• BMB Reports
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• 제40권4호
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• pp.532-538
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• 2007

Mouse ficolin A is a plasma protein with lectin activity, and plays a role in host defense by binding carbohydrates, especially GlcNAc, on microorganisms. The ficolin A subunit consists of an N-terminal signal peptide, a collagen-like domain, and a C-terminal fibrinogen-like domain. In this study, we show that ficolin A can be synthesized and oligomerized in a cell and secreted into culture medium. We also identify a functionally relevant signal peptide of ficolin A by using MS/MS analysis to determine the N-terminal sequence of secreted ficolin A. When the signal peptide of mouse ficolin A was fused with enhanced green fluorescent protein (EGFP), EGFP was released into HEK 293 cell medium, suggesting that the signal peptide can efficiently direct ficolin A secretion. Moreover, our results suggest that the signal peptide of ficolin A has potential application for the production of useful secretory proteins.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.511-519
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• 2009

A chimeric gene encoding enhanced green fluorescent protein (EGFP) and a S-layer protein from Lactobacillus brevis KCTC3102, and/or two copies of the Fe-binding Z-domain, a synthetic analog of the B-domain of protein A, was constructed and expressed in Escherichia coli BL21(DE3). The S-layer fusion proteins produced in a 500-1 fermentor were likely to be stable in the range of pH 5 to 8 and $0^{\circ}C$ to $40^{\circ}C$. Their adhesive property enabled an easy and rapid immobilization of enzymes or antibodies on solid materials such as plastics, glass, sol-gel films, and intestinal epithelial cells. Owing to their affinity towards intestinal cells and immunoglobulin G, the S-layer fusion proteins enabled the adhesion of antibodies to human epithelial cells. In addition, feeding a mixture of the S-layer fusion proteins and antibodies against neonatal calf diarrhea (coronavirus, rotavirus, Escherichia coli, and Salmonella typhimurium) to Hanwoo calves resulted in 100% prevention of neonatal calf diarrhea syndrome (p<0.01), whereas feeding antibodies only resulted in 56% prevention.

• Molecules and Cells
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• 제21권2호
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• pp.244-250
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• 2006

Gangliosides are receptors for various peptides and proteins including neuropeptides, ${\beta}$-amyloid proteins, and prions. Recently, the role of gangliosides in mucosal immunization has attracted attention due to the emerging interest in oral vaccination. Ganglioside GM1 exists in abundance on the surface of the M cells of Peyer's patch, a well-known mucosal immunity induction site. In the present study we identified a peptide ligand for GM1 and tested whether it played a role in immune induction. GM1-binding peptides were selected from a phage-displayed dodecapeptide library and one peptide motif, GWKERLSSWNRF, was fused to the C-terminus of enhanced green fluorescent protein (EGFP). The fusion protein, but not EGFP fused with a control peptide, was concentrated around Peyer's patch after incubation in the lumen of the intestine ex vivo. Furthermore, oral feeding of the fusion protein but not control EGFP induced mucosal and systemic immune responses against EGFP resembling Th2-type immune responses.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.387-390
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• 2011

Nude mice (BALB/c) were grafted with human 293 cells and PERV (porcine endogenous retrovirus)-IRES-EGFP (a packageable retroviral vector plasmid containing an internal ribosome entry site-enhanced green fluorescent protein)-producing pig PK15 cells in order to determine whether the pig cells could transmit PERV-IRES-EGFP to mice and human 293 cells in vivo. None of the transplanted human 293 cell lines were infected by PERV, but PCR analysis identified PERV-B provirus integration into both the heart and salivary gland of the inoculated nude mice. Our data indicate that hearts and salivary glands can be used to identify PERV-B receptors.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.91-91
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• 2002

There are many methods to introduce exogenous DNA into embryo for the purpose of producing transgenic animals. Exogenous gene can be integrated into oocyte as a form of sperm vector. In this study, sperm was used as a vector for transgene that is enhanced green fluorescent protein (EGFP). The objective of this study was to investigate the expression of exogenous gene in bovine embryos after injection of spermatozoa cocultured with EGFP fragment. Spermatozoa were plunged into liquid nitrogen and thawed several times or shaked in 0.2% Triton X-100 to remove sperm membrane which followed by DTT treatment. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.135.1-135.1
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• 2003

The rat mast cell line RBL-2H3 contains both phospholipase D (PLD)1 and PLD2. Previous studies with this cell line indicated that expressed PLD1 and PLD2 are both strongly activated by stimulants of secretion. We now show by use of PLDs tagged with enhanced green fluorescent protein that PLD1, which is largely associated with secretory granules, redistributes to the plasma membrane in stimulated cells by processes reminiscent of exocytosis and fusion of granules with the plasma membrane. (omitted)

• 한국가금학회지
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• 제50권4호
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• pp.261-266
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• 2023

