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)

Using a 17-mer synthetic peptide for immunization, a polyclonal antibody (WS933) directed against amino acid residues 395-411 of the mouse glucocorticoid receptor (GCR) has been raised and used to probe the significance of this region in forming the receptor oligomer and to localize the truncation site of the mutant GCR of the P1798 lymphosarcoma. This region of the receptor, which encompasses the BUGR epitope, is amino-terminal of and immediately adjacent to the DNA-binding domain. The polyclonal antibody WS933 reacted with both native and denatured forms of the wild-type mouse GCR as judged by its ability to shift the transformed receptor peak on Sephacryl S300 columns, to immunoadsorb the receptor to protein A Sepharose, and by immunoblot analysis where it identified the 98 kDa receptor protein in the cortisol-sensitive line of the P1798 mouse lymphosarcoma. WS933 also reacted with rat and rabbit GCR, but not human GCR. These characteristics were shared by the BUGR-2 monoclonal antibody. Unexpectedly, there were two highly significant differences between WS933 and BUGR-2. The first was the ability of WS933 to bind to the mutant 45 kDa GCR of the cortisol-resistant P1798 lymphosarcoma as judged by its capability of shifting the receptor peak on Sephacryl S300 columns. BUGR-2, in contrast, was unable to shift this mutant receptor peak. Secondly, WS933 was unable to react with the non-DNA-binding form of the wild-type (or mutant) GCR, whereas BUGR-2 could react with the non-DNA-binding form of the wild-type GCR. The first observation suggests that the truncation site of the mutant receptor may lie within a portion of the BUGR domain. Additionally, the second observation implies that at least part of the region lying within amino acid residues 395-411 of the mouse GCR is occluded in the receptor oligomer and that this site only becomes available upon transformation of the GCR to the DNA-binding form. This data provides the first mapping of the amino-terminus of the occluded region of the non-transformed receptor, and suggests that WS933 will be a useful probe for characterizing mutant as well as wild type glucocorticoid receptors.
J Steroid Biochem Mol Biol 1991 Oct
PMID:New site-directed polyclonal antibody maps N-terminus of occluded region of the non-transformed glucocorticoid receptor oligomer to within BUGR epitope. 171 70

Expression of prostate-specific antigen (PA) mRNA was tested at various time periods after incubation of the human prostate tumor cell line LNCaP with the synthetic androgen R1881. Androgen-stimulated expression was observed within 6 h after addition of R1881 to the cells. Run-on experiments with nuclei isolated from LNCaP cells showed that expression of the PA gene could be regulated by R1881 on the level of transcription. DNase I footprints of the promoter region of the PA gene (-320 to +12) with nuclear protein extracts from LNCaP cells showed at least four protected regions. The protected areas include the TATA-box, a GC-box sequence, and a sequence AGAACAgcaAGTGCT at position -170 to -156, which closely resembles the reverse complement of the consensus sequence GGTACAnnnTGTTCT for binding of the glucocorticoid receptor and the progesterone receptor. Fragments of the PA promoter region were cloned in front of the chloramphenicol acetyltransferase (CAT) reporter gene and cotransfected with an androgen receptor expression plasmid into COS cells in a transient expression assay. CAT activity of COS cells grown in the presence of 1 nM R1881 was compared to untreated controls. A 110-fold induction of CAT activity was found if a -1600 to +12 PA promoter fragment was used in the construct. By further deletion mapping of the PA promoter a minimal region (-320 to -155) was identified as being essential for androgen-regulated gene expression. Mutation of the sequence AGAACAgcaAGTGCT (at -170 to -156) to AAAAAAgcaAGTGCT almost completely abolished androgen inducibility of the reporter gene constructs. One or more copies of the sequence AGAACAgcaAGTGCT cloned in front of a thymidine kinase promoter-CAT reporter gene confers androgen regulation to the reporter gene. These findings provide strong evidence for transcription regulation of the PA gene by androgens via the sequence AGAACAgcaAGTGCT. Interestingly, in addition to the AGAACAgcaAGTGCT element, an upstream region (-539 to -320) is needed for optimal androgen inducibility of the PA promoter.
Mol Endocrinol 1991 Dec
PMID:The promoter of the prostate-specific antigen gene contains a functional androgen responsive element. 172 87

