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

The hepatic transcription of the angiotensinogen gene is regulated by both glucocorticoids and cytokines generated as products of the acute phase reaction. We have identified a multimodular enhancer in the 5'-flanking region of the rat angiotensinogen gene that mediates these responses and consists of an acute phase response element (APRE) flanked on both sides by adjacent glucocorticoid response element consensus motifs (GREs). Induction of transcription by the cytokine interleukin-1 (IL-1) is glucocorticoid dependent and mediated through the APRE. The APRE binds in a mutually exclusive manner a cytokine/phorbol ester-inducible protein (BPi), indistinguishable from nuclear factor kB, and a family of constitutive liver proteins (BPcs) related to the heat-stable transcription factor C/EBP. Using mutated 5'-flanking sequences of the angiotensinogen gene fused to a firefly luciferase reporter gene transfected into hepatoblastoma (HepG2) cells, we have mapped enhanson sequences required for the transcriptional response to glucocorticoids. Two functionally distinct GREs are identified by deletion and site-directed mutagenesis, both of which mediate glucocorticoid-stimulated transcription in vivo. Glucocorticoid-induced transcription mediated by the angiotensinogen gene enhancer is, furthermore, dependent on the occupancy of the APRE by either the BPi or a member of the BPc family because a mutant APRE that binds neither BPi nor BPc exhibits an attenuated glucocorticoid responsiveness. Mutant APREs that permit exclusive binding of either BPi or BPc synergistically transmit the glucocorticoid response mediated by one or the other of the adjacent GREs. Thus, the induction of angiotensinogen gene transcription involves interaction between the glucocorticoid receptor and either one of the APRE-binding proteins: either the cytokine-inducible NFkB or the constitutive family of C/EBP-like proteins, bound to adjacent enhansons in a mutually synergistic enhancer complex.
Mol Endocrinol 1990 Dec
PMID:Synergistic enhansons located within an acute phase responsive enhancer modulate glucocorticoid induction of angiotensinogen gene transcription. 170 27

The gene encoding mZP3, the mouse sperm receptor, is expressed exclusively in growing oocytes during oogenesis. To investigate the molecular basis of oocyte-specific mZP3 gene expression, we generated several lines of mice harboring a transgene that contains 470 bp of mZP3 gene 5'-flanking sequence (nucleotides -470 to +10) fused to the firefly luciferase gene coding region. Three of four expressing transgenic lines exhibited luciferase activity only in growing oocytes, suggesting that the 470-bp fragment is sufficient to direct Iocyte-specific expression of the luciferase gene. Results of DNase I footprinting and gel mobility shift assays suggested the presence of an ovary-specific protein that binds to a small region (nucleotides-99 to -86) within the 470-bp fragment of the mZP3 promoter, with 5'-G(G/A)T(G/A)A-3' representing the minimal sequence required for binding. Southwestern (DNA-protein) gel blots revealed the presence of an oocyte-specific, approximately 60,000-Mr protein, called OSP-1, that binds to the minimal sequence. Changes in levels of OSP-1 during oogenesis and early cleavage are consistent with the pattern of mZP3 gene expression during these developmental stages in mice. Therefore, OSP-1 may be a mammalian oocyte-specific transcription factor involved in regulating oocyte-specific mZP3 gene expression.
Mol Cell Biol 1992 Jan
PMID:A mouse oocyte-specific protein that binds to a region of mZP3 promoter responsible for oocyte-specific mZP3 gene expression. 172 94

We have investigated whether reporter genes influence cytoplasmic regulation of gene expression in tobacco and Chinese hamster ovary (CHO) cells. Two genes, uidA encoding beta-glucuronidase (GUS) from Escherichia coli and Luc, encoding firefly luciferase (LUC), were used to analyze the ability of a cap, polyadenylated tail, and the 5'- and 3'-untranslated regions (UTR) from tobacco mosaic virus (TMV) to regulate expression. The regulation associated with the 5' cap structure and the TMV 5'-UTR, both of which enhance translational efficiency, was reporter gene-independent. The poly(A) tail and the TMV 3'-UTR, which is functionally equivalent to a poly(A) tail, increase translational efficiency as well as mRNA stability. The regulation associated with these 3' ends was highly reporter gene-dependent; their effect on GUS expression was almost an order of magnitude greater than that on LUC expression. In tobacco, the tenfold reporter gene effect on poly(A) tail or TMV 3'-UTR function could not be explained by a differential impact on mRNA stability; GUS and LUC mRNA half-life increased only twofold when either the poly(A) tail or TMV 3'-UTR was present. In CHO cells, however, GUS mRNA was stabilized to a greater extent by a poly(A) tail or the TMV 3'-UTR than was LUC mRNA.
Mol Gen Genet 1991 Aug
PMID:Post-transcriptional regulation in higher eukaryotes: the role of the reporter gene in controlling expression. 188 10

