• Applied Microscopy
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• v.52
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• pp.11.1-11.9
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• 2022

Zoonotic poxvirus infections pose significant threat to human health as we have witnessed recent spread of monkeypox. Therefore, insights into molecular mechanism behind poxvirus replication cycle are needed for the development of efficient antiviral strategies. Virion assembly is one of the key steps that determine the fate of replicating poxviruses. However, in-depth understanding of poxvirus assembly is challenging due to the complex nature of multi-step morphogenesis and heterogeneous virion structures. Despite these challenges, decades of research have revealed virion morphologies at various maturation stages, critical protein components and interactions with host cell compartments. Transmission electron microscopy has been employed as an indispensable tool for the examination of virion morphology, and more recently for the structure determination of protein complexes. In this review, we describe some of the major findings in poxvirus morphogenesis and the contributions of continuously advancing electron microscopy techniques.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.92-92
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• 1993

Point mutations in a highly conserved central region of the HIV-1 integrase protein were analyzed for their effects on viral replication and virion morphogenesis. Conservative amino acid replacements of two amino acid residues invariant un retroviral integrases, D116 and E152 of HIV-1, as well as the highly conserved amino acid S147, completely blocked viral replication in two CD4$\^$＋/ human T cell lines. Mutation of four other highly conserved amino acids in the region had no detectable effect on viral replication, while Mutations at two positions, N117 and Y143, resulted in viruses with a delayed replication phenotype. Characteristic and reproducible defects id virion core structure were observed by electron microscopic analysis of sore of the replication defective integrase point mutants, indicating that mutant integrase proteins can interfere with the process of virion core maturation.

• BMB Reports
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• v.40 no.2
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• pp.156-162
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• 2007

Two lysis-defective but DNA synthesis non-defective temperature-sensitive (ts) mutants of mycobacteriophage L1, L1G23ts23 and L1G25ts889 were found to be defective also in phage-specific RNA synthesis in the late period of their growth at 42$^{\circ}C$each to the extent of 50% of that at 32$^{\circ}C$The double mutant, L1G23ts23G25ts889 showed the ts defect in phage RNA synthesis that was nearly additive of those shown individually by the two single-mutant parents. Both G23 and G25 were shown to start functioning sometimes between 30 and 45 min after infection but the former gene might be dispensable after 45 min, while the latter was not. Northern analysis also shows that at 42$^{\circ}C$>, L1G23ts23 affects RNA synthesis more strongly than L1G25ts889 from L1 DNA segments that serve as the template for late gene transcription. Among the 21 virion and 12 non-virion late proteins synthesized by L1, L1G23ts23 is defective in the synthesis of at least 9 virion and all of non-virion proteins at 42$^{\circ}C$>. In contrast, L1G25ts889 is completely defective in synthesis of all the 33 late proteins. Possible roles of G23 and G25 in the positive regulation of transcription of different sets of late genes of L1 have been discussed.

• Journal of fish pathology
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• v.13 no.1
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• pp.7-13
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• 2000

Beginning in the summer of 1993, a serious mortality among cultured penaeid shrimp occurred in the western sea of Korea. The typical sign of this disease was white spots inside the surface of the carapace. Cytopathic effect (CPE) were not observed by virus in CHSE-214, RTG-2, but not by pH 11. A nonoccluded rod-shaped form virus was observed by electron microscopy in the lymphoid organ. The virion was bacilliform virus and sourrounded by a virion envelope. Its virion protein was found to be similar to hypodermal and hematopoietic necrosis virus (HHNBV) by analysis of virion proteins in SDS-PAGE. The genome of virus is double stranded DNA molecule whose full length was about 114kb. It was similar to penaeus acute viremia (PAV) of Japan.

• BMB Reports
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• v.46 no.10
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• pp.495-500
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• 2013

Turnip yellow mosaic virus (TYMV) is a positive strand RNA virus. We have modified TYMV coat protein (CP) by inserting a c-Myc epitope peptide at the N- or C-terminus of the CP, and have examined its effect on assembly. We introduced the recombinant CP constructs into Nicotiana benthamiana leaves by agroinfiltration. Examination of the leaf extracts by agarose gel electrophoresis and Western blot analysis showed that the CP modified at the N-terminus produced a band co-migrating with wild-type virions. With C-terminal modification, however, the detected bands moved faster than the wild-type virions. To further examine the effect, TYMV constructs producing the modified CPs were prepared. With N-terminal modification, viral RNAs were protected from RNase A. In contrast, the viral RNAs were not protected with C-terminal modification. Overall, the results suggest that virion assembly and RNA packaging occur properly when the N-terminus of CP is modified, but not when the C-terminus is modified.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.107-114
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• 1996

