Steroid Biochem
Mol
Biol 2007 Oct
PMID:Steroid metabolism and profile of steroidogenic gene expression in Episkin: high similarity with human epidermis. 1766 97
The human adrenal reticularis produces the so-called adrenal androgens, dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S). As opposed to the cortisol and aldosterone little is known regarding the mechanisms that regulate the production of the adrenal androgens. Several recent studies have shown that type II 3beta-hydroxysteroid dehydrogenase (HSD3B2), cytochrome b5 (CYB5), and
steroid sulfotransferase
(SULT2A1) play an important role in the regulation of adrenal androgen production. Specifically, adrenal production of DHEA-S is correlated with reticularis expression of SULT2A1 and CYB5. In contrast, HSD3B2 has an inverse correlation with adrenal androgen production likely due to its unique ability to remove precursors from the pathway leading to DHEA. Therefore, its expression is limited to the adrenal glomerulosa/fasciculata but not in reticularis. The differential expression of these three proteins appears to be critical for reticularis function. In this review, we focus on studies that have begun to define the mechanisms regulating the transcription of these genes. Understanding the mechanisms controlling differential expression of these proteins should provide novel information about the human adrenal reticularis and its production of DHEA and DHEA-S.
J Steroid Biochem
Mol
Biol 2008 Feb
PMID:Regulation of the adrenal androgen biosynthesis. 1794 81