• International Journal of Industrial Entomology and Biomaterials
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• 제1권1호
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• pp.1-7
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• 2000

Early studies of the molecular biology of Bacillus thuringeinsis suggested that genetic manipulation of this species could create combinations of genes more useful than those known to occur in natural isolates. Breakthroughs that made these manipulations possible include the cloning of many genes encoding endotoxins, the development of transformation vectors, and various PCR techniques. This paper reviews several genetic factors such as promoters, a 5'mRNA stabilizing sequence, 3'transcription termination sequences, and helper proteins that have been used to enhance crystal protein synthesis, and shows how these genetic elements can be manipulated with new molecular tools to develop more efficacious strains of B. thuringiensis.

• 한국응용곤충학회지
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• 제36권4호
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• pp.341-350
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• 1997

Autographa californica 핵다각체병 바이러스(AcNPV)의 다각체 단백질과 Bacillus thuringiensis(Bt) cryIA(c) 내독소 단백질의 융합단백질을 생산하는 새로운 재조합 바이러스를 제작하고, 곤충세포주(Spodoptera frugiperda 9)에서 발현된 융합단백질의 특성을 분석하였다. Bt kurstaki HD-73의 cryIA(c) 내독소 단백질 유전자의 N-발단 AcNPV의 완전한 다각체 단백질 유전자의 앞쪽에 융합함에 의하여 또는 다닥체 단백질 유전자내의 제한효소 HindII부위에 삽입함에 의하여 다각체 단백질 유전자의 프로모터 조절하에 도입하였다. 이렇게 작성된 재조합 바이러스를 각각 Btrusl 또는 BtrusII라고 명명하였다. BtrusI은 분명히 단일 전사체를 보임에도 92kDa의 융합 단백질과 다각체 단백질의 두 단백질을 생산하였다. 또한 Btrusl에 의해 만들어진 융합 단백질은 다각체를 형성하지 않았다. 한편, BtrusII에 의해 감염된 곤충세포주에서는 33kDa의 다각체 단백질은 보이지 않았고 단지 융합 단백질만 생산하였으나 다각체는 형성하지 않았다. 따라서 Btrusl에 의해 생산된 융합 단백질의 독성을 조사하기 위하여, Btrusl으로 감염된 곤충세포주를 2령 누에(Bombyx mori)에 접종한 결과 융합 단백질에 의한 독성이 관찰되었다. 결론적으로 다각체 단백질과 Bt cryIA(c) 내독소 단백질에 의한 융합 단백질이 독성을 가지고 있음을 확인하였다.

• Food Science and Biotechnology
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• 제15권3호
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• pp.385-391
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• 2006

In Korea, different kinds of genetically modified (GM) crops are under development, including GM-rice expressing insecticidal crystal (Cry) proteins of Bacillus thuringiensis (Bt) modified to change a single amino acid. In this study, amino acid (aa) sequences of modified Cry proteins were compared to that of known allergens, and Cry proteins expressed in GM-rice were identified by using Cry protein specific polyclonal antibody. The antigen-antibody reactions were compared between GM and commercial rice to assess the allergic risk of Cry proteins. This analysis showed no known allergen to have more than 35% aa sequence homology with modified Cry proteins in Bt rice over an 80 aa window or to have more than 8 consecutive identical aa. Sera from allergic patients showed some IgE reactivity via immunoblotting and enzyme-linked immunosorbent assay (ELISA), although no differences were seen between GM and commercial rice. Based on these results we conclude that GM rice with modified Cry proteins has no differences in its protein composition or allergenicity relative to commercial rice.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 International Symposium of Silkworm/Insect Biotechnology and Annual Meeting of Korea Society of Sericultural Science
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• pp.118-119
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• 2003

Baculovirus occlusion bodies have been recently engineered to incorporate foreign protein such as the Bacillus thuringiensis (Bt) CrylAc protein for improvement of insecticidal activity. In this study, polyhedrin, cylAc, egfp and crylCa genes were fused to produce occlusion bodies that contain novel recombinant crystal protein by homologous recombination between cylAc and crylCa genes in insect cells. (omitted)

• 한국미생물·생명공학회지
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• 제18권6호
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• pp.647-652
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• 1990

Bacillus thuringiensis subsp. kurstaki HD1의 내 독소생산과 내독소단백질 유전자의 클로닝에 관한 연구를 하였다. 상기 균주는 아포생성기간 중에 이중피라미드형의 내독소를 생산하였고, 크리는 약 $2.9\times 1.0 \mu m$이었다. 상기 균주는 약 10개의 플라수미드 DNA를 가지고 있었으며, 플라스미드의 분자량의 범위는 2.1에서 80kilobases였다. 플라스미드 73kb, BamHI 절단 29Kb DNA 단편과 PstI 절단 7.9Kb DNA는 Probe DNA와 혼성화되었다. PstI 7.9Kb DNA를 추출하여 운반체인 pBR322 운반체의 PstI 절단부위에 삽입하여 클로닝한 후에 E.coli HB101 균주에 형질전환하였으며, 이 클로운을 pKL-20-1로 명명했고 이 형질전환체는 Bombyxmori 유충을 치사시키는 독소물질을 생산하였다.

