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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tissue-specific expression of the glycoprotein hormone alpha-subunit gene in pituitary gonadotropes relies on a gonadotrope-specific element (GSE), which binds an approximately 54-kilodalton protein termed GSE-binding protein 1 (GSEB1). We report here that GSEB1 is the orphan nuclear receptor steroidogenic factor-1 (SF-1), which has been shown to be a primary regulator of steroidogenic enzymes in the adrenal gland and gonadal tissues. GSEB1 from alpha T3-1 pituitary gonadotrope cells and SF-1 from Y1 adrenocortical cells and R2C testicular Leydig cells display identical binding properties with both the GSE and SF-1 elements. Antiserum specific to the SF-1 DNA-binding domain abolishes the binding of both GSEB1 and SF-1 to both elements. SF-1 mRNA is found in the mouse pituitary and in the alpha T3-1 cell line but not in other pituitary cell lines, consistent with the pattern of GSEB 1-binding activity. The GSE element specifically enhances transcription in SF-1-containing cells. The discovery that an orphan nuclear receptor regulates the expression of both the gonadotropin hormones in the pituitary and the steroidogenic enzymes in the gonad provides a potential molecular mechanism for coordinate control in reproductive function, perhaps through an as yet unidentified endocrine ligand for SF-1.
Mol Endocrinol 1994 Jul
PMID:The orphan nuclear receptor, steroidogenic factor-1, regulates the glycoprotein hormone alpha-subunit gene in pituitary gonadotropes. 752 22

ACTH-dependent transcriptional activation of the bovine CYP17 gene (the gene encoding cytochrome P450 steroid 17 alpha-hydroxylase) involves two cAMP-responsive sequences (CRS1 and CRS2) located in the promoter region. Here we demonstrate that two nuclear orphan receptors, chicken ovalbumin upstream promoter transcription factor (COUP-TF) and steroidogenic factor-1 (SF-1), bind to the part of the CRS2 element that contains the repeated sequences AAGTCA and AGGTCA spaced by six nucleotides (repCRS2). Overexpression of COUP-TF and SF-1 in both steroidogenic and nonsteroidogenic cells demonstrated that SF-1 is an activator of repCRS2-dependent transcription of reporter genes. Furthermore, the SF-1-dependent transcription could be further stimulated by activation of the cAMP-dependent protein kinase. In contrast, COUP-TF alone had no effect on repCRS2-dependent reporter gene activity. Mutations that interfere with the binding of SF-1 to repCRS2 in vitro abolished the cAMP-induced activities mediated by the element in transfected Y1 cells. The mutational analysis of repCRS2 further indicated that the binding sites for the two receptors overlap, and electrophoretic mobility shift assays demonstrated that the receptors bound in a mutually exclusive manner. Overexpression of both SF-1 and COUP-TFI simultaneously demonstrated that COUP-TFI inhibited SF-1-dependent activation of reporter genes. Transient transfection experiments with a construct containing a -100/+19 base pair fragment from the bovine CYP17 gene demonstrated that SF-1 and COUP-TF had similar effects on the intact promoter as on the repCRS2/reporter gene constructs. Our data suggest that the two orphan receptors bind in a mutually exclusive manner to repCRS2 and that SF-1 is involved in the activation and COUP-TF in the repression of repCRS2-dependent transcription.
Mol Endocrinol 1995 Mar
PMID:Mutually exclusive interactions of two nuclear orphan receptors determine activity of a cyclic adenosine 3',5'-monophosphate-responsive sequence in the bovine CYP17 gene. 777 79

Cytochrome P450 aromatase, which converts testosterone to estradiol, is transcriptionally induced by FSH and cAMP during ovarian follicular development. At least one promoter element [-82/-31 base pairs (bp)] required for stimulation of the rat gene in granulosa cells binds steroidogenic factor-1, an orphan steroid receptor. In this paper, we demonstrate that an additional region, -161/-138 bp is required for cAMP regulation. This region shares homology with promoter sequences in the bovine 21-hydroxylase and mouse 11 beta-hydroxylase genes that are also induced by cAMP, yet each binds different proteins in granulosa cell nuclear extracts. The aromatase -161/-138 bp region contains a cAMP-response element (CRE)-like sequence, TGCACGTCA. Deletion or mutation of this sequence reduces promoter activity of chimeric chloramphenicol acetyl transferase (CAT) reporter constructs that are transiently transfected into granulosa cells and R2C Leydig cells. Granulosa cell nuclear proteins and R2C cell nuclear proteins specifically bind the -161/-138 bp region and form three protein/DNA complexes. Recombinant CRE-binding protein (CREB) binds the CRE-like sequence and forms a single band, and a CREB antibody retards the migration of CREB and one granulosa cell protein-aromatase DNA binding complex. Using Western blot analysis, CREB was demonstrated in granulosa cell nuclear extracts from all stages of follicular development. Thus, aromatase is transcriptionally regulated by a hexameric sequence binding SF-1 and a CRE sequence binding CREB and other factors present in granulosa cells and in R2C Leydig cells. The presence of identical SF-1 and CRE-like sequences in the human ovarian aromatase promoter II suggests that the human promoter may also be regulated in a similar manner.
Mol Endocrinol 1994 Oct
PMID:Identification of a cyclic adenosine 3',5'-monophosphate-response element in the rat aromatase promoter that is required for transcriptional activation in rat granulosa cells and R2C leydig cells. 785 48