In order to investigate the molecular basis for the charge heterogeneity which has been reported for the glucocorticoid receptor, we have analyzed the [3H]dexamethasone mesylate ([3H]DM)1 affinity labeled receptor from HeLa S3 cells by high resolution two-dimensional gel analysis. The [3H]DM labeled glucocorticoid receptor from HeLa cells exists as a population of 5-6 isoforms which range over approx. 0.6 pI units but have similar molecular weights. This heterogeneity is apparently the result of modification(s) of a single gene product since the affinity labeled receptor from Chinese hamster ovary (CHO) cells transfected with the human glucocorticoid receptor cDNA displays the same pattern of heterogeneity on two-dimensional gels. Since previous one-dimensional gel studies from our laboratory showed that the structure of the [3H]DM labeled glucocorticoid receptor from HeLa cells is highly susceptible to sulfhydryl group modification, we investigated the potential role of the same modifications in the apparent charge heterogeneity of the glucocorticoid receptor. Treatment of the affinity labeled receptor with iodoacetamide which alkylates free sulfhydryl groups and irreversibly prevents the formation of intra- or intermolecular disulfide bonds, reproducibly resulted in the appearance of 5-6 discrete isoforms of the receptor protein. Treatment with dithiothreitol, a reversible reducing reagent, resulted in detection of 3 to 4 isoforms of the glucocorticoid receptor. In marked contrast, treatment with sodium tetrathionate, which induces intramolecular disulfide bond formation, resulted in only one detectable isoform of the [3H]DM labeled glucocorticoid receptor. These data demonstrate that the oxidation/reduction state of sulfhydryl groups within the receptor protein can account for much of the charge heterogeneity of this ligand dependent transcription factor.
J Steroid Biochem Mol Biol 1992 Jan
PMID:The effect of oxidation/reduction on the charge heterogeneity of the human glucocorticoid receptor. 173 32

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) dictates specificity for the mineralocorticoid receptor (MR) by converting the active steroid cortisol to cortisone in man (corticosterone to 11-dehydrocorticosterone in rodents), leaving aldosterone to occupy the MR. However cortisol is the principal circulating glucocorticoid in man and 11 beta-HSD, distributed in a tissue specific fashion, may represent a powerful mechanism in regulating exposure of active steroid to the glucocorticoid receptor (GR). A detailed localization study of 11 beta-HSD gene expression and activity in numerous rat tissues has been performed and compared with the presence of GR mRNA. 11 beta-HSD mRNA (1.4 kB) measured by hybridization to a cDNA derived from hepatic 11 beta-HSD, and enzyme activity, measured by percentage conversion of [3H]corticosterone to [3H]11-dehydrocorticosterone by tissue homogenate, was widespread, present in all tissues studied except spleen, brain cortex and heart. There was a close correlation between tissue 11 beta-HSD mRNA levels and activity (r = 0.91, P less than 0.001) suggesting pretranslational regulation of the enzyme at a tissue level. There was also close co-localization of GR mRNA (7 kB), measured by hybridization to a rat GR cRNA probe, and enzyme mRNA/activity in every tissue studied except heart and brain cortex in which GR mRNA was found. In the mineralocorticoid target tissues kidney and colon, additional 11 beta-HSD mRNA bands were seen (kidney 1.8 kB, colon 3.4 kB), suggesting the presence of multiple dehydrogenase species. 11 beta-HSD is widely distributed and suitably placed to modulate ligand occupancy of the GR. The possibility of multiple dehydrogenase species in mineralocorticoid target tissues is consistent with the hypothesis that the ubiquitous 'native' 1.4 kB hepatic enzyme regulates the GR, and these separate dehydrogenases regulate the MR.
J Steroid Biochem Mol Biol 1992 Jan
PMID:Tissue localization of 11 beta-hydroxysteroid dehydrogenase and its relationship to the glucocorticoid receptor. 173 33

