• BMB Reports
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• v.42 no.11
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• pp.737-742
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• 2009

Hypoxia-inducible factor-$1{\alpha}/{\beta}$ (HIF-$1{\alpha}/{\beta}$) is a heterodimeric transcriptional activator that mediates gene expression in response to hypoxia. HIF-$1{\alpha}$ has been noted as an effective therapeutic target for ischemic diseases such as myocardiac infarction, stroke and cancer. By using a yeast two-hybrid system and a random peptide library, we found a 16-mer peptide named F29 that directly interacts with the bHLH-PAS domain of HIF-$1{\alpha}$. We found that F29 facilitates the interaction of the HIF-$1{\alpha/\beta}$ heterodimer with its target DNA sequence, hypoxia-responsive element (HRE). The transient transfection of an F29-expressing plasmid increases the expression of both an HRE-driven luciferase gene and the endogenous HIF-1 target gene, vascular endothelial growth factor (VEGF). Taken together, we conclude that F29 increases the DNA-binding ability of HIF-$1{\alpha}$, leading to increased expression of its target gene VEGF. Our results suggest that F29 can be a lead compound that directly targets HIF-$1{\alpha}$ and increases its activity.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.29-29
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• 2003

Incompatible plant-pathogen interactions result in the rapid cell death response known as hypersensitive response (HR) and activation of host defense-related genes. To understand the molecular and cellular mechanism controlling defense response better, several approaches including isolation and characterization of novel genes, promoter analysis of those genes, protein-protein interaction analysis and reverse genetic approach etc. By using the yeast two-hybrid system a clone named Tsipl, Tsil -interacting protein 1, was isolated whose translation product apparently interacted with Tsil, an EREBP/AP2 type DNA binding protein. RNA gel blot analysis showed that the expression of Tsipl was increased by treatment with NaCl, ethylene, salicylic acid, or gibberellic acid. Transient expression analysis using a Tsipl::smGFP fusion gene in Arabidopsis protoplasts indicated that the Tsipl protein was targeted to the outer surface of chloroplasts. The targeted Tsipl::smGFP proteins were diffused to the cytoplasm of protoplasts in the presence of salicylic acid (SA) The PEG-mediated co-transfection analysis showed that Tsipl could interact with Tsil in the nucleus. These results suggest that Tsipl-Tsil interaction might serve to regulate defense-related gene expression. Basically the useful promoters are valuable tools for effective control of gene expression related to various developmental and environmental condition.(중략)

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.261.1-261
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• 1999

No Abstract, See Full Text

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.191-196
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• 2005

Genetic networks are a key to unraveling dynamic properties of biological processes and regulation of genes plays an essential role in dynamic behavior of the genetic networks. A popular characterization of regulation of the gene is a kinetic model. However, many kinetic parameters in the genetic regulation have not been available. To overcome this difficulty, in this report, state-space approach to modeling gene regulation is presented. Second-order systems are used to characterize gene regulation. Interpretation of coefficients in the second order systems as resistance, capacitance and inductance is studied. The mathematical methods for transient response analysis of gene regulation to external perturbation are investigated. Criterion for classifying gene into three categories: underdamped, overdamped and critical damped is discussed. The proposed models are applied to yeast cell cycle gene expression data.

• BMB Reports
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• v.40 no.5
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• pp.791-800
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• 2007

Ethylene performs an important function in plant growth and development. 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), the key enzyme involved in ethylene biosynthesis, has been the focus of most ethylene studies. Here, a cotton ACS gene referred to as Gossypium hirsutum ACS1 (GhACS1), was isolated. The full-length cDNA of GhACS1 encodes for a 476-amino acid protein which harbors seven conserved regions, 11 invariant amino acid residues, and the PLP binding active site, all of which characterize ACC synthases. Alignment analysis showed that GhACS1 shared a high degree of identity with other known ACC synthases from different species. Two introns were detected in the genomic DNA sequence, and the results of Southern blot analysis suggested that there might be a multi-gene family encoding for ACC synthase in cotton. From the phylogenetic tree constructed with 24 different kinds of ACC synthases, we determined that GhACS1 falls into group II, and was closely associated with the wound-inducible ACS of citrus. The analysis of the 5' flanking region of GhACS1 revealed a group of putative cis-acting elements. The results of expression analysis showed that GhACS1 displayed its transient expression nature after wounding, abscisic acid (ABA), and $CuCl_2$ treatments. These results indicate that GhACS1, which was transiently expressed in response to certain stimuli, may be involved in the production of ethylene for the transmission of stress signals.

