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Ribeiro TP, Martins-de-Sa D, Macedo LLP, Lourenço-Tessutti IT, Ruffo GC, Sousa JPA, Rósario Santana JMD, Oliveira-Neto OB, Moura SM, Silva MCM, Morgante CV, Oliveira NG, Basso MF, Grossi-de-Sa MF. Cotton plants overexpressing the Bacillus thuringiensis Cry23Aa and Cry37Aa binary-like toxins exhibit high resistance to the cotton boll weevil (Anthonomus grandis). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 344:112079. [PMID: 38588981 DOI: 10.1016/j.plantsci.2024.112079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/10/2024]
Abstract
The cotton boll weevil (CBW, Anthonomus grandis) stands as one of the most significant threats to cotton crops (Gossypium hirsutum). Despite substantial efforts, the development of a commercially viable transgenic cotton event for effective open-field control of CBW has remained elusive. This study describes a detailed characterization of the insecticidal toxins Cry23Aa and Cry37Aa against CBW. Our findings reveal that CBW larvae fed on artificial diets supplemented exclusively with Cry23Aa decreased larval survival by roughly by 69%, while supplementation with Cry37Aa alone displayed no statistical difference compared to the control. However, the combined provision of both toxins in the artificial diet led to mortality rates approaching 100% among CBW larvae (LC50 equal to 0.26 PPM). Additionally, we engineered transgenic cotton plants by introducing cry23Aa and cry37Aa genes under control of the flower bud-specific pGhFS4 and pGhFS1 promoters, respectively. Seven transgenic cotton events expressing high levels of Cry23Aa and Cry37Aa toxins in flower buds were selected for greenhouse bioassays, and the mortality rate of CBW larvae feeding on their T0 and T1 generations ranged from 75% to 100%. Our in silico analyses unveiled that Cry23Aa displays all the hallmark characteristics of β-pore-forming toxins (β-PFTs) that bind to sugar moieties in glycoproteins. Intriguingly, we also discovered a distinctive zinc-binding site within Cry23Aa, which appears to be involved in protein-protein interactions. Finally, we discuss the major structural features of Cry23Aa that likely play a role in the toxin's mechanism of action. In view of the low LC50 for CBW larvae and the significant accumulation of these toxins in the flower buds of both T0 and T1 plants, we anticipate that through successive generations of these transgenic lines, cotton plants engineered to overexpress cry23Aa and cry37Aa hold promise for effectively managing CBW infestations in cotton crops.
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Affiliation(s)
- Thuanne Pires Ribeiro
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Diogo Martins-de-Sa
- Department of Cellular Biology, University of Brasília, Brasília, DF 70910-900, Brazil; Genesilico Biotech, Brasília, DF 71503-508, Brazil
| | - Leonardo Lima Pepino Macedo
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Isabela Tristan Lourenço-Tessutti
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Gustavo Caseca Ruffo
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil
| | - João Pedro Abreu Sousa
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil
| | - Julia Moura do Rósario Santana
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil
| | - Osmundo Brilhante Oliveira-Neto
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Euroamerican University Center, Unieuro, Brasília, DF 70790-160, Brazil
| | - Stéfanie Menezes Moura
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Maria Cristina Mattar Silva
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Carolina Vianna Morgante
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Embrapa Semi-Arid, Pretrolina, PE 56302-970, Brazil
| | - Nelson Geraldo Oliveira
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Marcos Fernando Basso
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil
| | - Maria Fatima Grossi-de-Sa
- Embrapa Genetic Resources and Biotechnology, Brasília, DF 70770-917, Brazil; National Institute of Science and Technology, INCT PlantStress Biotech, Embrapa, Brasília, DF 70770-917, Brazil; Graduate Program in Genomic Science and Biotechnology, Catholic University of Brasília, Brasília, DF 71966-700, Brazil; Graduate Program in Biotechnology, Catholic University Dom Bosco, Campo Grande, MS 79117-900, Brazil.
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Williamson LJ, Galchenkova M, Best HL, Bean RJ, Munke A, Awel S, Pena G, Knoska J, Schubert R, Dörner K, Park HW, Bideshi DK, Henkel A, Kremling V, Klopprogge B, Lloyd-Evans E, Young MT, Valerio J, Kloos M, Sikorski M, Mills G, Bielecki J, Kirkwood H, Kim C, de Wijn R, Lorenzen K, Xavier PL, Rahmani Mashhour A, Gelisio L, Yefanov O, Mancuso AP, Federici BA, Chapman HN, Crickmore N, Rizkallah PJ, Berry C, Oberthür D. Structure of the Lysinibacillus sphaericus Tpp49Aa1 pesticidal protein elucidated from natural crystals using MHz-SFX. Proc Natl Acad Sci U S A 2023; 120:e2203241120. [PMID: 38015839 PMCID: PMC10710082 DOI: 10.1073/pnas.2203241120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 10/18/2023] [Indexed: 11/30/2023] Open
Abstract
The Lysinibacillus sphaericus proteins Tpp49Aa1 and Cry48Aa1 can together act as a toxin toward the mosquito Culex quinquefasciatus and have potential use in biocontrol. Given that proteins with sequence homology to the individual proteins can have activity alone against other insect species, the structure of Tpp49Aa1 was solved in order to understand this protein more fully and inform the design of improved biopesticides. Tpp49Aa1 is naturally expressed as a crystalline inclusion within the host bacterium, and MHz serial femtosecond crystallography using the novel nanofocus option at an X-ray free electron laser allowed rapid and high-quality data collection to determine the structure of Tpp49Aa1 at 1.62 Å resolution. This revealed the packing of Tpp49Aa1 within these natural nanocrystals as a homodimer with a large intermolecular interface. Complementary experiments conducted at varied pH also enabled investigation of the early structural events leading up to the dissolution of natural Tpp49Aa1 crystals-a crucial step in its mechanism of action. To better understand the cooperation between the two proteins, assays were performed on a range of different mosquito cell lines using both individual proteins and mixtures of the two. Finally, bioassays demonstrated Tpp49Aa1/Cry48Aa1 susceptibility of Anopheles stephensi, Aedes albopictus, and Culex tarsalis larvae-substantially increasing the potential use of this binary toxin in mosquito control.
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Affiliation(s)
| | - Marina Galchenkova
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Hannah L. Best
- School of Biosciences, Cardiff University, CardiffCF10 3AX, United Kingdom
| | | | - Anna Munke
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Salah Awel
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Gisel Pena
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Juraj Knoska
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | | | | | - Hyun-Woo Park
- Department of Biological Sciences, California Baptist University, Riverside, CA92504
| | - Dennis K. Bideshi
- Department of Biological Sciences, California Baptist University, Riverside, CA92504
| | - Alessandra Henkel
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Viviane Kremling
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Bjarne Klopprogge
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Emyr Lloyd-Evans
- School of Biosciences, Cardiff University, CardiffCF10 3AX, United Kingdom
| | - Mark T. Young
- School of Biosciences, Cardiff University, CardiffCF10 3AX, United Kingdom
| | | | - Marco Kloos
- European XFEL GmbH, 22869Schenefeld, Germany
| | | | - Grant Mills
- European XFEL GmbH, 22869Schenefeld, Germany
| | | | | | - Chan Kim
- European XFEL GmbH, 22869Schenefeld, Germany
| | | | | | - Paul Lourdu Xavier
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
- Max-Planck Institute for the Structure and Dynamics of Matter, 22761Hamburg, Germany
| | - Aida Rahmani Mashhour
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Luca Gelisio
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Oleksandr Yefanov
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
| | - Adrian P. Mancuso
- European XFEL GmbH, 22869Schenefeld, Germany
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC3086, Australia
| | - Brian A. Federici
- Department of Entomology and Institute for Integrative Genome Biology, University of California, Riverside, CA92521
| | - Henry N. Chapman
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
- Centre for Ultrafast Imaging, Universität Hamburg, 22761Hamburg, Germany
- Department of Physics, Universität Hamburg, 22761Hamburg, Germany
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Falmer, BrightonBN1 9QG, United Kingdom
| | | | - Colin Berry
- School of Biosciences, Cardiff University, CardiffCF10 3AX, United Kingdom
| | - Dominik Oberthür
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron, 22607Hamburg, Germany
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Chen Z, Shi Y, Wang D, Liu X, Jiao X, Gao X, Jiang K. Structural insight into Bacillus thuringiensis Sip1Ab reveals its similarity to ETX_MTX2 family beta-pore-forming toxin. PEST MANAGEMENT SCIENCE 2023; 79:4264-4273. [PMID: 37341620 DOI: 10.1002/ps.7622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/15/2023] [Accepted: 06/21/2023] [Indexed: 06/22/2023]
Abstract
BACKGROUND Microbially derived, protein-based biopesticides are an important approach for sustainable pest management. The secreted insecticidal proteins (Sips) produced by the bacterium Bacillus thuringiensis exhibit potent insecticidal activity against coleopteran pests and are, therefore, attractive as candidate biopesticides. However, the modes-of-action of Sips are unclear as comprehensive structural information for these proteins is lacking. RESULTS Using X-ray crystallography, we elucidated the structure of monomeric Sip1Ab at 2.28 Å resolution. Structural analyses revealed that Sip1Ab has the three domains and conserved fold characteristic of other aerolysin-like beta-pore-forming toxins (β-PFTs). Based on the sequence and structural similarities between Sip1Ab and other ETX_MTX2 subfamily toxins, we suggested the mechanism of these proteins and proposed that it is common to them all. CONCLUSION The atomic-level structural data for Sip1Ab generated by the present study could facilitate future structural and mechanistic research on Sips as well as their application in sustainable insect pest management. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Zhe Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yiting Shi
- Taishan College, Shandong University, Jinan, China
| | - Dongdong Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiaoyu Liu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xuyao Jiao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiang Gao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Kun Jiang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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4
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Cao B, Sun X, Shu C, Geng L, Zhang J. Identification and functional characterization of eight novel tpp family genes from Bacillus thuringiensis. PEST MANAGEMENT SCIENCE 2023; 79:4244-4253. [PMID: 37340998 DOI: 10.1002/ps.7620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 06/22/2023]
Abstract
BACKGROUND Bacillus thuringiensis (Bt) and its transgenic crops are widely used as biological control agents for agricultural pests. The tpp family is a branch of Bt insecticidal genes and consists of a few members. Research on the Tpp family proteins has focused on the binary toxins Gpp34Ab/Tpp35Ab and Tpp1/Tpp2, which need to function together to achieve insecticidal activity. However, only a few tpp family genes have been reported to exert insecticidal activity independently. This study aimed to identify and characterize tpp family genes that independently perform insecticidal functions. RESULTS A total of 162 nucleotide sequences homologous to the single component Bt insecticidal gene tpp78Aa were obtained from the genome data of 1368 wild-type Bt strains, and 25 new full-length tpp family genes were identified. Eight new tpp family genes were successfully cloned and expressed, and bioassays of the expressed products were performed against five different pests. Bioassay results showed that these proteins exerted high insecticidal activity only against Laodelphax striatellus, a globally important rice pest, and were named Tpp78Ab1, Tpp78Bb1, Tpp78Ca1, Tpp78Da1, Tpp80Aa3, Tpp80Ac1, Tpp80Ad1, and Tpp80Ae1. The LC50 values of Tpp78Ab1, Tpp78Bb1, Tpp78Ca1, and Tpp80Ae1 against L. striatum were 8.1, 8.6, 10.1, and 9.6 μg mL-1 , respectively. The phylogenetic tree and conserved motifs indicated that the Tpp family had a common evolutionary ancestor. During evolution, the C-terminal pore-forming domain of the Tpp family adopted a similar arrangement; however, the N-terminal conserved motif showed high variability. CONCLUSION Twenty-five full-length tpp family genes were identified. Eight new tpp family genes were cloned successfully, which could independently achieve insecticidal activity against L. striatellus. This provides abundant genetic resources for the biological control of important rice pests. In this study, we found that the relative conservation of the Tpp family proteins in the lengthy evolutionary process and the diversity generated for adapting to the environment can lay a theoretical foundation for an in-depth analysis of the function and evolution of the Tpp family. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Beibei Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaoni Sun
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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5
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Smith EM, Shrestha RB, Gassmann AJ. Inheritance and Fitness Costs of Laboratory-Selected Resistance to Gpp34/Tpp35Ab1 Corn in Western Corn Rootworm (Coleoptera: Chrysomelidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:565-573. [PMID: 36799000 PMCID: PMC10483582 DOI: 10.1093/jee/toad022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Indexed: 05/30/2023]
Abstract
Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a serious pest of corn and is currently managed with corn hybrids that produce insecticidal proteins derived from the bacterium Bacillus thuringiensis (Bt). Bt corn kills rootworm larvae and reduces larval feeding injury to corn roots. The Bt protein Gpp34/Tpp35Ab1, previously named Cry34/35Ab1, has been widely used in transgenic Bt corn for management of western corn rootworm, and field-evolved resistance has been found in some populations. In the United States, the refuge strategy is used to manage Bt resistance, with refuges of non-Bt host plants serving as a source of Bt-susceptible individuals, which in turn reduce the frequency of homozygous resistant individuals within a population. As such, the dominance of resistance strongly influences resistance evolution, with faster evolution of resistance when resistance is not recessive. Additionally, selection for resistance by a Bt crop leads to the accumulation of resistance alleles within refuge populations, thereby reducing the capacity of refuges to delay resistance. However, fitness costs can remove resistance alleles from refuge populations and preserve the dynamic of refuges producing Bt-susceptible genotypes. Bt-susceptible and Gpp34/Tpp35Ab1-resistant western corn rootworm were used to quantify the inheritance and fitness costs of resistance. We found that Gpp34/Tpp35Ab1 resistance was not recessive and had the accompanying fitness costs of slower developmental rate to adulthood and lower egg viability. This research will help improve insect resistance management by providing a better understanding of the risk of western corn rootworm evolving resistance to transgenic corn that produces Gpp34/Tpp35Ab1.
