• Title/Summary/Keyword: CAT-gene

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Replication of Hepatitis B Virus is repressed by tumor suppressor p53 (간암치료신약개발 및 이의 제제화 연구)

  • 이현숙;허윤실;이영호;김민재;김학대;윤영대;문홍모
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.178-178
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    • 1994
  • Hepatitis B Virus (HBV) is a DNA virus with a 3.2kb partially double-stranded genome. The life cycle of the virus involves a reverse transcription of the greater than genome length 3.5kb mRNA. This pegenomic RNA contains all the genetic information encoded by the virus and functions as an intermediate in viral replication. Tumor suppressor p53 has previously been shown to interact with the X-gene product of the HBV, which led us to hypothesize that p53 may act as a negative regulator of HBV replication and the role of the X-gene product is to overcome the p53-mediated restriction. As a first step to prove the above hypothesis, we tested whether p53 represses the propagation of HBV in in vitro replication system. By transient cotransfection of the plasmid containing a complete copy of the HBV genome and/or the plasmid encoding p53, we found that the replication of HBV is specifically blocked by wild-type p53. The levels of HBV DNA, HBs Ag and HBc/e Ag secreted in cell culture media were dramatically reduced upon coexpresion of wild-type p53 but not by the coexpression of the mutants of p53 (G154V and R273L). Furthermore, levels of RNAs originated from HBV genome were repressed more than 10 fold by the cotransfection of the p53 encoding plasmid. These results clearly states that p53 is a nesative regulator of the HBV replication. Next, to addresss the mechanism by which p53 represses the HBV replication, we performed the transient transfection experiments employing the pregenomic/core promoter-CAT(Chloramphenicol Acetyl Transferase) construct as a reporter. Cotransfection of wild-type p53 but not the mutant p53 expression plasmids repressed the CAT activity more than 8 fold. Integrating the above results, we propose that p53 represses the replication of HBV specifically by the down-regulation of the pregenomic/core promoter, which results in the reduced DNA synthesis of HBV. Currently, the mechanism by which HBV overcomes the observed p53-mediated restriction of replication is tinder investigation.

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A Cold-Adapted Epoxide Hydrolase from a Strict Marine Bacterium, Sphingophyxis alaskensis

  • Kang, Ji-Hyun;Woo, Jung-Hee;Kang, Sung-Gyun;Hwang, Young-Ok;Kim, Sang-Jin
    • Journal of Microbiology and Biotechnology
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    • v.18 no.8
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    • pp.1445-1452
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    • 2008
  • An open reading frame (ORF) encoding a putative epoxide hydrolase (EHase) was identified by analyzing the genome sequence of Sphingophyxis alaskensis. The EHase gene (seh) was cloned and expressed in E. coli. To facilitate purification, the gene was fused in-frame to 6$\times$ histidine at the C-terminus. The recombinant EHase (rSEH) was highly soluble and could be purified to apparent homogeneity by one step of metal affinity chromatography. The purified SEH displayed hydrolyzing activities toward various epoxides such as styrene oxide, glycidyl phenyl ether, epoxyhexane, epoxybutane, epichlorohydrin, and epifluorohydrin. The optimum activity toward styrene oxide was observed at pH 6.5 and $35^{\circ}C$. The purified SEH showed a cold-adapted property, displaying more than 40% of activity at low temperature of $10^{\circ}C$ compared with the optimum activity. Despite the catalytic efficiency, the purified SEH did not hydrolyze various epoxides enantioselectively. $K_m$ and $k_{cat}$ of SEH toward (R)-styrene oxide were calculated as 4$\pm$0.3 mM and 7.42$s^{-1}$ respectively, whereas $K_m$ and $k_{cat}$ of SEH toward (S)-styrene oxide were 5.25$\pm$0.3 mM and 10.08$s^{-1}$ respectively.

