• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.893-904
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• 2006

To improve sensitivity of biosensor as yeast two-hybrid detection system for estrogenic activity of suspected chemicals, we tested effects of several combinations of the bait and fish components in the two-hybrid system on Saccharomyces cerevisiae inducted a chromosome-integrated lacZ reporter gene that was under the control of CYC1 promoter and the upstream Gal4p-binding element $UAS_{GAL}$. The bait components that were fused with the Gal4p DNA binding domain are full-length human estrogen receptor ${\alpha}$ and its ligand-binding domain. The fish components that were fused with the Gal4p transcriptional activation domain were nuclear receptor-binding domains of co-activators SRC1 and TIF2. We found that the combination of the full-length human estrogen receptor ${\alpha}$ with the nuclear receptor-binding domain of co-activator SRC1 was most effective for the estrogen-dependent induction of reporter activity among the two-hybrid systems so far reported. The relative strength of transcriptional activation by representative natural and xenobiotic chemicals was well correlated with their estrogenic potency that had been reported with other assay systems.

• Quantitative Bio-Science
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• v.36 no.1
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• pp.23-31
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• 2017

Datasets from DNA microarray experiments, which are in the form of large matrices of expression levels of genes, often have missing values. However, the existing statistical methods including the principle components analysis (PCA) and Hotelling's t-test are not directly applicable for the datasets having missing values due to the fact that they assume the observed dataset is complete in general. Many methods have been proposed in previous literature to impute the missing in the observed data. Troyanskaya et al. [1] study the k-nearest neighbor (kNN) imputation, Kim et al. [2] propose the local least squares (LLS) method and Rubin [3] propose the multiple imputation (MI) for missing values. To identify differentially expressed genes, we propose a new testing procedure when the missing exists in the observed data. The proposed procedure uses the Stouffer's z-scores and combines the test results of individual imputed samples, which are dependent to each other. We numerically show that the proposed test procedure based on MI performs better than the existing test procedures based on single imputation (SI) by comparing their ROC curves. We apply the proposed method to analyzing a public microarray data.

• Fisheries and Aquatic Sciences
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• v.21 no.12
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• pp.38.1-38.9
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• 2018

Alzheimer's disease (AD) is a disturbing and advanced neurodegenerative disease and is characterized pathologically by the accumulation of amyloid beta ($A{\beta}$) and the hyperphosphorylation of tau proteins in the brain. The deposition of $A{\beta}$ aggregates triggers synaptic dysfunction, and neurodegeneration, which lead to cognitive disorders. Here, we found that FF isolated from an eatable perennial brown seaweed E.bicyclis protect against $A{\beta}$-induced neurotoxicity in neuroblastoma cells stably transfected with two amyloid precursor protein (APP) constructs: the APP695 cDNA (SH-SY5Y-APP695swe). The FF demonstrated strong inhibitory activity for ${\beta}$-secretase ($IC_{50}$ $16.1{\mu}M$) and its inhibition pattern was investigated using Lineweaver-Burk and Dixon plots, and found to be non-competitive. Then, we tested whether FF could inhibit production of $A{\beta}$ in SH-SY5Y-APP695swe. FF inhibited the production of $A{\beta}$ and soluble-APP, residue of APP from cleaved APP by ${\beta}$-secretase. Our data show that FF can inhibit the production of $A{\beta}$ and soluble-$APP{\beta}$ via inhibition of ${\beta}$-secretase activity. Taken together these results suggest that FF may be worthy of future study as an anti-AD treatment.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.297-302
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• 1988

The protoplasts of Saccharomyces cerevisiae D-71, a thermophilic strain and Zygosaccharomyces rouxii SR-S, an osmotolerant strain were fused, and a fusant (FS-RN 1) was selected, then was characterized for its genetic stability, DNA content, cell capacity, growth rate, tolerance to salts and chemicals, $\beta$-fructofuranosidase level and ethanol fermenting activity. After 6 months of preservation, 5.8% of the fusant clones were segregated to parental types. The DNA content and cell capacity of the fusant were greater than those of the parental strains. Lag period of growth for the fusant was longer than those for the parents. The fusant colonies showed pink-color reaction to triphenyltetrazolium chloride(TTC) test. The fusant appeared to have resistances to NaCl at moderate levels between both parental strains, and resistances to KCI, sodium propionate and cycloheximide similar to either one of the parents. $\beta$-Fructofuranosidase activity of the fusant was 24.2$\times$10$^{-3}$/IU/g(dry wt) for 3 days culture. Ethanol yields ofter 4 days of fermentation by the fusant at 3$0^{\circ}C$ were : 6.0%(v/v) from 40% of glucose and 8.8%(v/v) from 20% of sucrose.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.389-398
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• 2009

