• Parasites, Hosts and Diseases
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• 제44권1호
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• pp.21-26
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• 2006

A shuttle vector for Escherichia coli and Giardia lamblia was modified to produce a reporter plasmid, which monitors the expression of prescribed gene in G. lamblia by measuring its luciferase activity. Promoter regions of the gap2 gene, one of the genes induced during encystation, were cloned into this plasmid, and the resultant constructs were then transfected into trophozoites of G. lamblia. Transgenic trophozoites containing one of the 3 gap2-luc reporters were induced to encystation, and characterized with respect to gap2 gene expression by measuring their luciferase activities. Giardia containing a gap2-luc fusion of 112-bp upstream region showed full induction of luciferase activity during encystation.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.631-638
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• 2008

Tandem affinity purification (TAP) method combined with LC-MS/MS is the most accurate and reliable way to study the interaction of proteins or proteomics in a genome-wide scale. For the first time, we used a TAP-tag as a mutagenic tool to disrupt protein interactions at the specific site. Although lots of commonly used mutational tools exist to study functions of a gene, such as deletional mutations and site-directed mutagenesis, each method has its own demerit. To test the usefulness of a TAP-tag as a mutagenic tool, we applied a TAP-tag to RNA polymerase II, which is the key enzyme of gene expression and is controlled by hundreds of transcription factors even to transcribe a gene. Our experiment is based on the hypothesis that there will be interrupted interactions between Pol II and transcription factors owing to the TAP-tag attached at the C-terminus of each subunit of Pol II, and the abnormality caused by interrupted protein interactions can be observed by measuring a cell-cycle of each yeast strain. From ten different TAP-tagged strains, Rpb7- and Rpb12-TAP-tagged strains show severe defects in growth rate and morphology. Without a heterodimer of Rpb4/Rpb7, only the ten subunits Pol II can conduct transcription normally, and there is no previously known function of Rpb7. The observed defect of the Rpb7-TAP-tagged strain shows that Rpb7 forms a complex with other proteins or compounds and the interruption of the interaction can interfere with the normal cell cycle and morphology of the cell and nucleus. This is a novel attempt to use a TAP-tag as a proteomic tool to study protein interactions.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2447-2451
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• 2014

Human papillomavirus (HPV) is the primary etiologic agent of cervical cancer. Consideration of safety and non human leukocyte antigen restriction, protein vaccine has become the most likely form of HPV therapeutic vaccine, although none have so far been reported as effective. Since tumor cells consistently express the two proteins E6 and E7, most therapeutic vaccines target one or both of them. In this study, we fabricated DC vaccines by transducing replication-defective recombinant adenoviruses expressing E6/E7 fusion gene of HPV-16, to investigate the lethal effects of specific cytotoxic T lymphocytes (CTL) against CaSki cells in vitro. Mouse immature dendritic cells (DC) were generated from bone marrow, and transfected with pAd-E6/E7 to prepare a DC vaccine and to induce specific CTL. The surface expression of CD40, CD68, MHC II and CD11c was assessed by flow cytometry (FCM), and the lethal effects of CTL against CaSki cells were determined by DAPI, FCM and CCK-8 methods. Immature mouse DC was successfully transfected by pAd-E6/E7 in vitro, and the transfecting efficiency was 40%-50%. A DC vaccine was successfully prepared and was used to induce specific CTL. Experimental results showed that the percentage of apoptosis and killing rate of CaSki cells were significantly increased by coculturing with the specific CTL (p <0.05). These results illustrated that a DC vaccine modified by HPV-16 E6/E7 gene can induce apoptosis of CaSki cells by inducing CTL, which may be used as a new strategy for biological treatment of cervical cancer.

• Reproductive and Developmental Biology
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• 제29권4호
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• pp.235-239
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• 2005

This study was conducted to test whether the transgenic cattle pass the transgene to their progeny through germ cells, and whether the transgene is expressed in the mammary gland of ransgenic cows. Two male ransgenic calves were born from IVF-derived embryos injected with bovine $\beta-casein/human$ lactoferrin fusion gene and then grew up to be reproducible. Semen was collected from a transgenic bull after 18 mon of age and then frozen. Bovine oocytes matured in vitro were fertilized with spermatozoa of the transgenic bull and cultured in $50\;{\mu}L$ drops of CRlaa medium supplemented with 3 mg/mL BSA. After 48 h of culture, cleaved embryos were determined for the presence of transgenes by DNA polymerase chain reaction (PCR). Proportion of transgene positives among bovine embryos fertilized with sperm of the transgenic bull was $20.9\%$ (28/134). One of transgenic bulls did not produce transgenic sperm. Out of 34 calves produced from recipient heifers inseminated with semen of the other bull, 3 $(8.8\%)$ were transgenic animals (2 females and 1 male). Thus, one transgenic bull showed a low transmission frequency below Mendelian levels in both the IVF-derived embryos and his progeny. It was demonstrated by Southern blot that copy numbers of the transgene in the transgenic progeny enhanced about 1.8 times as compared to those of the founder bull The results demonstrate that the transgenic bull carrying human lactoferrin gene could pass his transgene to the progeny through germ cells, although he is a germ-line mosaic.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.74-74
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• 2002