Effects of Jowiseungcheung-tang Extract on the Lipid Metabolism, Anti-oxidation and Inflammatory Reflex High Fat Diet Obese Rats (조위승청탕(調胃升淸湯) 추출액이 비만유도 쥐의 지질대사, 항산화계 및 염증반응계에 미치는 영향)

  • Oh, Sung-Won;Kim, Byoung-Woo
    • The Journal of Internal Korean Medicine
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    • v.34 no.1
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    • pp.1-13
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    • 2013
  • Objectives : The purpose of this study was to investigate the effects of Jowiseungcheung-tang (JWSCT) extract on the lipid metabolism, anti-oxidation and inflammatory reflex. Methods : Male Sprague-Dawley rats were fed a high fat diet for 8 weeks and were randomly divided into 4 groups (10 mice in each group): control group, 100 mg/kg JWSCT group, 200 mg/kg JWSCT group, 300 mg/kg JWSCT group. The control group was administered 100 mg/kg of water, but the other three groups were administered 100, 200, 300 mg/kg JWSCT extract for 4 weeks. After 4 weeks, we measured lipid level, thiobarbituric acid reactive substance (TBARS), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and cytokines in plasma and liver. The gene expression level and the ratio of apo-B and apo-E were then investigated by way of reverse transcription -polymerase chain reaction (RT-PCR). Results : In the JWSCT group, compared with the control, free fatty acid, triglyceride, total cholesterol, LDL-cholesterol, TBARS, IL-$1{\beta}$, IL-6 and TNF-${\alpha}$ decreased significantly in plasma and liver. However HDL-cholesterol, IL-10, GSH-Px, SOD and CAT increased. In the JWSCT group, compared with the control, the gene expression level and the ratio of apo-A and apo-E decreased significantly in the RT-PCR analysis. Conclusions : The extract of JWSCT has anti-obesity, anti-inflammatory and anti-oxidant effects.

Protective Effect of Galgeun-Tang Against $CCl_4$ Induced Hepatotoxicity (갈근탕의 사염화탄소에 의한 간세포 독성 억제효과)

  • Oh, Su-Young;Seo, Sang-Hee;Lee, Ji-Hye;Lee, Ji-Seon;Ma, Jin-Yeul
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.4
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    • pp.663-668
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    • 2011
  • Galgeun-tang (GGT) has been a great source for treating cold diseases in the folk medicine recipe. Carbon tetrachloride ($CCl_4$) is one type of hepatotoxin that can eventually cause liver injury. During the experiment, we first studied the protective effects of GGT against $CC_4$-induced hepatotoxicity. GGT was pretreated for 3 h, and 1% $CCl_4$ was added to mouse primary liver cells. After 4 h, ROS generation and expression of antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)) were analyzed by FACS and real time PCR. Also, the activities of ALT and LDH were measured using cultured medium. The hepatic levels of TNF-alpha and iNOS, which are related to inflammation and stress response gene, HSP72 and HO-1 were analyzed by PCR or real time PCR. Liver tissues were analyzed by HE stain. From the observation, we discovered that GGT treatment protects $CCl_4$-induced hepatotoxicity, and that GGT pretreatment decreases ROS generation, TNF-alpha and iNOS expression. However, gene expression of CAT, SOD, GPx, HSP72 and HO-1 were increased by GGT. These results lead to the conclusion that GGT has protective effects against $CCl_4$-induced hepatotoxicity.

Structure and Function of the phnF Gene of Pseudomonas sp. Strain DJ77 (Pseudomonas sp. Strain DJ77에서 phnF 유전자의 구조)

  • 이성훈;김성재;신명수;김치경;임재윤;이기성;민경희;김영창
    • Korean Journal of Microbiology
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    • v.33 no.2
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    • pp.92-96
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    • 1997
  • The 6.8 kb Xhol fragment of chromosomal ONA of Pseudomonas sp. 0177 contains the phnDEFG genes involved in the degradation of polyaromatic hydrocarbons and chlorinated aromatics. Here, we report the nucleotide sequence of the ORF encoding a polypeptide consisted of 143 amino acids with a Mr of 13,859. The nucleotide sequence of the ORF is 99% and 68.6% identical to the downstream region of catE of Sphingomonas sp. strain HV3 and the ORF between xylE and xylG of Sphingomonas yanoikuyae Bl, respectively. The deduced amino acid sequence of the PhnF has 62.3% identity with the amino acid encoded hy orfY region of Citrobacter freundii DSM30040. We now confirm that the ORF is located between the catechol 2,3-dioxygenase (C230), phnE, and 2-hydroxymuconic semialdehyde dehydrogenase (2HMSO), phnG.

