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Wei J, Liang G, Wu K, Gu S, Guo Y, Ni X, Li X. Cytotoxicity and binding profiles of activated Cry1Ac and Cry2Ab to three insect cell lines. INSECT SCIENCE 2018; 25:655-666. [PMID: 28247982 DOI: 10.1111/1744-7917.12451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 11/24/2016] [Accepted: 01/03/2017] [Indexed: 06/06/2023]
Abstract
While Cry1Ac has been known to bind with larval midgut proteins cadherin, APN (amino peptidase N), ALP (alkaline phosphatase) and ABCC2 (adenosine triphosphate-binding cassette transporter subfamily C2), little is known about the receptors of Cry2Ab. To provide a clue to the receptors of Cry2Ab, we tested the baseline cytotoxicity of activated Cry1Ac and Cry2Ab against the midgut and fat body cell lines of Helicoverpa zea and the ovary cell line of Spodoptera frugiperda (SF9). As expected, the descending order of cytotoxicity of Cry1Ac against the three cell lines in terms of 50% lethal concetration (LC50 ) was midgut (31.0 μg/mL) > fat body (59.0 μg/mL) and SF9 cell (99.6 μg/mL). By contrast, the fat body cell line (LC50 = 7.55 μg/mL) was about twice more susceptible to Cry2Ab than the midgut cell line (16.0 μg/mL), the susceptibility of which was not significantly greater than that of SF9 cells (27.0 μg/mL). Further, ligand blot showed the binding differences between Cry1Ac and Cry2Ab in the three cell lines. These results indicated that the receptors of Cry2Ab were enriched in fat body cells and thus largely different from the receptors of Cry1Ac, which were enriched in midgut cells.
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Affiliation(s)
- Jizhen Wei
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Department of Entomology and BIO5 Institute, University of Arizona, Tucson, AZ, USA
| | - Gemei Liang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shaohua Gu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuyuan Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xinzhi Ni
- USDA-ARS, Crop Genetics and Breeding Research Unit, Tifton, GA, USA
| | - Xianchun Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Department of Entomology and BIO5 Institute, University of Arizona, Tucson, AZ, USA
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Liu M, Huang R, Weisman A, Yu X, Lee SH, Chen Y, Huang C, Hu S, Chen X, Tan W, Liu F, Chen H, Shea KJ. Synthetic Polymer Affinity Ligand for Bacillus thuringiensis (Bt) Cry1Ab/Ac Protein: The Use of Biomimicry Based on the Bt Protein–Insect Receptor Binding Mechanism. J Am Chem Soc 2018; 140:6853-6864. [DOI: 10.1021/jacs.8b01710] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mingming Liu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
| | - Rong Huang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Adam Weisman
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
| | - Xiaoyang Yu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Shih-Hui Lee
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
| | - Yalu Chen
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Chao Huang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Senhua Hu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiuhua Chen
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenfeng Tan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Fan Liu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Hao Chen
- College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Kenneth J. Shea
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
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Zhang J, Zhang Y, Li J, Liu M, Liu Z. Midgut Transcriptome of the Cockroach Periplaneta americana and Its Microbiota: Digestion, Detoxification and Oxidative Stress Response. PLoS One 2016; 11:e0155254. [PMID: 27153200 PMCID: PMC4859610 DOI: 10.1371/journal.pone.0155254] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/26/2016] [Indexed: 02/01/2023] Open
Abstract
The cockroach, Periplaneta americana, is an obnoxious and notorious pest of the world, with a strong ability to adapt to a variety of complex environments. However, the molecular mechanism of this adaptability is mostly unknown. In this study, the genes and microbiota composition associated with the adaptation mechanism were studied by analyzing the transcriptome and 16S rDNA pyrosequencing of the P. americana midgut, respectively. Midgut transcriptome analysis identified 82,905 unigenes, among which 64 genes putatively involved in digestion (11 genes), detoxification (37 genes) and oxidative stress response (16 genes) were found. Evaluation of gene expression following treatment with cycloxaprid further revealed that the selected genes (CYP6J1, CYP4C1, CYP6K1, Delta GST, alpha-amylase, beta-glucosidase and aminopeptidase) were upregulated at least 2.0-fold at the transcriptional level, and four genes were upregulated more than 10.0-fold. An interesting finding was that three digestive enzymes positively responded to cycloxaprid application. Tissue expression profiles further showed that most of the selected genes were midgut-biased, with the exception of CYP6K1. The midgut microbiota composition was obtained via 16S rDNA pyrosequencing and was found to be mainly dominated by organisms from the Firmicutes phylum, among which Clostridiales, Lactobacillales and Burkholderiales were the main orders which might assist the host in the food digestion or detoxification of noxious compounds. The preponderant species, Clostridium cellulovorans, was previously reported to degrade lignocellulose efficiently in insects. The abundance of genes involved in digestion, detoxification and response to oxidative stress, and the diversity of microbiota in the midgut might provide P. americana high capacity to adapt to complex environments.