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Affiliation(s)
- Eliott M Smith
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011, USA
| | - Ram B Shrestha
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011, USA
| | - Aaron J Gassmann
- Department of Plant Pathology, Entomology and Microbiology, Iowa State University, Ames, IA 50011, USA
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Towards Understanding the Function of Aegerolysins. Toxins (Basel) 2022; 14:toxins14090629. [PMID: 36136567 PMCID: PMC9505663 DOI: 10.3390/toxins14090629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Aegerolysins are remarkable proteins. They are distributed over the tree of life, being relatively widespread in bacteria and fungi, but also present in some insects, plants, protozoa, and viruses. Despite their abundance in cells of certain developmental stages and their presence in secretomes, only a few aegerolysins have been studied in detail. Their function, in particular, is intriguing. Here, we summarize previously published findings on the distribution, molecular interactions, and function of these versatile aegerolysins. They have very diverse protein sequences but a common fold. The machine learning approach of the AlphaFold2 algorithm, which incorporates physical and biological knowledge of protein structures and multisequence alignments, provides us new insights into the aegerolysins and their pore-forming partners, complemented by additional genomic support. We hypothesize that aegerolysins are involved in the mechanisms of competitive exclusion in the niche.
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Šolinc G, Švigelj T, Omersa N, Snoj T, Pirc K, Žnidaršič N, Yamaji-Hasegawa A, Kobayashi T, Anderluh G, Podobnik M. Pore-forming moss protein bryoporin is structurally and mechanistically related to actinoporins from evolutionarily distant cnidarians. J Biol Chem 2022; 298:102455. [PMID: 36063994 PMCID: PMC9526159 DOI: 10.1016/j.jbc.2022.102455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 10/26/2022] Open
Abstract
Pore-forming proteins perforate lipid membranes and consequently affect their integrity and cell fitness. Therefore, it is not surprising that many of these proteins from bacteria, fungi, or certain animals act as toxins. While pore-forming proteins have also been found in plants, there is little information on their molecular structure and mode of action. Bryoporin is a protein from the moss Physcomitrium patens, and its corresponding gene was found to be upregulated by various abiotic stresses, especially dehydration, as well as upon fungal infection. Based on the amino acid sequence, it was suggested that bryoporin was related to the actinoporin family of pore-forming proteins, originally discovered in sea anemones. Here, we provide the first detailed structural and functional analysis of this plant cytolysin. The crystal structure of the monomeric bryoporin is highly similar to those of actinoporins. Our cryo-EM analysis of its pores showed an actinoporin-like octameric structure, thereby revealing a close kinship of proteins from evolutionarily distant organisms. This was further confirmed by our observation of bryoporin's preferential binding to and formation of pores in membranes containing animal sphingolipids, such as sphingomyelin and ceramide phosphoethanolamine; however, its binding affinity was weaker than that of actinoporin equinatoxin II. We determined bryoporin did not bind to major sphingolipids found in fungi or plants, and its membrane-binding and pore-forming activity were enhanced by various sterols. Our results suggest that bryoporin could represent a part of the moss defense arsenal, acting as a pore-forming toxin against membranes of potential animal pathogens, parasites, or predators.
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Affiliation(s)
- Gašper Šolinc
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Tomaž Švigelj
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Tina Snoj
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Katja Pirc
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Nada Žnidaršič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, Ljubljana, Slovenia
| | | | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan; UMR 7021 CNRS, Université de Strasbourg, Illkirch, France
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia.
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Cao B, Nie Y, Guan Z, Chen C, Wang N, Wang Z, Shu C, Zhang J, Zhang D. The crystal structure of Cry78Aa from Bacillus thuringiensis provides insights into its insecticidal activity. Commun Biol 2022; 5:801. [PMID: 35945427 PMCID: PMC9363482 DOI: 10.1038/s42003-022-03754-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 07/22/2022] [Indexed: 11/09/2022] Open
Abstract
Genetically modified plants with insecticidal proteins from Bacillus thuringiensis (Bt) have been successfully utilized to control various kinds of pests in crop production and reduce the abuse of pesticides. However, a limited number of genes are available for the protection of crops from rice planthopper. Recently, Cry78Aa protein from Bt strain C9F1 has been found to have high insecticidal activity against Laodelphax striatellus and Nilaparvata lugens. It is the first reported single-component protein in the world to combat rice planthoppers, making it very promising for use in transgenic crops. The ambiguous mechanism of Cry78Aa functions prevented further engineering or application. Here, we report the crystal structure of Cry78Aa, which consists of two domains: a C-terminal β-pore forming domain belonging to the aerolysin family and an N-terminal trefoil domain resembling the S-type ricin B lectin. Thus, Cry78Aa could represent a distinctive type of β-pore forming toxin. We also found that Cry78Aa binds carbohydrates such as galactose derivatives and is essential for insecticidal activity against Laodelphax striatellus. Our results suggest a mechanism underlying the function of Cry78Aa against rice planthoppers and pave the way to maximizing the usage of the toxin. The crystal structure of the Bacillus thuringiensis protein Cry78Aa shows it consists of a C-terminal β-pore forming domain and an N-terminal trefoil domain and suggests a mechanism underlying the function of Cry78Aa against rice planthoppers.
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Affiliation(s)
- Beibei Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yangfan Nie
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zeyuan Guan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chuanyu Chen
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Nancong Wang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zeyu Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Delin Zhang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
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Guo Q, Gao Y, Xing C, Niu Y, Ding L, Dai X. Culex quinquefasciatus alpha-glucosidase serves as a putative receptor of the Cry48Aa toxin from Lysinibacillus sphaericus. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 147:103799. [PMID: 35662624 DOI: 10.1016/j.ibmb.2022.103799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 05/20/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
The Cry48Aa/Cry49Aa toxin of Lysinibacillus sphaericus shows specific toxicity towards larvae of Culex spp. Individual Cry48Aa and Cry49Aa subunits interact with distinct target sites in the larval midgut and overcome the resistance of Culex to the Bin toxin. However, the toxin-binding proteins have not yet been identified. The present study aimed to identify Cry48Aa-binding proteins in Culex quinquefasciatus. Pulldown assays using C. quinquefasciatus midgut brush-border membrane fractions (BBMFs) identified a class of proteins, including aminopeptidases (APNs), protease m1 zinc metalloproteases, alkaline phosphatases (ALPs), and maltases, that could be potentially involved in the mode of action of this toxin. RNA interference analysis showed that silenced larvae treated with dsRNA of the alpha-glucosidase (named Glu71) gene were more tolerant of the Cry48Aa/Cry49Aa toxin, which induced less than 20% mortality. The amino acid sequence of Glu71 exhibited 42% identity with Cqm1/Cpm1, which acted as a Bin toxin receptor. Toxin binding assays showed that Cry48Aa had a high specific binding capacity for the Glu71 protein, whereas Cry49Aa exhibited no specific binding. Overall, our results showed that Glu71 is a Cry48-binding protein involved in Cry48Aa/Cry49Aa toxicity.
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Affiliation(s)
- Qingyun Guo
- College of Life Sciences, Gannan Normal University, Ganzhou City of Jiangxi Province, 341000, PR China.
| | - Yuan Gao
- College of Life Sciences, Gannan Normal University, Ganzhou City of Jiangxi Province, 341000, PR China
| | - Chong Xing
- School of Information Engineering, Gannan Medical University, Ganzhou City of Jiangxi Province, 341000, PR China
| | - Yingchao Niu
- College of Life Sciences, Gannan Normal University, Ganzhou City of Jiangxi Province, 341000, PR China
| | - Lu Ding
- College of Life Sciences, Gannan Normal University, Ganzhou City of Jiangxi Province, 341000, PR China
| | - Xiaohua Dai
- College of Life Sciences, Gannan Normal University, Ganzhou City of Jiangxi Province, 341000, PR China
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10
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Towards a Fungal Science That Is Independent of Researchers’ Gender. J Fungi (Basel) 2022; 8:jof8070675. [PMID: 35887432 PMCID: PMC9321353 DOI: 10.3390/jof8070675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 02/04/2023] Open
Abstract
The main drivers of gender mainstreaming in basic and clinical research appear to be funding agencies and scientific journals. Some funding agencies have already recognized the importance of their actions for the global development of ideas in science, but further targeted efforts are needed. The challenges for women scientists in fungal research appear to be similar to those in other science, technology, engineering, and mathematics disciplines, although the gender gap in mycology publishing appears to be less pronounced; however, women are underrepresented as last (corresponding) authors. Two examples of best practices to bridge the gap have been promoted in the fungal community: “power hour” and a central resource database for women researchers of fungi and oomycetes. A more balanced ratio of women researchers among (plenary) session speakers, (plenary) session chairs, and committee members at the recent fungal genetics conference is an encouraging sign that the gender gap can be closed. The editorial policy of some journals follows the guidance “Sex and Gender Equality in Research,” and other journals should follow, and indicate the gender ratio among authors and reviewers.
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11
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Kuwar SS, Mishra R, Banerjee R, Milligan J, Rydel T, Du Z, Xie Z, Ivashuta S, Kouadio JL, Meyer JM, Bonning BC. Engineering of Cry3Bb1 provides mechanistic insights toward countering western corn rootworm resistance. CURRENT RESEARCH IN INSECT SCIENCE 2022; 2:100033. [PMID: 36003270 PMCID: PMC9387510 DOI: 10.1016/j.cris.2022.100033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 11/28/2022]
Abstract
Cry3Bb1 engineering for receptor retargeting to counter WCR resistance described Phage display screens against BBMV or recombinant insecticidal-protein receptors 77 gut binding peptides selected and engineered into 284 new variants of Cry3Bb1 112 variants were active against susceptible but not resistant WCR Engineering of Cry3Bb1 Domain II loops 1 and 2 disrupted insecticidal activity Sites for Cry3Bb1 engineering and implications for Cry3Bb1 resistance discussed
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is an economically important pest of corn (maize) in North America and Europe. Current management practices for WCR involve transgenic expression of insecticidal proteins to minimize larval feeding damage to corn roots. The evolution of resistant WCR populations to transgenic corn expressing insecticidal proteins (e.g. Cry3Bb1, Gpp34Ab1/Tpp35Ab1) necessitates efforts to discover and deploy new modes of action for WCR control. Here, we tested the hypothesis that the addition of short peptides selected for binding to the WCR gut would restore insecticidal activity of Cry3Bb1 to resistant insects. Phage display technology coupled with deep sequencing was used to identify peptides selected for binding to WCR brush border membrane vesicles and to recombinant putative receptors aminopeptidase and cadherin. The binding and specificity of selected peptides was confirmed by ELISA and pull-down assays, and candidate gut surface binding partners were identified. Although production of 284 novel Cry3Bb1 variants with these peptides did not restore activity against resistant WCR in artificial diet bioassays, 112 variants were active against susceptible insects. These results provided insights for the mechanism of Cry3Bb1 activity and toward engineering a new mode-of-action via receptor re-targeting in the context of protein structure and function.