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The effect of light on follicular development in laying hens

  • Cheng, Shi Bin;Li, Xian Qiang;Wang, Jia Xiang;Wu, Yan;Li, Peng;Pi, Jin Song
    • Animal Bioscience
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    • v.34 no.11
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    • pp.1766-1775
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    • 2021
  • Objective: The oxidative stress status and changes of chicken ovary tissue after shading were studied, to determine the mechanism of the effect of shading on follicular development. Methods: Twenty healthy laying hens (40 weeks old) with uniform body weight and the same laying rate were randomly divided into two groups (the shading group and normal light group). In the shading group, the cage was covered to reduce the light intensity inside the cage to 0 without affecting ventilation or food intake. The normal lighting group received no additional treatment. After 7 days of shading, oxidative stress related indicators and gene expression were detected. Results: Analysis of paraffin and ultrathin sections showed that apoptosis of ovarian granulosa cells (GCs) increased significantly after light shading. Enzyme linked immunosorbent assay results revealed that the levels of total antioxidant capacity, malondialdehyde, superoxide dismutase (SOD), glutathione, catalase (CAT), and other substances in the sera, livers, ovaries, and follicular GCs of laying hens increased significantly after shading for 7 days; and reactive oxygen species (ROS) levels in the livers of laying hens also increased significantly. ROS in the serum, ovarian and GCs also increased. After shading for 7 days, the levels of 8-hydroxy-2 deoxyguanosine in the sera and ovarian tissues of laying hens increased significantly. Cell counting kit-8 detection showed that the proliferation activity of GCs in layer follicles decreased after shading for 7 days; the expression level of the anti-apoptotic gene B-cell lymphoma-2 in ovarian tissue and follicular GCs was significantly reduced, and the expression levels of pro-apoptotic caspase 3 (casp3), and SOD, glutathione peroxidase 2 (GPX2), and CAT were all significantly increased. Conclusion: Oxidative stress induced by shading light has a serious inhibitory effect on follicular development during reproduction in laying hens.

Expression and Characterization of catA1 (catechol 1,2-dioxygenase I1) of Acinetobacter lwoffii K24 in Escherichia coli

  • Kim, Seung-Il;Kweon, Soo-Mi;Kim, Soo-Hyun;Ha, Kwon-Soo
    • BMB Reports
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    • v.30 no.5
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    • pp.342-345
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    • 1997
  • Catechol 1,2-dioxygenase $I_1$ (CD $I_1$) gene of Acinetobacter Iwoffii K24, $catA_1$ was expressed in Escherichia coli and was partially purified by using a MonoQ column. Expressed CD $I_1$ had the same molecular weight as purified CD $I_1$ from A. Iwoffii K24 on SDS-PAGE. Expressed CD $I_1$ was also identified by Western blotting and peptide sequencing of N-terminal and internal regions. When compared with purified CD $I_1$ of A. Iwoffii K24, expressed CD $I_1$ had similar substrate specificities and the effects of compounds on enzyme activity. N-terminal amino acid sequence of CD I expressed in E. coli was the same as that of purified CD $I_1$, suggesting that CD $I_1$ may be under the same posttranslational processing in E. coli and A. Iwoffii K24.

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Effect of Transgenic Genotype on Transgene Expression in Mud Loach (Misgurnus mizoIepis): I. Copy Number-Dependent Expression in Gynogenetically Derived Homozygous Transgenics

