Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.30.1 (S1 nuclease)
3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have determined the structure of the human glucocorticoid receptor (hGR) gene after the isolation and characterization of cosmid clones mapping to discrete regions of the cDNA. The gene contains a total of 10 exons and has a minimum size of 80 kilobases. Exon 1 consists solely of 5'-untranslated sequence, and exon 2 encodes the amino-terminal portion of the receptor. The two putative zinc fingers are separately encoded by two exons, and a total of five exons combine to form the cortisol-binding domain. By restriction mapping and sequence analysis of cosmids located on the 3'-end of the gene, we have established that the two receptor isoforms, hGR alpha and hGR beta, originate from the same gene by alternative splicing. Each hGR isoform is encoded by nine exons, of which the first eight are identical, whereas the ninth exons are heterologous. Multiple GC boxes and no obvious TATA or CAAT elements have been found in the 5'-flanking region. S1 nuclease analysis yielded one major band, and the transcription start site is localized to the *C residue within TAC*CCTC. Alignment of sequences around the splice junctions of hGR with those of other members of the steroid receptor superfamily revealed three different splice positions within the DNA-binding domain. This comparison also permitted the prediction of the positions of the splice sites and the sizes of the putative exons in the human mineralocorticoid receptor.
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PMID:The genomic structure of the human glucocorticoid receptor. 170 81

Anterior pituitary POMC transcription and peptide release are negatively regulated by glucocorticoids and stimulated by CRF. Although pretreatment of corticotrope cells with CRF markedly inhibits subsequent glucocorticoid effects, the mechanism of this action is unclear. We have thus used a mouse corticotrope tumor (AtT20) cell line, to examine the effects of CRF on glucocorticoid receptor (GR) messenger RNA levels and on GR capacity/nuclear translocation. GR mRNA levels were measured by solution hybridization/S1 nuclease protection, and both total cell binding and nuclear binding were determined with [3H]dexamethasone ([3H]DEX). CRF treatment of AtT20 cells led to a rapid time-dependent decrease in GR mRNA levels which preceded a dose- and time-dependent decrease in GR binding capacity. Scatchard analysis showed a single class of high affinity binding sites (GR) in both control and CRF-treated cultures, and a decrease in the total number of GR after CRF treatment. The relative proportion of nuclear vs. cytoplasmic localized [3H]DEX-bound GR did not differ between control and CRF-treated cultures, indicating that CRF does not interfere with GR nuclear translocation. To investigate whether CRF regulates GR expression through the adenylate cyclase system, as it does POMC, AtT20 cells were treated with either forskolin or 8-bromo-cAMP, and specific nuclear GR binding was determined. Both drugs mimic the CRF-induced decrease in GR binding, and in addition forskolin decreased GR mRNA levels; in contrast, forskolin had no effect on GH3 cell GR levels. These results suggest that CRF can decrease the cellular concentration of GR, and thus potentially the response to glucocorticoids, through the same mechanism by which it stimulates anterior pituitary POMC expression.
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PMID:Adrenocorticotropin-releasing factor down-regulates glucocorticoid receptor expression in mouse corticotrope tumor cells via an adenylate cyclase-dependent mechanism. 185 64

To study the regulation of the human glucocorticoid receptor (hGR), we characterized the promoter region by primer extension, S1 nuclease mapping and by DNA sequencing. We found that the promoter is extremely G + C rich (72% GC content) and contains a "TAATA" and a "CAT" box, eight "GGGCGG", three "CCGCCC" and two "CACCC" motifs and a motif similar to the glucocorticoid responsive element (GRE) which included two interchanged nucleotides "TCTTGT". In contrast to other steroid receptor genes, exon I or GHGR contains the major part of the 5' non-coding sequences of hGR mRNA while exon II contains coding sequences for the first 394 amino acid residues of the A/B region of hGR. The major transcriptional start site was found to be 134 bp upstream of the ATG initiation codon. Transfection of HeLa cells with plasmids containing various deletions of GHGR promoter fused to a promoterless CAT vector suggested the region between -470 and -1030, at the 5' end of the mRNA start site, to contain sequences required for down regulation by hormone.
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PMID:Human glucocorticoid receptor gene promotor-homologous down regulation. 195 37