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Affiliation(s)
- Suyog S. Kuwar
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Ruchir Mishra
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Rahul Banerjee
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
| | - Jason Milligan
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Timothy Rydel
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Zijin Du
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Zhidong Xie
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Sergey Ivashuta
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Jean-Louis Kouadio
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Jason M. Meyer
- Bayer U.S., Research and Development, Crop Science Plant Biotechnology, Chesterfield, MO, 63017 USA
| | - Bryony C. Bonning
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
- Corresponding author: Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL 32611.
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12
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Pacheco S, Gómez I, Chiñas M, Sánchez J, Soberón M, Bravo A. Whole Genome Sequencing Analysis of Bacillus thuringiensis GR007 Reveals Multiple Pesticidal Protein Genes. Front Microbiol 2021; 12:758314. [PMID: 34795652 PMCID: PMC8594373 DOI: 10.3389/fmicb.2021.758314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022] Open
Abstract
Bacillus thuringiensis (Bt) are soil ubiquitous bacteria. They produce a great variability of insecticidal proteins, where certain of these toxins are used worldwide for pest control. Through their adaptation to diverse ecosystems, certain Bt strains have acquired genetic mobile elements by horizontal transfer, harboring genes that encode for different virulent factors and pesticidal proteins (PP). Genomic characterization of Bt strains provides a valuable source of PP with potential biotechnological applications for pest control. In this work, we have sequenced the complete genome of the bacterium Bt GR007 strain that is toxic to Spodoptera frugiperda and Manduca sexta larvae. Four replicons (one circular chromosome and three megaplasmids) were identified. The two largest megaplasmids (pGR340 and pGR157) contain multiple genes that codify for pesticidal proteins: 10 cry genes (cry1Ab, cry1Bb, cry1Da, cry1Fb, cry1Hb, cry1Id, cry1Ja, cry1Ka, cry1Nb, and cry2Ad), two vip genes (vip3Af and vip3Ag), two binary toxin genes (vpa2Ac and vpb1Ca), five genes that codify for insecticidal toxin components (Tc’s), and a truncated cry1Bd-like gene. In addition, genes that codify for several virulent factors were also found in this strain. Proteomic analysis of the parasporal crystals of GR007 revealed that they are composed of eight Cry proteins. Further cloning of these genes for their individual expression in Bt acrystalliferous strain, by means of their own intrinsic promoter showed expression of seven Cry proteins. These proteins display differential toxicity against M. sexta and S. frugiperda larvae, where Cry1Bb showed to be the most active protein against S. frugiperda larvae and Cry1Ka the most active protein against M. sexta larvae.
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Affiliation(s)
- Sabino Pacheco
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Isabel Gómez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Marcos Chiñas
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Jorge Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mario Soberón
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Alejandra Bravo
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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13
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Kraševec N, Panevska A, Lemež Š, Razinger J, Sepčić K, Anderluh G, Podobnik M. Lipid-Binding Aegerolysin from Biocontrol Fungus Beauveria bassiana. Toxins (Basel) 2021; 13:820. [PMID: 34822604 PMCID: PMC8624791 DOI: 10.3390/toxins13110820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
Fungi are the most common pathogens of insects and thus important regulators of their populations. Lipid-binding aegerolysin proteins, which are commonly found in the fungal kingdom, may be involved in several biologically relevant processes including attack and defense against other organisms. Aegerolysins act alone or together with membrane-attack-complex/perforin (MACPF)-like proteins to form transmembrane pores that lead to cell lysis. We performed an in-depth bioinformatics analysis of aegerolysins in entomopathogenic fungi and selected a candidate aegerolysin, beauveriolysin A (BlyA) from Beauveria bassiana. BlyA was expressed as a recombinant protein in Escherichia coli, and purified to further determine its functional and structural properties, including lipid-binding ability. Aegerolysins were found to be encoded in genomes of entomopathogenic fungi, such as Beauveria, Cordyceps, Metarhizium and Ophiocordyceps. Detailed bioinformatics analysis revealed that they are linked to MACPF-like genes in most genomes. We also show that BlyA interacts with an insect-specific membrane lipid. These results were placed in the context of other fungal and bacterial aegerolysins and their partner proteins. We believe that aegerolysins play a role in promoting the entomopathogenic and antagonistic activity of B. bassiana, which is an active ingredient of bioinsecticides.
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Affiliation(s)
- Nada Kraševec
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
| | - Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (A.P.); (K.S.)
| | - Špela Lemež
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
- Biotechnology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Jaka Razinger
- Plant Protection Department, Agricultural Institute of Slovenia, Hacquetova 17, SI-1000 Ljubljana, Slovenia;
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (A.P.); (K.S.)
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, SI-1000 Ljubljana, Slovenia; (Š.L.); (G.A.); (M.P.)
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14
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Kouadio JL, Duff S, Aikins M, Zheng M, Rydel T, Chen D, Bretsnyder E, Xia C, Zhang J, Milligan J, Evdokimov A, Nageotte J, Yin Y, Moar W, Giddings K, Park Y, Jerga A, Haas J. Structural and functional characterization of Mpp75Aa1.1, a putative beta-pore forming protein from Brevibacillus laterosporus active against the western corn rootworm. PLoS One 2021; 16:e0258052. [PMID: 34634061 PMCID: PMC8504720 DOI: 10.1371/journal.pone.0258052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/16/2021] [Indexed: 12/16/2022] Open
Abstract
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major corn pest of significant economic importance in the United States. The continuous need to control this corn maize pest and the development of field-evolved resistance toward all existing transgenic maize (Zea mays L.) expressing Bacillus thuringiensis (Bt) insecticidal proteins against WCR has prompted the development of new insect-protected crops expressing distinct structural classes of insecticidal proteins. In this current study, we describe the crystal structure and functional characterization of Mpp75Aa1.1, which represents the first corn rootworm (CRW) active insecticidal protein member of the ETX_MTX2 sub-family of beta-pore forming proteins (β-PFPs), and provides new and effective protection against WCR feeding. The Mpp75Aa1.1 crystal structure was solved at 1.94 Å resolution. The Mpp75Aa1.1 is processed at its carboxyl-terminus by WCR midgut proteases, forms an oligomer, and specifically interacts with putative membrane-associated binding partners on the midgut apical microvilli to cause cellular tissue damage resulting in insect death. Alanine substitution of the surface-exposed amino acids W206, Y212, and G217 within the Mpp75Aa1.1 putative receptor binding domain I demonstrates that at least these three amino acids are required for WCR activity. The distinctive spatial arrangement of these amino acids suggests that they are part of a receptor binding epitope, which may be unique to Mpp75Aa1.1 and not present in other ETX_MTX2 proteins that do not have WCR activity. Overall, this work establishes that Mpp75Aa1.1 shares a mode of action consistent with traditional WCR-active Bt proteins despite significant structural differences.
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Affiliation(s)
- Jean-Louis Kouadio
- Bayer Crop Science, Chesterfield, Missouri, United States of America
- * E-mail:
| | - Stephen Duff
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Michael Aikins
- Department of Entomology, Kansas State University, Manhattan, Kansas, United States of America
| | - Meiying Zheng
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Timothy Rydel
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Danqi Chen
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Eric Bretsnyder
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Chunsheng Xia
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jun Zhang
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jason Milligan
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Artem Evdokimov
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jeffrey Nageotte
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Yong Yin
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - William Moar
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Kara Giddings
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Yoonseong Park
- Department of Entomology, Kansas State University, Manhattan, Kansas, United States of America
| | - Agoston Jerga
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jeffrey Haas
- Bayer Crop Science, Chesterfield, Missouri, United States of America
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15
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Bacterial Toxins Active against Mosquitoes: Mode of Action and Resistance. Toxins (Basel) 2021; 13:toxins13080523. [PMID: 34437394 PMCID: PMC8402332 DOI: 10.3390/toxins13080523] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 12/25/2022] Open
Abstract
Larvicides based on the bacteria Bacillus thuringiensis svar. israelensis (Bti) and Lysinibacillus sphaericus are effective and environmentally safe compounds for the control of dipteran insects of medical importance. They produce crystals that display specific and potent insecticidal activity against larvae. Bti crystals are composed of multiple protoxins: three from the three-domain Cry type family, which bind to different cell receptors in the midgut, and one cytolytic (Cyt1Aa) protoxin that can insert itself into the cell membrane and act as surrogate receptor of the Cry toxins. Together, those toxins display a complex mode of action that shows a low risk of resistance selection. L. sphaericus crystals contain one major binary toxin that display an outstanding persistence in field conditions, which is superior to Bti. However, the action of the Bin toxin based on its interaction with a single receptor is vulnerable for resistance selection in insects. In this review we present the most recent data on the mode of action and synergism of these toxins, resistance issues, and examples of their use worldwide. Data reported in recent years improved our understanding of the mechanism of action of these toxins, showed that their combined use can enhance their activity and counteract resistance, and reinforced their relevance for mosquito control programs in the future years.
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16
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Panevska A, Glavan G, Jemec Kokalj A, Kukuljan V, Trobec T, Žužek MC, Vrecl M, Drobne D, Frangež R, Sepčić K. Effects of Bioinsecticidal Aegerolysin-Based Cytolytic Complexes on Non-Target Organisms. Toxins (Basel) 2021; 13:457. [PMID: 34208927 PMCID: PMC8310125 DOI: 10.3390/toxins13070457] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 01/05/2023] Open
Abstract
Aegerolysin proteins ostreolysin A6 (OlyA6), pleurotolysin A2 (PlyA2) and erylysin A (EryA) produced by the mushroom genus Pleurotus bind strongly to an invertebrate-specific membrane sphingolipid, and together with a protein partner pleurotolysin B (PlyB), form transmembrane pore complexes. This pore formation is the basis for the selective insecticidal activity of aegerolysin/PlyB complexes against two economically important coleopteran pests: the Colorado potato beetle and the western corn rootworm. In this study, we evaluated the toxicities of these aegerolysin/PlyB complexes using feeding tests with two ecologically important non-target arthropod species: the woodlouse and the honey bee. The mammalian toxicity of the EryA/PlyB complex was also evaluated after intravenous administration to mice. None of the aegerolysin/PlyB complexes were toxic against woodlice, but OlyA6/PlyB and PlyA2/PlyB were toxic to honeybees, with 48 h mean lethal concentrations (LC50) of 0.22 and 0.39 mg/mL, respectively, in their food. EryA/PlyB was also tested intravenously in mice up to 3 mg/kg body mass, without showing toxicity. With no toxicity seen for EryA/PlyB for environmentally beneficial arthropods and mammals at the tested concentrations, these EryA/PlyB complexes are of particular interest for development of new bioinsecticides for control of selected coleopteran pests.
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Affiliation(s)
- Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Gordana Glavan
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Anita Jemec Kokalj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Veronika Kukuljan
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia;
| | - Tomaž Trobec
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Monika Cecilija Žužek
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Milka Vrecl
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Damjana Drobne
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
| | - Robert Frangež
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (T.T.); (M.C.Ž.); (M.V.)
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (A.P.); (G.G.); (A.J.K.); (D.D.)
