• Journal of Life Science
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• v.20 no.2
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• pp.202-207
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• 2010

Ras genes are responsible for up to 30% of human tumor mutations and are composed of three isoforms: H-Ras, K-Ras and N-Ras. The post-translational modification of the CAAX motif of the Ras protein is essential in Ras actions. In the present study, we studied the effects of novel farnesyl transferase inhibitors (FTIs), YH3938 and YH3945, on the actions of oncogenic mutants of H-Ras, K-Ras and N-Ras. YH3938 and YH3945 completely reverted the proliferation and morphology of oncogenic H-Ras-transformed Rat2 cells, but not of oncogenic K-Ras-transformed Rat2 cells. Oncogenic N-Ras-transformed Rat2 cells were slightly affected. Activation of SRE promoters by oncogenic H-Ras and N-Ras, but not by K-Ras, were inhibited by treatment with YH3938 and YH3945. Using bandshift analysis, YH3938 suppressed the processing of oncogenic H-Ras and N-Ras, but not that of oncogenic K-Ras protein. YH3945 only inhibited the processing of H-Ras. From these results, we conclude that YH3938 and YH3945 specifically inhibit actions of oncogenic H-Ras through inhibition of its farnesylation, that YH3938 also inhibits N-Ras activity in a dose-dependent manner, and that these drugs have no effect on oncogenic K-Ras activity.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.118-123
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• 2005

For the expression in Saccharomyces cerevisiae, Bacillus stearothermophilus cyclodextrin glucano­transferase gene (cgtS) in pCGTS (4.8 kb) was subcloned into the surface expression vector, pYD1 (GALl promoter). The constructed plasmid, pYDCGT (7.2 kb) was introduced into S. cerevisiae EBY100 cells, and then yeast transformants were selected on the synthetic defined media lacking tryptophan. The formation of cyclodextrin (CD) was confirmed with active staining of culture broth of transformant grown on starch medium. Enzymatic reaction products with respect to the culture time and the reaction time were examined by TLC analysis. The results indicated that the enzyme activity was exhibited after 12 h cultivation and CD was produced after 10min of enzymatic reaction. When the surface-engineered yeast cells were cultured on galactose medium, maximum activities of CGTase were about 21.3 unit/l and 16.5 unit/l at $25^{\circ}C\;and\;30^{\circ}C$, respectively. The plasmids stability showed about $80\%\;even\;at\;25^{\circ}C\;and\;30^{\circ}C$.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.95-99
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• 1995

We have previously established a system for plant regeneration through somatic embryogenesis and Agrobacterium-mediated transformation of Korean ginseng. In this study to produce a fungus-resistant plant, we introduced a bean chitinase gene into ginseng using the transformation system. A binary vector pChi/748 was constructed by introducing the bean basic chitinase gene into EcoRI site of pGA748 which carries the CaMV 35S promoter governing the introduced gene and neomycin phosphotransferase II(NPT-II)gene as a positive selection marker. Cotyledonary explants were cocultured with A. tumefaciens strain LBA4404 harboring the binary vertor pChi/748 for 48 h, and transferred to MS medium supplemented with l mg/L2,4-D,0.1mg/L kinetin, 100 mg/L kanamycin, and 500mg/L carbenicillin. Kanamycin-resistant calli were formed on the cut surface of cotyledonary explants after one month of culture, and subsequently they gave rise to somatic embryos. Upon transfer onto medium containing 1 mg/L each of BA and GA$_3$, most of them converted to plantlets after 5 weeks of culture. The genomic DNA of eight kanamycin-resistant regenerants was subjected to polymerase chain reaction (PCR) using two specific 21-mer oligonucleotides derived from the chitinase gene. PCR-Southern blot analysis confirmed that the chitinase gene was incorporated into six out of the eight regenerants..

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.207-208
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• 2000