The rat glucocorticoid receptor is a 795-amino acid protein with the hormone binding domain located in the C-terminal portion of the molecule. In the absence of hormone, this domain displays a protein inactivation activity that represses the nuclear localization, DNA binding, and transcriptional regulatory activities of the receptor. This inactivation activity, which appears to be mediated by the 90-kilodalton heat shock protein (HSP90), is stronger in the glucocorticoid receptor than the corresponding activity of the estrogen receptor hormone binding domain. In order to analyze these differences, we have directly compared in vitro translated glucocorticoid and estrogen receptors in terms of their interaction with HSP90 by a coimmunoprecipitation assay employing two monoclonal antibodies, AC88 and 8D3, which react with different regions of the HSP90 molecule. Intact forms of both the glucocorticoid receptor and the estrogen receptor coimmunoprecipitated with endogenous HSP90 in reticulocyte lysates, indicating that both receptors were capable of binding to HSP90 when translated in vitro. By assaying a series of receptor deletion mutants, we found that the sequences required for HSP90 binding mapped to a similar region within the hormone binding domain of both receptors. While the hormone binding domain was found to be the only structural requirement for HSP90 binding to the glucocorticoid receptor, additional sequences N-terminal to the hormone binding domain were shown to be required for HSP90 binding to the estrogen receptor. These results are consistent with a postulate that differences in the protein inactivation activities of the glucocorticoid and estrogen receptor hormone binding domains may be secondary to differences in the interactions of these domains with HSP90.
Mol Endocrinol 1992 Jan
PMID:Comparison of the 90-kilodalton heat shock protein interaction with in vitro translated glucocorticoid and estrogen receptors. 173 66

The concentration of the cytosolic glucocorticoid receptor (GR) was determined in skeletal muscles of calves in order to study possible differences in individual muscles from different parts of the body as well as the influence of sex and breed. In male and female Simmental calves the topographical distribution of GR was similar: the lowest concentrations were seen in abdominal muscle, whereas in neck, shoulder and hindleg the GR concentrations were higher; this difference was more pronounced in male than in female calves. In general, female calves had about 2-fold higher GR concentrations than males. The cytosolic cortisol concentrations were differing neither between individual muscles nor between sexes. The cortisol secretion during a 24-h sampling period 1 week prior to slaughter showed no sex difference. GR concentrations in neck muscle of female calves of four different German cattle breeds (Holstein Friesian, Brown Swiss, Simmental and German Gelbvieh) were rather similar; however, when Brown Swiss with the highest GR levels were compared to Holstein Friesian calves with the lowest concentrations, a significant difference was evident (P less than 0.05).
J Steroid Biochem Mol Biol 1991 Dec
PMID:Quantitation of glucocorticoid receptors in bovine skeletal muscle: topographical distribution, sex effect and breed comparisons. 175 94

In the rat anterior pituitary gland, estrogen increases both prolactin (PRL) mRNA levels and stimulates the proliferation of PRL-producing cells. The temporal sequence of these events suggests that PRL gene expression may be coordinated with cell proliferation. We investigated the relationship between cell cycle progression and the accumulation of the PRL mRNA, as well as several other mRNAs, in the rat pituitary tumor GH3 cell line. Serum-deprived cells progressed from G0 to S phase in 20-24 h following serum stimulation. During this time, beta-actin mRNA levels increased 7-fold in 5 h, then returned to basal levels prior to the beginning of S phase. Histone H1 mRNA levels increased approximately 3-fold as cells entered S phase. These data are consistent with the cell cycle-dependent regulation of beta-actin and histone H1 gene expression reported for other cell types. Glucocorticoid receptor mRNA levels were barely detectable in serum-deprived cells but rapidly increased 3- to 5-fold following serum stimulation. This increase resulted in glucocorticoid receptor mRNA levels that were equivalent to those seen in cells maintained in serum-containing medium, suggesting that serum factors regulate glucocorticoid receptor gene expression. In contrast to these changes in gene expression, the levels of PRL and growth hormone (GH) mRNAs gradually increased 2-fold while the cells progressed through G1 phase. Similarly, in cells synchronized to progress through S and G2 phases following aphidicolin treatment, histone H1 gene expression showed a specific increase in S phase cells, whereas PRL and GH mRNA levels changed little with cell cycle progression. These results indicate that the levels of PRL and GH mRNAs are not regulated in a cell cycle-dependent manner. When changes in estrogen responsiveness were determined during the cell cycle, we found that estradiol treatment was capable of increasing PRL mRNA accumulation independent of cell cycle progression and cell cycle distribution in synchronized GH3 cells. These results support the hypothesis that the hormonal regulation of PRL gene expression is not significantly affected by cell growth.
Mol Cell Endocrinol 1991 Nov
PMID:Growth and cell cycle regulation of mRNA levels in GH3 cells. 176 Nov 63

