• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.544-550
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• 2005

To develop a highly efficient mammalian expression vector, a series of vectors were constructed based on the murine cytomegalovirus (MCMV) immediate-early (IE) promoter and human ${\beta}$-globin second intron. The resulting MCMV promoter was several-fold stronger than the HCMV promoter in various mammalian cell lines, such as the NIH3T3, Neuro-2a, 293T, and HT1080 cell lines, and was only slightly weaker than the HCMV promoter in HeLa and CHO cells. The inclusion of the human ${\beta}$-globin second intron behind the MCMV promoter or HCMV promoter markedly enhanced the promoter activity in various mammalian cell lines, and the resultant MCMV/Glo-I expression system was stronger than the HCMV promoter from 4.7- to 11.2-fold in every cell line tested. Also, the MCMV/Glo-I promoter induced a higher level of the VSV-G protein in a transiently transfected 293T cell line, which is useful for the production of recombinant retrovirus and lentivirus vectors.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.65.1-65
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• 2003

In addition to the five well-characterized genes of Tobacco mosaic virus (TMV), this virus contains a sixth open reading frame (ORF6) that encodes a 4.8 kDa protein. TMV ORF6 overlaps the ORFs encoding the 30 kDa movement protein and the adjacent 17.5 kDa capsid protein. Although the 4.8 kDa protein could not be detected in vivo, alteration of the AUG codons of this ORF resulted in a mutant virus that attenuated the virulence of the mutated TMV in Nicotiana benthamiana, but not N. tabacum (tobacco). These sequence changes did not affect either the replication or movement of the mutated TMV. Expression of TMV ORF6 from the virus expression vector Potato virus X (PVX) intensified the virulence of this virus in N. benthmiana, but not tobacco, while expression of TMV ORF6 from the virus expression vector Tobacco rattle virus enhanced the pathogenicity observed in both N. benthamima and tobacco. Thus, the TMV ORF6 is a host- and virus-specific. virulence factor. However, two separate assays indicated that the TMV 4.8 kDa protein was not a suppression of RNA silencing. A fusion protein formed between the TMV 4.8 kDa protein and the green fluorescent protein was expressed from the PVX vector and localized to plasmodesmata. Possible roles of the 4.8 kDa protein in pathogenicity will be discussed

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.15-23
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• 2003

Lactadherin (formerly known as BA46), a major glycoprotein of the human milk fat globule membrane, is abundant in human breast milk and breast carcinomas and may prevent symptomatic rotavirus infections. In this study, under the control of tissue specific and hormonal inducible mouse whey acidic protein (WAP) promote., the expression pattern of lactadherin (Ltd) in lactogenic hormone-dependent mouse mammary epithelial cell line HC11 were tested. pLNWLtd construct containing 2.4 kilobases of the WAP promoter and 1.5 kilobases of human lactadherin gene was stably transfered into HC11 cells using retroviral vector system. Integration and expression level of the transgene was estimated using PCR and RT-PCR, respectively. Prominent induction of Ltd gene under the WAP promoter was accomplished in the presence of insulin, hydrocortisone and prolactin. Compared to the control (cells cultured with insulin alone), however we observed that the WAP promoter was leaky. These data indicate that luther studies are needed in finding an appropriate promoter other than WAP promoter because of its leakiness.

• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.177-184
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• 2008

Acid-labile subunit(ALS) is a 85-kDa glycosylated plasma protein which forms a 150-kDa ternary complex with 7.5-kDa insulin-like growth factor(IGF) and 40~45-kDa IGF-binding protein-3. In a previous study, the present authors prepared a porcine ALS(pALS) expression construct by inserting a pALS coding sequence into a plasmid vector following synthesis of the sequence by reverse transcription-polymerase chain reaction(RT-PCR). The expression construct, however, was subsequently found to have a mis-sense mutation at two bases of the pALS coding sequence which is presumed to have occurred through a PCR error. In the present study, the correct coding sequence was synthesized by the site-directed mutagenesis and inserted into the pET-28a(+) plasmid expression vector containing the His-tag sequence flanking the last codon of the insert DNA. After induction of the expression construct in E. coli BL21(DE3) cells, the resulting presumptive recombinant peptide was purified by the Ni-affinity chromatography. Upon SDS- PAGE, the affinity-purified peptide was resolved as a single band at a 66-kDa position which is consistent with the expected molecular mass of the presumptive recombinant pALS. Collectively, results indicate that a recombinant pALS peptide was successfully expressed and purified in the present study.