• 한국미생물·생명공학회지
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• 제19권1호
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• pp.25-30
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• 1991

국내농작물의 근부토양으로 분리한 Pseudomonas의 염색체 DNA에 Tn5를 사용하여 Bacillus thuringiensis subsp. kurstaki HD73의 독소유전자(cp)를 도입하였다. Tn5의 중심부위에 있는 BamHI위치 (Tn5-cp)와 BglII 위치 (IS5OL-cp)에 각각 독소유 전자를 도입하였으며 두 종류의 Pseudomonas 균주에는 Tn5-cp로써 그리고 다른 세 종류의 Pseudomonase 균주에는 IS5OL-cp로써 transposition하였다. 면역학적 방법과 흰불나방 애벌레에 대한 살충성 검정으로서 독소유전자의 도입과 발현을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.240-245
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• 1991

We have constructed a promoter-probe vector pKU20 using pKT230, a derivative of broad-host-range plsmid RSF1010, as a base. The pKU20 contains structural gene for aminoglycoside phos-photransferase (aph), without promoter, and a multiple cloning site upstream the aph. Using this vector, a 412base pairs (bp) PstI fragment showing strong promoter activity both in Escherichia coli LE392 and Pseudomonas putida KCTC1644 has been cloned from Pseudomonas fluorescens chromosomal DNA on the basis of streptomycin resistance. The nucleotide sequence of the 412 bp fragment has been determined and the putative - 35 and -10 region was observed. Insecticidal protein gene of Bacillus thuringiensis subsp. kurstaki HD-73 inserted on downstream of the promoterlike DNA fragment was efficiently expressed in E. coli and P. putida. The toxin protein was efficiently synthesized in an insoluble form in both strains.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1498-1503
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• 2007

To identify novel crystal proteins, Bacillus thuringiensis 2385-1 was isolated from Korean soil samples and characterized. The H-serotype of 2385-1 was identical to that of subsp. kenyae (H4a4c), and its crystal toxin was bipyramidal-shaped. However, 2385-1 showed a much higher toxicity towards Plutella xylostella and Spodoptera exigua larvae than subsp. kenyae. In addition, the crystal protein profile and plasmid DNA pattern of 2385-1 differed from those of subsp. kenyae. To verify the crystal protein gene types of 2385-1, a PCR-RFLP analysis was performed, and the results revealed that 2385-1 contained two novel cry1-type crystal protein genes, cryl-5 and cry1-12, in addition to the crylJal gene. The deduced amino acid sequences of cryl-5 and cry1-12 showed a 97.9% and 75.7% sequence similarity with the CrylAb and CrylJa crystal proteins, respectively. Among the novel crystal proteins, Cry1-5 showed a high toxicity towards P. xylostella and S. exigua larvae. In conclusion, B. thuringiensis 2385-1 is a new isolate in terms of its gene types, and should be a promising source for an insecticide to control lepidopteran larvae.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.710-715
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• 2005

A novel recombinant baculovirus, Bactrus, was constructed by the insertion of the Bacillus thuringiensis cry1Ac gene between two polyhedrin genes of Autographa californica nucleopolyhedrovirus (AcNPV) under the control of the polyhedrin gene promoter. Polyhedra produced by Bactrus in insect cells were incorporated with 130 kDa of polyhedrin-Cry1Ac-polyhedrin fusion protein, and 30 kDa of intact polyhedrin, resulting from a homologous recombination between two polyhedrin genes, was also expressed. The insecticidal activity of Bactrus against Spodoptera exigua larvae was similar to that of AcNPV, but it showed significantly higher toxicity towards Plutella xylostella larvae in comparison with that of AcNPV. The expression level of fusion protein and the insecticidal activity of recombinant polyhedra produced by the Bactrus against P. xylostella larvae were decreased after serial passages. In conclusion, the Bactrus had improved insecticidal activity and returned to wild-type AcNPV after several passages.

• Journal of Microbiology
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• 제42권4호
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• pp.340-345
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• 2004

To investigate the co-expression and crystallization of a fusion gene between the Bacillus thuringiensis crystal protein and a foreign protein in B. thuringiensis, the expression of the Cry1Ac fused with green fluorescent protein (GFP) genes in a B. thuringiensis $Cry^-B$ strain was examined. The cry1Ac gene was cloned in the B. thuringiensis-E. coli shuttle vector, pHT3101, under the control of the native cry1Ac gene promoter, while the GFP gene was inserted into the XhoI site upstream of the proteolytic cleavage site, in the middle region of the crylAc gene (pProAc-GFP). The B. thuringiensis $Cry^-B$ strain carrying pProAc-GFP (ProAc-GFP/CB) did not produce any inclusion bodies. However, the transformed strain expressed fusion protein forms although the expression level was relatively low. Furthermore, an immu­noblot analysis using GFP and Cry1Ac antibodies showed that the fusion protein was not a single spe­cies, but rather multiple forms. In addition, the N-terminal fragment of Cry1Ac and a non-fused GFP were also found in the B. thuringiensis $Cry^-B$ strain after autolysis. The sporulated cells before autolysis and the spore-crystal mixture after autolysis of ProAc-GFP/CB exhibited insecticidal activities against Plutella xylostella larvae. Accordingly, the current results suggest that a fusion crystal protein produced by the transfomant, ProAc-GFP/CB, can be functionally expressed but easily degraded in B. thuring­iensis.