scholarly journals Ca2+ administration stimulates the binding of AP-1 factor to the 5′-flanking region of the rat gene for the Ca2+-binding protein regucalcin

1998 ◽  
Vol 329 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Tomiyasu MURATA ◽  
Masayoshi YAMAGUCHI

mRNA of the Ca2+-binding protein, regucalcin, is mainly expressed in the liver and only to a small extent in the kidney, and the expression of hepatic regucalcin mRNA is markedly stimulated by Ca2+ administration [Shimokawa and Yamaguchi (1992) FEBS Lett. 305, 151-154]. The existence of nuclear factors that bind to the 5ʹ-flanking region of the rat regucalcin gene was investigated. When nuclear proteins obtained from various rat tissues were used in gel mobility-shift assays, tissue-specific formation of a protein-DNA complex was found in the liver and kidney. An additional novel protein-DNA complex was formed when liver nuclear extracts obtained from Ca2+-administered rats (10 mg of Ca2+/100 g body weight) were used. Competition gel mobility-shift experiments using consensus and mutant oligonucleotides for AP-1 factor showed that the additional novel complex was formed from binding of the AP-1 factor to the regucalcin gene. Ca2+-induced binding of the AP-1 factor to the regucalcin gene was completely inhibited by simultaneous administration of trifluoperazine, an antagonist of calmodulin, suggesting that the activation of nuclear AP-1 protein is partly mediated through a Ca2+/calmodulin-dependent pathway. Moreover, the 5ʹ-flanking region of the rat regucalcin gene ligated to a luciferase reporter gene possessed the promoter activity in H4-II-E hepatoma cells. This promoter activity was enhanced by treatment with Bay K 8644, a Ca2+-channel agonist. The present study demonstrates that the Ca2+-response sequences are located within the 5ʹ-flanking region of the rat regucalcin gene.

2002 ◽  
Vol 283 (4) ◽  
pp. C1065-C1072 ◽  
Author(s):  
Ashish K. Gupta ◽  
Bruce C. Kone

Transcriptional activation of the inducible nitric oxide synthase (iNOS) gene requires multiple interactions of cis elements and trans-acting factors. Previous in vivo footprinting studies (Goldring CE, Reveneau S, Algarte M, and Jeannin JF. Nucleic Acids Res 24: 1682–1687, 1996) of the murine iNOS gene demonstrated lipopolysaccharide-inducible protection of guanines in the region −904/−883, which includes an E-box motif. In this report, by using site-directed mutagenesis of the −893/−888 E-box and correlating functional assays of the mutated iNOS promoter with upstream stimulatory factor (USF) DNA-binding activities, we demonstrate that the −893/−888 E-box motif is functionally required for iNOS regulation in murine mesangial cells and that USFs are in vivo components of the iNOS transcriptional response complex. Mutation of the E-box sequence augmented the iNOS response to interleukin-1β (IL-1β) in transiently transfected mesangial cells. Gel mobility shift assays demonstrated that USFs cannot bind to the −893/−888 E-box promoter region when the E-box is mutated. Cotransfection of USF-1 and USF-2 expression vectors with iNOS promoter-luciferase reporter constructs suppressed IL-1β-simulated iNOS promoter activity. Cotransfection of dominant-negative USF-2 mutants lacking the DNA binding domain or cis-element decoys containing concatamers of the −904/−883 region augmented IL-1β stimulation of iNOS promoter activity. Gel mobility shift assays showed that only USF-1 and USF-2 supershifted the USF protein-DNA complexes. These results demonstrated that USF binding to the E-box at −893/−888 serves to trans-repress basal expression and IL-1β induction of the iNOS promoter.


1997 ◽  
Vol 325 (1) ◽  
pp. 259-267 ◽  
Author(s):  
James R. GUM ◽  
James W. HICKS ◽  
Young S. KIM

The initiation point for MUC2 gene transcription is located within a 7000-base GC-rich region of the mucin gene cluster found on chromosome 11p15.5. The promoter activity of the 5′-flanking region of the MUC2 gene was examined following its cloning into the luciferase-producing pGL2-Basic reporter vector. A short segment comprising bases -91 to -73 relative to the start of transcription was found to be important for basal promoter activity in all cell lines tested. Electrophoretic mobility shift assays demonstrated nuclear protein binding to this region, which contains the consensus CACCC motif (5′-GCCACACCC). This element has been shown to be functionally important in several promoters that are active in diverse cell types. Competition experiments using an Sp1 oligonucleotide and antibody supershift experiments indicated that both Sp1 and other Sp1 family members bind to this element. Inclusion of the region between bases -228 and -171 in pGL2-Basic constructs increased normalized luciferase reporter activity by almost 3-fold in C1a cells, which produce relatively high levels of MUC2 mRNA. Significantly lower levels of normalized luciferase activity resulted when the same construct was transfected into cultured cell lines that express low or undetectable levels of MUC2, suggesting a possible role for this region in conferring cell-type specificity of expression. We also demonstrate, using actinomycin D, that the MUC2 mRNA is long-lived, at least in cultured cells. Moreover, no evidence was found that the MUC2 mRNA turned over more rapidly in LS174T cells, which produce relatively low levels of MUC2 mRNA, as compared with C1a cells, which produce high levels of mRNA. Thus a long mRNA half-life appears to be an important mechanism involved in achieving elevated levels of MUC2 mRNA.