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17
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Milijaš Jotić M, Panevska A, Iacovache I, Kostanjšek R, Mravinec M, Skočaj M, Zuber B, Pavšič A, Razinger J, Modic Š, Trenti F, Guella G, Sepčić K. Dissecting Out the Molecular Mechanism of Insecticidal Activity of Ostreolysin A6/Pleurotolysin B Complexes on Western Corn Rootworm. Toxins (Basel) 2021; 13:toxins13070455. [PMID: 34209983 PMCID: PMC8310357 DOI: 10.3390/toxins13070455] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 02/04/2023] Open
Abstract
Ostreolysin A6 (OlyA6) is a protein produced by the oyster mushroom (Pleurotus ostreatus). It binds to membrane sphingomyelin/cholesterol domains, and together with its protein partner, pleurotolysin B (PlyB), it forms 13-meric transmembrane pore complexes. Further, OlyA6 binds 1000 times more strongly to the insect-specific membrane sphingolipid, ceramide phosphoethanolamine (CPE). In concert with PlyB, OlyA6 has potent and selective insecticidal activity against the western corn rootworm. We analysed the histological alterations of the midgut wall columnar epithelium of western corn rootworm larvae fed with OlyA6/PlyB, which showed vacuolisation of the cell cytoplasm, swelling of the apical cell surface into the gut lumen, and delamination of the basal lamina underlying the epithelium. Additionally, cryo-electron microscopy was used to explore the membrane interactions of the OlyA6/PlyB complex using lipid vesicles composed of artificial lipids containing CPE, and western corn rootworm brush border membrane vesicles. Multimeric transmembrane pores were formed in both vesicle preparations, similar to those described for sphingomyelin/cholesterol membranes. These results strongly suggest that the molecular mechanism of insecticidal action of OlyA6/PlyB arises from specific interactions of OlyA6 with CPE, and the consequent formation of transmembrane pores in the insect midgut.
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Affiliation(s)
- Matej Milijaš Jotić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Ioan Iacovache
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (I.I.); (B.Z.)
| | - Rok Kostanjšek
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Martina Mravinec
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Benoît Zuber
- Institute of Anatomy, University of Bern, 3012 Bern, Switzerland; (I.I.); (B.Z.)
| | - Ana Pavšič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
| | - Jaka Razinger
- Agricultural Institute of Slovenia, 1000 Ljubljana, Slovenia; (J.R.); (Š.M.)
| | - Špela Modic
- Agricultural Institute of Slovenia, 1000 Ljubljana, Slovenia; (J.R.); (Š.M.)
| | - Francesco Trenti
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, 38123 Trento, Italy; (F.T.); (G.G.)
| | - Graziano Guella
- Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, 38123 Trento, Italy; (F.T.); (G.G.)
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; (M.M.J.); (A.P.); (R.K.); (M.M.); (M.S.); (A.P.)
- Correspondence: ; Tel.: +386-1-320-3419
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How Does Bacillus thuringiensis Crystallize Such a Large Diversity of Toxins? Toxins (Basel) 2021; 13:toxins13070443. [PMID: 34206796 PMCID: PMC8309854 DOI: 10.3390/toxins13070443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a natural crystal-making bacterium. Bt diversified into many subspecies that have evolved to produce crystals of hundreds of pesticidal proteins with radically different structures. Their crystalline form ensures stability and controlled release of these major virulence factors. They are responsible for the toxicity and host specificity of Bt, explaining its worldwide use as a biological insecticide. Most research has been devoted to understanding the mechanisms of toxicity of these toxins while the features driving their crystallization have long remained elusive, essentially due to technical limitations. The evolution of methods in structural biology, pushing back the limits in size of amenable protein crystals now allows access to be gained to structural information hidden within natural crystals of such toxins. In this review, we present the main parameters that have been identified as key drivers of toxin crystallization in Bt, notably in the light of recent discoveries driven by structural biology studies. Then, we develop how the future evolution of structural biology will hopefully unveil new mechanisms of Bt toxin crystallization, opening the door to their hijacking with the aim of developing a versatile in vivo crystallization platform of high academic and industrial interest.
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Guo Q, Ding L, Gao Y, Niu Y, Dai X. Cys183 and Cys258 in Cry49Aa toxin from Lysinibacillus sphaericus are essential for toxicity to Culex quinquefasciatus larvae. Arch Microbiol 2021; 203:4587-4592. [PMID: 34160628 DOI: 10.1007/s00203-021-02436-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
The two-component Cry48Aa/Cry49Aa toxin produced by Lysinibacillus sphaericus shows specifically toxic to Culex quinquefasciatus mosquito larvae. Cry49Aa C-terminal domain is responsible for specific binding to the larval gut cell membrane, while its N-terminal domain is required for interaction with Cry48Aa. To investigate functional role of cysteine in Cry49Aa, four cysteine residues at positions 70, 91, 183, and 258 were substituted by alanine. All mutants showed similar crystalline morphology and comparable yield to that of the wild type except that the yield of the C91A mutant was low. Four cysteine residues did not involve in disulfide bond formation within or between Cry49Aa molecules. Cys91, Cys183, and Cys258 are essential for larvicidal activity against C. quinquefasciatus larvae, while Cys70 is not. Substitution at C91, C183, and C258 caused weaker Cry48Aa- Cry49Aa interaction, while mutations at C183 and C258 reduced the binding capacities to the larval gut cell membrane. Thus, Cysteine residues at position 91, 183, and 258 in Cry49Aa are required for full toxicity of Cry48Aa/Cry49Aa toxin.
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Affiliation(s)
- Qingyun Guo
- College of Life Sciences, Gannan Normal University, Shida South Road 1, Ganzhou City, Jiangxi Province, 341000, People's Republic of China.
| | - Lu Ding
- College of Life Sciences, Gannan Normal University, Shida South Road 1, Ganzhou City, Jiangxi Province, 341000, People's Republic of China
| | - Yuan Gao
- College of Life Sciences, Gannan Normal University, Shida South Road 1, Ganzhou City, Jiangxi Province, 341000, People's Republic of China
| | - Yingchao Niu
- College of Life Sciences, Gannan Normal University, Shida South Road 1, Ganzhou City, Jiangxi Province, 341000, People's Republic of China
| | - Xiaohua Dai
- College of Life Sciences, Gannan Normal University, Shida South Road 1, Ganzhou City, Jiangxi Province, 341000, People's Republic of China
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20
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Pérez Ortega C, Leininger C, Barry J, Poland B, Yalpani N, Altier D, Nelson ME, Lu AL. Coordinated binding of a two-component insecticidal protein from Alcaligenes faecalis to western corn rootworm midgut tissue. J Invertebr Pathol 2021; 183:107597. [PMID: 33945817 DOI: 10.1016/j.jip.2021.107597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 04/08/2021] [Accepted: 04/20/2021] [Indexed: 12/19/2022]
Abstract
AfIP-1A/1B is a two-component insecticidal protein identified from the soil bacterium Alcaligenes faecalis that has high activity against western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte). Previous results revealed that AfIP-1A/1B is cross-resistant to the binary protein from Bacillus thuringiensis (Bt), Cry34Ab1/Cry35Ab1 (also known as Gpp34Ab1/Tpp35Ab1; Crickmore et al., 2020), which was attributed to shared binding sites in WCR gut tissue (Yalpani et al., 2017). To better understand the interaction of AfIP-1A/1B with its receptor, we have systematically evaluated the binding of these proteins with WCR brush border membrane vesicles (BBMVs). Our findings show that AfIP-1A binds directly to BBMVs, while AfIP-1B does not; AfIP-1B binding only occurred in the presence of AfIP-1A which was accompanied by the presence of stable, high molecular weight oligomers of AfIP-1B observed on denaturing protein gels. Additionally, we show that AfIP-1A/1B forms pores in artificial lipid membranes. Finally, binding of AfIP-1A/1B was found to be reduced in BBMVs from Cry34Ab1/Cry35Ab1-resistant WCR where Cry34Ab1/Cry35Ab1 binding was also reduced. The reduced binding of both proteins is consistent with recognition of a shared receptor that has been altered in the resistant strain. The coordination of AfIP-1B binding by AfIP-1A, the similar structures between AfIP-1A and Cry34Ab1, along with their shared binding sites and cross-resistance, suggest a similar role for AfIP1A and Cry34Ab1 in receptor recognition and docking site for their cognate partners, AfIP-1B and Cry35Ab1, respectively.
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Affiliation(s)
| | - Chris Leininger
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA
| | - Jennifer Barry
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA
| | - Brad Poland
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA
| | - Nasser Yalpani
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA
| | - Dan Altier
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA
| | - Mark E Nelson
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA.
| | - Albert L Lu
- Corteva Agriscience, 7300 NW 62(nd) Ave., Johnston, IA 50131, USA
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21
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Paddock KJ, Hibbard BE, Barry J, Sethi A, Mueller AL, Shelby KS, Pereira AE. Restoration of susceptibility following removal of selection for Cry34/35Ab1 resistance documents fitness costs in resistant population of western corn rootworm, Diabrotica virgifera virgifera. PEST MANAGEMENT SCIENCE 2021; 77:2385-2394. [PMID: 33415809 DOI: 10.1002/ps.6266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/03/2021] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Management of the corn pest, western corn rootworm (WCR), Diabrotica virgifera virgifera (LeConte) (Coleoptera: Chrysomelidae), relies heavily on the planting of transgenic corn expressing toxins produced by the bacterium Bacillus thuringiensis (Bt). This has resulted in the evolution of resistance to all of the four commercially available Bt toxins targeting coleopteran insects. In this study, we evaluated the susceptibility of a Cry34/35Ab1-resistant WCR colony in seedling and diet toxicity assays after removal from selection for six and nine generations. In addition, female fecundity, egg fertility, adult lifespan, larval development, and adult emergence were evaluated in two Cry34/35Ab1-resistant and two susceptible WCR colonies to assess fitness costs. RESULTS Susceptibility to Cry34/35Ab1 was restored in a colony removed from selection after six and nine generations based on diet toxicity assays and comparisons of relative survival, head capsule width, and dry weight in plant assays. Thus, pronounced fitness costs associated with resistance to Cry34/35Ab1 were documented by susceptibility being restored within six generations. In separate studies evaluating specific fitness costs, larval fitness when reared on isoline corn did not differ between resistant and susceptible colonies. However, beetles from susceptible colonies lived longer than resistant beetles which resulted in females from susceptible colonies producing significantly more eggs than resistant colonies, with no differences in egg fertility. CONCLUSIONS The presence of a fitness cost that may contribute to the restoration of susceptibility to Bt has not been documented in other Cry3-resistant WCR populations and could have significant impact on the deployment of resistance management practices. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Kyle J Paddock
- Division of Plant Sciences, University of Missouri, Columbia, MO, USA
| | - Bruce E Hibbard
- USDA-ARS, Plant Genetics Research Unit, University of Missouri, Columbia, MO, USA
| | - Julie Barry
- USDA-ARS, Plant Genetics Research Unit, University of Missouri, Columbia, MO, USA
| | | | | | - Kent S Shelby
- USDA-ARS, Biological Control of Insects Laboratory, Columbia, MO, USA
| | - Adriano E Pereira
- Division of Plant Sciences, University of Missouri, Columbia, MO, USA
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22
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Challenges of automation and scale: Bioinformatics and the evaluation of proteins to support genetically modified product safety assessments. J Invertebr Pathol 2021; 186:107587. [PMID: 33838205 DOI: 10.1016/j.jip.2021.107587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 11/24/2022]
Abstract
Bioinformatic analyses of protein sequences play an important role in the discovery and subsequent safety assessment of insect control proteins in Genetically Modified (GM) crops. Due to the rapid adoption of high-throughput sequencing methods over the last decade, the number of protein sequences in GenBank and other public databases has increased dramatically. Many of these protein sequences are the product of whole genome sequencing efforts, coupled with automated protein sequence prediction and annotation pipelines. Published genome sequencing studies provide a rich and expanding foundation of new source organisms and proteins for insect control or other desirable traits in GM products. However, data generated by automated pipelines can also confound regulatory safety assessments that employ bioinformatics. Largely this issue does not arise due to underlying sequence, but rather its annotation or associated metadata, and the downstream integration of that data into existing repositories. Observations made during bioinformatic safety assessments are described.
