• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.140-140
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• 1998

The aim of this study was to find out the effect of hypoxic condition on the regulation of cyplal gene expression. pcyplal-Luc construct was cloned and transfected into Hepa I cells. When Hepa-I cells containing pcyplal-Luc were treated by DFO (desferrioxamine) which is iron-chelating agent, the stimulatory effect of luciferase by TCDD was decreased. This inhibitory effect of desferrioxamine on the luciferase activity was dose dependent and abolished by concomitant treatment with N$\^$G/-nitro-ι-arginine. And when cobalt chloride which is known as a hypoxia inducing chemical was administrated, the stimulatory effect of luciferase by TCDD was also decreased. This inhibitory effect of cobalt chloride on the luciferase activity was dose dependent and abolished by concomitant treatment with N$\^$G/-nitro-ι-arginine. These data showed that hypoxic condition down regulates cyplal gene expression and this might be through nitric oxide action.

• BMB Reports
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• v.40 no.4
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• pp.453-458
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• 2007

Bacterial luciferase is a heterodimeric enzyme, which catalyzes the light emission reaction, utilizing reduced FMN (FMNH2), a long chain aliphatic aldehyde and $O_2$, to produce green-blue light. This enzyme can be readily classed as slow or fast decay based on their rate of luminescence decay in a single turnover. Mutation of Glu175 in $\alpha$ subunit to Gly converted slow decay Xenorhabdus Luminescence luciferase to fast decay one. The following studies revealed that changing the luciferase flexibility and lake of Glu-flavin interactions are responsible for the unusual kinetic properties of mutant enzyme. Optical and thermodynamics studies have caused a decrease in free energy and anisotropy of mutant enzyme. Moreover, the role of Glu175 in transition state of folding pathway by use of stopped-flow fluorescence technique has been studied which suggesting that Glu175 is not involved in transition state of folding and appears as surface residue of the nucleus or as a member of one of a few alternative folding nuclei. These results suggest that mutation of Glu175 to Gly extended the structure of Xenorhabdus Luminescence luciferase, locally.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.811-817
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• 2013

The present study dealt with the isolation, identification and enzyme characterization of potential luminous bacteria from water, sediment, squid, and cuttle fish samples of the Karaikal coast, Bay of Bengal, India during the study period September 2007 - August 2008. Bioluminescent strains were screened in SWC agar and identified using biochemical tests. As Shewanella henadai was found to be the most common and abundant species with maximum light emission [69,702,240 photons per second (pps)], the optimum ranges of various physicochemical parameters that enhance the luciferase activity in Shewanella hanedai were worked out. The maximum luciferase activity was observed at the temperature of $25^{\circ}C$ (69,674,387 pps), pH of 8.0 (70,523,671 pps), salinity of 20 ppt (71,674,387 pps), incubation period of 16 h (69,895,714 pps), 4% peptone (70,895,152 pps) as nitrogen source, 0.9% glycerol (71,625,196 pps), and the ionic supplements of 0.3% $CaCO_3$ (73,991,591 pps), 0.3% $K_2HPO_4$ (73,919,915 pps), and 0.2% $MgSO_4$ (72,161,155 pps). Shewanella hanedai was cultured at optimum ranges for luciferase enzyme characterization. From the centrifuged supernatant, the proteins were precipitated with 60% ammonium sulfate, dialyzed, and purified using anion-exchange chromatography, and then luciferase was eluted with 500 mM phosphate of pH 7.0. The purified luciferase enzyme was subjected to SDS-PAGE and the molecular mass was determined as 78 kDa.

• Journal of Periodontal and Implant Science
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• v.36 no.4
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• pp.839-847
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• 2006

The aim of this study is to monitor reporter gene expression under osteocalcin gene promoter, using a real-time molecular imaging system, as tool to investigate osteoblast differentiation. The promoter region of mouse osteocalcin gene 2 (mOG2), the best-characterized osteoblast-specific gene, was inserted in promoterless luciferase reporter vector. Expression of reporter gene was confirmed and relationship between the reporter gene expression and osteoblastic differentiation was evaluated. Gene expression according to osteoblstic differentiation on biomaterials, utilizing a real-time molecular imaging system, was monitored. Luciferase was expressed at the only cells transduced with pGL4/mOGP and the level of expression was statistically higher at cells cultured in mineralization medium than cells in growth medium. CCCD camera detected the luciferase expression and was visible differentiation-dependent intensity of luminescence. The cells produced osteocalcin with time-dependent increment in BMP-2 treated cells and there was difference between BMP-2 treated cells and untreated cells at 14days. There was difference at the level of luciferase expression under pGL4/mOGP between BMP-2 treated cells and untreated cells at 3days. CCCD camera detected the luciferase expression at cells transduced with pGL4/mOGP on Ti disc and was visible differentiation-dependent intensity of luminescence This study shows that 1) expression of luciferase is regulated by the mouse OC promoter, 2) the CCCD detection system is a reliable quantitative gene detection tool for the osteoblast differentiation, 3) the dynamics of mouse OC promoter regulation during osteoblast differentiation is achieved in real time and quantitatively on biomaterial. The present system is a very reliable system for monitoring of osteoblast differentiation in real time and may be used for monitoring the effects of growth factors, drug, cytokines and biomaterials on osteoblast differentiation in animal.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.315-321
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• 1999