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Affiliation(s)
- Jianhua Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yixi Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jingjing Li
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Meiling Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zewen Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- * E-mail:
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Lin P, Cheng T, Jin S, Wu Y, Fu B, Long R, Zhao P, Xia Q. PC, a Novel Oral Insecticidal Toxin from Bacillus bombysepticus Involved in Host Lethality via APN and BtR-175. Sci Rep 2015; 5:11101. [PMID: 26057951 PMCID: PMC4460869 DOI: 10.1038/srep11101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 05/13/2015] [Indexed: 01/31/2023] Open
Abstract
Insect pests have developed resistance to chemical insecticides, insecticidal toxins as bioinsecticides or genetic protection built into crops. Consequently, novel, orally active insecticidal toxins would be valuable biological alternatives for pest control. Here, we identified a novel insecticidal toxin, parasporal crystal toxin (PC), from Bacillus bombysepticus (Bb). PC shows oral pathogenic activity and lethality towards silkworms and Cry1Ac-resistant Helicoverpa armigera strains. In vitro assays, PC after activated by trypsin binds to BmAPN4 and BtR-175 by interacting with CR7 and CR12 fragments. Additionally, trypsin-activated PC demonstrates cytotoxicity against Sf9 cells expressing BmAPN4, revealing that BmAPN4 serves as a functional receptor that participates in Bb and PC pathogenicity. In vivo assay, knocking out BtR-175 increased the resistance of silkworms to PC. These data suggest that PC is the first protein with insecticidal activity identified in Bb that is capable of causing silkworm death via receptor interactions, representing an important advance in our understanding of the toxicity of Bb and the contributions of interactions between microbial pathogens and insects to disease pathology. Furthermore, the potency of PC as an insecticidal protein makes it a good candidate for inclusion in integrated agricultural pest management systems.
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Affiliation(s)
- Ping Lin
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Tingcai Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Shengkai Jin
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yuqian Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Bohua Fu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Renwen Long
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
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Xu J, Strange JP, Welker DL, James RR. Detoxification and stress response genes expressed in a western North American bumble bee, Bombus huntii (Hymenoptera: Apidae). BMC Genomics 2013; 14:874. [PMID: 24330608 PMCID: PMC3878831 DOI: 10.1186/1471-2164-14-874] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 12/06/2013] [Indexed: 11/12/2022] Open
Abstract
Background The Hunt bumble bee (Bombus huntii Greene, Hymenoptera: Apidae) is a holometabolous, social insect important as a pollinator in natural and agricultural ecosystems in western North America. Bumble bees spend a significant amount of time foraging on a wide variety of flowering plants, and this activity exposes them to both plant toxins and pesticides, posing a threat to individual and colony survival. Little is known about what detoxification pathways are active in bumble bees, how the expression of detoxification genes changes across life stages, or how the number of detoxification genes expressed in B. huntii compares to other insects. Results We found B. huntii expressed at least 584 genes associated with detoxification and stress responses. The expression levels of some of these genes, such as those encoding the cytochrome P450s, glutathione S-transferases (GSTs) and glycosidases, vary among different life stages to a greater extent than do other genes. We also found that the number of P450s, GSTs and esterase genes expressed by B. huntii is similar to the number of these genes found in the genomes of other bees, namely Bombus terrestris, Bombus impatiens, Apis mellifera and Megachile rotundata, but many fewer than are found in the fly Drosophila melanogaster. Conclusions Bombus huntii has transcripts for a large number of detoxification and stress related proteins, including oxidation and reduction enzymes, conjugation enzymes, hydrolytic enzymes, ABC transporters, cadherins, and heat shock proteins. The diversity of genes expressed within some detoxification pathways varies among the life stages and castes, and we typically identified more genes in the adult females than in larvae, pupae, or adult males, for most pathways. Meanwhile, we found the numbers of detoxification and stress genes expressed by B. huntii to be more similar to other bees than to the fruit fly. The low number of detoxification genes, first noted in the honey bee, appears to be a common phenomenon among bees, and perhaps results from their symbiotic relationship with plants. Many flowering plants benefit from pollinators, and thus offer these insects rewards (such as nectar) rather than defensive plant toxins.