  • Nam Yoon Kwon;Noh Jae Koo;Kim Dong Soo
    • Fisheries and Aquatic Sciences
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    • v.4 no.1
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    • pp.39-46
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    • 2001
  • To examine the effect of copy number-dependent transgenic genotype on the expression of foreign gene, stable hemizygous and homozygous transgenic breeding line was established using artificial parthenogenesis. For this purpose, induced diploid gynogenetic transgenesis was optimized in mud loach (Misgurnus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to $4,050\;ergs/mm^2$ The UV-irradiated sperm were inseminated into eggs from recessive color strain (yellow) or heterozygous transgenic mud loach containing CAT gene. Cold shock at $2^{\circ}C$ for 60 min, 5 min post fertilization successfully restored the diploidy of eggs inseminated with UV-irradiated sperm. Restoration to diploidy was confirmed by flow cytometry and gynogenetic status was verified by examining maternal exclusive inheritance of multi-locus DNA fingerprints, body color and transgenic marker. Putative isogenic transgenic fish clearly showed homozygous status at trans gene locus based on Southern blot hybridization and progeny testing. Further, such homozygous gynogenetic diploids revealed the increased levels of transgene expression, when compared to those of heterozygous (hemizygous) transgenic fish.

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Cloning of Major Capsid Protein Gene of Pseudorabies Virus and Expression by Baculovirus Vector System (Pseudorabies Virus의 Major Capsid Protein 유전자의 클론닝과 Baculovirus Vector System에 의한 발현)

  • An, Dong-Jun;Jun, Moo-Hyung;Song, Jae-Young;Park, Jong-Hyeon;Hyun, Bang-Hun;Chang, Kyung-Soo;An, Soo-Hwan
    • The Journal of Korean Society of Virology
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    • v.26 no.2
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    • pp.151-162
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    • 1996
  • Pseudorabies is caused by Pseudorabies virus (PRV: Aujeszky's disease virus) of Herpesviridae that is characterized by 100 to 150nm in size with a linear double-stranded DNA molecule with of approximately $90{\times}10^6Da$. This disease affects most of domestic animals such as swine, cattle, dog, sheep, cat, chicken, etc. causing high mortality and economic losses. In swine, young piglets show high mortality and pregnant sows, reproductive failures. However the adult swine reveals no clinical signs in general. But they become a carrier state and play an important role for propagation of the disease. In this study, the nucleotide sequence of major casid protein gene of PRV, Yangsan strain isolated from the diseased swine in Korea was analyzed, and the recombinant MCP was produced by expression of the MCP gene in Sf-9 cell using baculovirus transfer vector system. As result, in BamHI digestion, MCP gene locus of PRV YS strain showed different from that of Indiana S strain. The patterns of enzyme mapping were also found to be unidentical each other. The sequence of the MCP gene partially analyzed showed 98.09% identity to Indiana S strain. The expression of MCP in Sf-9 cell cotransfected by pVLMCP-44 baculovirus expression vector was characterized by Southern blot hybridization, immunofluoresent and immunocytochemical tests, SDS-PAGE and Western blotting. The rMCP with M.W. 142kDa was most effectively expressed in Sf-9 cells at the 3-4th days post inoculation of the recombinant baculovirus by 2 moi.

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Transcriptional Regulation of the Murine Dopamine Receptor Regulating Factor (DRRF) Gene (생쥐 도파민 수용쳬 조절인자 (DRRF) 유전자의 전사조절)

  • Kim Ok Soo;Lee Young-Choon;Lee Sang-Hyeon
    • Journal of Life Science
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    • v.15 no.1 s.68
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    • pp.55-60
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    • 2005
  • The murine dopamine receptor regulating factor (DRRF) gene is transcribed from a TATA-less promoter that has several putative Sp1 binding sites. The present investigation identifies functional transcription factors that modulate the expression of this gene, In the $D_2-expressing$ NB41A3 cells, Spl potently activates transcription from the DRRF promoter in pCAT-DRRF-1153/+17, but DRRF effectively inhibits it. Deletion of the 31 bp fragment between -1153 and -1122 decreased transcription down to about $60\%$. This fragment contains a functional API binding site. In addition, deletion of the 129 bp region between -901 and -772 further decreased transcription. The latter region has a functional AP2 binding site. Using a DRRF_AP1 (bases -1153 to -1121) probe, a specific retarded band was observed, and the unlabeled AP1 consensus competitor could effectively compete away this retarded band. In addition, using a DRRF_AP2 (bases -873 to -846), a specific retarded band was observed, and the unlabeled AP2 consensus competitor could effectively compete away this retarded band. The present observations suggest that Spl and DRRF regulate the DRRF promoter and that both API and AP2 also modulate this gene.