• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1769-1771
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• 2010

The envelope glycoprotein E2 of hepatitis C virus (HCV) binds to various cell surface receptors for viral infection. We performed biopanning against this protein and selected peptides from phage display peptide libraries. Two short peptides, pep7-1 and pep12-1, were selected and their ability to inhibit the infection process was investigated. When pep7-1 was present, the infectivity of HCV particles in cell culture was notably decreased. This decrease was demonstrated by Western blot analysis, immunofluorescence assay, and reverse transcription PCR assay. However, pep12-1 showed little inhibitory effect on HCV infection.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.197-206
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• 1983

For the purpose of investigating the effect of nalidixic acid on the nucleic acid synthesis in chloroplast isolated from Chlorella ellipsoidea, cells were cultured in the media treated with nalidixic acid(20ppm) for 5 days. Aliquots cells were taken out at the inoculation and at intervals during the culture and growth rate of Chlorella cells measured. After extraction of nucleic acids in chloroplast isolated from these cells, their contents were analyzed by the base composition and the effect of nalidixic acid on the nucleic acid synthesis interpreted to compare with those of the control. 1. It was showed that the inhibitory concentration affected by nalidixic acid on the growth of Chlorella cells were 20ppm. 2. Because nalidixic acid had depressed the DNA replication in isolated chloroplast as well as whole cell system, these contents were markedly decreased in comparison with those of the control. 3. In the isolated chloroplast as well as in the whole cell system, nalidixic acid was decreased contents of base in the RNA by preventing RNA transcription.

• Journal of Veterinary Science
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• v.24 no.3
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• pp.40.1-40.6
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• 2023

Analysis of the VP1 gene sequence of the foot and mouth disease virus (FMDV) is critical to understanding viral evolution and disease epidemiology. A standard set of primers have been used for the detection and sequence analysis of the VP1 gene of FMDV directly from suspected clinical samples with limited success. The study validated VP1-specific degenerate primer-based reverse transcription polymerase chain reaction (RT-PCR) for the qualitative detection and sequencing of serotype O FMDV lineages circulating in India. The novel degenerate primer-based RT-PCR amplifying the VP1 gene can circumvent the genetic heterogeneity observed in viruses after cell culture adaptation and facilitate precise viral gene sequence analysis from clinical samples.

• Journal of Microbiology
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• v.37 no.2
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• pp.102-110
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• 1999

Genetic determinant for the secondary metabolism was studied in heterologous expression in Streptomyces lividans TK-24 using Streptomyces griseus ATCC 10137 as a donor strain. Chromosomal DNA of S. griseus was ligated into the high-copy number Streptomyces shuttle plasmid, pWHM3, and introduced into S. lividans TK-24. A plasmid clone with 4.3-kb BamHI DNA of S. griseus (pMJJ201) was isolated by detecting for stimulatory effect on actinorhodin production by visual inspection. The 4.3-kb BamHI DNA was cloned into pWHM3 under the control of the strong constitutive ermEp promoter in both directions (pMJJ202); ermEp promoter-mediated transcription for coding sequence reading right to left: pMJJ203; ermEp promoter-mediated transcription for coding sequence reading left to right) and reintroduced into S. lividans TK-24. The production of actinorhodin was markedly stimulated due to introduction of pMJJ202 on regeneration agar. The introduction of pMJJ202 also stimulated production of actinorhodin and undecylproidigiosin in submerged culture employing the actinorhodin production medium. Introduction of pMJJ203 resulted in a marked decrease of production of the two pigments. Nucleotide sequence analysis of the 4.3-kb region revealed three coding sequences: two coding sequences reading left to right, ORF1 and ORF2, one coding sequence reading right to left, ORF3. Therefore, it was suggested that the ORF3 product was responsible for the stimulation of antibiotic production. The C-terminal region of ORF3 product showed a local alignment with Myb-related transcriptional factors, which implicated that the ORF3 product might be a novel DNA-binding protein related to the regulation of secondary metabolism in Streptomyces.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.404-409
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• 1997

Trout CYP1A-CAT expression construct was generated by cloning -3.5 Kb $5^I$ flanking DNA of trout liver CYP1A gene in front of CAT gene at pCAT-basic vector. Hepa 1 cells, which are known to contain a functional arylhydrbcarbon $receptor^I$ were transfected with trout CYP1A-CAT using lipofectin. 3-Methylcholanthrene (1 nM) was added into hepa 1 cells in culture in order to examine if $5^I$ flanking DNA of trout CYP1A gene could interact with mouse transactivating factors to bring about transcription of the chloramphenicol acetyltransferase(CAT) reporter gene. The level of CAT protein was measured by CAT ELISA and the level of CAT mRNA was determined by RTPCR. The treatment of 1 nM 3-methylcholanthrene resulted in two fold increases in CAT protein as well as CAT mRNA compared to untreated control hepa 1 cells. These data indicate that arylhydrocarbon receptors of mouse hepa 1 cells are functional to activate exogenously transfected trout CYP1A-CAT construct in terms of both transcription and translation of CAT. We also examined the effect of 3-methylcholanthrene on endogenous cyplal activity in hepa 1 cell. 3-Methylcholanthrene (1 nM) treatment to hepa 1 cells trahsfected with trout CYP1A-CAT construct stimulated the level of cyp1a1 mRNA by two folds and the activity of ethoxyresorufin-O-deethylase by two fold compared to that of control cells. In this study we reported that trout CYP1A-CAT reporter gene expression construct could be expressed by 3-methylcholanthrene treatment in mouse hepa 1 cells. Thus trout CYP1A-CAT could serve as a good model to study the mechanism of regulation of CYP1A1 gene expression.