Since it has been known that hypoxia increases inducible nitric oxide synthase (iNOS) gene expression through hypoxia responsive element, it was possible to establish the hypothesis that nitric oxide could be a mediator of hypoxia to inhibit Cyplal promoter activity. In order to test this hypothesis, we have undertaken the study to examine the effects of hypoxia and nitric oxide on Cyplal promoter activity in Hepa I cells. Mouse Cyplal 5'flanking DNA, 1.6 Kb was cloned into pGL3 expression vector in order to construct pmCyplal-Luc. Hepa I cells were transfected with pmCyplal-Luc and were treated with $10^{-9}$ M TCDD and nitric oxide producing agents, such as lipopolysaccharide(LPS), sodium nitroprusside (SNP). Luciferase activity of reporter gene was measured from pmCyplal-Luc transfected Hepa I cell lysate which contains 2 g total protein using luciferin as a substrate. Nitric oxide producing agents, such as lipopolysaccharide (LPS), sodium nitroprusside(SNP) showed inhibition of luciferase activity that was induced by $10^{-9}$M TCDD treatment with dose dependent manner. Concomitant treatment of 1mM $N^G$-nitro-ι-arginine with $10^{-6}$~$10^{-4}$M sodium nitro-prusside recovered luciferase activity from the TCDD induced luciferase activity that was inhibited by nitric oxide producing agents. These demonstrated that nitric oxide could be a mediator of inhibitors on dioxin induced Cyplal expression in Hepa I cells.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.88-88
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.178-178
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this Is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to ＋64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. Here, we developed luciferase reporter gene assay system to detect SXR-based CYP 3A4 transcriptional activity. We have used CYP3A4-Luc plasmid that contains proximal promoter of human CYP3A4 gene upstream of the luciferase gene. We did transient transfection of 3A4-luciferase gene and SXR. In the HepG2 cells transfected with CYP3A4-Luc, when rifampicin treatment was combined with histone deacetylase inhibitor (HDAC Inhibitor), such as Trichostatin A, Hc-toxin and IN 2001 of the luciferase activity was induced 10-20 fold over control.

• Parasites, Hosts and Diseases
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• v.44 no.1 s.137
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• pp.21-26
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• 2006

A shuttle vector for Escherichia coli and Giardia lamblia was modified to produce a reporter plasmid, which monitors the expression of prescribed gene in G. lamblia by measuring its luciferase activity. Promoter regions of the gap2 gene, one of the genes induced during encystation, were cloned into this plasmid, and the resultant constructs were then transfected into trophozoites of G. lamblia. Transgenic trophozoites containing one of the 3 gap2-luc reporters were induced to encystation, and characterized with respect to gap2 gene expression by measuring their luciferase activities. Giardia containing a gap2-luc fusion of 112-bp upstream region showed full induction of luciferase activity during encystation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.141-141
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• 1998

In order to study the effect of nitric oxide on the regulation of mouse cyplal expression, 5' flanking DNA of mouse cytochrome P450 lal was cloned into pGL3 basic vector encoding luciferase gene. pcyplal-Luc was transfected into Hepa I cells and various chemicals were treated. Luciferase activity was stimulated 1000 folds over that of control by TCDD (2,3,7,8-tetrachloro-p-dioxin) treatment and this stimulation was dose dependent. When SNP (sodium nitroprusside) which donates nitric oxide was administrated, this stimulatory effect of TCDD on luciferase activity was decreased. And LPS (lipopolysaccharide) which is an iNOS (inducible nitric oxide synthase) inducer also decreased the stimulatory effect of TCDD on luciferase. And iNOS inhibitor N$\^$G/-nitro-ι-arginine + TCDD treatment increased the stimulation effect of TCDD and this effect was abolished when ι-arginine was added to N$\^$G/-nitro-ι-arginine + TCDD treatment. When N$\^$G/-nitro-ι-arginine was concomitantly administrated with SNP or LPS to confirm the effect of nitric oxide, the inhibitory effect of SNP or LPS was abolished. These data strongly suggest that nitric oxide might be an inhibitory regulator on the cytochrome P450 lal gene expression in Hepa cells.

• Journal of Life Science
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• v.21 no.10
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• pp.1466-1472
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• 2011

We characterized embryo early gene (EEG)-704 promoter of the silkworm Bombyx mori, which is specifically regulated in the development stages. To determine core promoter region, 10 different partial mutant clones were tested by luciferase assay in Sf9 cells. About 1.5 kb promoter shows higher luciferase activity than constitutive promoter (BmA3). Interestingly, EEG-704 shares the same DNA sequences with BmHsp20.8 by the result of BLAST analysis; its expression is also increased under heat shock condition. Development of such promoter inducible, directly or indirectly in the developmental-stage, is very useful in making recombinant proteins in transgenic silkworms.