We have cloned a novel member of the nuclear receptor superfamily that has been identified from complementary DNA libraries derived from mouse tissues using a low stringency cross hybridization strategy. The deduced protein sequence contains 495 amino acids and consists of the characteristic DNA-binding and ligand-binding domains of the nuclear receptor superfamily. The primary sequence of this new orphan is distinct from those of previously cloned members and subgroups. Analysis of the DNA-binding properties of the in vitro synthesized protein revealed that this new orphan receptor binds to the sequence TCAAGGTCA that includes the steroidogenic factor-1 half-site and direct repeat with 0 bp spacing elements. Northern blot and ribonuclease protection assays showed that the receptor was predominantly expressed in the testis. Results from in situ hybridization experiments confirmed this observation and showed it to be located in the spermatogenic cells. High level expression was also detected in developing oocytes in the ovary. Thus, high level expression of this gene is restricted to developing germ cells, the oocytes and spermatogenic cells. We speculate that this orphan receptor may be a molecule involved in regulating some aspect of meiosis, and that the major function of this factor is likely to be involved in the regulation of gene expression in germ cell development during gametogenesis. It has been designated germ cell nuclear factor.
Mol Endocrinol 1994 Oct
PMID:Cloning of a novel orphan receptor (GCNF) expressed during germ cell development. 785 58

As an initial step toward understanding its role in steroidogenesis, we studied the developmental profile of steroidogenic factor-1 (SF-1), a nuclear receptor that regulates the steroid hydroxylases. SF-1 transcripts first appear on embryonic day 9 (E9) in the urogenital ridge, the probable source of steroidogenic cells of both adrenals and gonads. By E11, after the adrenals and gonads are clearly separate, SF-1 transcripts are detected throughout the adrenal primordium. Thereafter, adrenal expression of SF-1 localizes to the cortex. Consistent with its proposed role in regulating cholesterol side-chain cleavage enzyme (SCC), SF-1 is expressed before SCC. During the sexually undifferentiated stage of gonadal development (E9-E12), all embryos express SF-1 in the genital ridge. As testicular cords form in males, SF-1 transcripts are diffusely expressed throughout the testis, whereas SCC mRNA is limited to the interstitium. These differences between SF-1 and SCC reflect SF-1 expression by Sertoli cells, as shown by Northern blotting and in situ hybridization. In contrast to its persistent expression in the embryonic testis, SF-1 transcripts disappear from the ovary between E13.5-E16.5, reappearing only during late gestation (E18.5). Thus, expression of SF-1 in the embryonic gonad is sexually dimorphic. Coupled with the demonstration of SF-1 mRNA in Sertoli cells, these data suggest that SF-1 plays a role in gonadal development distinct from regulating the steroidogenic enzymes. Additionally, SF-1 is expressed in the embryonic forebrain, implying a role in neural development.
Mol Endocrinol 1994 May
PMID:Developmental expression of mouse steroidogenic factor-1, an essential regulator of the steroid hydroxylases. 805 73