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23
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Branching out the aerolysin, ETX/MTX-2 and Toxin_10 family of pore forming proteins. J Invertebr Pathol 2021; 186:107570. [PMID: 33775676 DOI: 10.1016/j.jip.2021.107570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/15/2020] [Accepted: 03/09/2021] [Indexed: 01/28/2023]
Abstract
Organisms have evolved mechanisms in which cellular membranes can both be targeted and punctured thereby killing the targeted cell. One such mechanism involves the deployment of pore forming proteins (PFPs) which function by oligomerizing on cell membranes and inserting a physical pore spanning the membrane. This pore can lead to cell death by either causing osmotic flux or allowing the delivery of a secondary toxin. Pore forming proteins can be broadly classified into different families depending on the structure of the final pore; either α-PFPs using channels made from α -helices or β-PFPs using channels made from β-barrels. There are many different β-PFPs and an emerging superfamily is the aerolysin-ETX/MTX-2 superfamily. A comparison between the members of this superfamily reveals the pore forming domain is a common module yet the receptor binding region is highly variable. These structural and architectural variations lead to differences in the target recognition and determine the site of activity. Closer investigation of the topology of the family also suggests that the Toxin_10 family of PFPs could be considered as part of the aerolysin-ETX/MTX-2 superfamily. Comparatively, far less is known about how Toxin_10 proteins assemble into the final pore structure than aerolysin-ETX/MTX-2 proteins. This review aims to collate the pore forming protein members and bridge the structural similarities between the aerolysin-ETX/MTX-2 superfamily and the insecticidal Toxin_10 subfamily.
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24
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Crystal structure of RahU, an aegerolysin protein from the human pathogen Pseudomonas aeruginosa, and its interaction with membrane ceramide phosphorylethanolamine. Sci Rep 2021; 11:6572. [PMID: 33753805 PMCID: PMC7985367 DOI: 10.1038/s41598-021-85956-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 03/08/2021] [Indexed: 12/15/2022] Open
Abstract
Aegerolysins are proteins produced by bacteria, fungi, plants and protozoa. The most studied fungal aegerolysins share a common property of interacting with membranes enriched with cholesterol in combination with either sphingomyelin or ceramide phosphorylethanolamine (CPE), major sphingolipids in the cell membranes of vertebrates and invertebrates, respectively. However, genome analyses show a particularly high frequency of aegerolysin genes in bacteria, including the pathogenic genera Pseudomonas and Vibrio; these are human pathogens of high clinical relevance and can thrive in a variety of other species. The knowledge on bacterial aegerolysin-lipid interactions is scarce. We show that Pseudomonas aeruginosa aegerolysin RahU interacts with CPE, but not with sphingomyelin-enriched artificial membranes, and that RahU interacts with the insect cell line producing CPE. We report crystal structures of RahU alone and in complex with tris(hydroxymethyl)aminomethane (Tris), which, like the phosphorylethanolamine head group of CPE, contains a primary amine. The RahU structures reveal that the two loops proximal to the amino terminus form a cavity that accommodates Tris, and that the flexibility of these two loops is important for this interaction. We show that Tris interferes with CPE-enriched membranes for binding to RahU, implying on the importance of the ligand cavity between the loops and its proximity in RahU membrane interaction. We further support this by studying the interaction of single amino acid substitution mutants of RahU with the CPE-enriched membranes. Our results thus represent a starting point for a better understanding of the role of P. aeruginosa RahU, and possibly other bacterial aegerolysins, in bacterial interactions with other organisms.
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25
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Yin Y, Flasinski S, Moar W, Bowen D, Chay C, Milligan J, Kouadio JL, Pan A, Werner B, Buckman K, Zhang J, Mueller G, Preftakes C, Hibbard BE, Price P, Roberts J. A new Bacillus thuringiensis protein for Western corn rootworm control. PLoS One 2020; 15:e0242791. [PMID: 33253273 PMCID: PMC7703998 DOI: 10.1371/journal.pone.0242791] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/09/2020] [Indexed: 11/23/2022] Open
Abstract
The Western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte is one of the most economically important insect pests in North America. Since 2003, transgenic maize expressing WCR-active proteins from Bacillus thuringiensis (Bt) have been widely adopted as the main approach to controlling WCR in the U.S. However, the emergence of field resistance to the Bt proteins in current commercial products has been documented in recent years, highlighting the need to develop additional tools for controlling this devasting pest. Here we report the discovery of Vpb4Da2 (initially assigned as Vip4Da2), a new insecticidal protein highly selective against WCR, through high-throughput genome sequencing of a Bt strain sourced from grain dust samples collected in the eastern and central regions of the US. Vpb4Da2 contains a sequence and domain signature distinct from families of other WCR-active proteins. Under field conditions, transgenic maize expressing Vpb4Da2 demonstrates commercial-level (at or below NIS 0.25) root protection against WCR, and reduces WCR beetle emergence by ≥ 97%. Our studies also conclude that Vpb4Da2 controls WCR populations that are resistant to WCR-active transgenic maize expressing Cry3Bb1, Cry34Ab1/Cry35Ab1 (reassigned as Gpp34Ab1/Tpp35Ab1), or DvSnf7 RNA. Based on these findings, Vpb4Da2 represents a valuable new tool for protecting maize against WCR.
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Affiliation(s)
- Yong Yin
- Bayer Crop Science, Chesterfield, Missouri, United States of America
- * E-mail:
| | | | - William Moar
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - David Bowen
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Cathy Chay
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jason Milligan
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | | | - Aihong Pan
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Brent Werner
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Karrie Buckman
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jun Zhang
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Geoffrey Mueller
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Collin Preftakes
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Bruce E. Hibbard
- USDA-ARS, Plant Genetics Research Unit, University of Missouri, Columbia, Missouri, United States of America
| | - Paula Price
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - James Roberts
- Bayer Crop Science, Chesterfield, Missouri, United States of America
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26
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Panevska A, Skočaj M, Modic Š, Razinger J, Sepčić K. Aegerolysins from the fungal genus Pleurotus - Bioinsecticidal proteins with multiple potential applications. J Invertebr Pathol 2020; 186:107474. [PMID: 32971130 DOI: 10.1016/j.jip.2020.107474] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/24/2022]
Abstract
The aegerolysin proteins ostreolysin A6, pleurotolysin A2 and erylysin A are produced by mushrooms of the genus Pleurotus. These aegerolysins can interact specifically with sphingolipid-enriched membranes. In particular, they strongly bind insect cells and to artificial lipid membranes that contain physiologically relevant concentrations of the main invertebrate-specific sphingolipid, ceramide phosphoethanolamine. Moreover, the aegerolysins permeabilise these membranes when combined with their protein partner pleurotolysin B, which contains a membrane-attack-complex/perforin domain. These aegerolysin/ pleurotolysin B complexes show strong and selective toxicity towards western corn rootworm larvae and adults and Colorado potato beetle larvae. Their insecticidal activities arise through aegerolysin binding to ceramide phosphoethanolamine in the insect midgut. This mode of membrane binding is different from those described for similar aegerolysin-based complexes of bacterial origin (e.g., Cry34Ab1/Cry35Ab1), or other Bacillus thuringiensis proteinaceous crystal toxins, which associate with protein receptors. The ability of Pleurotus aegerolysins to specifically interact with sphingolipid-enriched domains in mammalian cells can be further exploited to visualize lipid rafts in living cells, and to treat certain types of tumours and metabolic disorders. Finally, these proteins can strongly enhance fruiting initiation of P. ostreatus even when applied externally. In this review, we summarise the current knowledge of the potential biotechnological and biomedical applications of the Pleurotus aegerolysins, either alone or when complexed with pleurotolysin B, with special emphasis on their bioinsecticidal effects.
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Affiliation(s)
- Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
| | - Špela Modic
- Plant Protection Department, Agricultural Institute of Slovenia, Hacquetova 17, 1000 Ljubljana, Slovenia.
| | - Jaka Razinger
- Plant Protection Department, Agricultural Institute of Slovenia, Hacquetova 17, 1000 Ljubljana, Slovenia.
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
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27
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Insecticidal Activity of Bacillus thuringiensis Proteins Against Coleopteran Pests. Toxins (Basel) 2020; 12:toxins12070430. [PMID: 32610662 PMCID: PMC7404982 DOI: 10.3390/toxins12070430] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/25/2020] [Accepted: 06/25/2020] [Indexed: 12/17/2022] Open
Abstract
Bacillus thuringiensis is the most successful microbial insecticide agent and its proteins have been studied for many years due to its toxicity against insects mainly belonging to the orders Lepidoptera, Diptera and Coleoptera, which are pests of agro-forestry and medical-veterinary interest. However, studies on the interactions between this bacterium and the insect species classified in the order Coleoptera are more limited when compared to other insect orders. To date, 45 Cry proteins, 2 Cyt proteins, 11 Vip proteins, and 2 Sip proteins have been reported with activity against coleopteran species. A number of these proteins have been successfully used in some insecticidal formulations and in the construction of transgenic crops to provide protection against main beetle pests. In this review, we provide an update on the activity of Bt toxins against coleopteran insects, as well as specific information about the structure and mode of action of coleopteran Bt proteins.
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28
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The Cry48Aa N-terminal Domain is Responsible for Cry48Aa–Cry49Aa Interaction in Lysinibacillus sphaericus Toxin. Curr Microbiol 2020; 77:1217-1222. [DOI: 10.1007/s00284-020-01907-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 01/29/2020] [Indexed: 10/24/2022]
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29
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Cao B, Shu C, Geng L, Song F, Zhang J. Cry78Ba1, One Novel Crystal Protein from Bacillus thuringiensis with High Insecticidal Activity against Rice Planthopper. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:2539-2546. [PMID: 32023056 DOI: 10.1021/acs.jafc.9b07429] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The rice planthopper is a very important hemipteran pest that preys on rice and substantially affects the safety of rice production. Moreover, the long-term prevention and control of these pests with chemical pesticides has led to an increase in the resistance of the rice planthopper as well as serious environmental pollution and food safety problems. Bacillus thuringiensis (Bt) has been used for the efficient and green control of a variety of rice pests. Therefore, based on the high-throughput screening of Bt strains that are active against the rice planthopper, we found that Bt strain B4F11 showed certain insecticidal activity against Laodelphax striatellus Fallén, and we have identified a novel insecticidal protein Cry78Ba1 from the Bt strain B4F11, which is expected to provide the specific and safe control of the rice planthopper. The Cry78Ba1 protein is composed of 380 amino acid residues with a molecular weight of 42.55 kDa and contains conserved Ricin_B_Lectin and Toxin_10 superfamily domains. It displays high insecticidal activity against L. striatellus with a lethal concentration (LC50) of 9.723 μg/mL. More importantly, this Toxin_10-like protein does not display sequence homology to any known allergen and can be degraded and inactivated rapidly when heated at 90 °C and in simulated gastrointestinal fluid. In summary, Cry78Ba1 has great potential for applications in the efficient and safe prevention and control of the rice planthopper.
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Affiliation(s)
- Beibei Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
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30
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Gerdol M, Cervelli M, Oliverio M, Modica MV. Piercing Fishes: Porin Expansion and Adaptation to Hematophagy in the Vampire Snail Cumia reticulata. Mol Biol Evol 2019; 35:2654-2668. [PMID: 30099551 PMCID: PMC6231492 DOI: 10.1093/molbev/msy156] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cytolytic pore-forming proteins are widespread in living organisms, being mostly involved in both sides of the host-pathogen interaction, either contributing to the innate defense or promoting infection. In venomous organisms, such as spiders, insects, scorpions, and sea anemones, pore-forming proteins are often secreted as key components of the venom. Coluporins are pore-forming proteins recently discovered in the Mediterranean hematophagous snail Cumia reticulata (Colubrariidae), highly expressed in the salivary glands that discharge their secretion at close contact with the host. To understand their putative functional role, we investigated coluporins' molecular diversity and evolutionary patterns. Coluporins is a well-diversified family including at least 30 proteins, with an overall low sequence similarity but sharing a remarkably conserved actinoporin-like predicted structure. Tracking the evolutionary history of the molluscan porin genes revealed a scattered distribution of this family, which is present in some other lineages of predatory gastropods, including venomous conoidean snails. Comparative transcriptomic analyses highlighted the expansion of porin genes as a lineage-specific feature of colubrariids. Coluporins seem to have evolved from a single ancestral porin gene present in the latest common ancestor of all Caenogastropoda, undergoing massive expansion and diversification in this colubrariid lineage through repeated gene duplication events paired with widespread episodic positive selection. As for other parasites, these findings are congruent with a "one-sided arms race," equipping the parasite with multiple variants in order to broaden its host spectrum. Overall, our results pinpoint a crucial adaptive role for coluporins in the evolution of the peculiar trophic ecology of vampire snails.