가축의 골격근은 동물성 단백질 식품으로서 중요한 역할을 하며, 가금육의 소비는 전세계적으로 꾸준히 증가하고 있다. 근육의 형성과 발달에는 근형성조절인자를 포함한 많은 유전자들이 관여하며, 발달 단계에 따라 유전자 발현의 정확한 조절이 필요하다. 본 연구에서는 근육에서 특이적으로 발현하는 유전자를 선발하고, 해당 유전자의 프로모터를 클로닝하고 기능을 분석하였다. 동물의 조직별 유전자 발현을 분석한 결과, 다수의 유전자들이 골격근 특이적인 발현양상을 보였는데, 특히 TNNT3와 TNNC2, MYF6 유전자들은 가금에서도 유사한 양상을 나타냈다. TNNT3, TNNC2, MYF6 유전자의 프로모터 부위를 중합효소연쇄반응을 통해 각각 1.2 kb, 1.03 kb, 1.43 kb씩 증폭하여, 녹색형광단백질 유전자를 포함한 벡터의 앞부분에 삽입하였다. 염기서열 분석 결과, 세 프로모터는 기존에 밝혀진 유전체 서열과 거의 일치함을 확인하였다. QM7 메추리 근육세포주에서 각각의 프로모터를 포함한 벡터를 도입한 결과, 세 프로모터 모두녹색형광단백질을 성공적으로 발현시켰다. 녹색 형광의 밝기는 대조군으로 사용한 CMV-IE 프로모터와 비교 시, 약 7배 정도 어두웠다. 클로닝한 프로모터들에는 230개 이상의 전사인자들이 결합할 수 있을 것으로 예측되었으며, 특히 MYF5나 MYOD, MYOG와 같은 근형성조절인자를 포함한 근육에서 발현하는 다양한 전사인자들이 결합할 수 있을 것으로 예측되었다. 이 프로모터들은 가금의 근육세포에서 유전자 발현을 유도하는 연구에 활용이 가능할 것이며, 추후연구를 통해 프로모터 부위별 발현 조절 기능 연구가 필요할 것으로 사료된다.

• Molecules and Cells
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• 제19권1호
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• pp.23-30
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• 2005

Spinocerebellar ataxia type 1 (SCA1) is an autosomal-dominant neurodegenerative disorder caused by expansion of the polyglutamine tract in the SCA1 gene product, ataxin-1. Using d2EGFP, a short-lived enhanced green fluorescent protein, we investigated whether polyglutamine-expanded ataxin-1 affects the function of the proteasome, a cellular multicatalytic protease that degrades most misfolded proteins and regulatory proteins. In Western blot analysis and immunofluorescence experiments, d2EGFP was less degraded in HEK 293T cells transfected with ataxin-1(82Q) than in cells transfected with lacZ or empty vector controls. To test whether the stability of the d2EGFP protein was due to aggregation of ataxin-1, we constructed a plasmid carrying $ataxin-1-{\Delta}114$, lacking the self-association region (SAR), and examined degradation of the d2EGFP. Both the level of $ataxin-1-{\Delta}114$ aggregates and the amount of d2EGFP were drastically reduced in cells containing $ataxin-1-{\Delta}114$. Furthermore, d2EGFP localization experiments showed that polyglutamine-expanded ataxin-1 inhibited the general function of the proteasome activity. Taken together, these results demonstrate that polyglutamine-expanded ataxin-1 decreases the activity of the proteasome, implying that a disturbance in the ubiquitin-proteasome pathway is directly involved in the development of spinocerebellar ataxia type1.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.144-151
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• 2014

Increasing the gene copy number has been commonly used to enhance the protein expression level in the yeast Pichia pastoris. However, this method has been shown to be effective up to a certain gene copy number, and a further increase of gene dosage can result in a decrease of expression level. Evidences indicate the gene dosage effect is product-dependent, which needs to be determined when expressing a new protein. Here, we describe a direct detection of the gene dosage effect on protein secretion through expressing the enhanced green fluorescent protein (EGFP) gene under the direction of the ${\alpha}$-factor preprosequence in a panel of yeast clones carrying increasing copies of the EGFP gene (from one to six copies). Directly examined under fluorescence microscopy, we found relatively lower levels of EGFP were secreted into the culture medium at one copy and two copies, substantial improvement of secretion appeared at three copies, plateau happened at four and five copies, and an apparent decrease of secretion happened at six copies. The secretion of EGFP being limiting at four and five copies was due to abundant intracellular accumulation of proteins, observed from the fluorescence image of yeast and confirmed by western blotting, which significantly activated the unfolded protein response indicated by the up-regulation of the BiP (the KAR2 gene product) and the protein disulfide isomerase. This study implies that tagging a reporter like GFP to a specific protein would facilitate a direct and rapid determination of the optimal gene copy number for high-yield expression.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권2호
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• pp.137-142
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• 2004

In this study, a simple procedure is described for patterning biotin on a glass substrate and then selectively immobilizing proteins of interest onto the biotin-patterned surface. Microcontact printing (CP) was used to generate the micropattern of biotin and to demonstrate the selective immobilization of proteins by using enhanced green fluorescent protein (EGFP) as a model protein, of which the C-terminus was fused to a core streptavidin (cSA) gene of Streptomyces avidinii. Confocal fluorescence microscopy was used to visualize the pattern of the immobilized protein (EGFP-cSA), and surface plasmon resonance was used to characterize biological activity of the immobilized EGFP-cSA. The results suggest that this strategy, which consists of a combination of $\mu$CP and cSA-fused proteins. is an effective way for fabricating biologically active substrates that are suitable for a wide variety of applications. one such being the use in protein-protein assays.