• Journal of Industrial Technology
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• v.28 no.B
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• pp.53-57
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• 2008

From the extensive screening for small cryptic plasmid among about 23 lactic acid bacteria (LAB), 2.4 kb of cryptic plasmid was isolated from Lactobacillus farciminis strain KCTC 3681 and named as pLF24. The plasmid pLF24 was a circular molecule of 2,396 base-pairs in length with a G+C content of 38%. Two protein-coding sequences could be predicted. ORF1 and ORF2 showed homologies to plasmids of gram-positive bacteria. The replication protein coded by ORF2 and the plus origin, were similar to replication regions of other gram-positive bacteria as shown in plasmids such as pLH2, pLS141-1 and pLC2. The nucleotide sequence of pLF24 was deposited into Genbank data base with an accession number of EU429343. The newly isolated plasmid can be used for construction of shuttle vector in Lactobacillus bacteria.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.545-554
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• 2013

Plasmid isolation of kimchi-derived Weissella cibaria KLC140 revealed six different plasmids. The smallest plasmid, pKW2124, was DNA sequenced and characterized, showing 2,126 bp with a GC content of 36.39% and five putative open reading frames (ORFs). In silico analysis of these ORFs showed ORF1 encodes a putative replication protein similar to rolling circular replication proteins from other lactic acid bacteria. However, a single-stranded intermediate was not detected when S1 nuclease was treated, suggesting it may follow theta replication. Interestingly, the replication initiation site of this plasmid is 100% identical to other plasmids from lactic acid bacteria, suggesting it may function for replication initiation. To construct a surface layer expression vector, pTSLGFP, slpA encoding the surface layer protein from Lactobacillus acidophilus was PCR amplified and fused with the gfp gene, forming a SLGFP fused gene. The plasmid pKW2124 was cloned into the XbaI site of pUC19, forming an Weissella-E. coli shuttle vector pKUW22. NheI-linearized pTSLGFP was ligated into pKUWCAT containing pKUW22 and the chloramphenicol acetyltransferase gene from pEK104, resulting in an 8.6 kb pKWCSLGFP surface layer expression vector. After transformation of this vector into W. cibaria KLC140, a GFP fluorescence signal was detected on the surface of the transformant, substantiating production of SLGFP fused protein and its secretion. This is the first report for construction of a Weissella surface layer expression vector, which may be useful for surface layer production of beneficial proteins in Weissella.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1168-1169
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• 2005

• BMB Reports
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• v.56 no.2
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• pp.108-113
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• 2023

Cohesin is a ring-shaped protein complex that comprises the SMC1, SMC3, and α-kleisin proteins, STAG1/2/3 subunits, and auxiliary factors. Cohesin participates in chromatin remodeling, chromosome segregation, DNA replication, and gene expression regulation during the cell cycle. Mitosis-specific α-kleisin factor RAD21 and meiosis-specific α-kleisin factor REC8 are expressed in embryonic stem cells (ESCs) to maintain pluripotency. Here, we demonstrated that RAD21 and REC8 were involved in maintaining genomic stability and modulating chromatin modification in murine ESCs. When the kleisin subunits were depleted, DNA repair genes were downregulated, thereby reducing cell viability and causing replication protein A (RPA) accumulation. This finding suggested that the repair of exposed single-stranded DNA was inefficient. Furthermore, the depletion of kleisin subunits induced DNA hypermethylation by upregulating DNA methylation proteins. Thus, we proposed that the cohesin complex plays two distinct roles in chromatin remodeling and genomic integrity to ensure the maintenance of pluripotency in ESCs.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1817-1829
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• 2019

Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus that causes diarrhea in neonatal piglets. Like other coronaviruses, PDCoV encodes at least three accessory or species-specific proteins; however, the biological roles of these proteins in PDCoV replication remain undetermined. As a first step toward understanding the biology of the PDCoV accessory proteins, we established a stable porcine cell line constitutively expressing the PDCoV NS7 protein in order to investigate the functional characteristics of NS7 for viral replication. Confocal microscopy and subcellular fractionation revealed that the NS7 protein was extensively distributed in the mitochondria. Proteomic analysis was then conducted to assess the expression dynamics of the host proteins in the PDCoV NS7-expressing cells. High-resolution two-dimensional gel electrophoresis initially identified 48 protein spots which were differentially expressed in the presence of NS7. Seven of these spots, including two up-regulated and five down-regulated protein spots, showed statistically significant alterations, and were selected for subsequent protein identification. The affected cellular proteins identified in this study were classified into functional groups involved in various cellular processes such as cytoskeleton networks and cell communication, metabolism, and protein biosynthesis. A substantial down-regulation of α-actinin-4 was confirmed in NS7-expressing and PDCoV-infected cells. These proteomic data will provide insights into the understanding of specific cellular responses to the accessory protein during PDCoV infection.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.291-297
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• 2018