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Affiliation(s)
- Marco Gerdol
- Department of Life Sciences, Trieste University, Italy
| | | | - Marco Oliverio
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University, Roma, Italy
| | - Maria Vittoria Modica
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy.,UMR5247, University of Montpellier, France
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31
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Panevska A, Hodnik V, Skočaj M, Novak M, Modic Š, Pavlic I, Podržaj S, Zarić M, Resnik N, Maček P, Veranič P, Razinger J, Sepčić K. Pore-forming protein complexes from Pleurotus mushrooms kill western corn rootworm and Colorado potato beetle through targeting membrane ceramide phosphoethanolamine. Sci Rep 2019; 9:5073. [PMID: 30911026 PMCID: PMC6433908 DOI: 10.1038/s41598-019-41450-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 03/08/2019] [Indexed: 01/13/2023] Open
Abstract
Aegerolysins ostreolysin A (OlyA) and pleurotolysin A (PlyA), and pleurotolysin B (PlyB) with the membrane-attack-complex/perforin domain are proteins from the mushroom genus Pleurotus. Upon binding to sphingomyelin/cholesterol-enriched membranes, OlyA and PlyA can recruit PlyB to form multimeric bi-component transmembrane pores. Recently, Pleurotus aegerolysins OlyA, PlyA2 and erylysin A (EryA) were demonstrated to preferentially bind to artificial lipid membranes containing 50 mol% ceramide phosphoethanolamine (CPE), the main sphingolipid in invertebrate cell membranes. In this study, we demonstrate that OlyA6, PlyA2 and EryA bind to insect cells and to artificial lipid membranes with physiologically relevant CPE concentrations. Moreover, these aegerolysins permeabilize these membranes when combined with PlyB. These aegerolysin/PlyB complexes show selective toxicity toward western corn rootworm larvae and adults and Colorado potato beetle larvae. These data strongly suggest that these aegerolysin/PlyB complexes recognize CPE as their receptor molecule in the insect midgut. This mode of binding is different from those described for similar aegerolysin-based bacterial complexes, or other Bacillus thuringiensis Cry toxins, which have protein receptors. Targeting of Pleurotus aegerolysins to CPE and formation of transmembrane pores in concert with PlyB suggest the use of aegerolysin/PlyB complexes as novel biopesticides for the control of western corn rootworm and Colorado potato beetle.
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Affiliation(s)
- Anastasija Panevska
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Vesna Hodnik
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Matej Skočaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Maruša Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Špela Modic
- Agricultural Institute of Slovenia, Hacquetova 17, 1000, Ljubljana, Slovenia
| | - Ivana Pavlic
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia.,Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000, Rijeka, Croatia
| | - Sara Podržaj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Miki Zarić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Nataša Resnik
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia
| | - Peter Maček
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Peter Veranič
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia
| | - Jaka Razinger
- Agricultural Institute of Slovenia, Hacquetova 17, 1000, Ljubljana, Slovenia.
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia.
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32
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Moar WJ, Berry C, Narva KE. The structure/function of new insecticidal proteins and regulatory challenges for commercialization. J Invertebr Pathol 2018; 142:1-4. [PMID: 28215319 DOI: 10.1016/j.jip.2017.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- William J Moar
- Monsanto Co., 800 North Lindbergh Blvd., St. Louis, MO, United States.
| | - Colin Berry
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3AT, UK
| | - Kenneth E Narva
- Dow AgroSciences, LLC 9330 Zionsville Road, Indianapolis, IN 46268, United States
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Wang Y, Liu Y, Zhang J, Crickmore N, Song F, Gao J, Shu C. Cry78Aa, a novel Bacillus thuringiensis insecticidal protein with activity against Laodelphax striatellus and Nilaparvata lugens. J Invertebr Pathol 2018; 158:1-5. [PMID: 30017953 DOI: 10.1016/j.jip.2018.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 11/29/2022]
Abstract
Transgenic plants expressing insecticidal proteins originating from Bacillus thuringiensis (Bt) have successfully been used to control lepidopteran and coleopteran pests with chewing mouthparts. However, only a handful of Bt proteins have been identified that have bioactivity against sap sucking pests (Hemiptera), including aphids, whiteflies, plant bugs and planthoppers. A novel Bt insecticidal protein with significant toxicity against a hemipteran insect pest is described here. The gene encoding the 359 amino acid, 40.7 kDa protein was cloned from strain C9F1. After expression and purification of the toxin, its median lethal concentration (LC50) values against Laodelphax striatellus and Nilaparvata lugens were determined as 6.89 μg/mL and 15.78 μg/mL respectively. Analysis of the toxin sequence revealed the presence of both Toxin_10 and Ricin_B_Lectin domains.
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Affiliation(s)
- Yinglong Wang
- School of Life Science, Northeast Agricultural University, Harbin 150030, PR China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Yonglei Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China; State Key Laboratory of Medical Vector Surveillance and Pathogen Detection, Beilun Entry and Exit Inspection and Quarantine Bureau, Ningbo 305012, PR China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Jiguo Gao
- School of Life Science, Northeast Agricultural University, Harbin 150030, PR China.
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
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Liu P, Zhou Y, Wu Z, Zhong H, Wei Y, Li Y, Liu S, Zhang Y, Fang X. Computational identification and evolutionary analysis of toxins in Mosquitocidal Bacillus thuringiensis strain S2160-1. 3 Biotech 2018; 8:293. [PMID: 29963353 DOI: 10.1007/s13205-018-1313-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/18/2018] [Indexed: 01/25/2023] Open
Abstract
Mosquitocidal Bacillus thuringiensis (Bt) strain S2160-1 was proposed to be an alternative to Bacillus thuringiensis subsp. israelensis (Bti). Discovering and validating a toxic gene by experimentation was a complex and time-consuming task, which can benefit from high-throughput sequencing analysis. In this research, we predicted and identified toxic proteins in the strain S2160-1 based on the draft whole genome sequence data. Through a local BLASP, 46 putative toxins were identified in S2160-1 genome, by searching against a customized B. thuringiensis toxin proteins database containing 653 protein or peptide sequences retrieved from public accessible resources and PCR/clone results in our laboratory (e value = 1e - 5). These putative toxins consist of 42 to 1216 amino acids. The molecular weights are ranged from 4.86 to 137.28 kDa. The isoelectric point of these candidate toxins varied from 4.3 to 10.06, and 16 out of which had a pH greater than 7.0. The analysis of tertiary structure and PFAM domain showed that 12 potential plasmid toxins may share higher similarity (9/12 QMEAN4 score > 0.3) with known Bt toxins. In addition, functional annotation indicated that these 12 potential toxins were involved in "sporulation resulting in formation of a cellular spore" and "toxin activity". Moreover, multiple alignment and phylogenetic analysis were carried out to elucidate the evolutionary relationship among 101 known crystal or toxin proteins from public database and them with MEGA 6.0. It indicated that PS2160P2_1 and PS2160P2_153 may be potential Cry4-like toxins in Bt S2160-1. This research may lay the foundation for future functional analysis of Bt S2160-1 toxin proteins to reveal their biological roles.
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Affiliation(s)
- Panpan Liu
- 1Northeast Forestry University, Harbin, 150040 China
| | - Yan Zhou
- 2College of Life Sciences and Technology, Guangxi University, Guangxi, China
- Hainan Institute of Tropical Agricultural Resources, Hainan, China
| | - Zhongqi Wu
- 1Northeast Forestry University, Harbin, 150040 China
- Hainan Institute of Tropical Agricultural Resources, Hainan, China
| | - Hao Zhong
- 2College of Life Sciences and Technology, Guangxi University, Guangxi, China
| | - Yanjun Wei
- School of Life Science and Technology, Harbin Institute of University, Heilongjiang, China
| | - Youzhi Li
- 2College of Life Sciences and Technology, Guangxi University, Guangxi, China
| | - Shenkui Liu
- 1Northeast Forestry University, Harbin, 150040 China
| | - Yan Zhang
- School of Life Science and Technology, Harbin Institute of University, Heilongjiang, China
| | - Xuanjun Fang
- 1Northeast Forestry University, Harbin, 150040 China
- 2College of Life Sciences and Technology, Guangxi University, Guangxi, China
- Hainan Institute of Tropical Agricultural Resources, Hainan, China
- 4Institute of Life Science, Jiyang College of Zhejiang A&F University, Zhejiang, China
- Cuixi Academy of Biotechnology, Zhejiang, China
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Recent advancement on chemical arsenal of Bt toxin and its application in pest management system in agricultural field. 3 Biotech 2018; 8:201. [PMID: 29607282 DOI: 10.1007/s13205-018-1223-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 03/22/2018] [Indexed: 10/17/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a Gram-positive, spore-forming, soil bacterium, which is very popular bio-control agent in agricultural and forestry. In general, B. thuringiensis secretes an array of insecticidal proteins including toxins produced during vegetative growth phase (such as secreted insecticidal protein, Sip; vegetative insecticidal proteins, Vip), parasporal crystalline δ-endotoxins produced during vegetative stationary phase (such as cytolytic toxin, Cyt; and crystal toxin, Cry), and β-exotoxins. Till date, a wide spectrum of Cry proteins has been reported and most of them belong to three-domain-Cry toxins, Bin-like toxin, and Etx_Mtx2-like toxins. To the best of our knowledge, neither Bt insecticidal toxins are exclusive to Bt nor all the strains of Bt are capable of producing insecticidal Bt toxins. The lacuna in their latest classification has also been discussed. In this review, the updated information regarding the insecticidal Bt toxins and their different mode of actions were summarized. Before applying the Bt toxins on agricultural field, the non-specific effects of toxins should be investigated. We also have summarized the problem of insect resistance and the strategies to combat with this problem. We strongly believe that this information will help a lot to the budding researchers in the field of modern pest control biotechnology.
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36
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Yalpani N, Altier D, Barry J, Kassa A, Nowatzki TM, Sethi A, Zhao JZ, Diehn S, Crane V, Sandahl G, Guan R, Poland B, Perez Ortega C, Nelson ME, Xie W, Liu L, Wu G. An Alcaligenes strain emulates Bacillus thuringiensis producing a binary protein that kills corn rootworm through a mechanism similar to Cry34Ab1/Cry35Ab1. Sci Rep 2017; 7:3063. [PMID: 28596570 PMCID: PMC5465095 DOI: 10.1038/s41598-017-03544-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 04/28/2017] [Indexed: 11/15/2022] Open
Abstract
Crops expressing Bacillus thuringiensis (Bt)-derived insecticidal protein genes have been commercially available for over 15 years and are providing significant value to growers. However, there remains the need for alternative insecticidal actives due to emerging insect resistance to certain Bt proteins. A screen of bacterial strains led to the discovery of a two-component insecticidal protein named AfIP-1A/1B from an Alcaligenes faecalis strain. This protein shows selectivity against coleopteran insects including western corn rootworm (WCR). Transgenic maize plants expressing AfIP-1A/1B demonstrate strong protection from rootworm injury. Surprisingly, although little sequence similarity exists to known insecticidal proteins, efficacy tests using WCR populations resistant to two different Cry proteins show that AfIP-1A/1B and mCry3A differ in their mode of action while AfIP-1A/1B and the binary Cry34Ab1/Cry35Ab1 protein share a similar mode. These findings are supported by results of competitive binding assays and the similarity of the x-ray structure of AfIP-1A to Cry34Ab1. Our work indicates that insecticidal proteins obtained from a non-Bt bacterial source can be useful for developing genetically modified crops and can function similarly to familiar proteins from Bt.
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Affiliation(s)
| | - Dan Altier
- DuPont Pioneer, Johnston, IA, 50131, USA
| | | | | | | | - Amit Sethi
- DuPont Pioneer, Johnston, IA, 50131, USA
| | | | | | | | | | - Rongjin Guan
- Nexomics Biosciences, Bordentown, NJ, 08505, USA
| | | | | | | | | | - Lu Liu
- DuPont Pioneer, Hayward, CA, 94545, USA
| | - Gusui Wu
- DuPont Pioneer, Johnston, IA, 50131, USA
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37
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Butala M, Novak M, Kraševec N, Skočaj M, Veranič P, Maček P, Sepčić K. Aegerolysins: Lipid-binding proteins with versatile functions. Semin Cell Dev Biol 2017; 72:142-151. [PMID: 28506897 DOI: 10.1016/j.semcdb.2017.05.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 04/13/2017] [Accepted: 05/11/2017] [Indexed: 01/21/2023]
Abstract
Proteins of the aegerolysin family span many kingdoms of life. They are relatively widely distributed in bacteria and fungi, but also appear in plants, protozoa and insects. Despite being produced in abundance in cells at specific developmental stages and present in secretomes, only a few aegerolysins have been studied in detail. In particular, their organism-specific physiological roles are intriguing. Here, we review published findings to date on the distribution, molecular interactions and biological activities of this family of structurally and functionally versatile proteins, the aegerolysins.