Nucleolin, a eukaryotic nucleolar phosphoprotein, is involved in the synthesis and maturation of ribosomes. To characterize the genomic organization and regulatory sequences of this gene, two overlapping lambda clones containing the human nucleolin gene plus flanking regions were isolated from a genomic library using human nucleolin cDNA. Southern blots of genomic DNA from human, several mammals, chicken, and yeast revealed that the nucleolin gene is well conserved across these species. The gene consists of 14 exons with 13 intervening sequences and spans approximately 11 kilobases of DNA. Analysis of the splice junctions indicated that the amino-terminal domain and the four RNA binding domains plus the nuclear localization signal are split into adjacent exons. Sequences from the 5'-flanking and the first intron contain a high content of GC residues which is consistent with nucleolin being a "housekeeping" gene. Promoter elements include an atypical TATA box (GTTA), one CCAAT box much further from the initiation site, three reverse compliments of CCAAT (ATTGG), and two pyrimidine-rich nucleotide stretches. In addition, this region and the first intron contain numerous potential Sp1, GCF, CRE-fos, GCN, AP-1, AP-2, UCE, and sequences similar to the glucocorticoid receptor binding site. The transcription start site was determined by primer extension and S1 nuclease mapping of RNA from human liver. One Kpn and three Alu repeats were found within two of the middle introns. The 3'-untranslated portion of the gene contains five homology blocks in a 100-base pair region that are highly conserved among human, mouse, and hamster genomes. Finally, we have determined that the human nucleolin gene is located on chromosome 2q12-qter and is present at one copy per haploid genome. A restriction fragment length polymorphism with EcoRI has been detected in the gene.
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PMID:Genomic organization and chromosomal localization of the human nucleolin gene. 239 7

The cytosolic untransformed molybdate-stabilized glucocorticoid-receptor complex from rat liver was eluted as a heterogenous peak containing two components with Stokes radii (Rs) of 8.3 nm and 7.1 nm when analyzed by size-exclusion HPLC even in the absence of molybdate. In contrast, the highly purified glucocorticoid receptor yielded a sharp symmetrical peak of Rs = 7.1 nm. We demonstrate that the 7.1-nm component could not result from a proteolytic degradation of the 8.3-nm receptor form. The same receptor heterogeneity was observed in thymus cytosol which contains less proteases than liver. After labeling with [3H]dexamethasone 21-mesylate and SDS/PAGE the same 94-kDa receptor band was revealed in both the 8.3-nm and 7.1-nm forms. Immunoblotting experiments showed that both the 94-kDa hormone-binding subunit and the 90-kDa heat-shock protein were present in the two different receptor forms. The 8.3-nm receptor form was converted to the 7.1-nm receptor form after treatment by ribonuclease A in the presence of molybdate and this effect was dose-dependent, being completely prevented by placental ribonuclease inhibitor (RNasin). In contrast, in the presence of molybdate, the 7.1-nm receptor form was ribonuclease-insensitive. Treatment of cytosol with RNase A in the absence of molybdate, partially shifted the untransformed receptor towards the 5.2-nm transformed receptor form. This effect was abolished by placental ribonuclease inhibitor. RNase S protein, an enzymatically inactive proteolytic fragment of RNase A, or S1 nuclease, which is specific for single-stranded nucleic acids, were ineffective when used instead of RNase A. In contrast, cobra venom endonuclease, which preferentially attacks double-stranded regions of small RNAs, caused a complete conversion of the 7-8-nm untransformed receptor to the 5.2-nm transformed receptor form. These results were not observed in the presence of molybdate. Addition of RNasin prior to heating cytosol in the absence of molybdate did not prevent the receptor from dissociating to the 5.2-nm form, suggesting that an endogenous RNase is not involved in the transformation process. The 7.1-nm receptor form was shifted to a 9.2-nm complex when incubated with an excess of GR 49 antireceptor antibody, whereas the 8.3-nm receptor form did not bind to the antibody.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:RNA binding to the untransformed glucocorticoid receptor. Sensitivity to substrate-specific ribonucleases and characterization of a ribonucleic acid associated with the purified receptor. 246 3

We have determined the structure of the gene that encodes the alpha 2 isoform of the human Na,K-ATPase. The gene contains 23 exons and spans approximately 25 kilobases. The amino acid sequence of the human alpha 2 isoform deduced from the genomic sequence exhibits 99% identity to the rat alpha 2 isoform. One of the nine amino acid differences between the human and rat sequences occurs at an amino acid position which is known to be involved in species differences in sensitivity of the alpha 1 isoform to cardiac glycosides. Approximately 1500 base pairs of sequence flanking the 5' end of the alpha 2 gene have been determined. This region contains numerous potential AP-1, AP-2, and NF-1-binding sites, a potential Sp1 recognition site, and several sequences that are similar to the glucocorticoid receptor-binding site. The transcription start site was mapped by primer extension and S1 nuclease protection analyses of RNA from human brain, skeletal muscle, and heart. Multiple transcription initiation sites are clustered between residues -104 to -99 relative to the translation initiation codon. A potential TATA box is located 29 base pairs upstream of the first transcription initiation site. Immediately 5' to the apparent TATA box is a 35-base pair polypurine.polypyrimidine tract containing an imperfect mirror repeat which resembles sequences that form triple-stranded structures. Two intragenic DNA probes which detect restriction fragment length polymorphisms associated with the alpha 2 gene have been identified. These probes will be useful in genetic linkage analyses designed to define the possible role of the Na,K-ATPase in certain hereditary disorders.
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PMID:Characterization of the human Na,K-ATPase alpha 2 gene and identification of intragenic restriction fragment length polymorphisms. 247 73