A number of alternative mechanisms by which the DNA-bound glucocorticoid receptor transactivates gene expression have been suggested. The fact that the glucocorticoid and other steroid hormone receptors function in yeast suggests that at least one of these mechanisms has been conserved throughout evolution. Here we show that overexpression of one of the glucocorticoid receptor transactivation domains (tau 1) in yeast causes a reduction in expression of a yeast reporter gene, followed by a severe reduction in the growth rate of the yeast cells. This is analogous to the phenomenon of squelching, first described for the GAL4 protein, and suggests that the tau 1 domain of the glucocorticoid receptor functions by contacting limiting transcription factors needed for efficient gene activity. A similar level of squelching was seen after removal of the up-stream activation sequences from the yeast reporter gene, suggesting that the squelching interactions were with transcription factors needed for the activity of a basal promoter.
Mol Endocrinol 1991 Oct
PMID:High level expression of the major transactivation domain of the human glucocorticoid receptor in yeast cells inhibits endogenous gene expression and cell growth. 177 28

Steroid induction of responsive genes functions through the synergistic activity of steroid receptor-binding sequences with adjacent transcription factor-binding sites. To analyze the mechanism of synergy we tested different human glucocorticoid receptor mutants for synergistic function with another transcription factor in comparison with intrinsic trans-activation obtained with a single receptor binding site (glucocorticoid response element). Multiple domains were found to be involved in synergistic activity of the glucocorticoid receptor with the CACCC box factor. Deletions within the N-terminal receptor half affected simultaneously intrinsic trans-activation and synergism. However, deletion of the hormone-binding domain mainly impaired synergism rather than intrinsic trans-activation, clearly showing that this domain synergizes by a mechanism independent of intrinsic activation. A chimeric protein where the DNA-binding domain of the glucocorticoid receptor was replaced by that of the yeast GAL4 protein also showed functional synergism. These data suggest that some of the receptor domains outside the DNA-binding domain synergize by their intrinsic trans-activating property, but the hormone-binding domain contributes to synergism by a different mechanism.
Mol Endocrinol 1991 Oct
PMID:Multiple domains of the glucocorticoid receptor involved in synergism with the CACCC box factor(s). 177 33

The POMC gene is expressed predominantly in the anterior pituitary. The high level of POMC transcription in this tissue is modulated by peptide hormones and repressed by glucocorticoids. In this present study we have investigated promoter elements required for the high basal transcription and glucocorticoid repression using transient transfection and in vitro transcription assays. We first determined that the region between -77 to -51 of the promoter, which has previously been shown to harbor a glucocorticoid receptor-binding site, is required for high basal expression both in vivo and in vitro. This promoter domain is also required for glucocorticoid repression of transcription in vivo. Two site-directed mutants within this area both decreased basal transcription, but were fully repressed by glucocorticoids, implying that the -77 to -51 region is a complex regulatory region harboring separable basal and glucocorticoid-repressible elements. Electrophoretic mobility shift and exonuclease III footprinting analysis revealed the existence of two factors that bind in this region. We also examined the effect of broad promoter deletions on basal expression and glucocorticoid repression. These experiments revealed that the region between -480 and -320 is also required for glucocorticoid repression. Taken together, the data suggest a model in which high basal transcription is generated by direct interaction of factors binding between -480 to -320 and -77 to -51. Glucocorticoid repression could occur by direct receptor disruption of these interactions.
Mol Endocrinol 1991 Dec
PMID:Proopiomelanocortin gene promoter elements required for constitutive and glucocorticoid-repressed transcription. 179 42


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