2004 ◽  
Vol 287 (1) ◽  
pp. L52-L59 ◽  
Author(s):  
Wei Ding ◽  
Saverio Bellusci ◽  
Wei Shi ◽  
David Warburton

The expression of Sprouty4 ( Spry4), an intracellular FGF receptor antagonist, shows a temporally and spatially restricted pattern in embryonic lung and is induced by ERK signaling. To clarify the molecular mechanisms regulating Spry4 transcription, the genomic structure of the human Sprouty4 ( hSpry4) gene was first determined by using the GenomeWalker kit. The hSpry4 gene spans > 14 kb and is organized in three exons and two introns. Multiple transcription start sites were subsequently mapped by 5′-rapid amplification of cDNA ends. Analysis of up to 4 kb of sequence in the 5′-flanking region of the gene showed the presence of multiple potential transcription factor binding sites but no TATA or CAAT boxes. Transient transfection using luciferase reporter gene constructs with progressive deletions of the hSpry4 5′-flanking region revealed that the core promoter activity is located within the proximal 0.4-kb region, whereas the minimal ERK-inducible promoter activity is between −69 and −31. Homology analysis further showed that the core promoter region of the hSpry4 gene exhibits significant similarity to the 5′-flanking region of the mouse gene.


Endocrinology ◽  
2000 ◽  
Vol 141 (10) ◽  
pp. 3587-3594 ◽  
Author(s):  
Xiao-Li Wang ◽  
Mary Bassett ◽  
Yin Zhang ◽  
Su Yin ◽  
Colin Clyne ◽  
...  

Abstract Steroid 11β-hydroxylase is a mitochondrial enzyme that catalyzes the conversion of deoxycortisol to cortisol. The gene encoding human 11β-hydroxylase (hCYP11B1) is expressed in the adrenal cortex under the control of circulating levels of ACTH. The current study was undertaken to define the cis-regulatory elements and transacting factors that regulate hCYP11B1 transcription. The hCYP11B1 5′-flanking DNA was studied using transient transfection of luciferase reporter constructs in NCI-H295R human adrenocortical cells. A cAMP analogue ((Bu)2cAMP) increased expression of a construct containing −1102 bp of hCYP11B1 5′-flanking DNA (pB1–1102). An element at position −71/−64 (TGACGTGA, previously termed Ad1) resembling a consensus cAMP response element (CRE) was required for maximal induction by cAMP. The Ad1 element bound several transcriptional factors in electrophoretic mobility shift assays, including CRE-binding protein, activating transcription factor-1 (ATF-1), and ATF-2, but only the ATF-2 complex migrated similarly to a complex seen using H295R nuclear extract. In addition, Western analysis of H295R and adrenal lysates demonstrated expression of high levels of ATF-2 and ATF-1. CRE-binding protein levels varied among the strains of H295R cells tested. Transcription of CYP11B1 also appeared to be regulated by steroidogenic factor-1 (SF-1). Luciferase reporter gene activity was increased after cotransfection with expression vectors containing SF-1. An element in hCYP11B1 at positions −242/−234 (CCAAGGCTC), previously termed Ad4, was required for maximal induction by SF-1 and was found to bind SF-1 in electrophoretic mobility shift assays. The key role for SF-1 in hCYP11B1 transcription is in contrast to its lack of an effect on expression of the hCYP11B2 (aldosterone synthase) isozyme. The differential effects of SF-1 on transcription of hCYP11B1 and hCYP11B2 may be one of the mechanisms controlling differential expression of these isozymes within the zonae fasciculata and glomerulosa of the human adrenal cortex.