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Affiliation(s)
| | | | | | - Rosalind R James
- USDA-ARS, Pollinating Insects Research Unit, Department of Biology, Utah State University, Logan, UT 84322-5310, USA.
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Structural, evolutionary and functional analysis of APN genes in the Lepidoptera Bombyx mori. Gene 2013; 535:303-11. [PMID: 24286860 DOI: 10.1016/j.gene.2013.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 11/07/2013] [Accepted: 11/09/2013] [Indexed: 12/27/2022]
Abstract
Aminopeptidases N (APNs), the receptors of Bacillus thuringiensis (Bt) toxin in the lepidopteran midgut, are involved in the Bt pathogen infection mechanism. In the present work, we screened 102 APNs from SilkDB, ButterflyBase and MonarchBase; 16 APNs were identified from the silkworm (Bombyx mori) and 24 from the monarch butterfly (Danaus plexippus). Syntenic and phylogenetic tree analysis showed that APN genes have developed multi-family genes before evolutionary divergence of the Lepidoptera. The tissue-expression pattern shows some BmAPNs are specifically or highly expressed in the midgut. Bacillus bombysepticus (Bb) is a specific pathogen of B. mori, leading to acute fuliginosa septicemia of the larva. BmAPNs were modulated by real time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis after Bb or Bt oral infection. There were different patterns of induced expression between Bb and Bt challenges, suggesting that B. mori has different responses to infection by the specific pathogen Bb and the nonspecific pathogen Bt. Research on BmAPNs will help us to better understand the evolutionary conservation and functions in Bb or Bt pathogen interaction with the host and to apply this knowledge in agricultural and forestry pest control.
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Crava CM, Bel Y, Jakubowska AK, Ferré J, Escriche B. Midgut aminopeptidase N isoforms from Ostrinia nubilalis: activity characterization and differential binding to Cry1Ab and Cry1Fa proteins from Bacillus thuringiensis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:924-935. [PMID: 23933214 DOI: 10.1016/j.ibmb.2013.07.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 07/23/2013] [Accepted: 07/29/2013] [Indexed: 06/02/2023]
Abstract
Aminopeptidase N (APN) isoforms from Lepidoptera are known for their involvement in the mode of action of insecticidal Cry proteins from Bacillus thuringiensis. These enzymes belong to a protein family with at least eight different members that are expressed simultaneously in the midgut of lepidopteran larvae. Here, we focus on the characterization of the APNs from Ostrinia nubilalis (OnAPNs) to identify potential Cry receptors. We expressed OnAPNs in insect cells using a baculovirus system and analyzed their enzymatic activity by probing substrate specificity and inhibitor susceptibility. The interaction with Cry1Ab and Cry1Fa proteins (both found in transgenic insect-resistant maize) was evaluated by ligand blot assays and immunocytochemistry. Ligand blots of brush border membrane proteins showed that both Cry proteins bound mainly to a 150 kDa-band, in which OnAPNs were greatly represented. Binding analysis of Cry proteins to the cell-expressed OnAPNs showed that OnAPN1 interacted with both Cry1Ab and Cry1Fa, whereas OnAPN3a and OnAPN8 only bound to Cry1Fa. Two isoforms, OnAPN2 and OnAPN3b, did not interact with any of these two proteins. This work provides the first evidence of a differential role of OnAPN isoforms in the mode of action of Cry proteins in O. nubilalis.
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Affiliation(s)
- Cristina M Crava
- Department of Genetics, University of Valencia, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain.