Liver-type arginase (EC 3.5.3.1) catalyzes the last step of urea synthesis and is expressed specifically in the liver of ureotelic animals. Expression of liver arginase is developmentally and hormonally regulated in coordination with other urea cycle enzymes. The gene for the rat enzyme was cloned and the structure determined. This gene is 12 kilobases long and is split into eight exons. All of the splice donor and acceptor sites conform to the GT/AG rule. The transcription initiation site was determined by nuclease S1 mapping and primer extension. A "TATA box"-like sequence and a "CAAT box"-like sequence are present 27 and 60 bases upstream from the cap site, respectively. Upstream and downstream from the cap site, there are several sets of direct repeats and inverted repeats and several sequences resembling the transcription factor Sp1 binding sites, the enhancer core sequences, the glucocorticoid receptor binding sites, the 12-O-tetradecanoylphorbol-13-acetate responsive elements, and the putative elements for liver-specific expression of albumin genes. A 15-nucleotide sequence in the 5'-flanking region of the arginase gene is highly homologous with sequences in the 5'-flanking regions of the genes for rat ornithine carbamoyltransferase (EC 2.1.3.3) and for human argininosuccinate synthetase (EC 6.3.4.5), other two enzymes of the urea cycle.
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PMID:Structural organization of the gene for rat liver-type arginase. 289 37

We have cloned and sequenced the rat gene coding for the acute phase reactant protein alpha 1-acid glycoprotein in order to determine which sequences are necessary for its regulation by glucocorticoids and which sequences are responsible for the sensitivity of this regulation to protein synthesis inhibitors. The gene contains six exons, as determined from the alpha 1-acid glycoprotein cDNA sequence, and five introns. Primer extension and S1 nuclease experiments have shown that there are two transcriptional start sites 4 base pairs apart. After cotransfection into mouse L-cells, the gene retains its inducibility by glucocorticoids, indicating that the sequences required for induction are within or around the gene. The induction of alpha 1-acid glycoprotein levels in transfected L-cells is sensitive to protein synthesis inhibitors, implying that in addition to the glucocorticoid receptor another protein(s) is necessary for full induction.
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PMID:Rat alpha 1-acid glycoprotein. Gene sequence and regulation by glucocorticoids in transfected L-cells. 383 47

Tyrosine aminotransferase (TAT; L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) from rat liver is subject to glucocorticoid, cAMP, and developmental control. To study the underlying regulatory mechanisms, the TAT structural gene was isolated from a lambda bacteriophage rat DNA library. Heteroduplex analysis revealed that the 2.4-kilobase-long TAT mRNA is encoded by a gene that extends over 11 kilobases and is interrupted by 11 introns. To characterize the presumptive control region, the DNA sequence around the 5' end of the gene was determined and the start site of transcription was identified by nuclease S1 protection experiments. A short sequence homology in an equivalent position relative to the cap site was detected between TAT and tryptophan oxygenase, another glucocorticoid-controlled gene from rat liver. This sequence is related to the sequence 5' T-G-T-T-C-T 3' found in regions of the long terminal repeat of mouse mammary tumor virus, which has been shown to interact with the glucocorticoid receptor [Scheidereit, C., Geisse, J., Westphal, H. M. & Beato, M. (1983) Nature (London) 304, 749-752].
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PMID:Isolation and characterization of the rat tyrosine aminotransferase gene. 614 18

Steroid hormones complexed with their receptors play an essential role in the regulation of mouse mammary tumor virus (MMTV) transcription. However, the need for additional tissue-specific regulatory factors is suggested by the lack of virus expression in liver, in which glucocorticoid receptors are highly abundant, and by the tissue-specific transcription of reporter genes linked to an MMTV long terminal repeat in transgenic mice. In this study, we characterized two distal-region regulatory elements, DRa and DRc, which, together with the distal glucocorticoid receptor binding site (DRb), increased transcription from the MMTV promoter in permissive cells. This was demonstrated by transfection of these sequences (DRa, DRb, and DRc) in different combinations with the natural MMTV promoter in mouse fibroblasts and mammary epithelial cells, followed by quantitative S1 nuclease mapping of the transcripts. We further showed by DNase I footprinting, methylation interference, and gel retardation assays with various nuclear extracts from permissive or nonpermissive tissues and cell lines that the factors binding to the DRa site are distinct and tissue-specific whereas those binding to DRc are ubiquitous.
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PMID:Tissue-specific and ubiquitous factors binding next to the glucocorticoid receptor modulate transcription from the mouse mammary tumor virus promoter. 774 24


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