2002 ◽  
Vol 282 (3) ◽  
pp. C518-C527 ◽  
Author(s):  
Julia M. Giger ◽  
Fadia Haddad ◽  
Anqi X. Qin ◽  
Kenneth M. Baldwin

Functional overload (OL) of the rat plantaris muscle by the removal of synergistic muscles induces a shift in the myosin heavy chain (MHC) isoform expression profile from the fast isoforms toward the slow type I, or, β-MHC isoform. Different length rat β-MHC promoters were linked to a firefly luciferase reporter gene and injected in control and OL plantaris muscles. Reporter activities of −3,500, −914, −408, and −215 bp promoters increased in response to 1 wk of OL. The smallest −171 bp promoter was not responsive to OL. Mutation analyses of putative regulatory elements within the −171 and −408 bp region were performed. The −408 bp promoters containing mutations of the βe1, distal muscle CAT (MCAT; βe2), CACC, or A/T-rich (GATA), were still responsive to OL. Only the proximal MCAT (βe3) mutation abolished the OL response. Gel mobility shift assays revealed a significantly higher level of complex formation of the βe3 probe with nuclear protein from OL plantaris compared with control plantaris. These results suggest that the βe3 site functions as a putative OL-responsive element in the rat β-MHC gene promoter.


2002 ◽  
Vol 283 (1) ◽  
pp. E50-E57 ◽  
Author(s):  
Quan He ◽  
Mariela Mendez ◽  
Margot C. LaPointe

Brain natriuretic peptide (BNP) is a cardiac hormone constitutively expressed in the adult heart. We previously showed that the human BNP (hBNP) proximal promoter region from −127 to −40 confers myocyte-specific expression. The proximal hBNP promoter contains several putative cis elements. Here we tested whether the proximal GATA element plays a role in basal and inducible regulation of the hBNP promoter. The hBNP promoter was coupled to a luciferase reporter gene (1818hBNPLuc) and transferred into neonatal ventricular myocytes (NVM), and luciferase activity was measured as an index of hBNP promoter activity. Mutation of the putative GATA element at −85 of the hBNP promoter [1818(mGATA)hBNPLuc] reduced activity by 97%. To study transactivation of the hBNP promoter, we co-transfected 1818hBNPLuc with the GATA-4 expression vector. GATA-4 activated 1818hBNPLuc, and this effect was eliminated by mutation of the proximal GATA element. Electrophoretic mobility shift assay showed that an oligonucleotide containing the hBNP GATA motif bound to cardiomyocyte nuclear protein, which was competed for by a consensus GATA oligonucleotide but not a mutated hBNP GATA element. The β-adrenergic agonist isoproterenol and its second messenger cAMP stimulated hBNP promoter activity and binding of nuclear protein to the proximal GATA element. Thus the GATA element in the proximal hBNP promoter is involved in both basal and inducible transcriptional regulation in cardiac myocytes.


2014 ◽  
Vol 104 (6) ◽  
pp. 801-808 ◽  
Author(s):  
F. Li ◽  
X.N. Liu ◽  
Y. Zhu ◽  
J. Ma ◽  
N. Liu ◽  
...  

AbstractEukaryote transcription is controlled by regulatory DNA sequences and transcription factors, so transcriptional control of gene plays a pivotal role in gene expression. In this study, we identified the region of the CYP6B6 gene promoter of Helicoverpa armigera which responds to the plant secondary toxicant 2-tridecanone. Transient transfection assay results from five of stepwise deletion fragments linked to the luciferase reporter gene revealed that the promoter activity of each CYP6B6 fragment was significantly higher than that of their basal activity after the Sf9 cells were treated with 2-tridecanone. Among all, the fragment spanning −373 to +405 bp of the CYP6B6 promoter showed an obviously 2-tridecanone inducibility (P<0.0001), which might have the 2-tridecanone responsive element based on promoter activity. Electrophoretic mobility shift assays revealed that the nuclear protein extracted from midgut of the 6th instar larva of H. armigera, reared on 10 mg 2-tridecanone per gram artificial diet for 48 h, could specifically bind to the active region from −373 to 21 bp of the CYP6B6 promoter. The combination feature also appeared when using a shorter fragment from −292 to −154 bp of the CYP6B6 promoter. Taken together, we found a 2-tridecanone core responsive region between −292 and −154 bp of the CYP6B6 promoter. This may lead us to a better understanding of transcriptional mechanism of P450 gene and provide very useful information for the pest control.


2002 ◽  
Vol 282 (3) ◽  
pp. G491-G500 ◽  
Author(s):  
Jaleh Malakooti ◽  
V. C. Memark ◽  
Pradeep K. Dudeja ◽  
Krishnamurthy Ramaswamy