Regulation of steroidogenesis in classic endocrine tissues is mediated by transcriptional regulation of the P450scc gene, which encodes the first and rate-limiting cholesterol side-chain cleavage enzyme. We previously showed that P450scc messenger RNA is regionally expressed in the adult rat brain, primary glial cultures, and C6 glioma cells. Expression of P450scc in the brain results in the de novo synthesis of neurosteroids, a class of steroid hormones that are active at gamma-aminobutyric acidA and N-methyl-D-aspartate receptors. We determined whether P450scc expression is transcriptionally regulated in neural cells, using the same DNA sequences and nuclear proteins as classic steroidogenic adrenal and Leydig cells. The transcriptional activity of deletional mutants of 2.5 kilobases of the 5'-flanking regulatory region of the rat P450scc gene cloned into a luciferase reporter gene was assessed in mouse adrenocortical Y-1, mouse Leydig MA-10, rat C6 glioma, rat GC somatotrope, and mouse GT1-7 neurosecretory cell lines. P450scc was transcriptionally regulated in Y-1, MA-10, and C6 glioma cells, but not in GC or GT1-7 cells. In one region (-94/-35), putative steroidogenic factor-1-binding sites appeared to be critical for the basal transcriptional activity and cAMP responsiveness in steroidogenic Y-1 and MA-10 cells, but had no function in rat C6 cells. DNA sequences between -94/-130 mediated both basal and cAMP-inducible transcriptional activity in C6 cells. Gel mobility shift assays showed that one nuclear protein binding to DNA sequences between -54 and -35 was abundant in MA-10 and Y-1 cells, but was absent from C6 cells, whereas another nuclear protein, binding to DNA sequences between -94 and -130 was abundant in C6 cells, but was rare in MA-10 cells and absent from Y-1 and other adrenocortical cells. Although the DNA sequence between -94 and -130 contains an Sp1 site, Sp1 did not bind to this site. Nevertheless, this GC-rich region was critical for nuclear protein binding and for basal and cAMP-induced transcriptional regulation in both C6 and MA-10 cells. These observations demonstrate that the rat P450scc gene is transcriptionally regulated in glioma cells, but its regulation in glial cells involves a DNA element different from those used in classic steroidogenic tissues. The results further suggest that steroidogenic factor-1 is not involved in regulating neurosteroidogenesis.
Mol Endocrinol 1995 Nov
PMID:Transcriptional regulation of P450scc gene expression in neural and steroidogenic cells: implications for regulation of neurosteroidogenesis. 858 34

DAX-1, an orphan member of the nuclear hormone receptor superfamily, is responsible for X-linked adrenal hypoplasia congenita (AHC) and the frequently associated hypogonadotropic hypogonadism (HH). The entire DAX-1 genomic region has been sequenced and a putative steroidogenic factor-1 response element has been identified in the promoter region of the gene. The purpose of these investigations was to determine if DAX-1 was expressed in the central nervous system, particularly the hypothalamus and pituitary, in order to better understand the relationship of mutations in this gene to HH associated with AHC. We used Northern blot analysis and reverse transcription PCR to demonstrate that DAX-1 was expressed in the hypothalamus and the pituitary, and to confirm its expression in adrenal cortex and gonads. The expression of DAX-1 in these tissues indicates the involvement of DAX-1 in the development of the reproductive system at multiple levels within the hypothalamic-pituitary-adrenal/gonadal axis. We also observed the expression of DAX-1 in a human adrenocortical carcinoma cell line, NCI-H295, that has features characteristic of the fetal adrenal cortex. Therefore, NCI-H295 cells will be a useful cellular model for investigating the involvement of DAX-1 in the regulation of steroidogenesis.
Biochem Mol Med 1995 Oct
PMID:Expression of DAX-1, the gene responsible for X-linked adrenal hypoplasia congenita and hypogonadotropic hypogonadism, in the hypothalamic-pituitary-adrenal/gonadal axis. 859 42

Trophoblast giant cell differentiation is accompanied by transcriptional activation of the cytochrome P-450 side-chain cleavage (P450scc) gene. The Rcho-1 trophoblast cell line has the capacity to differentiate along the trophoblast giant cell lineage and has been used to study trophoblast-specific P450scc gene expression. In this report, P450scc gene promoter activities in trophoblast-specific P450scc gene expression. In this report, P450scc gene promoter activities in trophoblast cells have been mapped and the involvement of known modulators of steroid hydroxylase gene expression, the cyclic AMP/protein kinase A pathway and steroidogenic factor-1 (SF-1), evaluated. Comparisons were made with Y-1 adrenal and R2C Leydig cells. The cumulative results from transient and stable transfection experiments implicate the region between -428 and -511 bp of 5'-flanking DNA in the developmental activation of the P450scc promoter during trophoblast giant cell differentiation. Differences in basal activities of the P450scc promoter constructs were also observed in Y-1 adrenal and R2C Leydig cells; however, the magnitude of the differences was modest. Activators of the protein kinase A pathway stimulated P450scc promoter activity in Y-1 cells, whereas similar treatment of Rcho-1 trophoblast cells did not stimulate but actually inhibited P450scc promoter activity. The inhibitory activity was localized between -639 and -894 bp of the P450scc promoter. SF-1 mRNA and protein were detected in adrenal and gonadal cells but not in rat placenta or Rcho-1 trophoblast cells by Northern and Western blotting, respectively. Thus, P450scc gene activation during trophoblast cell differentiation involves an 83-bp region of its 5'-flanking DNA between -428 and -511 but does not appear to involve cyclic AMP-activated pathways or SF-1. In conclusion, the mechanism of P450scc gene activation during trophoblast cell differentiation appears different from the regulation of P450scc gene activation in other steroidogenic tissues.
Mol Cell Endocrinol 1995 Sep 22
PMID:Analysis of cytochrome P-450 side-chain cleavage gene promoter activation during trophoblast cell differentiation. 867 26

