• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.247-265
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• 1998

To determine the sequence and expression of the VP7 gene of Korean isolates (CAU-9), viral RNA was purified and used for cDNA amplification by RT-PCR. The VP7 cDNA was cloned, sequenced, and expressed using baculovirus expression system. The result showed that the sequence homologies CAU-9 compared with foreign isolated strains Wa, 417, TMC-II, 95B and SA11 were ranged from 74.0% to 95.1 % of nucleotide sequence and 35% to 43% of amino acid sequence, respectively. High homology of CAU-9 was observed in Japanease isolates 417 (nucleotide sequence homology was 95.1% and amino acid sequence homology was 43%). To express VP7 gene, the VP7 cDNA was cloned into pCR-Bac vector and inserted into the genome of baculovirus adjacent to the polyhedrin promoter by cotransfection of Spodoptera frugiperda (Sf9) insect cells with wild type baculovirus DNA. In antigenic analysis of Sf9 cells inoculated with the recombinant VP7, immunofluorescence assay revealed positive for viral antigens. In metabolic labeling of Sf9 cell lysates infected with recombinant baculoviruses, it was revealed that the protein of 34 kDa was expressed. The limited study of expressed VP7 protein inoculated with guinea pigs failed to elicit neutalizing antibody. As a results, the sequence analysis and expression of VP7 protein of rotavirus CAU-9 isolated from an infant in Korea could permit the conformation and development of virus like particles which may be useful in designing vaccine strategy.

• Environmental Mutagens and Carcinogens
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• v.24 no.4
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• pp.171-179
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• 2004

Cytochrome P4503A4(CYP3A4) is the most abundnat CYPs in human liver, comparising approximately 30% of the total liver CYPs contents ans is involbed in the metabolism of more than 60% of currently used therapeutic drugs. The expression of CYP3A4 is induced by a variety of structurally unrelated xonobiotics including the antibiotic rifampicin and endogenous hormones, and might be mediated through steroid and xenobiotic receptor(SXR) system. The molecular mechanisms underlying regulation of CYP3A4 gene expression hae not been understood. In order to gain the insight of the molecular mechanism of CYP3A4 gene expression, study has been undertaken to investigate if the histone deacelylation is involved in the regulation of CYP3A4 gene expression by proximal promoter or not. Also SXR was investigated to see if they were involved in the regulation of CYP3A4 proximal promoter activity. HepG2 or Hena-I cells were transfected with a plasmid containing~1kb of the CYP3A4 proximal promoter region (-863 to +64bp) cloned in front of a reporter gene, luciferase, in the presence or absence of SXR or hER. Transfected cells were treated with CYP3A4 inducers such as rifampicin, PCN and RU 486, or with estradiol, in order to exmine to regulation of CYP3A4 gene expression in the presence or absence of trichostatin A (TSA). In HepG2 cells, CYP3A4 inducers and estradiol increased significantly the luciferase activity by CYP3A4 proximal promoter, only when TSA was co-treated after SXR cotransfection. In the case of Hepa-I cells CYP3A4 inducers and estradiol incressed modestly the luciferase activity when TSA was co-treated, but this increment was not enhanced by SXR cotransfection in contrast to HepG2 cells. Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated. Futher a trans-activation by SXR may demand other species-specific transcription factors.

• Journal of Life Science
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• v.28 no.2
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• pp.257-264
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• 2018

The YrdC superfamily is a group of proteins that are highly conserved in almost all organisms sequenced so far. YrdC in Escherichia coli was suggested to be involved in ribosome biogenesis, translation termination, cold adaptation, and threonylcarbamoyl adenosine formation in tRNA. In this study, to unambiguously demonstrate that yrdC is essential in E. coli, we constructed two yrdC mutant strains of E. coli and examined their phenotypes. In the temperature-sensitive yrdC mutant strain, cell growth stopped almost immediately under nonpermissive conditions and it appeared to accumulate 16S ribosomal RNA precursors without significant accumulation of 30S ribosomal subunits. We also cloned yeast and human homologs and demonstrated that they complement the E. coli yrdC-deletion strain. By mutational study, we demonstrated that the concave surface in the middle of the YrdC protein plays an important role in E. coli, yeast, and human versions. By comparison of two yrdC-deletion strains, we also unambiguously demonstrated that yrdC is essential for viability in E. coli and that the functions of its yeast and human homologs overlap with that of E. coli YrdC.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.8
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• pp.1175-1182
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• 2017