• International Journal of Oral Biology
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• v.34 no.4
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• pp.177-183
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• 2009

Human mesenchymal stem cell (hMSCs) isolated from human adult bone marrow have self-renewal capacity and can differentiate into multiple cell types in vitro and in vivo. A number of studies have now demonstrated that MSCs can differentiate into various neuronal populations. Due to their autologous characteristics, replacement therapy using MSCs is considered to be safe and does not involve immunological complications. The basic helix-loop-helix (bHLH) transcription factor Olig2 is necessary for the specification of both oligodendrocytes and motor neurons during vertebrate embryogenesis. To develop an efficient method for inducing neuronal differentiation from MSCs, we attempted to optimize the culture conditions and combination with Olig2 gene overexpression. We observed neuron-like morphological changes in the hMSCs under these induction conditions and examined neuronal marker expression in these cells by RTPCR and immunocytochemistry. Our data demonstrate that the combination of Olig2 overexpression and neuron-specific conditioned medium facilitates the neuronal differentiation of hMSCs in vitro. These results will advance the development of an efficient stem cell-mediated cell therapy for human neurodegenerative diseases.

• KSBB Journal
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• v.11 no.2
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• pp.165-172
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• 1996

To obtain a correctly folded human proinsulin, export of proinsulin using Staphylococcal protein A signal sequence-mediated secretion pathway has been attempted in E.coli. A secretion operon for proinsulin was constructed by consecutively connecting T7 promoter, SPA ribosome binding site, SPA signal sequence gene, and human proinsulin gene. Little immunoreactive proinsulin was detected in the periplasmic space and. culture medium, and not even in cytoplasmic space. The qualitative analysis of transcribed proinsulin mRNA and the in vitro transcription/translation experiment suggests that the negligible level of proinsulin export appears to be due to intracellular degradation of proinsulin, rather than due to the blockage during translocation. However, expression of proinsulin fusion protein such as MBP-proinsulin could dramatically increase export of proinsulin in E.coli.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.239-247
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• 1996

An embryonic stem (ES) cell-based in vitro model system was examined to determine whether a simple differentiation of embryoid bodies (EB) in the suspension medium is useful to dissect early erythropoiesis. Characteristics of the differentiating EBs were monitored for their differentiation potential to generate hematopoietic cell types by general morphology, benzidine staining and two-step colony assays, and expressivity of several erythroid marker genes by the RT-PCR analysis for total cellular RNA prepared from the differentiating EBs. Every ematopoietic lineage cells were generated from the differentiating EBs with reproducible frequencies, similar to the other sophisticated differentiation protocols. Furthermore, the globin gene switching in differentiating ES cells paralleled the sequence of events found in the mouse embryo, and such that their expression was activated by at least 12 hrs later than those of erythroid-specific transcription factors, GATA-1 and Tal-1 The erythropoietic differentiation program initiated reproducibly and efficiently in this simple differentiation system in a suspension culture, such that this system may be useful for dissection of the molecular events of early erythropoiesis.

• Development and Reproduction
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• v.22 no.3
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• pp.235-244
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• 2018

We investigate the effect of endoplasmic reticulum (ER) stress inhibitor treatment during parthenogenetic activation of oocytes on the ER stress generation, apoptosis, and in vitro development of parthenogenetic porcine embryos. Porcine in vitro matured oocytes were activated by 1) electric stimulus (E) or 2) $E+10{\mu}M$ Ca-ionophore (A23187) treatment (EC). Oocytes were then treated by ER stress inhibitors such as salubrinal (200 nM) and tauroursodeoxychloic acid (TUDCA, $100{\mu}M$) for 3 h prior to in vitro culture. Parthenogenetic embryos were sampled to analyze ER stress and apoptosis at the 1-cell and blastocyst stages. The x-box binding protein 1 (Xbp1) mRNA and ER stress-associated genes were analyzed by RT-PCR or RT-qPCR. Apoptotic gene expression was analyzed by RT-PCR. At the 1-cell stage, although no difference was observed in Xbp1 splicing among treatments, BiP transcription level in the E group was significantly reduced by salubrinal treatment, and GRP94 and ATF4 transcription levels in EC group were significantly reduced by all treatments (p<0.05) compared to control. In the EC group, both apoptotic genes were reduced by ER stress inhibitor treatments compared to control (p<0.05) except Caspase-3 gene by TUDCA treatment. These results suggest that the treatment of ER stress inhibitor during parthenogenetic activation can reduce ER stress, and thereby reduce apoptosis and promote in vitro development of porcine parthenogenetic embryos.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1152-1157
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• 2005

The effect of carbon sources on nisin Z biosynthesis in Lactococcus lactis subsp. lactis A164 was studied in batch culture using M17 broth containing different carbon sources. Among the eleven carbon sources tested, glucose, sucrose, and lactose were suitable carbon sources for cell growth of L. lactis A164. In particular, cells grown on lactose produced at least 3-fold greater amount of nisin Z than those on other carbon sources. Galactose resulted in less amount of cell mass than did sucrose or glucose, but gave a higher level of nisin Z activity. Northern blot analysis revealed. that lactose increased the transcription of the nisZ pre-peptide gene. Although galactose was less efficient than lactose, it increased the transcription of nisZ along with a higher level of nisin Z than did sucrose and glucose. These results suggest that the increased nisin Z production is correlated with the induction of nisZ by lactose and galactose. Among all the carbon sources tested, no remarkable differences were observed in nisRK and nisFEG transcripts, indicating that the lactose- or galactose-mediated induction is unique to the nisZ promoter.