• Journal of Plant Biotechnology
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• v.3 no.3
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• pp.123-129
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• 2001

Electroporation of microcalli and embryonic axes of a Brazilian Indica rice cultivar was performed. Some parameters influencing the recovery of transformed callus have been defined through transient npt II expression. Such parameters included the presence of light during incubation of microcalli used as target for electroporation, heat shock at 45$^{\circ}C$, macerozyme pre-digestion of target tissues and the number of pulses during electroporation. Transgenic calli were obtained from embryonic axes after electroporation with plasmid pDM302, which encodes the gene phosphinotricin acetyl transferase (bar) under the control of Act-1 promoter. Integration of the introduced gene into the genome was demonstrated by Southern blot hybridization.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.170-170
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• 2002

College of Pharmacy, Ewha womans University, Seoul, 120-750, Korea 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent halogenated aromatic hydrocarbon congener that induces expression of several genes including CYP1A1. Exposure to TCDD results in many toxic actions such as carcinogenesis, hepatotoxicity, immune suppression, and reproductive and developmental toxicity. Dramatic differences in dioxin toxicity have been observed between the sexes of some animal species, suggesting hormonal modulation of dioxin action. Many studies have been reported and propose several mechanisms of anti-estrogenic effects of TCDD. In contrast, the effect of estrogen on the regulation of CYP1A1 are not clear at present. There are several reports showing conflicting results. It seems that induction/inhibition of CYP1A1 may be dependent on cell-type and concentration. The purpose of this study was to investigate the regulation of TCDD-induced CYP1A1 gene expression by estradiol and its metabolites. We examined whether estradiol and its metabolites altered TCDD-mediated induction of CYP1A1 enzyme activity. 17 ${\beta}$ estradiol and 16 ${\alpha}$ estriol at non cytotoxic concentrations caused a significant concentration dependent decline of TCDD-induced EROD activity To determine whether reduced EROD activity reflected altered CYP1A1 mRNA expression, we measured CYP1A1 mRNA level by RT-PCR. And to examine whether estradiol and its metabolites have effects on TCDD-induced CYP1A1 gene expression at the transcription level, we also peformed transient transfection with an AhR responsive reporter plasmid containing the 5' flanking region of the human CYP1A1 gene to examine whether estradiol and its metabolites have effects on TCDD-induced CYP1A1 gene expression at the transcription level.

• Molecules and Cells
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• v.26 no.1
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• pp.74-80
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• 2008

Bisphenol A bis (2,3-dihydroxypropyl) ether ($BADGE.2H_2O$) is a component of commercial liquid epoxy resins commonly used in the food-packing industry and in dental sealants. There is evidence that it has significant estrogenic activity. Nur77 plays a crucial role in the regulation of certain genes involved in LH-mediated steroidogenesis in testicular Leydig cells. It was previously demonstrated that Bisphenol A (BPA) stimulates Nur77 gene induction and steroidogenesis. In this study, we investigated the effects of $BADGE.2H_2O$ on Nur77 gene expression and steroidogenesis. Northern blot analysis showed that it increased the expression of Nur77 mRNA and protein, and transient transfection assays demonstrated that it increased the promoter activity and transactivation of Nur77. It also increased the expression of certain steroidogenic genes, such as StAR and $3{\beta}$-HSD. Finally, over-expression of a dominant negative Nur77 cDNA via adenoviral infection reduced $BADGE.2H_2O$-mediated progesterone biosynthesis. These results indicate that $BADGE.2H_2O$ disrupts testicular steroidogenesis by increasing Nur77 gene expression.

• Journal of Plant Biotechnology
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• v.7 no.4
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• pp.219-223
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• 2005

We investigated chemical-wounding effect on Agrobacterium-mediated Chinese cabbage transformation via vacuum infiltration. Pre-germinated or germinating Chinese cabbage seeds were infiltrated with Agrobacterium tumefaciens LBA4404 cells carrying either GUS gene (pBI121) or hepatitis B virus surface antigen DNA (pBIHBsAg). Prior to agroinfiltration process, the seeds were soaked in sodium hydrosulfite (SHS) solution or just in sterile water as a control. Comparative transformation efficiency was determined by both of histochemistry and ELISA. We could demonstrate that SHS solution treatment especially to 1-day or 2-days old germinating seeds efficiently improved transformation process, and therefore, transient expression level. This strongly indicated that Agrobacterium infection could be facilitated indeed by SHS-causing wounds on Chinese cabbage seeds.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.91-94
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• 2000

The suspension cells of Taxus cuspidata were transformed with Agrobacterium tumefaciens harboring binary vector pCAMBIE1302 encoding mgfp. Transient transfection efficiency was compared by using the fluoremetric measurement. The transient transfection efficiency was improved by transformation with DMSO and/or sonication treatment. Optimum conditions for DMSO and sonication treatment were 3% and 30sec, respectively. selection and maintenance of transformed cells were continued for 3 months. An insertion of the mgfp gene in transformed cells was detected by PCR and an expression of GFP confirmed by the western blot analysis.