본 연구는 인간면역결핍바이러스의 입자를 비이온성 계면활성제로 처리할 때 바이러스 입자구조에서 분리되어 방출되는 바이러스 구조단백질들의 분포를 sucrose gradient로 분석하여, 바이러스 입자를 구성하는 바이러스 구조단백질과 바이러스입자의 생물리학적 특성을 연구하였다. 바이러스입자들을 0.16% NP40 (Nonidet P-40)으로 처리할 때, 바이러스 capsid 단백질과 바이러스 막 단백질 (membrance protein)들은 다른 바이러스 구성성분들과 잘 분리되었다. 계면활성제처리에서 방출되지 않은 구성 성분들은 matrix 단백질, nucleocapsid 단백질, reverse transcriptase, integrase 및 바이러스 RNA genome로써, 이들은 subviral 구조를 형성한다. 이러한 결과는 상대적으로 다른 바이러스들의 capsid 단백질과 면역 결핍 바이러스의 capsid 단백질 (p24)를 비교할 때, 면역결핍바이러스의 capsid 단백질은 바이러스핵을 형성할 때, capsid 단백질 사이의 결합력이 매우 약한 것으로 추정된다. 또한 바이러스 조절단백질의 하나인 vpr 단백질을 함유하는 바이러스입자를 NP40 처리하여 분석하였을 때, vpr 단백질은 subviral 구조에 존재하는 것으로 나타났다.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.248-252
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• 2005

The virions of causative virus for white spot syndrome in cultured Fresh shrimp, Penaeus chinensis were rod-shaped, double envelope. An average size of the virion was 70 nm in diameter and $250\~300$ nm in length. Histopathological test of affected stomach, heart, and lymphoid organ revealed nuclear hypertrophy. Infectivity trials carried out by injection and feeding with purified virus revealed high cumulative mortality to healthy shrimp. The twenty one different protein species were detected in the analysis of virion. The length of total DNA from the purified virus particles were detected as a single band, double-stranded DNA molecule of approximately 114 kb.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.103-108
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• 2000

We have cloned and analyzed cDNA coding for non-virion (NV) protein of the m V - P R T The NV gene contained 336 bp open readmg frame and encoded a protein of 11 1 amino acids with a molecular weight of 13.2 kDa. The deduced amino acid sequence of NV of IHNVPRT was found to be 90-95% identical to those of foreign isolates of IHNV. These results indicate that NV gene of the MNV is highly conserved among &ifferent strains of THNV Northern blot analyses revealed that the levels of NV gene expression were strongly elevated after 20 h post-infection. In order to identify the role of NV in the replication of MNV in fish cells, IHNVinfected cells were treated with antisense oligonucleotides. While IHNV-PRT exposed to glycoprotein (G) antisense oligonucleotide showed severely reduced growth, the growth of virus exposed to NV antisense oligonucleotide was not affected by NV antisense oligonucleotide, which suggests that NV is not essential for replication of IHNV in fish cells.

• The Journal of Korean Medicine
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• v.19 no.2
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• pp.244-270
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• 1998

This study was performed to investigate an anti-HBV activities of the aqueous extracts from 10 Korean herbal medicines in the HepG2 2.2.15 cell culture system and the results were as follows: 1. The extracts of 6 plants (Herba Artemisiae Capillaris, Radix et Rhizoma Rhei, Cortex Cinnamomi, Fructus Chebulae, Fructus Rubi and Radix Rubi) decreased, significantly and dose-dependently, the levels of extracellular HBV virion in the concentrations (10, 100, 500 and $1,000\;{\mu}g/m{\ell}$) tested. 2. However, others (Radix lsatidis, Lignum Sappan, Herba Lysimachiae and Fructus Lycii) did not show any effect either on the replication of HBV or on the levels of virion DNA in the culture media of HepG2 2.2.15 cell. 3. Among the 6 plants which showed the inhibitory potency on the production of extracellular HBV virion, Radix et Rhizoma Rhei, Cortex Cinnamomi, Fructus Chebulae, Fructus Rubi and Radix Rubi except Herba Artemisiae Capillaris also showed the inhibition of the replication of intracellular HEV DNA in the range of $100{\sim}500\;{\mu}g/m{\ell}$. Considering the above results, it is thought that 6 plants(Herba Artemisiae Capillaris, Radix et Rhizoma Rhei, Cortex Cinnamomi, Fructus Chebulae, Fructus Rubi and Radix Rubi) possess the anti-HBV activities in the HepG2 2.2.15 cell culture system. We thus suggest that these plants possess a potential as a therapeutic agent for the chronic viral hepatitis. These results might be useful as a basic data for the development of the new preventive drugs for HBV diseases.

• Korean journal of applied entomology
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• v.28 no.3
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• pp.105-112
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• 1989

The nuclear polyhedrosis viruses of Bombyx mori (BmNPV) and Hyphantria cunea (HcNPV) were characterized by electron microscopic observation, SDS-PAGE of polyhedral and virion proteins, and restriction endonuclease analysis of viral DNAs. Polyhedra of BmNPV were octadecahedral in shape with the diameter of $3 \mu\textrm{m}$, whereas those of HcNPV showed irregular appearances having the diameter of $1.5~2\mu\textrm{m}$. Under alkaline protease inactivated condition, polyhedral proteins of two NPVs were resolved into a major polypeptide, 30~31 KD, and several minor polypeptides by SDS-PAGE. Examination of virion proteins by silver staining after SDS-PAGE showed that BmNPV was composed of 47 polypeptides with M.W. range of 9.6~112 KD and HcNPV was composed of 48 polypeptides with M.W. range of 9.4~111 KD. The approximate genome size of two NPVs were determined by restriction endonuclease analysis: BmNPV and HcNPV were 114.6 Kb, respectively.