Production of u 1-antitrypsin ($\alpha$AT) in transgenic cows has a great value in the field of medicine. The present study was conducted to determine the effect of chemically defined KSOM media on in vitro development of bovine transgenic nuclear transfer (NT) embryos. An expression plasmid for human $\alpha$AT was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human $\alpha$AT target gene into a pcDNA3 plasmid. Cumulus cells as donor nuclei in NT were collected from a Holstein cow and transfected by lipid-mediated method using FuGene6 (Roche Molecular Biochemicals, USA) as reagent. GFP expressed cumulus cells were introduced into recipient oocytes under DIC microscopy equipped with FITC filter set. After electrical fusion and chemical activation, reconstructed embryos were cultured in 1) SOF + 0.8% BSA, 2) KSOM + 0.8% BSA, 3) KSOM + 10% FBS and 4) KSOM +0.01% PVA for 192 h at 39$^{\circ}C$ with 5% $CO_2$, 5% $O_2$ and 90% $N_2$in humidified condition. The development of the embryos was recorded and the GFP expression in blastocyst was determined under FITC filter. The average fusion rate was 73.8% (251/340; n=8). The development rates to 2-4 cells, morula, blastocysts and expression rates in blastocysts varied from 70.3 to 76.5%, 30.2 to 33.8%, 25.4 to 33.8% and 11.8 to 15.6%, respectively. The difference in development and expression rates of embryos among 4 culture groups was not significant (P>0.05). This study indicates that chemically defined KSOM medium is also able to support development of bovine transgenic NT embryos at similar rate of SOF or KSOM supplemented with BSA or serum.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.90-90
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• 2017

Regulation of seed dormancy is important in many grains to prevent pre-harvest sprouting. To identify and understand the gene related to seed dormancy regulation, we have screened for viviparous phenotypes of rice mutant lines generated by insertion of Ds transposon in a Korean Japonica cultivar (Dongjin) background. One of the mutants, which represented viviparous phenotype, was selected for further seed dormancy regulation studies and designated dor1. The dor1 mutant has single Ds insertion in the second exon of OsDor1 gene encoding glycine-rich protein. The seeds of dor1 mutant showed a higher germination potential and reduced abscisic acid (ABA) sensitivity compared to wild type Dongjin. Over-expression of Dor1 complements the viviparous phenotype of dor1 mutant, indicating that Dor1 function in seed dormancy regulation. Subcellular localization assay of Dor1-GFP fusion protein revealed that the OsDor1 protein mainly localized to membrane and the localization of OsDOR1 was influenced by presence of a giberelin (GA) receptor OsGID1. Further bimolecular fluorescence complementation (BiFC) analysis indicated that OsDOR1 interact with OsGID1. The combined results suggested that OsDOR1 regulates seed dormancy by interacting with OsGID1 in GA response. Additionally, expression of OsDOR1 partially complemented the cold sensitivity of Escherichia coli BX04 mutant lacking four cold shock proteins, indicating that OsDOR1 possessed RNA chaperone activity.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.781-784
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• 2012

The aim of this study was to evaluate the effect of the adenovirus-mediated double suicide gene (CD/TK) for selective killing of gastric cancer cells. Gastric cancer cells SCG7901 and normal gastric epithelial cell lines were infected by adenoviruses Ad-survivin/GFP and Ad-survivin/CD/TK. GFP expression and CD-TK were detected by fluorescence microscopy and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. After treatment of the infected cells with the pro-drugs ganciclovir (GCV) and/or 5-FC, the cell growth status was evaluated by methyl thiazolyl tetrazolium assay. Cell cycle changes were detected using flow cytometry. In nude mice bearing human gastric cancer, the recombinant adenovirus vector was injected directly into the tumor followed by an intraperitoneal injection of GCV and/or 5-FC. The subsequent tumor growth was then observed. The GFP gene driven by survivin could be expressed within the gastric cancer line SCG7901, but not in normal gastric epithelial cells. RT-PCR demonstrated the presence of the CD/TK gene product in the infected SCG7901 cells, but not in the infected normal gastric epithelial cells. The infected gastric cancer SCG7901, but not the gastric cells, was highly sensitive to the pro-drugs. The CD/TK fusion gene system showed significantly greater efficiency than either of the single suicide genes in killing the target cells (P<0.01). Treatment of the infected cells with the pro-drugs resulted in increased cell percentage in G0-Gl phase and decreased percentage in S phase. In nude mice bearing SCG7901 cells, treatment with the double suicide gene system significantly inhibited tumor growth, showing much stronger effects than either of the single suicide genes (P<0.01). The adenovirus-mediated CD/TK double suicide gene driven by survivin promoter combined with GCV an 5-FC treatment could be an effective therapy against experimental gastric cancer with much greater efficacy than the single suicide gene CD/TK combined with GCV or 5-FC.