Development of expression vectors is important for the basic and applied researches on kimchi LAB (lactic acid bacteria). An expression vector, pSJE6c was constructed by inserting P6C promoter sequence from Lactococcus lactis into pSJE, a shuttle vector for E. coli and Leuconostoc species. To test the efficiency of pSJE6c, aga ($\alpha$-galactosidase) and lacZ ($\beta$-galactosidase) genes were expressed in Lactobacillus brevis 2.14. Compared to the pSJE, expression levels of both genes were increased, indicating P6C promoter was better than indigenous promoters. Enzyme activities of L. brevis cells harboring pSJE6caga (pSJE6c with aga) or pSJE6Z (pSJE6c with lacZ) were 1.5-2 fold higher than those with pSJEaga (pSJE with aga) or pSJEZ (pSJE with lacZ). More RNA transcripts were detected in cells harboring pSJE6c based recombinant plasmid. The results indicated that heterologous gene expressions in kimchi LAB could be improved significantly by use of efficient expression vectors.

• Environmental Analysis Health and Toxicology
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• v.18 no.2
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• pp.89-94
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• 2003

Tributyltin (TBT) used world-wide in antifouling paints for ships is a widespread environmental pollutant and cause reproductive organs atrophy in rodents. At low doses, antiproliferative modes of action have been shown to be involved, whereas at higher doses apoptosis seems to be the mechanism of toxicity in reproductive organs by TBT. In this study, we investigated that the mechanisms underlying DNA fragmentation induced by TBT in the rat leyding cell line, R2C. Effects of TBT on intracellular Ca$\^$2+/ level and reactive oxygen species (ROS) were investigated in R2C cells by fluorescence detector. TBT significantly induced intracellular Ca$\^$2+/ level in a time-dependent manner. The rise in intracellular Ca$\^$2+/ level was followed by a time-dependent generation of reactive oxygen species (ROS) at the cytosol level. Simultaneously, TBT induced the release of cytochrome c from the mitochondrial membrane into the cytosol. Furthermore, ROS production and the release of cytochrome c were reduced by BAPTA, an intracellular Ca$\^$2+/ chelator, indicating the important role of Ca$\^$2+/ in R2C during these early intracellular events. In addition, Z-DEVD FMK, a caspase-3 inhibitor, decreased apoptosis by TBT. Taken together, the present results indicated that the apoptotic pathway by TBT might start with an increase in intracellular Ca$\^$2+/ level, continues with release of ROS and cytochrome c from mitochondria, activation of caspases,and finally results in DNA fragmentation.

• Journal of Life Science
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• v.25 no.8
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• pp.849-860
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• 2015

The anti-cancer activities of Rhus verniciflua Stokes (GC), Ulmus davidiana var. japonica Nakai (UGP) and arsenium sublimatum (SS) extracts, which have been used Oriental medicine therapy for various diseases, were investigated. The treatment of GC, UGP and SS alone, and combined treatment with GC, UGP and SS did not affect the cell viability in the mouse normal cell lines (RAW 264.7 macrophages and C2C12 myoblasts). However, co-treatment with GC, UGP and SS markedly induces apoptosis in human gastric cancer AGS cells, but not in other various cancer cell lines (human lung cancer A549, colon cancer HCT116, liver cancer Hep3B and bladder T24 cells) as evidenced by formation of apoptotic bodies, chromatin condensation, and accumulation of annexin-V positive cells. Co-treatment with GC, UGP and SS effectively induced the expression levels of Fas and Fas ligand, and inhibited the levels IAP family proteins such as XIAP, cIAP-1 and survivin, and anti-apoptotic Bcl-xL proteins compared with treatment with either agent alone. Combined treatment also significantly induced the loss of mitochondrial membrane potential, which was associated with the activation of caspases (-3, -8, and -9) and degradation of poly (ADP-ribose) polymerase. However, the cytotoxic effects induced by co-treatment with GC, UGP and SS were significantly attenuated by pan-caspases inhibitor, z-VAD-fmk, indicating an important role for caspases. These results indicated that the caspases were key regulators of apoptosis in response to co-treatment of GC, UGP and SS in human gastric cancer AGS cells and further studies will be needed to identify the active compounds.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.337-344
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• 2011