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Affiliation(s)
- Matej Butala
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Maruša Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Nada Kraševec
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Matej Skočaj
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
| | - Peter Veranič
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
| | - Peter Maček
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
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38
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Bowling AJ, Pence HE, Li H, Tan SY, Evans SL, Narva KE. Histopathological Effects of Bt and TcdA Insecticidal Proteins on the Midgut Epithelium of Western Corn Rootworm Larvae (Diabrotica virgifera virgifera). Toxins (Basel) 2017; 9:toxins9050156. [PMID: 28481307 PMCID: PMC5450704 DOI: 10.3390/toxins9050156] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 04/20/2017] [Accepted: 04/28/2017] [Indexed: 01/21/2023] Open
Abstract
Western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) is a major corn pest in the United States, causing annual losses of over $1 billion. One approach to protect against crop loss by this insect is the use of transgenic corn hybrids expressing one or more crystal (Cry) proteins derived from Bacillus thuringiensis. Cry34Ab1 and Cry35Ab1 together comprise a binary insecticidal toxin with specific activity against WCR. These proteins have been developed as insect resistance traits in commercialized corn hybrids resistant to WCR feeding damage. Cry34/35Ab1 is a pore forming toxin, but the specific effects of Cry34/35Ab1 on WCR cells and tissues have not been well characterized microscopically, and the overall histopathology is poorly understood. Using high-resolution resin-based histopathology methods, the effects of Cry34/35Ab1 as well as Cry3Aa1, Cry6Aa1, and the Photorhabdus toxin complex protein TcdA have been directly visualized and documented. Clear symptoms of intoxication were observed for all insecticidal proteins tested, including swelling and sloughing of enterocytes, constriction of midgut circular muscles, stem cell activation, and obstruction of the midgut lumen. These data demonstrate the effects of these insecticidal proteins on WCR midgut cells, and the collective response of the midgut to intoxication. Taken together, these results advance our understanding of the insect cell biology and pathology of these insecticidal proteins, which should further the field of insect resistance traits and corn rootworm management.
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Affiliation(s)
| | | | - Huarong Li
- Dow AgroSciences, Indianapolis, IN 46268, USA.
| | - Sek Yee Tan
- Dow AgroSciences, Indianapolis, IN 46268, USA.
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Abstract
In this review, we focus on an important aspect of ion mobility (IM) research, namely the reporting of quantitative ion mobility measurements in the form of the gas-phase collision cross section (CCS), which has provided a common basis for comparison across different instrument platforms and offers a unique form of structural information, namely size and shape preferences of analytes in the absence of bulk solvent. This review surveys the over 24,000 CCS values reported from IM methods spanning the era between 1975 to 2015, which provides both a historical and analytical context for the contributions made thus far, as well as insight into the future directions that quantitative ion mobility measurements will have in the analytical sciences. The analysis was conducted in 2016, so CCS values reported in that year are purposely omitted. In another few years, a review of this scope will be intractable, as the number of CCS values which will be reported in the next three to five years is expected to exceed the total amount currently published in the literature.
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Affiliation(s)
- Jody C May
- Department of Chemistry, Center for Innovative Technology, Vanderbilt Institute for Chemical Biology, Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University , Nashville, Tennessee 37235, United States
| | - Caleb B Morris
- Department of Chemistry, Center for Innovative Technology, Vanderbilt Institute for Chemical Biology, Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University , Nashville, Tennessee 37235, United States
| | - John A McLean
- Department of Chemistry, Center for Innovative Technology, Vanderbilt Institute for Chemical Biology, Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University , Nashville, Tennessee 37235, United States
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40
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Bachman PM, Ahmad A, Ahrens JE, Akbar W, Baum JA, Brown S, Clark TL, Fridley JM, Gowda A, Greenplate JT, Jensen PD, Mueller GM, Odegaard ML, Tan J, Uffman JP, Levine SL. Characterization of the Activity Spectrum of MON 88702 and the Plant-Incorporated Protectant Cry51Aa2.834_16. PLoS One 2017; 12:e0169409. [PMID: 28072875 PMCID: PMC5224830 DOI: 10.1371/journal.pone.0169409] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 12/16/2016] [Indexed: 11/19/2022] Open
Abstract
The spectrum of insecticidal activity of Cry51Aa2.834_16 protein targeting hemipteran and thysanopteran insect pests in cotton was characterized by selecting and screening multiple pest and non-pest species, based on representation of ecological functional groups, taxonomic relatedness (e.g. relationship to species where activity was observed), and availability for effective testing. Seven invertebrate orders, comprising 12 families and 17 representative species were screened for susceptibility to Cry51Aa2.834_16 protein and/or the ability of the protein to protect against feeding damage in laboratory, controlled environments (e.g. greenhouse/growth chamber), and/or field studies when present in cotton plants. The screening results presented for Cry51Aa2.834_16 demonstrate selective and limited activity within three insect orders. Other than Orius insidiosus, no activity was observed for Cry51Aa2.834_16 against several groups of arthropods that perform key ecological roles in some agricultural ecosystems (e.g. pollinators, decomposers, and natural enemies).
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Affiliation(s)
- Pamela M. Bachman
- Monsanto Company, St. Louis, Missouri, United States of America
- * E-mail: (PMB); (AA)
| | - Aqeel Ahmad
- Monsanto Company, St. Louis, Missouri, United States of America
- * E-mail: (PMB); (AA)
| | | | - Waseem Akbar
- Monsanto Company, Chesterfield, Missouri, United States of America
| | - James A. Baum
- Monsanto Company, Chesterfield, Missouri, United States of America
| | - Scott Brown
- Monsanto Company, Chesterfield, Missouri, United States of America
| | - Thomas L. Clark
- Monsanto Company, Chesterfield, Missouri, United States of America
| | | | - Anilkumar Gowda
- Monsanto Company, Chesterfield, Missouri, United States of America
| | | | - Peter D. Jensen
- Monsanto Company, St. Louis, Missouri, United States of America
| | | | | | - Jianguo Tan
- Monsanto Company, St. Louis, Missouri, United States of America
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41
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Structural classification of insecticidal proteins – Towards an in silico characterisation of novel toxins. J Invertebr Pathol 2017; 142:16-22. [DOI: 10.1016/j.jip.2016.07.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/01/2016] [Accepted: 07/28/2016] [Indexed: 11/23/2022]
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42
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Moar WJ, Evans AJ, Kessenich CR, Baum JA, Bowen DJ, Edrington TC, Haas JA, Kouadio JLK, Roberts JK, Silvanovich A, Yin Y, Weiner BE, Glenn KC, Odegaard ML. The sequence, structural, and functional diversity within a protein family and implications for specificity and safety: The case for ETX_MTX2 insecticidal proteins. J Invertebr Pathol 2017; 142:50-59. [DOI: 10.1016/j.jip.2016.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 11/26/2022]
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43
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Colletier JP, Sawaya MR, Gingery M, Rodriguez JA, Cascio D, Brewster AS, Michels-Clark T, Hice RH, Coquelle N, Boutet S, Williams GJ, Messerschmidt M, DePonte DP, Sierra RG, Laksmono H, Koglin JE, Hunter MS, Park HW, Uervirojnangkoorn M, Bideshi DK, Brunger AT, Federici BA, Sauter NK, Eisenberg DS. De novo phasing with X-ray laser reveals mosquito larvicide BinAB structure. Nature 2016; 539:43-47. [PMID: 27680699 PMCID: PMC5161637 DOI: 10.1038/nature19825] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 09/07/2016] [Indexed: 11/30/2022]
Abstract
BinAB is a naturally occurring paracrystalline larvicide distributed worldwide to combat the devastating diseases borne by mosquitoes. These crystals are composed of homologous molecules, BinA and BinB, which play distinct roles in the multi-step intoxication process, transforming from harmless, robust crystals, to soluble protoxin heterodimers, to internalized mature toxin, and finally toxic oligomeric pores. The small size of the crystals, 50 unit cells per edge, on average, has impeded structural characterization by conventional means. Here, we report the structure of BinAB solved de novo by serial-femtosecond crystallography at an X-ray free-electron laser (XFEL). The structure reveals tyrosine and carboxylate-mediated contacts acting as pH switches to release soluble protoxin in the alkaline larval midgut. An enormous heterodimeric interface appears responsible for anchoring BinA to receptor-bound BinB for co-internalization. Remarkably, this interface is largely composed of propeptides, suggesting that proteolytic maturation would trigger dissociation of the heterodimer and progression to pore formation.
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Affiliation(s)
| | - Michael R Sawaya
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California, Los Angeles, California 90095-1570, USA.,Howard Hughes Medical Institute, University of California, Los Angeles, California 90095-1570, USA
| | - Mari Gingery
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California, Los Angeles, California 90095-1570, USA
| | - Jose A Rodriguez
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California, Los Angeles, California 90095-1570, USA
| | - Duilio Cascio
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California, Los Angeles, California 90095-1570, USA
| | - Aaron S Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Tara Michels-Clark
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Robert H Hice
- Department of Entomology and Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, California 92521, USA
| | - Nicolas Coquelle
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Garth J Williams
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Marc Messerschmidt
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Daniel P DePonte
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Raymond G Sierra
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Hartawan Laksmono
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Jason E Koglin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Mark S Hunter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Hyun-Woo Park
- Department of Entomology and Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, California 92521, USA.,Department of Biological Sciences, California Baptist University, Riverside, California 92504, USA
| | - Monarin Uervirojnangkoorn
- Molecular and Cellular Physiology, and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - Dennis K Bideshi
- Department of Entomology and Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, California 92521, USA.,Department of Biological Sciences, California Baptist University, Riverside, California 92504, USA
| | - Axel T Brunger
- Molecular and Cellular Physiology, and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - Brian A Federici
- Department of Entomology and Graduate Program in Cell, Molecular and Developmental Biology, University of California, Riverside, California 92521, USA
| | - Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - David S Eisenberg
- UCLA-DOE Institute for Genomics and Proteomics, Department of Biological Chemistry, University of California, Los Angeles, California 90095-1570, USA.,Howard Hughes Medical Institute, University of California, Los Angeles, California 90095-1570, USA
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44
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Dementiev A, Board J, Sitaram A, Hey T, Kelker MS, Xu X, Hu Y, Vidal-Quist C, Chikwana V, Griffin S, McCaskill D, Wang NX, Hung SC, Chan MK, Lee MM, Hughes J, Wegener A, Aroian RV, Narva KE, Berry C. The pesticidal Cry6Aa toxin from Bacillus thuringiensis is structurally similar to HlyE-family alpha pore-forming toxins. BMC Biol 2016; 14:71. [PMID: 27576487 PMCID: PMC5004264 DOI: 10.1186/s12915-016-0295-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/10/2016] [Indexed: 12/02/2022] Open
Abstract
Background The Cry6 family of proteins from Bacillus thuringiensis represents a group of powerful toxins with great potential for use in the control of coleopteran insects and of nematode parasites of importance to agriculture. These proteins are unrelated to other insecticidal toxins at the level of their primary sequences and the structure and function of these proteins has been poorly studied to date. This has inhibited our understanding of these toxins and their mode of action, along with our ability to manipulate the proteins to alter their activity to our advantage. To increase our understanding of their mode of action and to facilitate further development of these proteins we have determined the structure of Cry6Aa in protoxin and trypsin-activated forms and demonstrated a pore-forming mechanism of action. Results The two forms of the toxin were resolved to 2.7 Å and 2.0 Å respectively and showed very similar structures. Cry6Aa shows structural homology to a known class of pore-forming toxins including hemolysin E from Escherichia coli and two Bacillus cereus proteins: the hemolytic toxin HblB and the NheA component of the non-hemolytic toxin (pfam05791). Cry6Aa also shows atypical features compared to other members of this family, including internal repeat sequences and small loop regions within major alpha helices. Trypsin processing was found to result in the loss of some internal sequences while the C-terminal region remains disulfide-linked to the main core of the toxin. Based on the structural similarity of Cry6Aa to other toxins, the mechanism of action of the toxin was probed and its ability to form pores in vivo in Caenorhabditis elegans was demonstrated. A non-toxic mutant was also produced, consistent with the proposed pore-forming mode of action. Conclusions Cry6 proteins are members of the alpha helical pore-forming toxins – a structural class not previously recognized among the Cry toxins of B. thuringiensis and representing a new paradigm for nematocidal and insecticidal proteins. Elucidation of both the structure and the pore-forming mechanism of action of Cry6Aa now opens the way to more detailed analysis of toxin specificity and the development of new toxin variants with novel activities. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0295-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Jason Board
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff, CF15 8FA, UK
| | - Anand Sitaram
- University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA, 01605-2377, USA
| | - Timothy Hey
- Dow AgroSciences, LLC, Indianapolis, IN, USA.,Present address: Indiana State Department of Health Laboratories, Indianapolis, IN, USA
| | - Matthew S Kelker
- Dow AgroSciences, LLC, Indianapolis, IN, USA.,Present address: Xylogenics, LLC, Indianapolis, IN, USA
| | - Xiaoping Xu
- Dow AgroSciences, LLC, Indianapolis, IN, USA
| | - Yan Hu
- University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA, 01605-2377, USA
| | - Cristian Vidal-Quist
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff, CF15 8FA, UK.,Present address: Laboratorio de Interacción Planta-Insecto, Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas - CSIC, Madrid, Spain
| | | | | | | | - Nick X Wang
- Dow AgroSciences, LLC, Indianapolis, IN, USA
| | | | - Michael K Chan
- School of Life Sciences and Center of Novel Biomaterials, The Chinese University of Hong Kong, Shatin, HK SAR, China
| | - Marianne M Lee
- School of Life Sciences and Center of Novel Biomaterials, The Chinese University of Hong Kong, Shatin, HK SAR, China
| | - Jessica Hughes
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff, CF15 8FA, UK.,Present address: Antimicrobial Reference Laboratory, Southmead Hospital, Westbury-on-Trym, Bristol, BS10 5NB, UK
| | - Alice Wegener
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff, CF15 8FA, UK
| | - Raffi V Aroian
- University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA, 01605-2377, USA
| | | | - Colin Berry
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff, CF15 8FA, UK.