Since trichloroethylene (TCE), dichloroethylene (DCE), and vinyl chloride (VC) arise from anaerobic degradation of tetrachloroethylene (PCE) and TCE, there is interest in creating aerobic remediation systems that avoid the highly toxic VC and cis-DCE which predonominate in anaerobic degradation. However, it seemed TCE could not be degraded aerobically without an inducing compound (which also competitively inhibits TCE degradation). It has been shown that TCE induces expression of both the toluene dioxygenase of p. putida F1 as well as toluene-p-monooxygenase of P.mendocina KRI. We investigated here the ability of PCE, TCE, and chlorinated phenols to induce toluene-o-xylene monooxygenase (ToMO) from P.stutzeri OX1. ToMO has a relaxed regio-specificity since it hydroxylates toluene in the ortho, meta, and para positions; it also has a broad substrate range as it oxidizes o-xylene, m-xylene, p-xylene, toluene, benzene, ethylbenzene, styrene, and naphthalene; chlorinated compounds including TCE, 1, 1-DCE, cis-DCE, trans-DCE, VC, and chloroform : as well as mixtures of chlorinated aliphatics (Pseudomonas 1999 Maui Meeting). ToMO is a multicomponent enzyme with greatest similarity to the aromatic monooxygenases of Burkholderia pickettii PKO1 and P.mendocina KR1. Using P.sturzeri OX1, it was found that PCE induces P.mendocina KR1 Using P.situtzeri OX1, it was found that PCE induces ToMO activity measured as naphthalene oxygenase activity 2.5-fold, TCE induces 2.3-fold, and toluene induces 3.0 fold. With the mutant P.stutzeri M1 which does not express ToMO, it was also found there was no naphthalene oxygenate activity induced by PCE and TCE; hence, PCE and TCE induce the tow path. Using P.putida PaW340(pPP4062, pFP3028) which has the tow promoter fused to the reporter catechol-2, 3-dioxygenase and the regulator gene touR, it was determined that the tow promoter was induced 5.7-, 7.1-, and 5.2-fold for 2-, 3-, 4-chlorophenol, respectively (cf. 8.9-fold induction with o-cresol) : however, TCE and PCE did not directly induce the tou path. Gas chromatography and chloride ion analysis also showed that TCE induced ToMO expression in P.stutzeri OX1 and was degraded and mineralized. This is the first report of significant PCE induction of any enzyme as well as the first report of chlorinated compound induction of the tou operon. The results indicate TCE and chlorinated phenols can be degraded by P.stutzeri OX1 without a separate inducer of the tou pathway and without competitive inhibition.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.220-228
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• 2017

Many crops including cereals, tuber crops, feeds, and turf grasses are often damaged by various environmental stresses such as drought, salt, cold, and high temperature, causing the reduction of their productivity. Plants are sessile and cannot escape from environmental stresses. Thus, plants evolve in the direction of overcoming the environmental stresses. Some plant genes such as ARF, ABI3, NAC, HSF, and WRKY are known to respond to environmental stresses as they transcriptionally regulate the stress response pathways. For example, the OsWRKY76 gene contributes to the enhanced resistance to low temperatures and pathogenic infections. The AtWRKY28 also plays a role in environmental stresses. Zoysiagrass (Zoysia japonica Steud.) is popularly grown for gardens and golf courses. However, the function of the WRKY gene, another environmental stress-related gene, is not known in zoysiagrass. In this study, the ZjWRKY3 and ZjWRKY7 genes with one shared WRKY domain have been isolated in zoysiagrass. The expression of these genes increased in response to low temperature, drought, and salt stresses. Furthermore, the infection of the brown patch-causing Rhozoctonia solani induced the expression of ZjWRKY3 and ZjWRKY7. The corresponding proteins bind to the W-box of the Zjchi promoter, possibly regulating their transcriptions. The researchers suggest that the ZjWRKY3 and ZjWRKY7 genes transcriptionally regulate abiotic and biotic stress related downstream genes.

• Neonatal Medicine
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• v.16 no.2
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• pp.137-145
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• 2009

Purpose: The aim of this study was to determine the genotype frequencies of interleukin 10 (IL-10) gene polymorphisms and to investigate their association with the risk of respiratory distress syndrome (RDS) in preterm Korean infants. Methods: Two hundred fourteen preterm infants born at Ewha Womans University Mok Dong Hospital between November 2003 and July 2008 were studied. The cord blood of preterm neonates and the corresponding maternal blood were analyzed by PCR for IL-10 gene (IL-10 -1082A/G, -819T/C, and -592A/C) polymorphisms. The clinical data of patients were collected retrospectively by chart review. Results: The genotype frequencies of IL-10 genes in Korean mothers with preterm infants differ from other reports. The prevalence of two promoter SNPs of the IL-10 cytokine gene was similar but none had the IL-10-1082GG homozygote. Multiple logistic regression analysis demonstrated the risk of RDS to be significantly lower in the infants of the mothers with an IL-10-592AC/CC genotype than in those with an AA genotype (P=0.033). The risk of RDS was significantly lower in the mother with an IL-10-819TC/CC genotype than in those with a TT genotype (P=0.030). However, IL-10 polymorphisms in the cord blood were not significantly different in preterm infants with RDS compared with the preterm infants without RDS. When we compared the incidence of RDS and each IL-10A-1082G/T-819C/A-592C haplotype, the ACC haplotype had a protective effect on RDS (P=0.007). Conclusion: We conclude that the maternal IL-10-592A/C and IL-10-819T/C polymorphisms may have a role in the development of the RDS in preterm infants.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.111-117
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• 1995