Integrase MJ1 from the bacteriophage ${\Phi}FC1$ carries out recombination between two DNA sequences (the phage attachment site, attP and the bacterial attachment site, attB) in NIH3T3 mouse cells. In this study, the integration vector containing attP, attB and the integrase gene MJ, was constructed. The integration mediated by integrase MJ1 in Escherichia coli led to excision of LacZ. Therefore, the frequency of integration was measured by the counting of the white colony, which is detectable on X-Gal plates. The extrachromosomal integration in NIH3T3 mouse cells was monitored by the expression of the green fluorescent protein (GFP) as a reporter. To demonstrate integration mediated integrase MJ1 in NIH3T3 cells, vectors containing attP and attB were co-transfected into NIH3T3 cells. The integration was confirmed by fluorescent microscopy. The expression of GFP was induced in NIH3T3 cells expressing MJ1 without accessory factors. By contrast, the excision mediated by the MJ1 between attR and attL had no effect on the expression of GFP. These results suggest that integrase MJ1 may enable a variety of genomic modifications for research and therapeutic purposes in higher living cells.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.313-318
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• 2009

TIAF1 is a TGF-${\beta}$1-induced anti-apoptotic factor that plays a critical role in blocking TNF (tumor necrosis factor) cytotoxicity in mouse fibroblasts and participates in TGF-${\beta}$-mediated growth regulation. In this study, we obtained the full-length cDNA sequence of the porcine TIAF1 gene. Real-time PCR further revealed that the TIAF1 gene was expressed at the highest level in liver and kidney with prominent expressions detected in uterus, and lower levels detected in heart, spleen, lung, stomach, small intestine, skeletal muscle and fat of Large White pigs. Sequence analysis indicated that a 6 base-pair deletion mutation existed in the exon of the TIAF1 gene between Meishan and Large White pigs. This mutation induced deletion of Gln and Val amino acids. PCR-RFLP was used to detect the polymorphism in 394 pigs of a "Large White${\times}$Meishan" $F_{2}$ resource population and four purebred pig populations. The frequencies of the A allele (with a 6 bp deletion) were dominant in Chinese Meishan and Bamei pigs, and the frequencies of the B allele (no 6 bp deletion) were dominant in Large White and Landrace pigs. Association analyses revealed that the deletion mutation had highly significant associations (p<0.01) with meat marbling score of the thorax-waist longissimus dorsi (LD) muscle (MM1) and intramuscular fat percentage (IMF), and significant associations (p<0.05) with carcass length (CL). The results presented here supply evidence that the 6 bp deletion mutation in the TIAF1 gene affects porcine meat quality and provides useful information for further porcine breeding.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.215-221
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• 2009

Site-specific incorporation of unnatural amino acids into proteins in vivo can be achieved by co-expression of an orthogonal pair of suppressor tRNA and engineered aminoacyl-tRNA synthetase (ARS) that specifically ligates an unnatural amino acid to the suppressor tRNA. As a step to establish this technique, here we generated an Escherichia coli reporter strain DH10B(Tn:lacZam) by integrating amber mutated lacZ gene into the chromosome of E. coli DH10B strain. In vivo expression of E. coli amber suppressor $tRNA^{Gln}$ produced blue colonies in culture plates containing X-Gal as well as dramatically increased $\beta$-galactosidase activity. In addition, expression of an orthogonal pair of Saccharomyces cerevisiae suppressor $tRNA^{Tyr}$ and tyrosyl-tRNA synthetase also produced blue colonies as well as moderate increase of $\beta$-galactosidase activity. These data demonstrate that our reporter strain will provide an efficient method to assess amber suppression in both qualitative and quantitative manners.