• Journal of Microbiology and Biotechnology
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• v.2 no.2
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• pp.122-128
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• 1992

Post-translational modifications of the nucleocapsid protein of bovine coronavirus (Quebec strain) were investigated. Coronavirions were radiolabelled in vivo with inorganic $[^{32}P]$orthophosphate and analysed by SDS-PAGE, followed by autoradiography. A single polypeptide with a migration rate of 55 KDa was identified by metabolic phosphate labelling, demonstrating that the nucleocapsid protein of bovine coronavirus was a phosphoprotein. A gene encoding the nucleocapsid protein was inserted immediately downstream from the polyhedrin promoter of Autographa californica nuclear polyhedrosis baculovirus. Spodoptera frugiperda cells infected with this recombinant baculovirus synthesized a 55 KDa polypeptide, as demonstrated by immunoprecipitation with anti-nucleocapsid monoclonal antibody. The recombinant nucleocapsid protein synthesized in Spodoptera cells could also be labelled by $[^{32}P]$orthophosphate. Phosphoamino acid analysis showed that both serine and threonine residues were phosphorylated in authentic, as well as in recombinant nucleocapsid proteins, with a relative phosphorylation ratio of 7:3. Our studies demonstrated that the nucleocapsid protein of bovine coronavirus was a serine and threonine-phosphorylated protein and that Spodoptera insect cells were able to properly phosphorylate the relevant foreign proteins.

• KSBB Journal
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• v.13 no.6
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• pp.656-661
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• 1998

Hantaan virus belonging to the genus Hantavirus and family Bunyaviridae causes an acute severe illness of human, Haemorrhagic Fever with Renal Syndrome (HFRS). It is a rodent host-borne pathogen and distributed in Asia and Eastern Europe. Hantaviruses have three major antigens, i.e., G1, G2 glycoproteins and nucleocapsid protein (N). Among them, nucleocapsid protein was reported to be the most invaluable antigen as for diagnosis. We have cloned and expressed Hantaan viral nucleocapsid gene in E. coli BL21(DE3). In this study, we have tried to purify the nucleocapsid protein produced by recombinant E. coli, and could attained a purity of >90% by anti-N monoclonal antibody-coupled immunoaffinity chromatography or phenyl sepharose hydrophobic interaction chromatography.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1103-1108
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• 2009

The human immunodeficiency virus (HIV)-l protein Tat acts as a transcription transactivator that stimulates expression of the infected viral genome. It is released from infected cells and can similarly affect neighboring cells. The nucleocapsid is an important protein that has a related significant role in early mRNA expression, and which contributes to the rapid viral replication that occurs during HIV-1 infection. To investigate the interaction between the Tat and nucleocapsid proteins, we utilized cDNA micro arrays using pTat and flag NC cotransfection in HEK 293T cells and reverse transcription-polymerase chain reaction to validate the micro array data. Four upregulated genes and nine downregulated genes were selected as candidate genes. Gene ontology analysis was conducted to define the biological process of the input genes. A proteomic approach using PathwayStudio determined the relationship between Tat and nucleocapsid; two automatically built pathways represented the interactions between the upregulated and downregulated genes. The results indicate that the up- and downregulated genes regulate HIV-1 replication and proliferation, and viral entry.

• KSBB Journal
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• v.13 no.6
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• pp.649-655
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• 1998

Hantaviruses are rodent hosts-borne viruses belonging to the family Bunyaviridae, and are etiologic agents for two acute diseases, i.e., Haemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS). There have been a lot of reports on prophylactic vaccines and diagnostics for the diseases, but most of viral antigens have been prepared by eukaryotic cell culture. Nucleocapsid proteins of Hantaviruses are known as the major viral antigens. Thereby, we prepared nucleocapsid genes of Hantaan virus and Seoul virus by RT-PCR and cloned into plasmid vectors, pET-3a and pKK223-3. Both genes were expressed in Escherichia coli with higher expression level of Seoul viral nucleocapsid protein compared to that of Hantaan in pET-3a. Hantaan viral gene was expressed much higher level in plasmid pET-3a that in pKK223-3. About 30% of expressed nucleocapsid protein was soluble and the rest was remained in insoluble fraction.

• KSBB Journal
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• v.13 no.6
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• pp.662-668
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• 1998

Viruses belonging to the Hantavirus genus cause two acute severe illness in humans, i.e., Haemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome(HPS). Among them, Hantaan virus is one of the most important viruses causing HFRS. Recombinant expression vectors, pKK-NP and pET-NP, with Hantaan viral nucleocapsid gene were constructed, and used to transform Eschericia coli BL21(DE3). Stability of the vectors in the host strain, and effects of some environmental conditions on the expression of nucleocapsid gene were studied. Expression vector, pKK-NP, was very unstable, and the expression level of nucleocapsid gene was very low compared to that of pET-NP. BL21(pET-NP) produced about 100 mg of N protein per liter of culture broth. Induction time did not show any significant difference on the expression level of nucleocapsid gen and cell growth. BL21(pET-NP) culture at 35$^{\circ}C$ showed a little higher expression level than at 30$^{\circ}C$ during growth phase, but reached to the same level at stationary phase. Total expression level was proportional to supplemented glucose concentration of media up to 0.5% along with cell growth, but expression level per unit cell mass was inversely proportional to glucose concentration and maximal when glucose was not supplemented at all.