The inclusion of the alcohol dehydrogenase 1-S(Adh 1-S) intron 1 in the transcription unit of maize gene constructs has been shown to increase gene expression in cultured maize cells. We have extended these studies with Adh1-S intron 1 using the firefly luciferase, Escherichia coli beta-glucuronidase and chloramphenicol acetyltransferase reporter genes adjoined to different plant promoters and find enhancement of transient gene expression in all cases but one. We also show that the enhancement phenomenon can be mediated by the third intron of the maize actin gene. In all cases tested, the inclusion of an intron results in increased levels of steady-state RNA. The degree of enhancement depends on the exon sequences flanking the intron; flanking exons also influence the efficiency of intron splicing. Unexpectedly, unspliced RNAs accumulate during the transient assay.
Mol Gen Genet 1991 Jan
PMID:Intron enhancement of gene expression and the splicing efficiency of introns in maize cells. 200 94

Expression of the firefly luciferase gene in transgenic plants produces light emission patterns when the plants are supplied with luciferin. We explored whether in in vivo pattern of light emission truly reveals the pattern of luciferase gene expression or whether it reflects other parameters such as the availability of the substrate, luciferin, or the tissue-specific distribution of organelles in which luciferase was localized. The tissue-specific distribution of luciferase activity and the in vivo pattern of light were examined when the luciferase gene was driven by different promoters and when luciferase was was redirected from the peroxisome, where it is normally targeted, to the chloroplast compartment. It was found that the distribution of luciferase activity closely correlated with the tissue-specific pattern of luciferase mRNA. However, the in vivo light pattern appeared to reflect not only tissue-specific distribution of luciferase activity, but also the pattern of luciferin uptake.
Plant Mol Biol 1990 Jun
PMID:The in vivo pattern of firefly luciferase expression in transgenic plants. 210 77

Proliferation-competent and differentiation-competent adult rat hepatocytes in primary culture were investigated for their ability to express reporter genes (firefly luciferase, bacterial chloramphenicol acetyltransferase, and bacterial beta-galactosidase) driven by tumor virus or eucaryotic promoters that vary in transcriptional efficiency and tissue specificity. Supercoiled plasmid DNA molecules were introduced into the cells by the calcium phosphate coprecipitation protocol of C. Chen and H. Okayama (Mol. Cell. Biol. 7:2745-2752, 1987). Reporter gene expression was virtually restricted to hepatocytes and was efficient (2 to 20% of the cells). The patterns and absolute levels of reporter gene expression depended on assay conditions employed (plasmid concentration [optimal at 2.4 micrograms of DNA per ml] and duration of exposure [optimal between 5 and 10 h]), culture growth cycle stages (lag, log, or stationary phase), properties and tissue specificity of the promoter(s) tested, and composition (and timing of fluid change) of the culture medium with or without the hepatocyte mitogen human transforming growth factor-alpha. Initial observations suggest that during hepatocellular growth transitions, human transforming growth factor-alpha differentially regulates exogenously introduced promoters associated with hepatocyte-specific function and proliferation. These findings provide a simple, fast, and powerful approach to analyzing the molecular and cellular biology of hepatocyte growth control.
Mol Cell Biol 1990 Feb
PMID:DNA-mediated gene transfer into adult rat hepatocytes in primary culture. 210 58

We have cloned the promoter for the human third component of complement (C3) gene and have identified sequences involved in its regulation during the acute-phase response. A construct linking 199 bp of the C3 promoter to the firefly luciferase gene was found to be very responsive to interleukin-1 (IL-1) and modestly responsive to interleukin-6 (IL-6) by transfection analysis in the human hepatoma line Hep3B2. Simultaneous treatment with the two cytokines showed a strong synergy between the actions of the two molecules. A 58-bp fragment (-127 to -70 bp) was shown by 5' and 3' deletional mutagenesis to contain cis-acting elements that mediated both the IL-1 response and the IL-1-plus-IL-6 synergistic response of this promoter. When coupled to a heterologous promoter, this fragment enabled the synergistic induction by IL-1 plus IL-6. Sequences homologous to the palindrome ACATTGCACAATCT, which mediates the induction of the IL-6 gene by IL-1 (S. Akira, H. Isshiki, T. Sugita, O. Tanabe, S. Kinoshita, Y. Nishio, T. Nakajima, T. Hirano, and T. Kishimoto, EMBO J. 9:1897-1906, 1990), and the core sequence of the IL-6-responsive element of the rat alpha 2-macroglobulin gene (CTGGGA; M. Hattori, L. J. Abraham, W. Northemann, and G. H. Fey, Proc. Natl. Acad. Sci. USA 87:2364-2368, 1990) are contained within this fragment in immediate juxtaposition and partially overlapping. Site-directed mutagenesis within this homology region drastically reduced the inducibility of the C3 promoter by either cytokine. DNase I footprinting analysis defined a binding site for the transcription factor CCAAT/enhancer-binding protein (C/EBP), which included the IL-1-responsive element-like sequence. No differences were seen between the footprints generated by using extracts from unstimulated and IL-1-stimulated Hep3B2 cells. However, gel retardation analyses revealed two IL-1-specific bands. The data suggest that the induction by IL-1 is mediated by a factor belonging to the family of C/EBP-related proteins.
Mol Cell Biol 1990 Dec
PMID:A 58-base-pair region of the human C3 gene confers synergistic inducibility by interleukin-1 and interleukin-6. 224 55

