• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.114-114
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• 2001

Since hypoxia-inducible factor-lalpha (HIF-lalpha) and the arylhydrocarbon receptor (AhR) shared the AhR nuclear translocator (Arnt) for hypoxia- and AhR-mediated signaling, respectively, it was possible to establish the hypothesis that hypoxia could regulate Cyplal expression. In order to understand the mechanism of Cyplal gene expression, we demonstrated here that hypoxic agents such as cobalt chloride, desferrioxarnine, and picolinic acid reduced the TCDD induced Cyplal promoter activity based on the determination of luciferase activity in Hepa I cells transfected with pmCypla1-Luc. Also cobalt chloride inhibited the TCDD stimulated Cyplal mRNA level as well as EROD activities in both Hepa I and MCF-7 cells. Hypoxic agents such as cobalt chloride, picolinic acid, and desferrioxamine showed inhibition of luciferase activity that was induced by lnM TCDD treatment with dose dependent manner. Concomitant treatment of 150${\mu}$M ferrous sulfate with 1∼100${\mu}$M desferrioxarnine or 1∼100${\mu}$M picolinic acid recovered from the hypoxic agents-inhibited luciferase activity that was stimulated by TCDD. Reciprocally, the hypoxic agents down regulated TCDD induced Cyplal mRNA level and CYP1A1 enzyme activity in Hepa I cells.

• Molecules and Cells
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• v.25 no.2
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• pp.172-177
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• 2008

Eukaryotic translation initiation factor 5B (eIF5B) plays a role in recognition of the AUG codon in conjunction with translation factor eIF2, and promotes joining of the 60S ribosomal subunit. To see whether the eIF5B proteins of other organisms function in Saccharomyces cerevisiae, we cloned the corresponding genes from Oryza sativa, Arabidopsis thaliana, Aspergillus nidulans and Candida albican and expressed them under the control of the galactose-inducible GAL promoter in the $fun12{\Delta}$ strain of Saccharomyces cerevisiae. Expression of Candida albicans eIF5B complemented the slow-growth phenotype of the $fun12{\Delta}$ strain, but that of Aspergillus nidulance did not, despite the fact that its protein was expressed better than that of Candida albicans. The Arabidopsis thaliana protein was also not functional in Saccharomyces. These results reveal that the eIF5B in Candida albicans has a close functional relationship with that of Sacharomyces cerevisiae, as also shown by a phylogenetic analysis based on the amino acid sequences of the eIF5Bs.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.319-323
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• 2004

Cytochrome P450 (CYP) 3A4 is of great interest because of its important roles in the oxidation of numerous drugs and xenobiotics. HDJ-1, a molecular chaperone in human, is known to assist the correct folding of unfolded proteins. To achieve a high yield of recombinant human CYP3A4 in Escherichia coli, the CYP3A4 encoding gene was co-expressed with the chaperone HDJ-1, under the control of an inducible tac promoter in a bicistronic format. The levels of expression of the CYP3A4 in the bicistronic construct reached up to 715 nmol $(liter culture)^{-1}$ within 16 h at $37^{\circ}C$, which was about a 3.3-fold increase compared to that of the CYP3A4 alone without the HDJ-1. By co-expression with HDJ-1, the catalytic activity of CYP3A4 was also increased by -15-fold. The amount of activity increase was similar to that of the CYP production at the whole cell level. The present over-expression system may be useful for the rapid production of large amounts of active CYP3A4 in E. coli.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.195-206
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• 2005

Spatial and temporal expression of pathogenesis-related (PR) gene and proteins has been recognized as inducible defense response in pepper plants. Gene expression and/or protein accumulation of PR-1, $\beta-1,3-glucanase$ and chitinase was predominantly found in pepper plants during the inoculations by Xanthomonas campestris pv. vesicatoria, Phytophthora capsici and Colletotrichum coccodes. PR-1 and chitinase genes were also induced in pepper plants in response to environmental stresses, such as high salinity and drought. PR-1 and chitinase gene expressions by biotic and abiotic stresses were regulated by their own promoter regions containing several stress-related cis-acting elements. Overexpression of pepper PR-1 or chitinase genes in heterogeneous transgenic plants showed enhanced disease resistance as well as environmental stress tolerances. In this review, we focused on the putative function of pepper PR-1, $\beta-1,3-glucanase$ and chitinase proteins and/or genes at the biochemical, molecular and cytological aspects.

• Natural Product Sciences
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• v.12 no.2
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• pp.113-117
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• 2006

Quercitrin gallate was previously isolated from Persicaria lapathifolia (Polygonaceae) as an inhibitor of superoxide production. In the present study, quercitrin gallate was found to inhibit interleukin (IL)-6 production in lipopolysaccharide (LPS)-stimulated macrophages RAW 264.7 with an $IC_{50}$ value of $63\;{\mu}M$. Furthermore, quercitrin gallate attenuated LPS-induced synthesis of IL-6 transcript but also inhibited LPS-induced IL-6 promoter activity, indicating that the compound could down-regulate IL-6 expression at the transcription level. Since nuclear factor (NF)-kB has been shown to play a key role in LPS-inducible IL-6 expression, an effect of quercitrin gallate on LPS-induced NF-kB activation was further analyzed. Quercitrin gallate exhibited a dosedependent inhibitory effect on LPS-induced nuclear translocation of NF-kB without affecting inhibitory kB (IkB) degradation, and subsequently inhibited LPS-induced NF-kB transcriptional activity in macrophages RAW 264.7. Taken together, quercitrin gallate down-regulated LPS-induced IL-6 expression by inhibiting NF-kB activation, which could provide a pharmacological potential of the compound in IL-6-related immune and inflammatory diseases.