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Wang F, Hu C, Hua X, Song L, Xia Q. Translationally controlled tumor protein, a dual functional protein involved in the immune response of the silkworm, Bombyx mori. PLoS One 2013; 8:e69284. [PMID: 23894441 PMCID: PMC3718729 DOI: 10.1371/journal.pone.0069284] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/07/2013] [Indexed: 12/20/2022] Open
Abstract
Insect gut immunity is the first line of defense against oral infection. Although a few immune-related molecules in insect intestine has been identified by genomics or proteomics approach with comparison to well-studied tissues, such as hemolymph or fat body, our knowledge about the molecular mechanism underlying the gut immunity which would involve a variety of unidentified molecules is still limited. To uncover additional molecules that might take part in pathogen recognition, signal transduction or immune regulation in insect intestine, a T7 phage display cDNA library of the silkworm midgut is constructed. By use of different ligands for biopanning, Translationally Controlled Tumor Protein (TCTP) has been selected. BmTCTP is produced in intestinal epithelial cells and released into the gut lumen. The protein level of BmTCTP increases at the early time points during oral microbial infection and declines afterwards. In vitro binding assay confirms its activity as a multi-ligand binding molecule and it can further function as an opsonin that promotes the phagocytosis of microorganisms. Moreover, it can induce the production of anti-microbial peptide via a signaling pathway in which ERK is required and a dynamic tyrosine phosphorylation of certain cytoplasmic membrane protein. Taken together, our results characterize BmTCTP as a dual-functional protein involved in both the cellular and the humoral immune response of the silkworm, Bombyx mori.
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Affiliation(s)
- Fei Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Cuimei Hu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Xiaoting Hua
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Liang Song
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- * E-mail:
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A 50-kilodalton Cry2A peptide is lethal to Bombyx mori and Lymantria dispar. Appl Environ Microbiol 2012; 78:4755-7. [PMID: 22544240 DOI: 10.1128/aem.07123-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Cry2Aa3 gene was introduced into asporogenic Bacillus thuringiensis, and the synthesized protoxin killed Bombyx mori and Lymantria dispar larvae. Chymotrypsin hydrolyzed the linkages between 49Tyr/Val50 and 145Lys/Ser146 in the protoxin, and 50- and 58-kDa fragments were generated, respectively. Both peptides killed the larvae of both insects.
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Formation of Macromolecule Complex with Bacillus thuringiensis Cry1A Toxins and Chlorophyllide Binding 252-kDa Lipocalin-Like Protein Locating on Bombyx mori Midgut Membrane. J Membr Biol 2010; 237:125-36. [DOI: 10.1007/s00232-010-9314-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 10/26/2010] [Indexed: 11/26/2022]
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Huang L, Cheng T, Xu P, Cheng D, Fang T, Xia Q. A genome-wide survey for host response of silkworm, Bombyx mori during pathogen Bacillus bombyseptieus infection. PLoS One 2009; 4:e8098. [PMID: 19956592 PMCID: PMC2780328 DOI: 10.1371/journal.pone.0008098] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Accepted: 11/04/2009] [Indexed: 11/18/2022] Open
Abstract
Host-pathogen interactions are complex relationships, and a central challenge is to reveal the interactions between pathogens and their hosts. Bacillus bombysepticus (Bb) which can produces spores and parasporal crystals was firstly separated from the corpses of the infected silkworms (Bombyx mori). Bb naturally infects the silkworm can cause an acute fuliginosa septicaemia and kill the silkworm larvae generally within one day in the hot and humid season. Bb pathogen of the silkworm can be used for investigating the host responses after the infection. Gene expression profiling during four time-points of silkworm whole larvae after Bb infection was performed to gain insight into the mechanism of Bb-associated host whole body effect. Genome-wide survey of the host genes demonstrated many genes and pathways modulated after the infection. GO analysis of the induced genes indicated that their functions could be divided into 14 categories. KEGG pathway analysis identified that six types of basal metabolic pathway were regulated, including genetic information processing and transcription, carbohydrate metabolism, amino acid and nitrogen metabolism, nucleotide metabolism, metabolism of cofactors and vitamins, and xenobiotic biodegradation and metabolism. Similar to Bacillus thuringiensis (Bt), Bb can also induce a silkworm poisoning-related response. In this process, genes encoding midgut peritrophic membrane proteins, aminopeptidase N receptors and sodium/calcium exchange protein showed modulation. For the first time, we found that Bb induced a lot of genes involved in juvenile hormone synthesis and metabolism pathway upregulated. Bb also triggered the host immune responses, including cellular immune response and serine protease cascade melanization response. Real time PCR analysis showed that Bb can induce the silkworm systemic immune response, mainly by the Toll pathway. Anti-microorganism peptides (AMPs), including of Attacin, Lebocin, Enbocin, Gloverin and Moricin families, were upregulated at 24 hours post the infection.