Coxsackievirus B3 (CVB3) is a very well-known causative agent for viral myocarditis and meningitis in human. However, the effective vaccine and therapeutic drug are not developed yet. CVB3 infection activates host cell AKT signaling. Inhibition of AKT signaling pathway may attenuate CVB3 replication and prevent CVB3-mediate viral myocarditis. In this study, we determined antiviral effect of the selected natural plant extract to develop a therapeutic drug for CVB3 treatment. We screened several chemically extracted natural compounds by using HeLa cell-based cell survival assay. Among them, Linum usitatissimum L. extract was selected for antiviral drug candidate. L. usitatissimum extract significantly decreased CVB3 replication and cell death in CVB3 infected HeLa cells with no cytotoxicity. CVB3 protease 2A induced eIF4G1 cleavage and viral capsid protein VP1 production were dramatically decreased by L. usitatissimum extract treatment. In addition, virus positive and negative strand genome amplification were significantly decreased by 1 mg/ml L. usitatissimum extract treatment. Especially, L. usitatissimum extract was associated with inhibition of AKT signal and maintain mTOR activity. In contrast, Atg12 and LC3 expression were not changed by L. usitatissimum extract treatment. In this study, the potential AKT signal inhibitor, L. usitatissimum extract, was significantly inhibited viral genome replication and protein production by inhibition of AKT signal. These results suggested that L. usitatissimum extract is a novel therapeutic agent for treatment of CVB3-mediated diseases.

• Bulletin of the Korean Chemical Society
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• v.21 no.12
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• pp.1171-1172
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• 2000

• Journal of Microbiology
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• v.43 no.6
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• pp.529-536
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• 2005

Viral infection causes stress to the endoplasmic reticulum (ER). The response to endoplasmic reticulum stress, known as the unfolded protein response (UPR), is designed to eliminate misfolded proteins and allow the cell to recover. The role of hepatitis C virus (HCV) non-structural protein NS4B, a component of the HCV replicons that induce UPR, is incompletely understood. We demonstrate that HCV NS4B could induce activating transcription factor (ATF6) and inositol-requiring enzyme 1 (IRE1), to favor the HCV subreplicon and HCV viral replication. HCV NS4B activated the IRE1 pathway, as indicated by splicing of X box-binding protein (Xbp-1) mRNA. However, transcriptional activation of the XBP-1 target gene, EDEM (ER degradation-enhancing $\alpha-mannosidase-like$ protein, a protein degradation factor), was inhibited. These results imply that NS4B might induce UPR through ATF6 and IRE1-XBP1 pathways, but might also modify the outcome to benefit HCV or HCV subreplicon replication.

• Genomics & Informatics
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• v.18 no.4
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• pp.43.1-43.13
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• 2020

The coronavirus disease 2019 is a contagious disease and had caused havoc throughout the world by creating widespread mortality and morbidity. The unavailability of vaccines and proper antiviral drugs encourages the researchers to identify potential antiviral drugs to be used against the virus. The presence of RNA binding domain in the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be a potential drug target, which serves multiple critical functions during the viral life cycle, especially the viral replication. Since vaccine development might take some time, the identification of a drug compound targeting viral replication might offer a solution for treatment. The study analyzed the phylogenetic relationship of N protein sequence divergence with other 49 coronavirus species and also identified the conserved regions according to protein families through conserved domain search. Good structural binding affinities of a few natural and/or synthetic phytocompounds or drugs against N protein were determined using the molecular docking approaches. The analyzed compounds presented the higher numbers of hydrogen bonds of selected chemicals supporting the drug-ability of these compounds. Among them, the established antiviral drug glycyrrhizic acid and the phytochemical theaflavin can be considered as possible drug compounds against target N protein of SARS-CoV-2 as they showed lower binding affinities. The findings of this study might lead to the development of a drug for the SARS-CoV-2 mediated disease and offer solution to treatment of SARS-CoV-2 infection.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.281-286
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• 2007

Interactions between viral proteins and host proteins are essential for virus replication. Especially, translation of viral genes completely depends on the host machinery. In potyviruses, interactions of genome-linked viral protein (VPg) with host translation factors including eIF4E, eIF(iso)4E, and poly(A)-binding protein (PABP) has previously been characterized. In this study, we investigated interactions between Soybean mosaic virus (SMV) viral proteins and host translation factors by yeast two-hybrid system. SMV VPg interacted with eIF4E, eIF(iso)4E, and PABP in yeast two-hybrid system, while SMV helper component proteinase (HC-pro) interacted with neither of those proteins. The interaction between SMV NIb and PABP was also detected. These results are consistent with those reported previously in other potyviruses. Interestingly, we found reproducible and specific interactions between SMV coat protein (CP) and PABP. Deletion analysis showed that the region of CP comprising amino acids 116 to 206 and the region of PABP comprising amino acids 520 to 580 are involved in CP/PABP interactions. Soybean library screening with SMV NIb by yeast two-hybrid assay also identified several soybean proteins including chlorophyll a/b binding preprotein, photo-system I-N subunit, ribulose 1,5-biphosphate carboxylase, ST-LSI protein, translation initiation factor 1, TIR-NBS type R protein, RNA binding protein, ubiquitin, and LRR protein kinase. Altogether, these results suggest that potyviral replicase may comprise a multi-protein complex with PABP, CP, and other host factors.