Objective: To create genetically modified goat as a biopharming source of recombinant human lacotoferrin (hLF) with transcription activator-like effector nucleases. Methods: TALENs and targeting vector were transferred into cultured fibroblasts to insert hLF cDNA in the goat beta-lactoglobulin (BLG) locus with homology-directed repair. The gene targeted efficiency was checked using sequencing and TE7I assay. The bi-allelic gene targeted colonies were isolated and confirmed with polymerase chain reaction, and used as donor cells for somatic cell nuclear transfer (SCNT). Results: The targeted efficiency for BLG gene was approximately 10%. Among 12 Bi-allelic gene targeted colonies, five were used in first round SCNT and 4 recipients (23%) were confirmed pregnant at 30 d. In second round SCNT, 7 (53%), 4 (31%), and 3 (23%) recipients were confirmed to be pregnant by ultrasound on 30 d, 60 d, and 90 d. Conclusion: This finding signifies the combined use of TALENs and SCNT can generate biallelic knock-in fibroblasts that can be cloned in a fetus. Therefore, it might lay the foundation for transgenic hLF goat generation and possible use of their mammary gland as a bioreactor for large-scale production of recombinant hLF.

• Environmental Mutagens and Carcinogens
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• v.24 no.3
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• pp.121-127
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• 2004

Cytochrome P4501B1(CYP1B1) is known to be inducible by xenobiotic compounds such as policyclic aromatic hydrocarbon(PAH) and dioxins such as 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). And these induction of CYP1B1 is also regulated by many categories of chemicals. In order to investigate the effects of several chemicals on CYP1B1 gene expression in Hepa-I and MCF-7 cells, 5' flanking DNA of human CYP1B1 was cloned into pGL3 basic vector containing luciferase gene, and then transfected into these cells. After treatment of chemicals, the luciferase activity was measured. CYP1B1 enzyme metabolize PAHs and estradiol. CYP1B1 metabolize estradiol to 4-hydrozyestradiol that is considered as carcinogenic metabolite. Luciferase activity was induced about 20 folds over that control by 1 nM TCDD (2,3,7,8-tetrachloto-p-dioxin). Recent industrialized society, human has been widely been exposed to widespread environmental contaminants such as PAHs(polycyclic aromatic hydrocarbon) that are originated from the imcomplete combustion of hydrocarbons. PAHs are known to be ligands of the AhR(aryl hydrocarbon receptor). Induction of cytochrome P4501B1(CYP1B1) in cell culture is widely used as a biomarker for PAHs. Therefore we have studied the effect of PAHs in the human breast cancer cells MCF-7 to evaluate bioactivity of PAHs. We have used the United State of America EPA selected 13 different PAHs, PAHs mixtures and extracts from environmental samples to evaluate the bioassay system. We examined effects of PAHs on the CYP1B1-luciferase reporter gene and CYP1B1 mRNA level. Benzo(k)fluoranthene and dibenzo(a, h)anthracene showed strong response to CYP1B1 promoter activity stimulation, and also CYP1B1 mRNAs increase in MCF-7 cells in a concentration-dependent manner. Acenaphthene, anthracene, benzo(b)fluoranthene, fluorene, fluoranthene, anphthanlene, pyrene, phenanthrene and carbazole were weak responders in MCF-7 cells. RT-PCR analysis indicated that PAHs significantly up-regulate the level of CYP1B1 mRNA.

• KSBB Journal
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• v.17 no.4
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• pp.370-375
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• 2002

Isolation of a gene and determination of its expression pattern are essential in understanding its function. Among the genes localized in 12ql3, stSG3435 EST was chosen to study its expression pattern. The full-length CDNA was cloned by screening of human brain CDNA library and its sequence was determined by serial deletion followed by automated sequencing of the clones with overlapping fragments. The sequence analysis revealed that stSG 3435 CDNA displayed 100% identity to human MYGI and 86% identity to mouse melanocyte proliferation gene-1 (Gamm 1) originally identified from melanocyte, suggesting that MYGI determined by Northern blot analysis revealed the strongest expression in testes with ubiquitous expression in all the tissues tested. In order to investigate the cellular localization of its protein product, the green fluorescence protein gene was fused into the full-length coding sequence of MYGI, Transfection of the fusion construct followed by confocal microscopy resulted in the green fluorescence signal as a punctate state in cytoplasm indication that MYGI was localized in one of the cellular organelles.

• Environmental Mutagens and Carcinogens
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• v.24 no.4
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• pp.198-205
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• 2004