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45
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Buzatto D, de Castro França S, Zingaretti SM. CryGetter: a tool to automate retrieval and analysis of Cry protein data. BMC Bioinformatics 2016; 17:325. [PMID: 27578522 PMCID: PMC5004295 DOI: 10.1186/s12859-016-1207-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/24/2016] [Indexed: 11/30/2022] Open
Abstract
Background For many years, the use of chemical agents to control crop pests has been degrading the environment, bringing problems to humans and all living things. An alternative to deal with the pests is the use of biopesticides, biological agents capable of controlling these harmful organisms. One kind of biopesticide is Bacillus thuringiensis, a Gram-positive bacterium that synthesizes a protein that, when ingested by the pests, kills them and does not harm other species. Results Since the economical importance of Bacillus thuringiensis and its proteins significance, this work presents a software tool, called CryGetter, that is capable of retrieving data related to these proteins, store it and present it in a user friendly manner. The tool also aims to align the protein sequences and generate reports containing some statistical data concerning the alignments that were made. Conclusions CryGetter was created to help researchers of Bacillus thuringiensis and its proteins to speed up their data retrieval and analysis, allowing them to generate more accurate results. In this sense, the tool circumvents the error prone task of manually getting all the necessary data and processing them in various software systems to get the same result as CryGetter gets in a unique semiautomatic environment.
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Affiliation(s)
- David Buzatto
- Instituto Federal de Educação, Ciência e Tecnologia de São Paulo - IFSP, Câmpus São João da Boa Vista, Acesso Dr. João Batista Merlin, s/n, Jardim Itália, São João da Boa Vista, 13872-551, SP, Brazil.
| | - Suzelei de Castro França
- Universidade de Ribeirão Preto - UNAERP, Av. Costábile Romano, 2201, Ribeirânia, Ribeirão Preto, 14096-000, SP, Brazil
| | - Sônia Marli Zingaretti
- Universidade de Ribeirão Preto - UNAERP, Av. Costábile Romano, 2201, Ribeirânia, Ribeirão Preto, 14096-000, SP, Brazil
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46
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Berry C, Board J. The use of structural modelling to infer structure and function in biocontrol agents. J Invertebr Pathol 2016; 142:23-26. [PMID: 27498218 DOI: 10.1016/j.jip.2016.07.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 06/02/2016] [Accepted: 07/28/2016] [Indexed: 10/21/2022]
Abstract
Homology modelling can provide important insights into the structures of proteins when a related protein structure has already been solved. However, for many proteins, including a number of invertebrate-active toxins and accessory proteins, no such templates exist. In these cases, techniques of ab initio, template-independent modelling can be employed to generate models that may give insight into structure and function. In this overview, examples of both the problems and the potential benefits of ab initio techniques are illustrated. Consistent modelling results may indicate useful approximations to actual protein structures and can thus allow the generation of hypotheses regarding activity that can be tested experimentally.
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Affiliation(s)
- Colin Berry
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3AT, UK.
| | - Jason Board
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3AT, UK
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47
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Tan SY, Rangasamy M, Wang H, Vélez AM, Hasler J, McCaskill D, Xu T, Chen H, Jurzenski J, Kelker M, Xu X, Narva K, Siegfried BD. RNAi induced knockdown of a cadherin-like protein (EF531715) does not affect toxicity of Cry34/35Ab1 or Cry3Aa to Diabrotica virgifera virgifera larvae (Coleoptera: Chrysomelidae). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 75:117-124. [PMID: 27334721 DOI: 10.1016/j.ibmb.2016.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 06/06/2023]
Abstract
The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is an important maize pest throughout most of the U.S. Corn Belt. Bacillus thuringiensis (Bt) insecticidal proteins including modified Cry3Aa and Cry34/35Ab1 have been expressed in transgenic maize to protect against WCR feeding damage. To date, there is limited information regarding the WCR midgut target sites for these proteins. In this study, we examined whether a cadherin-like gene from Diabrotica virgifera virgifera (DvvCad; GenBank accession # EF531715) associated with WCR larval midgut tissue is necessary for Cry3Aa or Cry34/35Ab1 toxicity. Experiments were designed to examine the sensitivity of WCR to trypsin activated Cry3Aa and Cry34/35Ab1 after oral feeding of the DvvCad dsRNA to knockdown gene expression. Quantitative real-time PCR confirmed that DvvCad mRNA transcript levels were reduced in larvae treated with cadherin dsRNA. Relative cadherin expression by immunoblot analysis and nano-liquid chromatography - mass spectrometry (nanoLC-MS) of WCR neonate brush border membrane vesicle (BBMV) preparations exposed to DvvCad dsRNA confirmed reduced cadherin expression when compared to BBMV from untreated larvae. However, the larval mortality and growth inhibition of WCR neonates exposed to cadherin dsRNA for two days followed by feeding exposure to either Cry3Aa or Cry34/35Ab1 for four days was not significantly different to that observed in insects exposed to either Cry3Aa or Cry34/35Ab1 alone. In combination, these results suggest that cadherin is unlikely to be involved in the toxicity of Cry3Aa or Cry34/35Ab1 to WCR.
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Affiliation(s)
- Sek Yee Tan
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | | | - Haichuan Wang
- University of Nebraska-Lincoln, 103 Entomology Hall, Lincoln, NE 68583, United States
| | - Ana María Vélez
- University of Nebraska-Lincoln, 103 Entomology Hall, Lincoln, NE 68583, United States
| | - James Hasler
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | - David McCaskill
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | - Tao Xu
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | - Hong Chen
- University of Nebraska-Lincoln, 103 Entomology Hall, Lincoln, NE 68583, United States
| | - Jessica Jurzenski
- University of Nebraska-Lincoln, 103 Entomology Hall, Lincoln, NE 68583, United States
| | - Matthew Kelker
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | - Xiaoping Xu
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | - Kenneth Narva
- Dow AgroSciences, 9330 Zionsville Rd, Indianapolis, IN 46268, United States
| | - Blair D Siegfried
- University of Florida, Entomology and Nematology Department, Charles Steinmetz Hall, PO Box 110620, Gainesville, FL 32611-0620, United States.
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48
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Narva KE, Wang NX, Herman R. Safety considerations derived from Cry34Ab1/Cry35Ab1 structure and function. J Invertebr Pathol 2016; 142:27-33. [PMID: 27480405 DOI: 10.1016/j.jip.2016.07.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/15/2016] [Accepted: 07/28/2016] [Indexed: 11/16/2022]
Abstract
Insecticidal proteins developed for in-plant protection against crop pests undergo extensive safety testing during the product development process. Safety considerations for insecticidal proteins expressed in crops follow recommended, science-based guidelines and specific studies are conducted on a case by case basis. Corn events expressing Bacillus thuringiensis (Bt) Cry34Ab1 and Cry35Ab1 were developed to protect maize from Diabrotica virgifera virgifera (western corn rootworm) feeding damage. The protein crystal structures of Cry34Ab1 and Cry35Ab1 are different from the more common three-domain Cry or Vip3 proteins expressed in insect resistant maize varieties. Cry34Ab1 is a single domain protein that folds into a beta sandwich structure that resembles membrane-active proteins, including several cytolysins, from a variety of natural sources. Cry35Ab1 has two domains, one domain with structural relatedness to sugar binding motifs and a second domain with an extended beta sheet structure that is clearly related to beta pore forming proteins, some of which are insecticidal, e.g. B. sphaericus BinA/BinB. In this review we discuss Cry34Ab1/Cry35Ab1 structure and function in the context of protein safety studies for insect resistant crops.
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Affiliation(s)
- Kenneth E Narva
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, USA.
| | - Nick X Wang
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Rod Herman
- Dow AgroSciences, 9330 Zionsville Road, Indianapolis, IN 46268, USA
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49
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Can Pyramids and Seed Mixtures Delay Resistance to Bt Crops? Trends Biotechnol 2016; 34:291-302. [DOI: 10.1016/j.tibtech.2015.12.011] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 01/29/2023]
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50
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Guo QY, Hu XM, Cai QX, Yan JP, Yuan ZM. Interaction of Lysinibacillus sphaericus Cry48Aa/Cry49Aa toxin with midgut brush-border membrane fractions from Culex quinquefasciatus larvae. INSECT MOLECULAR BIOLOGY 2016; 25:163-170. [PMID: 26748768 DOI: 10.1111/imb.12209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The Cry48Aa/Cry49Aa mosquitocidal toxin from Lysinibacillus sphaericus was uniquely composed of a three-domain (Cry) toxin and binary (Bin) toxin-like protein, with high toxicity against Culex spp. However, its mode of action against the target mosquitoes is still unknown. In this study, Cry48Aa, Cry49Aa and its N- and C-terminal truncated proteins were expressed and purified, and the binding affinities of the purified proteins with midgut brush-border membrane fractions (BBMFs) from Culex quin-quefasciatus larvae were performed. The results showed that both Cry48Aa and Cry49Aa have specific and high binding affinity to BBMFs, with dissociation constants of 9.5 ± 1.8 and 25.4 ± 3.8 nM, respectively. Competition assays demonstrated that Cry49Aa C-terminal derivatives were able to bind to the BBMFs, whereas Far-Western dot blot analysis revealed that its N-terminal constructs interacted with Cry48Aa. Nevertheless, larvicidal activity was almost lost when Cry49Aa truncated proteins, either individually or in pairs, combined with Cry48Aa. It is concluded that Cry49Aa is responsible for receptor binding and interaction with Cry48Aa and plays an important role in the mechanism of action of these two-component toxins.
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Affiliation(s)
- Q-Y Guo
- College of Life and Environmental Sciences, Gannan Normal University, Ganzhou, China
| | - X-M Hu
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Q-X Cai
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - J-P Yan
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Z-M Yuan
- Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
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