• Journal of the Korea Society of Computer and Information
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• v.15 no.4
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• pp.47-55
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• 2010

In this paper, we proposed a recognition system of smile facial expression for smile treatment training. The proposed system detects face candidate regions by using Haar-like features from camera images. After that, it verifies if the detected face candidate region is a face or non-face by using SVM(Support Vector Machine) classification. For the detected face image, it applies illumination normalization based on histogram matching in order to minimize the effect of illumination change. In the facial expression recognition step, it computes facial feature vector by using PCA(Principal Component Analysis) and recognizes smile expression by using a multilayer perceptron artificial network. The proposed system let the user train smile expression by recognizing the user's smile expression in real-time and displaying the amount of smile expression. Experimental result show that the proposed system improve the correct recognition rate by using face region verification based on SVM and using illumination normalization based on histogram matching.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.85-91
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• 2001

To construct an efficient Bacillus subtilis expression vector, strong promoters were isolated from the chromosomal DNA libraries of Clostridium acetobutylicum ATCC 4259, Thermoactinomyces sp. E79, and Bacillus thermoglucosidasius KCTC 3400. The $P_{C27}$ promoter cloned from the clostridial chromosmal DNA showed a 5-fold higher promoter strength than the $P_{SP02}$ promoter in the expression of the cat gene, and its sequence was estimated as an upstream region of the predicted hypothetical gene (tet-R family bacterial transcription regulator gene) in C. acetobutylicum. As a promoter element, $P_{C27}$ exhibited putative nucleotide sequences that can bind with bacterial RNAP and the 3'end of the 16S rRNA just upstream of the start codon. In addition, the promoter activity of $P_{C27}$ was distinctively repressed in the presence of glucose. Using $P_{C27}$ as the promoter element, a glucose controllable B. subtilis expression vector was constructed and the lipase gene from Staphylococcus haemolyticus KCTC 8957P was expressed in B. subtilis. When compared with the lipase expression by the T7 promoter induced by IPTG in E. coli, the $P_{C27}$ promoter showed about a 1.5-fold higher expression level in B. subtilis than that without induction.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.141-148
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• 1992

In order to overexpress bacteriophage PRD1 DNA polymerase in E. coli cells, the 2 kb HaeII fragment was isolated from phage genomic DNA. This fragment was then cloned into pEMBL/sup ex/ 3-expression vector. A specific 57bp deletion was performed by using uracil containing ss DNA and oligonucleotide spanning each region to remove an unwanted non-coding region. After this deletion, the PRD1 DNA polymerase gene is totally under the control of the vector promoter and SD sequence. Upon heat induction, a protein with an apparent size of 68 kdal was overexpressed as an active PRD1 DNA polymerase. The expression of PRD1 DNA polymerase was about 1% of total E. coli protein.

• Microbiology and Biotechnology Letters
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• v.21 no.3
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• pp.214-220
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• 1993

The mating type a of yeast, Saccharomyces cerevisiae mutant with hmla2-102 and sir3-8ts was changed to type alpha by changing the growth temperature from 25C to 35C. A temperature-sensitive expression vector system was constructed using mating factor alpha1 (Mfalpha1) gene encoding alpha factor which is expressed in the type alpha cells. Vectors with different copy numbers were constructed by joining the promoter and pre or prepro-secretion single sequence of Mfalpha1 to promoterless PHO5' gene as a reporter gene.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.186-189
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• 2003

Helicobacter pylori is the etiologic agent of human gastritis and peptic ulceration and produces urease as the major protein component on its surface. H. pylori urease is known to serve as a potent immunogen as well as major virulence factor. In order to express the recombinant urease in tobacco plants, a DNA fragment containing the minimal H. pylori urease gene cluster was subcloned into a plant expression vector. The recombinant vector was transformed to tobacco plants. The integration of the recombinant plasmids into tobacco chromosomal genome was verified by genomic PCR. Expression to mRNA was confirmed by Northern blot analysis, and expression to recombinant urease protein was observed by Western blot analysis. These results showed that the recombinant urease can be produced in tobacco plants and will be tested for immune response to use as an edible vaccine.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.155-160
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• 2001

We have generated a novel baculovirus genome which can be maintained in Escherichia coli that facilitates the rapid and efficient generation of recombinant baculovirus expression vectors. To make $Occ^{+}$ recombinant expression vectors, polyhedrin gene under the control of p10 promoter was inserted to bAcGOZA and this genome was designated bApGOZA. As in bAcGOZA, bApGOZA lacks a portion of the essential ORF1629 gene, but includes a mini-F replicon and selectable kanamycin-resistance marker, This occasion-producing activity of bApGOZA can be used very conveniently for its oral infectivity to insect larvae in mass production of foreign protein and insecticides.