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.157-164
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• 1999

To determine molecular mechanisms of Aquaporin-CD (AQP2) gene regulation, the promoter region of the AQP2 gene was examined by transiently transfecting a promoter-luciferase reporter fusion gene into mouse renal collecting duct cell lines such as mIMCD-3, mIMCD-K2, and M-1 cells, and NIH3T3 mouse embryo fibroblast cells. PCR-Southern analysis reveals that mIMCD-3 and mIMCD-K2 cells express AQP2, but M-1 and NIH3T3 cells do not, and that the treatment with cpt-cAMP $(400\;{\mu}M)$) or forskolin/isobutylmethylxanthine (IBMX) increased the AQP2 expression in IMCD cells. In both IMCD and NIH3T3 cells, the constructs containing the promoter of AQP2 gene showed promoter activities, indicating lack of tissue-specific element in the 1.4 kb 5'-flanking region of the mouse AQP2 gene. Luciferase activity in the IMCD cells transfected with the construct containing 5-flanking region showed responsiveness to cpt-cAMP, indicating that the 1.4 kb 5'-flanking region contains the element necessary for the regulatory mechanism by cAMP. The promoter-luciferase constructs which do not have a cAMP-responsible element (CRE) still showed the cAMP responsiveness in IMCD cells, but not in NIH3T3 cells. Increase in medium osmolarity did not affect AQP2 promoter activity in mIMCD-K2 cells. These results demonstrate that AQP2 gene transcription is increased with cAMP treatment through multiple motifs including CRE in the 5'-flanking region of the gene in vitro, and the regulatory mechanism may be important for in vivo regulation of AQP2 expression.

• Journal of Korean Neurosurgical Society
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• 제30권sup1호
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• pp.13-19
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• 2001

Objective : We investigated the feasibility of a double suicide gene/prodrug therapy, involving direct introduction of the herpes simplex virus Type 1 thymidine kinase(TK) gene and the Escherichia coli cytosine deaminase(CD) gene, via a recombinant adenoviral vector and ganciclovir(GCV) and/or 5-fluorocytosine(5-FC) treatment, in C6 glioma cells. Methods : Efficient gene transfer and transduction of C6 glioma cells via a recombinant adenovirus were evaluated by infecting cells with adenovirus bearing the ${\beta}$-galactosidase gene and then staining cells with 5-bromo-4-chloro-3-indolyl-13-D-galactoside. CD/TK expression in cells infected with adenovirus bearing the CD/TK gene(ad-CD/TK) was examined by immunoblotting analysis. For in vitro cytotoxicity experiments, the cells were infected with ad-CD/TK or ad-${\Delta}E1$(as a control). After addition of a variety of concentrations of GCV and 5-FU, either separately or in combination, cell viability was determined by staining the cells with crystal violet solution 6 days after infection. Result : C6 glioma cells were efficiently transduced with recombinant adenoviral vector at multiplicities of infection of 200 or more. In vitro cytotoxicity of GCV and/or 5-FC, either alone or in combination, was exclusively observed in the cells transduced with ad-CD/TK. Obvious cytotoxicity(>50% inhibition) was observed in the presence of 5-FC at concentrations greater than 30ug/ml or GCV at concentrations greater than 0.3ug/ml at a multiplicity of infection of 100. Additionally, cytotoxicity in the presence of both GCV and 5-FC was greater than that after sinlge-prodrug treatments, indicating additive effects of the prodrug treatments. Conclusion : The administration of a double-suicide gene/prodrug therapy might have great potential in the treatment of brain tumors.

• KSBB Journal
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• 제10권1호
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• pp.38-45
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• 1995

Aspergillus oryzae에서 A. nidulans의 glyceral d dehyde-3-phosphate dehydrogenase (gpdA)와 trpC, prmoter의 발현 능력 을 E. coli lacZ gene fusion을 이용하여 비교.분석하였다. A. oryzae 내에서 발현된 E. coli $\beta$galactosidase의 specific activIty를 조사하여 본 결과, gpdA promoter를 가지는 transformant들 에서는 2,000unit/ug of protem 정도의 activity를 보이는 반면, trpC, promater를 가지고 있는 transformant들에서는 10.5~52.3unit/ug of protein 정도의 activity를 보였다. 이 결과로부터 A. oryzae 내에서 A. nidulans의 gpdA promoter가 trpC, promoter에 비해 70 배 정도 더 강한 발현 능력을 보이고 있음을 알 수 있다. Western blot 분석에서도 gpdA promoter를 가지고 있는 transf ormant에서 더 많은 E. coli $\beta$-galactosidase가 발현된 것 을 보여 주고 있다. 또한 southern blot 분석에서는 이러한 강한 발현이 transform된 plasmid의 copy number와 상관 없음을 보여주고 있다.