• 미생물학회지
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• 제27권2호
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• pp.85-91
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• 1989

조직특이적 및 일반적 유전자 발현에 미치는 SV40와 murine cytomegalovirus (MCMV) enhancer의 영향을 조사하였다. 이를 위하여 chloramphenicol acetyl transferase (CAT) 유전자의 아래쪽에 이들 enhancer들을 삽입한 재조합 플라스미드 들을 제조하였다. 원숭이세포(CV1PO)와 HeLa 세포에 이들 플라스미드들을 이입시킨 후, CAT 유전자가 발현되는 정도를 조사하였다. Enhancer가 없는 플라스미드에 비해 SV40와 MCMV enhancer는 CAT의 발현을 각각 20배와 150배로 가중시켰다. CAT 유전자의 앞에 있는 SV40 프로모터를 2.2kbp의 소성장호르몬(bGH) 유전자의 조절부위로 치환한 경우는 enhancer가 있어도 전혀 CAT 의 말현이 검출되지 않았다. 조절부위을 230 bp 로 짧게 하여 치환한 경우는, SV 40 enhancer 가 있을 때, CAT의 말현이 매우 증가하였다. 이와는 내조적으로 더 강한 MCMV enhancer는 bGH 특이적인 발현을 별로 증가시키지 못하였다.

• 한국양식학회지
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• 제10권4호
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• pp.409-415
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• 1997

The carp $\beta$-actin regulatory sequences and RSV/LTR promoter were tested whether they are functinal to express linked structure gene (chloramphenicol acetyltransferas, CAT) in olive flounder (Paralichthys olivaceus) by determining the patterns of gene expression following intramuscular in vivo direct injection. The injection experiments with various concentrations of both pRSVCAT and pFV4CAT clearly revealed the effectiveness of DNA dosage on expression of CAT. The increase of CAT activity was linear in both plasmids, and maximal CAT activity was obtained with 100 ug of pFV4CAT injection. The amounts of CAT expression with pFV4CAT-injected fist were higher than those with pRSVCAT-injected fish. CAT activity was readily detectable as early as one day after injection, slightly increased at day 2, and declined over time. Most amount of DNA intramuscularly injected into olive flounder muscles persisted extrachromosomally without showing any integrated or replicated form in vivo.

• Archives of Pharmacal Research
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• 제20권5호
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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.

• Journal of Microbiology
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• 제34권4호
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• pp.334-340
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• 1996

The enzyme, cis,cis-muconate lactonizing enzyme has been proposed to play a key role in the $\beta$-ketoadipate pathway of benzoate degradation. A 3.2-kb EcoRI fragment termed as pRSU2, isolated from a Pseudomonas cepacia genomic library was able to complement the catB defective mutant. Several relevant restriction enzyme sites were determined within the cloned fragment. In Pseudomonas putida SUC2 carrying pRSU2, the enzyme activity was relatively higher than those of the induced or partially induced state of wild type P. putida PRS2000. It was probably due to higher expression of P. cepacia catB in P. putida PRS2000. It was probably due to higher expression of P. cepacia catB in P. putida. One possible interpretation of these results is that the catB promoter in P. cepacia is recognized within P. putida, resulting in the almost same expression level.

• Journal of Microbiology
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• 제35권2호
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• pp.152-157
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• 1997

Infection of human fibroblast (HF) cells with human cytomegalovirus (HCMV) result in changes in the intracellular level of second messengers. Since nitric oxide (NO) production has been known to be related with other second messengers, it is probable that HCMV infection of HF cells may involve NO. To test this possibility, the amount of NO was measured following ogenous addition of NO generators such as sodium nitroprusside (SNP) or S-nitroso-N-a-cetylpenicillamine (SNAP) immediately after HCMV infection, however, inhibited virus multiplication. Furthermore, immunoblot experiment using monoclonal antibody to HCMV major immediate early (MIE) proteins or CAT assay using pCMVIE/CAT (plasmid containing CAT gene driven by HCMV MIE promoter) revealed that SNP or SNAP blocked the MIE gene expression. SNP was more effective than SNAP in hibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP in inhibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP. Although the mechanism for the inhibition of HCMV multiplication and MIE gene expression by NO is still elusive some correlation with NO-mediated inhibition of HCMV-induced increase in cytosolic free Ca$\^$2+/ concentration ([Ca$\^$2+/]) was observed. The increase of [Ca$\^$2+/] following HCMV infection was inhibited by SNP, and less effectively by SNAP. Raising [Ca$\^$2+/ with bromo-A23187 partially reversed the SNP block of MIE gene expression. Thus, there appear to e some relationships among NO. [Ca$\^$2+/], and HCMV MIE gene expression.