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Affiliation(s)
- Lulin Huang
- Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China
- Institute of Economic Crops Breeding and Cultivation, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Tingcai Cheng
- Institute of Agronomy and Life Science, Chongqing University, Chongqing, China
| | - Pingzhen Xu
- Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China
| | - Daojun Cheng
- Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China
| | - Ting Fang
- Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China
- Institute of Agronomy and Life Science, Chongqing University, Chongqing, China
- * E-mail:
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12
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Pauchet Y, Muck A, Svatos A, Heckel DG. Chromatographic and electrophoretic resolution of proteins and protein complexes from the larval midgut microvilli of Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2009; 39:467-474. [PMID: 19464367 DOI: 10.1016/j.ibmb.2009.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/11/2009] [Accepted: 05/13/2009] [Indexed: 05/27/2023]
Abstract
The microvillar proteome of Manduca sexta larval midguts was analyzed by subjecting brush border membrane vesicles (BBMV) to two different two-dimensional approaches: (i) Anion exchange chromatography followed by SDS-PAGE and (ii) Blue Native-PAGE followed by SDS-PAGE. The first technique was superior to conventional 2-D gel electrophoresis in resolving the most abundant proteins associated with the midgut microvilli. Twenty of them were successfully identified as digestive enzymes, binding targets of the insecticidal Cry1A toxins from Bacillus thuringiensis (Bt), and signal transduction proteins. A homolog of the chlorophyllide A binding protein from the silkworm and several aminopeptidases N represent the most abundant proteins associated with the BBMV. The second technique revealed protein oligomeric complexes associated with midgut microvilli in vivo. Two such complexes contained subunits of the vacuolar ATP synthase complex, and one was an oligomer of the chlorophyllide A binding protein. An additional complex consisted of homo- or hetero-tetramers of three different aminopeptidases N (APNs). As APNs are well-known binding partners of Cry1A toxins, their quaternary structure has implications for Bt toxin mode of action. Both techniques provide a useful complement to conventional 2-D gel electrophoresis in analyzing the complex proteome of the microvillar membrane fraction.
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Affiliation(s)
- Yannick Pauchet
- Entomology Department, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, D-07745 Jena, Germany.
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Pandian GN, Ishikawa T, Togashi M, Shitomi Y, Haginoya K, Yamamoto S, Nishiumi T, Hori H. Bombyx mori midgut membrane protein P252, which binds to Bacillus thuringiensis Cry1A, is a chlorophyllide-binding protein, and the resulting complex has antimicrobial activity. Appl Environ Microbiol 2008; 74:1324-31. [PMID: 18192432 PMCID: PMC2258650 DOI: 10.1128/aem.01901-07] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Accepted: 12/28/2007] [Indexed: 11/20/2022] Open
Abstract
The epithelial cell membrane 252-kDa protein (P252) isolated in our laboratory from Bombyx mori midgut was shown to bind strongly with Cry1Aa, Cry1Ab, and Cry1Ac toxins of Bacillus thuringiensis (15). In the current paper, P252 was shown to bind with chlorophyllide (Chlide) to form red fluorescent protein (RFP) complex, termed Bm252RFP, with absorbance and fluorescence emission peaks at 600 nm and 620 nm, respectively. P252 at a concentration of 1 microM is shown to bind with about 50 microM Chlide in a positively cooperative reaction to form Bm252RFP under aerobic conditions and in the presence of light at 37 degrees C. Various parameters influencing this reaction have been optimized for efficient in vitro chemical synthesis of Bm252RFP. Circular dichroism spectra revealed that P252 is composed of a beta-structure (39.8% +/- 2.2%, based on 5 samples) with negligible contribution of alpha-helix structure. When bound to Chlide, the beta-structure content in the complex is reduced to 21.6% +/- 3.1% (n = 5). Since Chlide had no secondary structure, the observed reduction suggests significant conformational changes of P252 during the formation of Bm252RFP complex. Bm252RFP had antimicrobial activity against Escherichia coli, Serratia marcescens, B. thuringiensis, and Saccharomyces cerevisiae with 50% effective concentrations of 2.82, 2.94, 5.88 microM, and 21.6 microM, respectively. This is the first report ever to show clear, concrete binding characteristics of the midgut protein to form an RFP having significant antimicrobial activity.