Na+/H+ exchanger (NHE) isoforms NHE2 and NHE3, colocalized to the brush border membrane of the epithelial cells, exhibit differences in their pattern of tissue expression and regulation by various molecular signals. To investigate the mechanisms involved in regulation of NHE3 gene expression, the human NHE3 promoter region was cloned and characterized. Primer extension experiments located the transcription start site to a position 116 nucleotides upstream from the translation start codon. The 5′-flanking region lacked a CCAAT box but contained a TATA-like sequence. Nucleotide sequencing of the 5′-flanking region revealed the presence of a number of cis elements including Sp1, AP-2, MZF-1, CdxA, Cdx-2, steroid and nonsteroid hormone receptor half sites, and a phorbol 12-myristate 13-acetate-response element. Transient transfection experiments using C2/bbe cell line defined a maximal promoter activity in −95/+5 region. The regulatory response elements clustered within this region include a potential transcription factor IID (TF IID), a CACCC, two Sp1, and two AP-2 motifs. Deletion of a fragment containing the AP-2 and Sp1 motifs resulted in a drastic decrease in promoter activity. In gel mobility shift assays, an oligonucleotide spanning from −78 to −56 bp bound a recombinant AP-2, and the corresponding binding activity in nuclear extracts was supershifted with anti-AP2α antibody. Our studies suggest that the NHE3 expression is regulated by a combination of ciselements and their cognate transcription factors that include the AP-2 and Sp1 family members.


2018 ◽  
Vol 8 (4) ◽  
pp. 42 ◽  
Author(s):  
Kristin Bokelmann ◽  
Jürgen Brockmöller ◽  
Mladen Tzvetkov

The organic cation transporter 1 (OCT1, SLC22A1) is strongly expressed in the human liver and facilitates the hepatic uptake of drugs such as morphine, metformin, tropisetron, sumatriptan and fenoterol and of endogenous substances such as thiamine. OCT1 expression is inter-individually highly variable. Here, we analyzed SNPs in the OCT1 promoter concerning their potential contribution to the variability in OCT1 expression. Using electrophoretic mobility shift and luciferase reporter gene assays in HepG2, Hep3B, and Huh7 cell lines, we identified the SNPs −1795G>A (rs6935207) and −201C>G (rs58812592) as having effects on transcription factor binding and/or promoter activity. The A-allele of the −1795G>A SNP showed allele-specific binding of the transcription factor NF-Y leading to 2.5-fold increased enhancer activity of the artificial SV40 promoter. However, the −1795G>A SNP showed no significant effects on the native OCT1 promoter activity. Furthermore, the −1795G>A SNP was not associated with the pharmacokinetics of metformin, fenoterol, sumatriptan and proguanil in healthy individuals or tropisetron efficacy in patients undergoing chemotherapy. Allele-dependent differences in USF1/2 binding and nearly total loss in OCT1 promoter activity were detected for the G-allele of −201C>G, but the SNP is apparently very rare. In conclusion, common OCT1 promoter SNPs have only minor effects on OCT1 expression.


2000 ◽  
Vol 348 (3) ◽  
pp. 675-686 ◽  
Author(s):  
Isabelle VAN SEUNINGEN ◽  
Michaël PERRAIS ◽  
Pascal PIGNY ◽  
Nicole PORCHET ◽  
Jean-Pierre AUBERT

Control of gene expression in intestinal cells is poorly understood. Molecular mechanisms that regulate transcription of cellular genes are the foundation for understanding developmental and differentiation events. Mucin gene expression has been shown to be altered in many intestinal diseases and especially cancers of the gastrointestinal tract. Towards understanding the transcriptional regulation of a member of the 11p15.5 human mucin gene cluster, we have characterized 3.55 kb of the 5ʹ-flanking region of the human mucin gene MUC5B, including the promoter, the first two exons and the first intron. We report here the promoter activity of successively 5ʹ-truncated sections of 956 bases of this region by fusing it to the coding region of a luciferase reporter gene. The transcription start site was determined by primer-extension analysis. The region upstream of the transcription start site is characterized by the presence of a TATA box at bases -32/-26, DNA-binding elements for transcription factors c-Myc, N-Myc, Sp1 and nuclear factor ĸB as well as putative activator protein (AP)-1-, cAMP-response-element-binding protein (CREB)-, hepatocyte nuclear factor (HNF)-1-, HNF-3-, TGT3-, gut-enriched Krüppel factor (GKLF)-, thyroid transcription factor (TTF)-1- and glucocorticoid receptor element (GRE)-binding sites. Intron 1 of MUC5B was also characterized, it is 2511 nucleotides long and contains a DNA segment of 259 bp in which are clustered eight tandemly repeated GA boxes and a CACCC box that bind Sp1. AP-2α and GATA-1 nuclear factors were also shown to bind to their respective cognate elements in intron 1. In transfection studies the MUC5B promoter showed a cell-specific activity as it is very active in mucus-secreting LS174T cells, whereas it is inactive in Caco-2 enterocytes and HT-29 STD (standard) undifferentiated cells. Within the promoter, maximal transcription activity was found in a segment covering the first 223 bp upstream of the transcription start site. Finally, in co-transfection experiments a transactivating effect of Sp1 on to MUC5B promoter was seen in LS174T and Caco-2 cells.


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