• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.87-94
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• 2007

In this study, we describe Korean isolates of Trichomonas vaginalis infected with double-stranded (ds) RNA virus (TVV). One T. vaginalis isolate infected with TVV IH-2 evidenced weak pathogenicity in the mouse assay coupled with the persistent presence of a dsRNA, thereby indicating a hypovirulence effect of dsRNA in T. vaginalis. Cloning and sequence analysis results revealed that the genomic dsRNA of TVV IH-2 was 4,647 bp in length and evidenced a sequence identity of 80% with the previously-described TVV 1-1 and 1-5, but only a 42% identity with TVV 2-1 and 3 isolates. It harbored 2 overlapping open reading frames of the putative capsid protein and dsRNA-dependent RNA polymerase (RdRp). As previously observed in the TVV isolates 1-1 and 1-5, a conserved ribosomal slip-page heptamer (CCUUUUU) and its surrounding sequence context within the consensus 14-nt overlap implied the gene expression of a capsid protein-RdRp fusion protein, occurring as the result of a potential ribosomal frameshift event. The phylogenetic analysis of RdRp showed that the Korean TVV If-2 isolate formed a compact group with TVV 1-1 and 1-5 isolates, which was divergent from TVV 2-1, 3 and other viral isolates classified as members of the Giardiavirus genus.

• Molecules and Cells
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• v.21 no.3
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• pp.330-336
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• 2006

Since its identification in 1989, hepatitis C virus has been the subject of extensive research. The biology of the virus and the development of antiviral drugs are closely related. The RNA polymerase activity of nonstructural protein 5B was first demonstrated in 1996. NS5B is believed to localize to the perinuclear region, forming a replicase complex with other viral proteins. It has a typical polymerase structure with thumb, palm, and finger domains encircling the active site. A de novo replication initiation mechanism has been suggested. To date, many small molecule inhibitors are known including nucleoside analogues, non-nucleoside analogues, and pyrophosphate mimics. NS5B interacts with other viral proteins such as core, NS3, 4A, 4B, and 5A. The helicase activity of NS3 seems necessary for RNA strand unwinding during replication, with other nonstructural proteins performing modulatory roles. Cellular proteins interacting with NS5B include VAMP-associated proteins, heIF4AII, hPLIC1, nucleolin, PRK2, ${\alpha}$-actinin, and p68 helicase. The interactions of NS5B with these proteins might play roles in cellular trafficking, signal transduction, and RNA polymerization, as well as the regulation of replication/translation processes.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2000.10a
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• pp.57.1-57
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• 2000

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1919-1922
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• 2006

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.834-837
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• 2017

A distinct double-stranded RNA (dsRNA) cryptic virus, named spinach cryptic virus 1 (SpCV1), was identified from spinach transcriptome datasets. The SpCV1 genome has two dsRNA genome segments. The larger dsRNA1 has an open reading frame for a conserved RNA-dependent RNA polymerase (RdRp). The smaller dsRNA2 encodes a putative coat protein (CP). The sequence identity of SpCV1 RdRp and CP to the closest cryptic virus is 81% and 60%, respectively. Phylogenetic analysis indicates that SpCV1 is a novel member of the genus Alphapartitivirus (family Partitiviridae).

• The Plant Pathology Journal
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• v.21 no.4
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• pp.343-348
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• 2005

The partial nucleotide sequences of the genomic dsRNA mycoviruses infecting Pleurotus ostreatus (isolates ASI2596, ASI2597, and Bupyungbokhoe) and Agaricus blazei Murrill were determined and compared with those of the other dsRNA mycoviruses. Partial nucleotide sequences of the purified dsRNA from ASI2596 and ASI2597 revealed RNA-dependent RNA polymerase sequences that are closely related to Oyster mushroom isometric virus 2, while nucleotide sequences and the deduced amino acid sequence from dsRNA mycovirus infecting Agaricus blazei did not show any significant homology to the other dsRNA mycoviruses. Specific primers were designed for RT-PCR detection of these dsRNA viruses and were found to specifically detect each dsRNA virus. Northern blot analysis confirmed the homogeneity of RT-PCR products to each purified dsRNA. Altogether, our results suggest that these virus-specific primer sets can be employed for the specific detection of each dsRNA mycovirus in infected mushrooms.