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Affiliation(s)
- Ganesh N Pandian
- Laboratories of Applied Biosciences, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan
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Pigott CR, Ellar DJ. Role of receptors in Bacillus thuringiensis crystal toxin activity. Microbiol Mol Biol Rev 2007; 71:255-81. [PMID: 17554045 PMCID: PMC1899880 DOI: 10.1128/mmbr.00034-06] [Citation(s) in RCA: 402] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Bacillus thuringiensis produces crystalline protein inclusions with insecticidal or nematocidal properties. These crystal (Cry) proteins determine a particular strain's toxicity profile. Transgenic crops expressing one or more recombinant Cry toxins have become agriculturally important. Individual Cry toxins are usually toxic to only a few species within an order, and receptors on midgut epithelial cells have been shown to be critical determinants of Cry specificity. The best characterized of these receptors have been identified for lepidopterans, and two major receptor classes have emerged: the aminopeptidase N (APN) receptors and the cadherin-like receptors. Currently, 38 different APNs have been reported for 12 different lepidopterans. Each APN belongs to one of five groups that have unique structural features and Cry-binding properties. While 17 different APNs have been reported to bind to Cry toxins, only 2 have been shown to mediate toxin susceptibly in vivo. In contrast, several cadherin-like proteins bind to Cry toxins and confer toxin susceptibility in vitro, and disruption of the cadherin gene has been associated with toxin resistance. Nonetheless, only a small subset of the lepidopteran-specific Cry toxins has been shown to interact with cadherin-like proteins. This review analyzes the interactions between Cry toxins and their receptors, focusing on the identification and validation of receptors, the molecular basis for receptor recognition, the role of the receptor in resistant insects, and proposed models to explain the sequence of events at the cell surface by which receptor binding leads to cell death.
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Affiliation(s)
- Craig R Pigott
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
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Stumpff F, Bondzio A, Einspanier R, Martens H. Effects of the Bacillus thuringiensis Toxin Cry1Ab on Membrane Currents of Isolated Cells of the Ruminal Epithelium. J Membr Biol 2007; 219:37-47. [PMID: 17676405 DOI: 10.1007/s00232-007-9059-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Accepted: 06/18/2007] [Indexed: 10/23/2022]
Abstract
A previous study has shown that Cry1Ab, a lepidopteran-specific toxin derived from Bacillus thuringiensis, does not affect the vitality of cultured cells of the ruminal epithelium of the sheep. While this may be due to lack of specific receptors for toxin action, other mechanisms of resistance should also be considered. In order to directly assess the pore-forming potential of Cry1Ab, we studied the interaction of this toxin with isolated, perfused cells of the ruminal epithelium using the whole-cell and single-channel configurations of the patch-clamp technique. At concentrations found in vivo in the rumen of cows (<10 ng/ml) and at a temperature of 37 degrees C, no significant effects of Cry1Ab could be observed. At 100 ng/ml, exposure of ruminal cells to Cry1Ab induced a significant rise in outward current in 16 of 34 cells, with a fourfold increase in the conductance for potassium. The cell membrane remained selective for potassium over sodium (p(K)/p(Na) = 1.8 + or - 0.3), with a considerable additional chloride conductance. In outside-out patches, exposure to high Cry1Ab concentrations induced channel-like events that reached levels of over 500 pS. We conclude that the unchanged vitality of intact ruminal epithelial cells exposed to Cry1Ab in vitro at high concentrations may be related to other factors besides the proposed absence of a specific receptor for the membrane insertion of this toxin.