• BMB Reports
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• 제30권4호
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• pp.269-273
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• 1997

Heptocvte-specific expression induced by Hepatitis B virus (HBV) enhancer 2-core gene promoter was examined in various hepatocyte and non-hepatocyte cell lines. using non-viral and retroviral vector systems in which chloramphenicol acetyltransferase (CAT) is used as a reporter. The non-viral plasmid containing the HBV enhancer 2-core promoter exhibited 22 and 66% of CAT activities in hepatoma cell lines. HepG2 and Hep3B, respectively when compared with CAT activity expressed by CMV promoter. The CAT activities, however. were found to be marginal in other tested hepatoma cell lines as well as mouse primary hepatocytes and non-hepatocytes. The HBV enhancer 2 located upstream the CMV promoter did not affect the CMV promoter activity nor provided hepatocyte-specific expression. Transfection of retroviral plasmid DNA containing the HBV enhancer 2-core promoter as an internal promoter exhibited high and specific CAT expression in HepG2 and Hep3B cell lines but the activity value was 5 to 10 fold lower than the non-viral plasmid with identical promoter. These results suggest that the usage of HBV enhancer 2-core promoter for liver specific expression is limited to certain vectors and hepatocyte cell lines.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.128-128
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• 1995

To investigate the mechanism of the regulation of cytochrome P450IA1 gene expression, ethoxyresorufin deethylase(EROD) and benzo(a)pyrene hydroxylase in B6 mouse liver, in isolated perfused rat liver system. and in B6 mouse hepatocyte Hepa-I cells were examined. In C57BL/6N mouse, 3-methylcholan- throne( 3MC ) treatment have resulted in the stimulation of EROD activity based on fluorometry by 2.79 fold comparirng with that of control. Measurement of mRNA of cytochrome P450 was carried out by either nothern blot or dot blot analysis. Findings are similar to that of studies with enzymes. Furhtermore, when RTPCR method was applied to detect mRNA in Hepa I cell and liver tissues the results were more clear. Cytochrome P450IA1 upstream DNA containing CAT construct was transfected into Hepa-1 cells. After transfection of CAT construct, 3MC and flavonoids, such as, chrysin, hesperetin, kaempferol, morin, myricetin and aminoyrine were treated. 48 Hours after treatments, cells were harvested and assayed for CAT mRNA by RTPCR. 3MC treatment to hepa I cells transfected with trout P450IA1-CAT construct increased CAT mRNA by 2.81 fold when it was compared with that of control. This increase CAT mRNA was decreased by concomitantly treated flavonoids and aminopyrine. The level of CAT protein was 29.2-58.0% of 3MC stimulated CAT protein. Results of this study suggested that RTPCR seems to be a very good method to study regulation of gene expression in liver tissue or Hepa cells.

• 한국동물학회지
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• 제37권2호
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• pp.137-143
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• 1994

Microiniection of genes Into Xenopus laeuis oocvtes in highly useful in the annvsis of gene regulation, since a large number of oocvtes can be injected in a relatively short time. The GRP78 enhancer has been identified to a 291-bp fragment that spans a region of GRP78 promoter between -378 and -87 (Lin et at., 1986: Kim and Lee, 1989). We examined whether this GRP78 enhancer is effective in directing expression of heterologous gene in Xenopus laeuis oocytes. The chloramphenicol acetvltransferase (CAT) fusion constructs containing the GRP78 promoter and the SV4O early promoter were constructed and were injected into nuclei of Xencpus laeuis oocvtes. The recipient oocvtes were then assayed for CAT activity. The fusion constructs exhibited higher activity as compared to SV40 promoter tested here. The GRP78 enhancer showed 8.5- to 9.2-fold enhancement over that of the SV4O promoter. The orientation of GRP78 enhancer with respect to the direction of CAT transcription unit had no significant effect. Thus, the GRP78 enhancer is a viable candidate for the construction of expression system for use in Xenopus laevss oocvtes and will be important for the studY of a gene expression throughout development.

• 한국미생물·생명공학회지
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• 제20권6호
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• pp.637-641
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• 1992

한국 재래식 된장.간장 발효균 Bacillus sp. SSA3 균주의 expression vector를 개발하기 위해 Bacillus sp. SSA3의 chromosomal DNA로부터 유전자의 promoter 부위를 cloning 하였다. Recombinant plasmid를 제작하기 위하여 Bacillus sp. SSA3의 chromosomal DNA을 HindIII로 절단한 단편을 pGR71 plasmid의 CAT gene과 pUC18 plasmid의 $\beta$-galactosidase gene의 전방에 삽입시킨 후, E.coli JM109에 형질전환하였다.E. coli JM109의 chloramphenicol 내성 clones으로부터 6 recombinant plasmid를 선별하였다. 이들 선별된 plasmid는 Bacillus sp. SSA3의 expression vector로 사용시 각 재조합 plasmid 중에 삽입된 promoter의 염에 대한 영향의 정도를확인하기 위해 10% NaCl이 첨가된 LB medium상에서 배양하였을 때, 이들 중 Bacillus sp. SSA3의 4 clones은 융합 CAT gene의 발현이 강하게 감소되었으나 2 clones은 약하게 저해되었다.

• Current Research on Agriculture and Life Sciences
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• 제11권
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• pp.81-89
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• 1993

xylA 유전자의 발현에 관한 xylR 유전자의 조절 메카니즘을 밝히기 위한 연구의 일환으로 xylA 프로모터 하류에 cat 유전자를 삽입시켜 Pxyl-cat-xylA 융합 플라스미드인 pEXC131을 제작하였고 이 플라스미드를 xylA 변이주인DH77로 형질전환시킨 결과 xylose의 유도시에만 Cm 내성과 xylose isomerase활성이 나타났다. pEXC1131/DH77에 NTG를 처리하여 xylose 유도없이도 Cm 내성과 xylose isomerase의 활성을 나타내는 xylA 유전자의 구성적 변이주인 pEXC131-39를 xylR 변이주인 DH60으로 형질전환시킨 균주가 xylose에 의한 유도와 무관하게 Cm 내성 및 xylose isomerase 활성을 가지는 것으로 보아 xylA 유전자의 프로모터부위의 변이에 의한 구성적 변이주임을 확인하였다.