• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.15-20
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• 2018

Most proteins produced in the endoplasmic reticulum (ER) of eukaryotic cells fold via disulfide formation (oxidative folding). Oxidative folding is catalyzed by protein disulfide isomerase (PDI) and PDI-related ER protein thiol disulfide oxidoreductases (ER oxidoreductases). In yeast and mammals, ER oxidoreductin-1s (ERO1s) supply oxidizing equivalent to the active centers of PDI. We previously identified and characterized the ERO1 of Bombyx mori (bERO1) as a thioredoxin-like protein that shares primary sequence homology with other ERO1s. Here we compare the reactivation of inactivated rRNase and sRNase by bERO1, and show that bERO1 and bPDI cooperatively refold denatured RNase A. This is the first result suggesting that bERO1 plays an essential role in ER quality control through the combined activities of bERO1 and bPDI as a catalyst of protein folding in the ER and sustaining cellular redox homeostasis.

• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.227-232
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• 2015

Akabane and bovine ephemeral fever (BEF) viruses cause vector-borne diseases. In this study, inactivated Akabane virus (AKAV)+Bovine ephemeral fever virus (BEFV) vaccines with or without recombinant vibrio flagellin (revibFlaB) protein were expressed in a baculovirus expression system to measure their safety and immunogenicity. Blood was collected from mice, guinea pigs, sows, and cattle that had been inoculated with the vaccine twice. Inactivated AKAV+BEFV vaccine induced high virus neutralizing antibody (VNA) titer against AKAV and BEFV in mice and guinea pigs. VNA titers against AKAV were higher in mice and guinea pigs immunized with the inactivated AKAV+BEFV vaccine than in animals inoculated with vaccine containing revibFlaB protein. Inactivated AKAV+BEFV vaccine elicited slightly higher VNA titers against AKAV and BEFV than the live AKAV and live BEFV vaccines in mice and guinea pigs. In addition, the inactivated AKAV+BEFV vaccine was safe, and induced high VNA titers, ranging from 1 : 64 to 1 : 512, against both AKAV and BEFV in sows and cattle. Moreover, there were no side effects observed in any treated animals. These results indicate that the inactivated AKAV+BEFV vaccine could be used in cattle with high immunogenicity and good safety.

• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.20-25
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• 1992

The location of the polyhedrin gene of Bmbyx mori nuclear polyhedrosis virus(BmNPV) was determined by using a cloned polyhedrin gene from the Autographa californica nuclear polyhedrosis virus(AcNPV) as a hybridization probe. The 7.4 Kb PstⅠ fragment DNA of Bm-NPV was cloned to plasmid pUC19 vector. A fragment containing this gene was mapped and sequenced in its entire polyhedrin reading frame. Nucleotide sequences comparison of the polyhedrin of the BmNPV to that of previously reported by Ⅰatrou(1985) revealed that the sequence varied in 10 base, Comparison of the amino acid sequence of the two structured gene revealed that coding sequence varied 74 valine to isoleucine, 76 aspargine to serine and 155 methionine to valine.

• Korean journal of applied entomology
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• v.36 no.4
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• pp.331-340
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• 1997

Hyalophora cecropia attacin-like antibacterial gene was isolated from Bombyx mori induced with nonpathogenic bacteria. It was expressed in Spodopfera frugiperda 9 (Sf9 cells using baculovirus expression vector system (BEVS), and examined its antibacterial activity. With a cDNA library constructed from fifthinstar B. mori injected with Escherichia coli(4 X IOhcellsllarva), differential screening was performed using naive and induced mRNA probes. BmInc6 clone was screened by partial nucleotide sequence and GenBank database analysis. A complete nucleotide sequence of Bmlnc6 cDNA was determined (GenBank, AF005384). Its insert size was 852 bp and had open reading frame that started translation at position 35 and stopped at 679. And its putative polyadenylational signal existed at 812 bp. The number of amino acid deduced from Bmlnc6 cDNA was 214 and hydropathy analysis showed that this peptide was hydrophilic. This peptide deduced by BmInc6 was named nuecin. When the nuecin gene was expressed in Sf9 cells using BEVS, about 950 bp of the transcripts was detected. In addition, SDS-PAGE analysis showed that the molecular weights of intracellular expressed protein and the mature protein secreted to culture media were approximately 23 and 20 kDa, respectively. The antibacterial activity of nuecin against E. coli and Bacillus subtilis was significantly high, demonstrating that nuecin had a wider antibacterial spectrum with gram negative and positive bacteria than attacin.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.359-366
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• 1997

The usefulness of host range expanded recombinant viruses for economical viral insecticide and expression vector system has been studied. Host range expanded recombinant viruses, RecS-B6 and RecB-8, constructed by cotransfection of Bombyx mori nuclear polyhedrosis virus (BmNPV) and Autographa californica NPV (AcNPV), and a host range expanded AcNPV recombinant, Ac-BH, constructed by substitution of the 0.6Kb fragment of the BmNPV helicase gene were compared. The restriction enzyme digestion patterns showed that RecS-B6 and RecB-8 had expanded host ranges by genomic recombination and were more similar to genome of AcNPV than that of BmNPV. SDS-PAGE and PCR analysis showed that the polyhedrin gene of RecS-B6 and RecB-8 was derived from BmNPV genomic DNA. The morphology of polyhedra of recombinant viruses showed a slight difference between the two host cells, Sf and BmN cells, indicating that the morphology of polyhedra was influenced by host cells. The bioassay data for insect larvae showed that Ac-BH, compared to wild type viruses, had superior pathogenicity against Bombyx mori larvae but inferior pathogenicity against Spodoptera exigua larvae. Although the pathogenicity was lower than that of wild type viruses in both larvae, RecS-B6 showed the pathogenicity in both larvae. These results suggested that Ac-BH was a less useful economical insecticide than random genomic recombinant virus RecS-B6.

• Korean journal of applied entomology
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• v.56 no.1
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• pp.19-28
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• 2017

Polydnaviruses (PDVs) are a group of double-stranded DNA viruses symbiotic to some endoparasitoid wasps. Cotesia plutellae bracovirus (CpBV) is a PDV symbiotic to an endoparasitoid wasp, C. plutellae, parasitizing young larvae of Plutella xylostella. An early expressed gene, CpBV-ELP1, plays an important role in the parasitism by suppressing host cellular immunity by its cytotoxic activity against hemocytes. This study aimed to test its oral toxicity against insect pest by expressing it in a recombinant tobacco plant. A recombinant CpBV-ELP1 protein was produced using a baculovirus expression system and secreted to cell culture medium. The cell cultured media were used to purify CpBV-ELP1 by a sequential array of purification steps: ammonium sulfate fractionation, size exclusion chromatography, and ion exchange chromatography. Purified rCpBV-ELP1 exhibited a significant cytotoxicity against Spodoptera exigua hemocytes. CpBV-ELP1 was highly toxic to the fifth instar larvae of S. exigua by injection to hemocoel. It also showed a significant oral toxicity to fifth instar larvae of S. exigua by a leaf-dipping assay. CpBV-ELP1 was cloned into pBI121 vector under CaMV 35S promoter with opaline synthase terminator. Resulting recombinant vector (pBI121-ELP1) was used to transform Agrobacterium tumefaciens LBA4404. The recombinant bacteria were then used to induce callus of a tobacco (Nicotiana tabacum Xanthi) leaves and subsequent generation (T1) plants were selected. T1 generation tobacco plants expressing CpBV-ELP1 gave significant insecticidal activities against S. exigua larvae. These results suggest that CpBV-ELP1 gene can be used to control insect pests by constructing transgenic crops.