Angiotensinogen is the glycoprotein precursor of angiotensin II, an octapeptide hormone important for the regulation of blood pressure and volume homeostasis. The gene encoding angiotensinogen is expressed in liver and several other tissues, providing a model gene for understanding the role of cis-acting DNA control elements and trans-acting factors in tissue-type specific gene expression. To identify DNA control elements in the rat angiotensinogen gene we prepared an array of fusion genes consisting of either 5' or 3'-deleted sequences of the 5'-flanking region of the gene linked to a firefly luciferase reporter gene and analyzed the relative cellular specificity of expression of these genes after their introduction into hepato-carcinoma cells (Hep G2) that do express and placental cells (JEG-3) that do not express the endogenous angiotensinogen gene. Six transcriptionally active elements were found within 688 base pairs of 5'-flanking DNA. The interactions of DNA binding proteins with these elements was demonstrated by their specific protection to digestion with DNase I in the presence of liver cell extracts. The orientation and spatial requirements for transcription of two of the elements were analyzed further by the construction and expression of synthetic oligonucleotide cassettes incorporating the sequences of these elements when linked to a homologous (angiotensinogen) or a heterologous Simian virus 40 promoter and enhancer. One element located between 60 and 108 base pairs from the start of gene transcription functioned either as a silencer or an enhancer of transcription (SOAP box element), depending upon the distance from the angiotensinogen and viral gene promoters. Moreover, the SOAP box element demonstrated enhancer activity in JEG-3 cells when linked to the Simian virus 40 early promoter. An oligonucleotide mutation of the SOAP box element interfered with protein binding in a gel mobility shift assay and this mutant was transcriptionally inactive in both homologous and heterologous promoters. These observations indicate that expression of the angiotensinogen gene in liver cells is coordinately regulated by multiple cis-acting elements that interact with DNA binding proteins.
Mol Endocrinol 1989 Jun
PMID:Multiple cis-acting DNA regulatory elements mediate hepatic angiotensinogen gene expression. 254

The nucleotide sequence of the luciferase gene from the firefly Photinus pyralis was determined from the analysis of cDNA and genomic clones. The gene contains six introns, all less than 60 bases in length. The 5' end of the luciferase mRNA was determined by both S1 nuclease analysis and primer extension. Although the luciferase cDNA clone lacked the six N-terminal codons of the open reading frame, we were able to reconstruct the equivalent of a full-length cDNA using the genomic clone as a source of the missing 5' sequence. The full-length, intronless luciferase gene was inserted into mammalian expression vectors and introduced into monkey (CV-1) cells in which enzymatically active firefly luciferase was transiently expressed. In addition, cell lines stably expressing firefly luciferase were isolated. Deleting a portion of the 5'-untranslated region of the luciferase gene removed an upstream initiation (AUG) codon and resulted in a twofold increase in the level of luciferase expression. The ability of the full-length luciferase gene to activate cryptic or enhancerless promoters was also greatly reduced or eliminated by this 5' deletion. Assaying the expression of luciferase provides a rapid and inexpensive method for monitoring promoter activity. Depending on the instrumentation employed to detect luciferase activity, we estimate this assay to be from 30- to 1,000-fold more sensitive than assaying chloramphenicol acetyltransferase expression.
Mol Cell Biol 1987 Feb
PMID:Firefly luciferase gene: structure and expression in mammalian cells. 382 27

Previous reports have indicated that, in vivo, the serotonin-2 (5-HT2) receptor is responsive to exogenously administered glucocorticoids. The ability of the glucocorticoid receptor (GR) to influence transcription of the rat 5-HT2 receptor gene was tested in two different experimental paradigms. In both sets of experiments transcription of the 5-HT2 gene was monitored with a promoter-reporter plasmid in which the promoter for the 5-HT2 gene was driving the expression of the firefly luciferase gene. In the first, the 5-HT2 promoter-reporter plasmid was transfected directly into RS1 cells followed by dexamethasone treatment. In the second set of experiments, the cDNA encoding the GR carried on a separate expression vector was cotransfected into CCL-39 or Neuro-2a cells along with the 5-HT2 promoter-reporter plasmid. These cells were then exposed to dexamethasone. In the RS-1 and CCL-39 transfection experiments, the dexamethasone treatment caused an inhibition of transcription of the 5-HT2 promoter, whereas in the Neuro-2a cells, the dexamethasone treatment stimulated transcription from the 5-HT2 promoter. These responses were dependent on the presence of the GR. The effect of the activated GR would seem to be indirect as sequence analysis of the 4.2 kb preceding the site of transcription initiation revealed only an 11/15 nt match to a putative glucocorticoid response element (GRE), and deletion of this sequence did not alter the response to dexamethasone. Sequence analysis revealed a variety of potential response elements for other known transcription factors, including four potential AP-1 response elements.(ABSTRACT TRUNCATED AT 250 WORDS)
Brain Res Mol Brain Res 1995 Jul
PMID:Transcriptional control of the rat serotonin-2 receptor gene. 747 30


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