• BMB Reports
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• v.33 no.1
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• pp.59-62
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• 2000

Hepatitis C virus (HCV) nonstructural 5B (NS5B) protein is an RNA-dependent RNA polymerase (RdRp). To determine whether it can contribute to viral replication by interaction with cellular proteins, the yeast two-hybrid screening system was employed to screen a human liver cDNA library. Using the HCV NS5B as a bait, we have isolated positive clones encoding a cellular protein. The NS5B interacting protein, 5BIP, is a novel cellular protein of 170 amino acids. Interaction of the HCV NS5B protein with 5BIP was confirmed by a protein-protein blotting assay. Recently, we have demonstrated that NS5B possesses an RdRp activity and thus it is possible that 5BIP, in association with NS5B, plays a role in HCV replication.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.142-142
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• 1998

This study has been undertaken to examine the effect of biphenyl dimethyl dicarboxylate (DDB) on rat liver drug metabolizing enzyme in order to understand the mechanism of DDB on improving hepatic toxicity in rat liver. After DDB was administered into male rats for different periods of time, mRNA level of CYP1A1 and CYP2B1 was measured by polymerase chain reaction (PCR). DDB treatment resulted in increase in CYP2B1 mRNA level whereas there was no change in CYP1A1 mRNA level. This effect of DDB was time dependent reaching maximal level by 2-day treatment. DDB dose response study showed that 50mg/kg DDB induced CYP2B1 mRNA to maximal level and DDB icreased CYP2B1 gene expression with dose-dependent manner. Based on studies of lipid peroxidation, serum ALT and AST levels and histopathologic examination showed DDB protection on CCl4 induced hepatotoxiccity.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.285-291
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• 2007

According to the Baltimore Scheme, viruses are classified into 6 main classes based on their replication and coding strategies. Except for some small DNA viruses, most viruses code for their own polymerases: DNA-dependent DNA, RNA-dependent RNA and RNA-dependent DNA polymerases, all of which contain 4 common motifs. We undertook a phylogenetic study to establish the relationship between the Baltimore Scheme and viral polymerases. Amino acid sequence data sets of viral polymerases were taken from NCBI GenBank, and a multiple alignment was performed with CLUSTAL X program. Phylogenetic trees of viral polymerases constructed from the distance matrices were generally consistent with Baltimore Scheme with some minor exceptions. Interestingly, negative RNA viruses (Class V) could be further divided into 2 subgroups with segmented and non-segmented genomes. Thus, Baltimore Scheme for viral taxonomy could be supported by phylogenetic analysis based on the amino acid sequences of viral polymerases.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.301-310
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• 2005

Foot-and-mouth disease (FMD) is a highly contagious disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals, such as cattle, pigs, sheep, goats and buffalo. FMDV, a member of the Aphthovirus genus in the Picornaviridae family, is a non-enveloped icosahedral virus that contains a positive sense RNA of about 8.2 kb in size. The genome carries one open reading frame consisting of 3 regions: capsid protein coding region P1, replication related protein coding region P2, and RNA-dependent RNA polymerase coding region P3. FMDV infects pharynx epithelial cell in the respiratory tract and viral replication is active in lung epithelial cell. Morbidity is extremely high. A FMD outbreak in Korea in 2002 caused severe economic loss. Although intense research is undergoing to develop appropriate drugs to treat FMDV infection, there is no specific therapeutic for controlling FMDV infection. Moreover, there is an increasing demand for the development of vaccine strategies against FMDV infection in many countries. In this report, more effective prevention strategies against FMDV infection were reviewed.