• Journal of Applied Biological Chemistry
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• v.49 no.3
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• pp.75-81
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• 2006

A full-length cDNA encoding dihydroflavonol 4-reductase (st-dfr) of potato was isolated by rapid amplification of cDNA ends, and their expression was investigated from purple-fleshed potato (Solanum tuberosum L. cv. Jashim). The st-dfr exists as a member of a small gene family and its transcripts was abundant in the order of tuber flesh, stem, leaf, and root. The expressions of st-dfr gene were light inducible and cultivar dependant. Transgenic potato plants harboring antisense st-dfr (AS-DFR) sequences were analyzed. The accumulation of mRNA was nearly completely inhibited as a result of introducing an AS-DFR gene under the control of the 35S CaMV promoter into the red tuber skin Solanum tuberosum L. cv. Desiree. The anthocyanin content of the tuber peels of the transgenic lines was dramatically decreased by up to 70%. The possible production of flavonols in the peels of AS-DFR transgenic potatoes was discussed.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.578-583
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• 2003

The desulfurization genes (dszABC) were cloned from Gordonia nitida. Nucleotide sequences similarity between the dszABC genes of G. nitida and those of Rhodococcus rhodochrous IGTS8 was 89%. The similarities of deduced amino acids between the two were 86% for DszA, 86% for DszB, and 90% for DszC. The G. nitida dszABC genes were expressed in several different Escherichia coli strains under an inducible trc promoter. Cultivation of these metabolically engineered E. coli strains in the presence of 0.2 mM dibenzothiophene (DBT) allowed the conversion of DBT to 2-hydroxybiphenyl (2-HBP), which is the final metabolite of the sulfur-specific desulfurization pathway. The maximum conversion of DBT to 2-HBP was 16% in 60 h. Recombinant E. coli was applied for the deep desulfurization of diesel oil supplemented into the medium at 5% (v/v). Sulfur content in diesel oil was decreased from 250 mg sulfur/1 to 212.5 mg sulfur/1, resulting in the removal of 15% of sulfur in diesel oil in 60 h.

• The Plant Pathology Journal
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• v.17 no.2
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• pp.88-93
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• 2001

Oxidative stress is one of the major limiting factor in plant productivity. Reactive oxygens species (ROS) generated during metabolic processes damage cellular functions and consequently lead to disease, senescence and cell death. Plants have evolved an efficient defense system by which the ROS is scavenged by antioxidant enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). Attempts to reduce oxidative damages under the stress conditions have included the manipulation of 갠 scavenging enzymes by gene transfer technology. Increased SOD activities of transgenic plants lead to increased resistance against oxidative stresses derived from methyl viologen (MV), and from photooxidative damage caused by high light and low temperature. Transgenic tobacco plants overexpressing APX showed reduced damage following either MV treatment of photooxidative treatment. Overexpression of glutathion reductase (GR) leads to increase in pool of ascorbate and GSH, known as small antioxidant molecules. These results indicate through overexpression of enzymes involved in ROS-scavenging could maintain or improve the plant productivities under environment stress condition. In this study, the rational approaches to develop stress-tolerant plants by gene manipulation of antioxidant enzymes will be introduced to provide solutions for the global food and environmental problems in the $21^\textrm{st}$ century.

• Molecules and Cells
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• v.21 no.1
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• pp.1-6
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• 2006

Bcl-2/adenovirus E1B 19 kDa-interacting protein 3 (BNIP3) is a mitochondrial pro-apoptotic protein that has a single Bcl-2 homology 3 (BH3) domain and a COOH-terminal transmembrane (TM) domain. Although it belongs to the Bcl-2 family and can heterodimerize with Bcl-2, its pro-apoptotic activity is distinct from those of other members of the Bcl-2 family. For example, cell death mediated by BNIP3 is independent of caspases and shows several characteristics of necrosis. Furthermore, the TM domain, but not the BH3 domain, is required for dimerization, mitochondrial targeting and pro-apoptotic activity. BNIP3 plays an important role in hypoxia-induced death of normal and malignant cells. Its expression is markedly increased in the hypoxic regions of some solid tumors and appears to be regulated by hypoxia-inducible factor (HIF), which binds to a site on the BNIP3 promoter. Silencing, followed by methylation, of the BNIP3 gene occurs in a significant proportion of cancer cases, especially in pancreatic cancers. BNIP3 also has a role in the death of cardiac myocytes in ischemia. Further studies of BNIP3 should provide insight into hypoxic cell death and may contribute to improved treatment of cancers and cardiovascular diseases.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.243-248
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• 2016

Argonaute 2 (AtAGO2) is a well characterized effector protein in Arabidopsis for its functionalities associated with DNA double-strand break (DSB)-induced small RNAs (diRNAs) and for its inducible expression upon ${\gamma}$-irradiation. However, its transcriptional regulation depending on the recovery time after the irradiation and on the specific response to DSBs has been poorly understood. We analyzed the 1,313 bp promoter sequence of the AtAGO2 gene ($1.3kb_{pro}$) to characterize the transcriptional regulation of AtAGO2 at various recovery times after ${\gamma}$-irradiation. A stable transformant harboring $1.3kb_{pro}$ fused with GUS gene showed that the AtAGO2 is highly expressed in response to ${\gamma}$-irradiation, after which the expression of the gene is gradually decreased until 5 days of DNA damage recovery. We also confirm that the AtAGO2 expression patterns are similar to that of ${\gamma}$-irradiation after the treatments of radiomimetic genotoxins (bleomycin and zeocin). However, methyl methanesulfonate and mitomycin C, which are associated with the inhibition of DNA replication, do not induce the expression of the AtAGO2, suggesting that the expression of the AtAGO2 is closely related with DNA DSBs rather than DNA replication.