Cytochrome P4501B1(CYP1B1) is known to be inducible by xenobiotic compounds such as policyclic aromatic hydrocarbon(PAH) and dioxins such as 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). And these induction of CYP1B1 is also regulated by many categories of chemicals. In order to investigate the effects of several chemicals on CYP1B1 gene expression in Hepa-I and MCF-7 cells, 5' flanking DNA of human CYP1B1 was cloned into pGL3 basic vector containing luciferase gene, and then transfected into these cells. After treatment of chemicals, the luciferase activity was measured. CYP1B1 enzyme metabolize PAHs and estradiol. CYP1B1 metabolize estradiol to 4-hydrozyestradiol that is considered as carcinogenic metabolite. Recent industrialized industrialized society, human has been widely been exposed to widespread environmental contaminants such as PAHs(polycyclic aromatic hydrocarbon) that are originated from the imcomplete combustion of hydrocarbons. PAHs are known to be ligands of the AhR(aryl hydrocarbon receptor). Induction of cytochrome P4501B1(CYP1B1) in cell culture is widely used as a biomarker for PAHs. Therefore we have studied the effect of PAHs in the human breast cancer cells MCF-7 to evaluate bioactivity of PAHs. We have used the United State of America EPA selected 13 different PAHs, PAHs mixtures and extracts from environmental samples to evaluate the bioassay system. We examined effects of PAHs on the CYP1B1-luciferase reporter gene and CYP1B1 mRNA level. Benzo(k)fluoranthene and dibenzo(a, h)anthracene showed strong response to CYP1B1 promoter activity stimulation, and also CYP1B1 mRNAs increase in MCF-7 cells in a concentration-dependent manner. RT-PCR analysis indicated that PAHs significantly up-regulate the level of CYP1B1 mRNA. Some flavonoids such as genistein, daidzein, chrysin, naringenin and morin were also investigeted. These flavonoids decreased B(k)F infuced luciferase activity at low concentration. But, these flavonoids exhibited stimulatory effect at high concentration.

• Journal of Life Science
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• v.17 no.11
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• pp.1497-1504
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• 2007

To investigate the function and secretion of human thrombopoietin (TPO) in mammalian cells, hTPO cDNA was cloned using human liver cDNA, and recombinant hTPO (rec-hTPO) was produced in CHO cell lines. In addition, six N-linked glycosylation sites were substituted for Ala to elucidate the role of each carbohydrate chain. To analyze the biological activity, rec-hTPO protein was injected subcutaneously. Blood was withdrawn for platelet determination. The metabolic clearance rate (MCR) was also analyzed at the 1, 4, 10 and 24 hr after tail vein injection. Wild-type TPO (WT) was efficiently secreted into the medium. However, a hTPO mutant with 116 deleted nucleotides detected by PCR cloning was not secreted. The N-linked glycosylation sites had nearly the same expression quantity as rec-hTPO WT apart from mutants 3 and 4. The glycosylation site of mutant 4 appeared to be an indispensable site for hTPO secretion. Also characterized was the biological activity through an injection with rec-hTPO (10 ng) to ICR mice (7 weeks). The result of the blood analysis showed a considerable increase in the platelet number six days after He injection. To analyze the pharmacokinetics, rec-hTPO was injected into the tail vein (5 ng). The result was 200 pg/ml 1hr after this injection. Following this, it dramatically decreased and virtually disappeared 10 hours after the injection. Thus, rec-hTPO may be a treatment for thrombopenia by the production of the high active rec-hTPO. In addition, hTPO can permit the development of potent new analogues that stimulate the platelet value.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.46-51
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• 2000

Salmonella typhi is one of important causes of human enteric infections. S. typhi KNIH100 was isolated from a patient of typhoid fever in Korea. We cloned a 5.0 kb SalⅠ fragment containing the aroA gene encoding a 5-enolpyruvylshikimate-3-phosphate synthetase from chromosomal DNA of this strain. This recombinant plasmid was named pSAL80. E. coli CGSC2829, an aroA- mutant, was not grown on the M9 minimal medium but E. coli CGSC2829 (pSAL80) was grown on the M9 minimal medium. The aroA gene was composed of 1,284 base pairs with ATG initiation codon and TAA termination codon. Sequence comparison of the aroA gene exhibited 99%, 98%, and 77% identity with those of S. typhi Ty2, S. typhimurium, and E. coli respectively. As in the cases of Shigella sonnei and E. coli, the serC and aroA genes lie in a single operonic structure.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.603-609
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• 2016

Brucellosis affects a wide range of host species, including humans and many livestock animals. Chronic infections of the disease make antibiotic treatment costly, and the current vaccine used in livestock has not been approved for human use. This study investigated the possible use of the Brucella abortus outer membrane protein A (OmpA) as a candidate subunit vaccine in an infected mouse model. The ompA gene was cloned and overexpressed, and the recombinant OmpA (rOmpA) protein fused to maltose binding protein (MBP) was purified in Escherichia coli. Immunogenicity was verified through western blotting, and mice were immunized and challenged to evaluate its protective effect. Mice treated with rOmpA exhibited induced humoral and host cell-mediated responses, with a significant increase in immunoglobulin G (IgG1 and IgG2a) and cytokine levels, especially TNF-α and IL-12, compared with the control groups treated with either MBP or PBS. In conclusion, rOmpA should be highly considered as a future subunit vaccine for brucellosis, and further studies regarding rOmpA and its protective ability are suggested.