• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.663-669
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• 2000

The fur (ferric uptake regulation) expression vector pMON2064 was modified to produce a Fur-fusion expression vector. A kinker site, factor Xa cleavage site, and several restriction endonuclease sites were introduced to facilitate easy cloning and isolating of the fusion protein. The resulting fusion expression vector, pMONSTER, was then used to make fusion expression vector, pMONSTER, was then used to make fusion proteins with $\beta$-galactosidase and the protease of the human immunodeficiency virus type 1 (HIV-1 PR). Strain SW4020 harboring the Fur $\beta$-galactosidase fusion vector produced blue colonies on a 5-bromo-4-chloro-3-indolyl-$\beta$-D-galactoside plate and the resulting 133 kDa fusion protein reacted with an anti-Fur antibody. The strain harboring the Fur-HIV-1 PR fusion vector produced a 29 kDa fusion protein, which also reacted with an anti-Fur antibody. The Fur-HIV-1 PR fusion protein was purified by a single column application that was designed to isolate the Fur protein. The purified Fur-HIV-1 PR fusion protein digested with factor Xa cleaved a recombinant Gag protein to release smaller fragments, including a p24 capsid protein. The Fur-HIV-1 PR fusion protein itself did not exhibit any proteolytic activity.

• 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

• Journal of Life Science
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• v.28 no.4
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• pp.478-482
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• 2018

Human rotavirus is a causative agent of acute diarrhea among children. The artificial gene encoding the truncated $VP8^*$ protein of human rotavirus A (serotype 1 strain WA) was synthesized according to the Escherichia coli codon preference. The synthetic $VP8^*$ gene also possessed the NdeI and HindIII restriction sites for the convenient in-frame cloning for translation and a 6-histidine tag at C-terminus for Ni+ affinity purification. Molecular weight of the truncated $VP8^*$ protein deduced from the nucleotide sequences of the artificial gene was a 19.7-kDa. This synthetic $VP8^*$ DNA fragment was inserted into the pT7-7 expression vector and transformed into E. coli BL21 (DE3). Transformants harboring the synthetic gene encoding the $VP8^*$ protein was induced by supplement of a final concentration of 0.05 mM ITPG at $20^{\circ}C$. Protein crude extract from the E. coli transformants was subjected to Western blotting with the mouse anti-rotavirus capsid antibody, showing ~20-kDa $VP8^*$ protein band. The truncated $VP8^*$ protein band was also observed by Western blotting using the rabbit polyclonal antibody serum made against the truncated $VP8^*$ protein. This study suggested that the synthetic gene could be used as an easy way to produce the antigenic vaccine candidate for control of virus-associated diseases or to develop antibodies for diagnostic purpose.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.100-100
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• 2001

• Journal of fish pathology
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• v.28 no.3
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• pp.133-143
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• 2015

The antigenic proteins of Lymphocystis disease virus (LCDV) from tumors of olive flounder, Paralichthys olivaceus, are described following characterization by mass spectrometry. In SDS-PAGE, predominant protein bands were observed at 114, 88, 70, 54, 52, 47, 42 and 24 kDa. Western blot analysis showed that antisera reacted strongly at molecular weights of 114, 67 and 54 kDa, and reacted weakly at molecular weights of 74, 70, 36, 24 and 22 kDa. In the identification of LCDV antigenic proteins by matrix-assisted laser desorption ionization (MALDI) TOF mass spectrometry, 10 of 14 excised bands consisted mostly of proteins with amino acid sequences that matched LCDV-C (lymphocystis disease virus isolate China) ORFs. Strong antigens with molecular weights of 114, 67 and 54 kDa were identified as LDVICp236 (chromosome segregation ATPase), LDVICp033 (membrane bound metallopeptidase) and LDVICp157 (hypothetical protein), respectively. Minor antigens with molecular weights of 70, 36, 24 and 22 kDa proteins were identified as LDVICp160 (acetyl-coA hydrolase), LDVICp213 (hypothetical protein), LDVICp039 (hypothetical protein) and LDVICp213 (hypothetical protein). However, the major capsid protein (LDVICp043) did not react with the polyclonal antibody.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.508-513
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• 2017

The complete genome sequence of a Slovak SL-1 isolate of Tomato mosaic virus (ToMV) was determined from the next generation sequencing (NGS) data, further confirming a limited sequence divergence in this tobamovirus species. Tomato genotypes Monalbo, Mobaci and Moperou, respectively carrying the susceptible tm-2 allele or the Tm-1 and Tm-2 resistant alleles, were tested for their susceptibility to ToMV SL-1. Although the three tomato genotypes accumulated ToMV SL-1 to similar amounts as judged by semiquantitative DAS-ELISA, they showed variations in the rate of infection and symptomatology. Possible differences in the intra-isolate variability and polymorphism between viral populations propagating in these tomato genotypes were evaluated by analysis of the capsid protein (CP) encoding region. Irrespective of genotype infected, the intra-isolate haplotype structure showed the presence of the same highly dominant CP sequence and the low level of population diversity (0.08-0.19%). Our results suggest that ToMV CP encoding sequence is relatively stable in the viral population during its replication in vivo and provides further demonstration that RNA viruses may show high sequence stability, probably as a result of purifying selection.