In Escherichia coli, CRP forms a complex with cAMP and acts as a transcriptional regulator of many genes, including sugar metabolism operons. The E. coli MK2001, which is introduced the altered crp, is functional in the expression of lac, ara and man, in the absence of cAMP. However, the expression of mal gene is fully activated by the addition of cAMP or cGMP. The object of the study is cloning of the sfs (sugar fermentation stimulation) genes, which was involved in regulation of mal gene expression with the altered crp gene, and structural analysis and characterization of the genes at the molecular level. We have cloned 5 different E. coli genes which stimulate the maltose metabolism in a crp, cya::km (MK2001) background. Newly identified genes were designated as sfs. One of the sfs genes (pPC1), located at the 53.2 min map position on the E. coli chromosome, was further analyzed. Expression of the genes, which is involved in maltose metabolism, malQ (amylomaltase), was increased to 5.8-fold in the presence of a plasmid, pAP5, containing the subcloned sfs4 gene. The nucleotide seguence of a common 2,126 bp segment of the pPCM1 was determined and two open reading frames (ORF1 and ORF2) were detected. The ORF1 encodes the sfs4 gene and ORF2 encodes a truncated protein. Potential CRP binding site is located in the upstream of the putative promoter in the regulatory region. Expression of the cloned sfs4 gene was positively regulated by the cAMP-CRP complex.

• Journal of Food Hygiene and Safety
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• v.6 no.1
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• pp.13-26
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• 1991

This study was performed for searching for non-hepatectomy medium-term bioassay model by using newborn female rats. Newborn female Sprague-Dawley rats (1 day old) were given an intraperitoneal injection of 150 mg/kg of diethylnitrosamine (DENA). After three weeks, all rats were weaned and divided into three groups. Group 1 were fed on diets containing 0.01% 2-acetylaminofluorene (2-AAF) as a promoter for three weeks. Group 2 were given 0.05% phenobarbital (PB) in drinking water as a promoter for 8 weeks. Group 3 was control group. The autopsy was carried out at 4 weeks and 8 weeks after weaning. Preneoplastic lesions were indentified with immunohistochemical staining for glutathione S-transferase placental form (GST-P). In liver weight to body weight ratios, group 2 showed significant difference from group 1 (p<0.001) at 4 weeks after weaning. Group 1 and group 2 showed significant difference from group 3 at 8 weeks after weaning (p<0.0I, p<0.001), respectively. In quantitative analysis for GST-P positive lesion area by using Image Analyzer, group 1 and group 2 represented significant difference in comparison with group 3 at early 4 weeks after weaning (p

• Journal of Life Science
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• v.25 no.6
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• pp.631-637
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• 2015

Streptavidin, a protein produced by Streptomyces avidinii, strongly binds up to four molecules of vitamin H, d-biotin exhibiting the dissociation constant of about 10⁻¹⁵ M. This strong binding affinity has been applied for detection and characterization of numerous biological molecules suggesting expression and purification of functional streptavidin should be very useful for the application of this streptavidin-biotin interaction. To express a soluble streptavidin in Escherichia coli, We synthesized streptavidin genes and cloned into pET-22b plasmid, which uses T7 RNA polymerase/T7 promoter expression systems containing pelB leader for secretion into periplasmic space and six polyhistidine tags at C-terminus for purification of expressed proteins. Although streptavidin is toxic to Escherichia coli due to strong biotin binding property, streptavidin was expressed very sufficiently in a range of 10-20 mg/ml. In SDS-PAGE, the size of purified protein was shown as 17 kDa in denatured condition (boiling) and 68 kDa in native condition (without boiling) suggesting tetramerization of monomeric subunit by non-covalent association. Further analysis by size-exclusion chromatography supported streptavidin’s tetrameric structure as well. In addition, soluble streptavidin detected biotinylated proteins in westernblot indicating its functional activity to biotin. Taken these results together, it concluded that our simple expression system was able to show high yield, homotetrameric formation and biotin binding activity analogous to natural streptavidin.

• Journal of Life Science
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• v.26 no.10
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• pp.1137-1152
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• 2016

Cells sense, respond, and adapt to a low oxygen environment called hypoxia, which is widely involved in a variety of human diseases. Adaptation to low oxygen concentrations includes gene expression changes by inducing hypoxic genes and reducing aerobic genes. Recently, the mitochondrial respiratory chain has been implicated in the control of these oxygen-regulated genes when cells experience hypoxia. In order to obtain an insight into an effect of the mitochondrial respiratory chain on cellular response to hyxpoxia, we here examined whole genome transcript signatures of respiration-proficient and respiration-deficient budding yeasts exposed to hypoxia using DNA microarrays. By comparing whole transcriptomes to hypoxia in respiration-proficient and respiration-deficient yeasts, we found that there are several classes of oxygen-regulated genes. Some of them require the mitochondrial respiratory chain for their expression under hypoxia while others do not. We found that the majority of hypoxic genes and aerobic genes need the mitochondrial respiratory chain for their expression under hypoxia. However, we also found that there are some hypoxic and aerobic genes whose expression under hypoxia is independent of the mitochondrial respiratory chain. These results indicate a key involvement of the mitochondrial respiratory chain in oxygen-regulated gene expression and multiple mechanisms for controlling oxygen-regulated gene expression. In addition, we provided gene ontology analyses and computational promoter analyses for hypoxic genes identified in the study. Together with differentially regulated genes under hypoxia, these post-analysis data will be useful resources for understanding the biology of response to hypoxia.