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Affiliation(s)
- Friederike Stumpff
- Department of Veterinary Physiology, Free University of Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
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Higuchi M, Haginoya K, Yamazaki T, Miyamoto K, Katagiri T, Tomimoto K, Shitomi Y, Hayakawa T, Sato R, Hori H. Binding of Bacillus thuringiensis Cry1A toxins to brush border membrane vesicles of midgut from Cry1Ac susceptible and resistant Plutella xylostella. Comp Biochem Physiol B Biochem Mol Biol 2007; 147:716-24. [PMID: 17543562 DOI: 10.1016/j.cbpb.2007.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 04/18/2007] [Accepted: 04/18/2007] [Indexed: 11/24/2022]
Abstract
Plutella xylostella strain resistant (PXR) to Bacillus thuringiensis Cry1Ac toxin was not killed at even more than 1000 microg Cry1Ac/g diet but killed by Cry1Ab at 0.5 microg/g diet. In contrast, susceptible strain (PXS) was killed by Cry1Ac at 1 microg/g diet. Cy3-labeld Cry1A(s) binding to brush border membrane vesicles (BBMV) prepared from both strains were analyzed with direct binding assay. The Kd value of Cry1Aa to both BBMV was almost identical: 213.2 and 205.8 nM, and 263.5 and 265.0 nM for Cry1Ac. The highest Kd values were in Cry1Ab which showed most effective insecticidal activity in PXS and PXR, 2126 and 2463 nM, respectively. These results clearly showed that the BBMV from PXR and PXS could equally bind to Cry1Ac. The binding between BBMV and Cy3-labeled Cry1Ac was inhibited only by anti-175 kDa cadherin-like protein (CadLP) and -252 kDa protein antisera, but not by anti-120 kDa aminopeptidase. This supports that resistance in PXR resulted from the abortion of pore formation after the binding of Cry1Ac to the BBMV. And furthermore, the importance of 175K CadLP and P252 proteins in those bindings was suggested. We briefly discuss possible mechanisms of the resistance.
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Affiliation(s)
- Masahiro Higuchi
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan
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Budatha M, Meur G, Dutta-Gupta A. A novel aminopeptidase in the fat body of the moth Achaea janata as a receptor for Bacillus thuringiensis Cry toxins and its comparison with midgut aminopeptidase. Biochem J 2007; 405:287-97. [PMID: 17402938 PMCID: PMC1904524 DOI: 10.1042/bj20070054] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bacillus thuringiensis insecticidal crystal proteins bind to cell-surface receptors which represent a family of aminopeptidases [APN (aminopeptidase N)] present on the brush border membrane of insect midgut cells of susceptible insects leading to pore formation and death of the insect. We report here for the first time the presence of a novel APN in the fat body of the moth Achaea janata. Northern blotting detected at least one APN-specific transcript in the fat body, whereas two transcripts of different sizes were detected in the midgut. We have cloned two full-length APN cDNAs of 3015 bp and 2850 bp from fat body and midgut respectively, which encode proteins of 1004 and 950 amino acids. These two APNs share only 33% amino acid sequence identity, but both display the typical APN features, such as the N-terminal signal peptide, several putative glycosylation sites, C-terminal glycosylphosphatidylinositol anchor signal, the APN-specific zinc-binding/gluzincin motif HEXXHX(18)E and gluzincin motif GAMENWG. The fat body APN manifested a variation in its expression with respect to tissue and developmental stage. In spite of the abundance of the APN transcript in the fat body, fairly low APN activity was detected in this tissue. The fat-body- and midgut-specific APNs showed differential interaction with various Cry1A toxins. Besides, the level of toxicity of different Cry subtypes varied enormously with mode/site of delivery, such as intrahaemocoelic injections and feeding bioassays. These data indicate that the fat body might be a potential alternative Cry toxin target site in the moth.
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Affiliation(s)
| | - Gargi Meur
- School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
| | - Aparna Dutta-Gupta
- School of Life Sciences, University of Hyderabad, Hyderabad 500046, India
- To whom correspondence should be addressed (email )
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Rich RL, Myszka DG. Survey of the year 2006 commercial optical biosensor literature. J Mol Recognit 2007; 20:300-66. [DOI: 10.1002/jmr.862] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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