• Journal of Veterinary Science
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• v.24 no.2
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• pp.29.1-29.12
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• 2023

Background: Feline panleukopenia virus (FPV) is a widespread and highly infectious pathogen in cats with a high mortality rate. Although Yanji has a developed cat breeding industry, the variation of FPV locally is still unclear. Objectives: This study aimed to isolate and investigate the epidemiology of FPV in Yanji between 2021 and 2022. Methods: A strain of FPV was isolated from F81 cells. Cats suspected of FPV infection (n = 80) between 2021 and 2022 from Yanji were enrolled in this study. The capsid protein 2 (VP2) of FPV was amplified. It was cloned into the pMD-19T vector and transformed into a competent Escherichia coli strain. The positive colonies were analyzed via VP2 Sanger sequencing. A phylogenetic analysis based on a VP2 coding sequence was performed to identify the genetic relationships between the strains. Results: An FPV strain named YBYJ-1 was successfully isolated. The virus diameter was approximately 20-24 nm, 50% tissue culture infectious dose = 1 × 10^-4.94/mL, which caused cytopathic effect in F81 cells. The epidemiological survey from 2021 to 2022 showed that 27 of the 80 samples were FPV-positive. Additionally, three strains positive for CPV-2c were unexpectedly found. Phylogenetic analysis showed that most of the 27 FPV strains belonged to the same group, and no mutations were found in the critical amino acids. Conclusions: A local FPV strain named YBYJ-1 was successfully isolated. There was no critical mutation in FPV in Yanji, but some cases with CPV-2c infected cats were identified.

• Journal of fish pathology
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• v.37 no.1
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• pp.1-8
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• 2024

The advantages of replicon vectors of RNA viruses include a high ability to stimulate innate immunity and exponential amplification of target mRNA leading to high expression of foreign antigens. The present study aimed to construct a DNA-layered nervous necrosis virus (NNV) replicon vector system in which the capsid protein gene was replaced with a foreign antigen gene and to compare the efficiency of foreign antigen expression between the conventional DNA vaccine vector and the present replicon vector. We presented the first report of a nodavirus DNA replicon-based foreign antigen expression system. Instead of a two-vector system, we devised a one-vector system containing both an NNV RNA-dependent RNA polymerase cassette and a foreign antigen-expressing cassette. This single-vector approach circumvents the issue of low foreign protein expression associated with the low co-transfection efficiency of a two-vector system. Cells transfected with a vector harboring hammerhead ribozyme-fused RNA1 and RNA2 (with the capsid gene ORF replaced with VHSV glycoprotein ORF) exhibited significantly higher transcription of the VHSV glycoprotein gene compared to cells transfected with either a vector without hammerhead ribozyme or a conventional DNA vaccine vector expressing the VHSV glycoprotein. Furthermore, the transcription level of the VHSV glycoprotein in cells transfected with a vector harboring hammerhead ribozyme-fused RNA1 and RNA2 showed a significant increase over time. These results suggest that NNV genome-based DNA replicon vectors have the potential to induce stronger and longer expression of target antigens compared to conventional DNA vaccine vectors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.588-591
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• 2018

Baculovirus was originally isolated from the alfalfa looper and contains a 134-kbp genome with 154 open reading frames (ORF). The major capsid protein VP39 together with some minor proteins forms the nucleocapsid ($21nm{\times}260nm$) that encloses the DNA with p6.9 protein. They are double-stranded, circular, supercoiled DNA molecules in a rod-shaped capsid. Wild-type baculoviruses exhibit both lytic and occluded life cycles that develop independently throughout the three phases of virus replication. Recombinant baculoviruses can transfer their vectors and express their recombinant proteins in a wide range of mammalian cell types. Especially, inclusion of a dominant selectable marker in these baculoviral vectors can express diverse recombinant genes in many cells. Baculoviral vectors were reconstructed with cytomegalovirus (CMV) promoter,uroplakin II promoter, polyhedron promoter, vesicular stomatitis virus G (VSVG), enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) gene and so on. These reconstructed vectors were infected into various cell and cell lines. We performed transfection and expression of these recombinant vectors comparison with other control vectors. From this study, we knew that transfection and expression of these recombinant vectors have higher efficacy than any control vector. This work was supported by a grant from Mid-Career Researcher Program(NRF-2016R1A2B4016552) through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(MSIP).

• Journal of Life Science
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• v.30 no.4
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• pp.402-409
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• 2020

Nervous necrosis virus (NNV) contains a bi-segmented viral genome, RNA1 (3.4 kb, RdRp), and RNA2 (1.4 kb, capsid protein) in a small particle (25 nm). Despite its extremely compact size, NNV has caused serious damage by infecting approximately 120 fish species worldwide since it was first reported in the late 1980s. In order to minimize the damage caused by NNV infection and develop effective vaccines, it is necessary to understand the intra cellular signaling system according to NNV infection. NNV infection induces cell cycle arrest at the G1 phase via the p53-dependent pathway to use the cellular system for its replication. Otherwise, host cells recognize NNV infection through the RIG-1-like receptor (RLR) signaling pathway to control the virus and infected cells, and then ISGs required for antiviral action are activated via the IFN signaling pathway. Moreover, apoptosis of infected cells is triggered by the unfolded protein response (UPR) through ER stress and mitochondria-mediated cell death. Cell signaling studies on the NNV infection mechanisms are still at an early stage and many pathways have yet to be identified. Understanding the various disease-specific cellular signaling systems associated with NNV infection is essential for rapid and accurate diagnosis and vaccine development.