• Journal of Microbiology
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• v.39 no.4
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• pp.293-299
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• 2001

The nucleocapsid(NP) protein of Newcastle disease virus (NDV) and its derivative (NP$\sub$cfus)containing the myc region and six histidine residues fused to its C-terminus were pcpressed aboundantly in Escherichia coli. The proteins were purified by sucrose gradient centrifugation. Both the NP and NP$\sub$cfus/ proteins self-assem- bled into ring-like particles stacked together to from nucleocapsid-like structure which are heterogeneous in length with a diameter of 20${\pm}$2 nm and central holow of 5${\pm}$1 nm. Only a very small amount of the monomers in the particles was linked by inter-molecular disulfide bonds. Fusion of the C-terminal end to 29 amino acids inclusive of the myc epitope and His tag did not impair ring assembly buy inhibited the formation of the long herringbone structures. Immunogold lableing of the particles with the anti-myc antibody showed that the C-terminus of the NP$\sub$cfus/ protein is exposed on the surface of these ring-like particles.

• Journal of Microbiology
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• v.44 no.5
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• pp.577-580
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• 2006

GST pull-down assays were used to characterize the SARS-CoV membrane (M) and nucleocapsid (N) interaction, and it was found that the amino acids 211-254 of N protein were essential for this interaction. When tetrad glutamines (Q) were replaced with glutamic acids (E) at positions of 240-243 of the N protein, the interaction was disrupted.

• Journal of Microbiology
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• v.44 no.1
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• pp.77-82
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• 2006

The tea looper caterpillar, Ectropis obliqua, is one of the major pests of tea bushes. E. obliqua single-nucleocapsid nucleopolyhedrovirus (EcobSNPV) has been used as a commercial pesticide for biocontrol of this insect. However only limited genetic analysis for this important virus has been done up to now. EcobSNPV was characterized in this study. Electron microscopy analysis of the occlusion body showed polyhedra of 0.7 to $1.7\;{\mu}m$ in diameter containing a single nucleocapsid per envelope of the virion. A 15.5 kb genomic fragment containing EcoRI-L, EcoRI-N and HindIII-F fragments, was sequenced. Analysis of the sequence revealed that the fragment contained eleven potential open reading frames (ORFs): lef-1, egt, 38.7k, rrl, polyhedrin, orfl629, pk-1, hoar and homologues to Spodoptera exigua multicapsid NPV (SeMNPV) ORFs 15, 28, and 29. Gene arrangement and phylogeny analysis suggest that EcobSNPV is closely related to the previously described Group II NPV. Bioassays on lethal concentration $(LC_{50}\;and\;LC_{90})$ and lethal time $(LT_{50}\;and\;LT({90})$ were conducted to test the susceptibility of E. obliqua larvae to the virus.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2421-2427
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• 2024

In this research, the Omicron variant of the SARS-CoV-2 virus was simulated and exposed to electron radiation with up to 20 keV energy. Absorbed energy was measured for spike protein, nucleocapsid protein, and envelope of the virus. Simulations were performed by Geant4-DNA in a water environment at temperature of 20 ℃ and pressure of 1 atm. Since the viral RNA is kept inside the nucleocapsid protein, damage to this area could destroy the viral RNA strand and create an inactive virus. Our findings showed that electron beams with an energy of 2.5 keV could cause a maximum absorption dose and consequently maximum damage to the nucleocapsid and effectively be used for inactivation virus.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.129-137
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• 2003

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failures in sows and respiratory problems in piglets. The nucleocapsid(N) protein, encoded by the open reading frame 7 (ORF7) gene, is known to be the most abundant and antigenic protein in PRRS virus. Therefore, it was suggested that the N protein could be a suitable candidate for the detection of PRRS virus-specific antibodies and diagnosis of PRRS. In the present study, the ORF7 gene encoding the N protein was cloned and expressed as a fusion protein with the glutathione S-transferase (GST) in Escherichia coli. The resulting GST-N recombinant protein was used as an antigen for an indirect sandwich enzyme-linked immunosorbent assay (i-ELISA). Expressed GST-N recombinant protein was migrated at 41 kDa and reacted with ORF7-specific monoclonal antibody by Western blotting. In order to increase the specificity of the ELISA for the detection of PRRS virus-specific antibodes, an i-ELISA was developed using an anti-GST antibody as a capture antibody. The sensitivity and specificity of developed i-ELISA were 92% and 96%, respectively. Based on these results, it was suggested that the i-ELISA is a simple and rapid test for screening a large number of swine sera for the anti-PRRS virus antibodies.