The rat steroid cytochrome P450 17 alpha-hydroxylase/c17-20 lyase (rP450c17) gene is transcriptionally regulated in steroidogenic tissues. Previous studies showed that one DNA element located between -75 and -50 base pairs (bp) upstream from the transcriptional initiation site mediated both the basal and cAMP-regulated transcription of rP450c17. Using a series of mutant oligonucleotides in gel mobility shift assays and in functional assays, it is now shown that a core sequence of 12 bp, located at -58/-69 bp, is essential for nuclear protein binding and transcriptional activation. Mutant oligonucleotides cloned into a luciferase reporter gene construct containing a heterologous thymidine kinase promoter, transfected into mouse Leydig MA-10 and adrenocortical Y-1 cells, gave results consistent with those of gel shift assays. Mutants that abolished binding of the nuclear protein to DNA abolished the basal transcription of the gene as well as the responsiveness to cAMP, whereas those mutants that did not abolish binding of the nuclear protein to DNA still showed strong basal transcription as well as responsiveness to cAMP. Comparison of the binding sequence with the consensus binding site for the orphan nuclear receptor steroidogenic factor-1 (SF-1) showed that eight of nine bases were identical. However, the sequence from rP450c17 includes an additional three bases at the 5'-end, not previously demonstrated to be important for SF-1 binding. Recombinant rat SF-1 protein expressed in Escherichia coli binds to this sequence, and antibodies raised against rat SF-1 abolish binding of both recombinant SF-1 and the nuclear protein from Y-1 and MA-10 cells. These observations demonstrate that this region of the rP450c17 gene is responsible for both the basal transcription and cAMP inducibility and is bound by the orphan nuclear receptor SF-1. It is further shown that SF-1 can be phosphorylated in vitro by protein kinase A. This phosphorylation occurs at serine and threonine residues and results in decreased binding to the rP450c17 -58/-69 element. Since SF-1 mediates cAMP-induced transcriptional regulation of the rat P450c17 gene, phosphorylation of SF-1 via protein kinase A is likely to play a regulatory role in transcriptional activation.
Mol Endocrinol 1996 Feb
PMID:The orphan nuclear receptor steroidogenic factor-1 regulates the cyclic adenosine 3',5'-monophosphate-mediated transcriptional activation of rat cytochrome P450c17 (17 alpha-hydroxylase/c17-20 lyase). 882 55

The orphan nuclear receptor steroidogenic factor-1 (SF-1) regulates the expression of several genes involved in the reproductive function and development of the adrenal, the gonads, and the pituitary gonadotropes. It also confers the gonadotrope-specific expression of the glycoprotein hormone a subunit gene by the binding to a gonadotrope-specific element (GSE). In this study, we have shown that SF-1 transactivates the salmon gonadotropin II beta subunit (sGTHII beta) gene expression. SF-1 alone offered a slight but significant enhancement on sGTHII beta promoter activity (7.2 +/- 0.6 fold). However, it stimulated sGTHII beta gene expression dramatically (127 +/- 37 fold) when combined with the estrogen receptor (ER). This synergistic interaction was specific for sGTHII beta promoter as well as for both SF-1 and ER and was estradiol-dose dependent. 5'-Deletion studies of the sGTHII beta promoter identified two putative SF-1 binding sites (GSE) and one previously identified proximal estrogen-responsive element (pERE) at -274 bp involved in this activation. The two GSE sequences located at -354 bp (sGSE(3) and -162 bp (sGSE(2) upstream of the transcription site, although imperfect as compared with the consensus GSE, bound specifically to the in vitro-translated mouse SF-1 protein. 5'-Deletion studies, competition experiments, and site-directed mutagenesis showed that binding to pERE and GSE(2) were necessary for the SF-1/ER synergistic effect. These studies suggest that the synergistic interaction of SF-1 and ER, possibly through cooperative binding or protein-protein interaction, is essential in conferring a cell type-specific expression of the GTHII beta subunit gene.
Mol Endocrinol 1996 Mar
PMID:Steroidogenic factor 1 and estradiol receptor act in synergism to regulate the expression of the salmon gonadotropin II beta subunit gene. 883 51


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