1
|
Zhou Y, Zhang W, Wan Y, Jin W, Zhang Y, Li Y, Chen B, Jiang M, Fang X. Mosquitocidal toxin-like islands in Bacillus thuringiensis S2160-1 revealed by complete-genome sequence and MS proteomic analysis. Sci Rep 2024; 14:15216. [PMID: 38956138 PMCID: PMC11219804 DOI: 10.1038/s41598-024-66048-3] [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: 12/12/2023] [Accepted: 06/26/2024] [Indexed: 07/04/2024] Open
Abstract
Here, we present the whole genome sequence of Bt S2160-1, a potential alternative to the mosquitocidal model strain, Bti. One chromosome genome and four mega-plasmids were contained in Bt S2160-1, and 13 predicted genes encoding predicted insecticidal crystal proteins were identified clustered on one plasmid pS2160-1p2 containing two pathogenic islands (PAIs) designed as PAI-1 (Cry54Ba, Cry30Ea4, Cry69Aa-like, Cry50Ba2-like, Cry4Ca1-like, Cry30Ga2, Cry71Aa-like, Cry72Aa-like, Cry70Aa-like, Cyt1Da2-like and Vpb4C1-like) and PAI-2 (Cyt1Aa-like, and Tpp80Aa1-like). The clusters appear to represent mosquitocidal toxin islands similar to pathogenicity islands. Transcription/translation of 10 of the 13 predicted genes was confirmed by whole-proteome analysis using LTQ-Orbitrap LC-MS/MS. In summary, the present study identified the existence of a mosquitocidal toxin island in Bacillus thuringiensis, and provides important genomic information for understanding the insecticidal mechanism of B. thuringiensis.
Collapse
Affiliation(s)
- Yan Zhou
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, 530006, China
| | - Wenfei Zhang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou, 571158, Hainan, China
| | - Yusong Wan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Wujun Jin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yan Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, 150001, China
| | - Youzhi Li
- Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, 530004, Guangxi, China
| | - Baoshan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Agriculture, Guangxi University, Nanning, 530004, Guangxi, China
| | - Mingguo Jiang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, 530006, China
| | - Xuanjun Fang
- Hainan Institute of Tropical Agricultural Resources, Sanya, 572025, Hainan, China.
- Institute of Life Science, Jiyang College of Zhejiang A&F University, Zhuji, 311800, Zhejiang, China.
| |
Collapse
|
2
|
Kinkar OU, Prashar A, Yadav B, Kumar A, Hadapad AB, Hire RS, Makde RD. Purification, characterization and proteolytic processing of mosquito larvicidal protein Cry11Aa from Bacillus thuringensis subsp. isralensis ISPC-12. Int J Biol Macromol 2023:124979. [PMID: 37245748 DOI: 10.1016/j.ijbiomac.2023.124979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/30/2023]
Abstract
Cry11Aa is the most potent mosquito larvicidal protein of Bacillus thuringiensis subsp. israelensis (Bti). Development of resistance against insecticidal proteins including Cry11Aa is known but no field resistance was observed with Bti. The phenomenon of increasing resistance in insect pests necessitates the development of new strategies and techniques to enhance efficacy of insecticidal proteins. Recombinant technology offers better control over the molecule and allows modification of protein to achieve maximal effect against target pests. In this study, we standardised protocol for recombinant purification of Cry11Aa. Recombinant Cry11Aa found active against larvae of Aedes and Culex mosquito species and LC50 were estimated. Detailed biophysical characterization provides crucial insights into stability and in-vitro behaviour of the recombinant Cry11Aa. Moreover, trypsin hydrolysis doesn't improve overall toxicity of recombinant Cry11Aa. Proteolytic processing suggests domain I and II are more prone to proteolysis in comparison to domain III. Significance of structural features for proteolysis of Cry11Aa was observed after performing molecular dynamics simulations. Findings reported here are contributing significantly in method for purification, understanding in-vitro behaviour and proteolytic processing of Cry11Aa which could facilitate in efficient utilisation of Bti for insect pests and vectors control.
Collapse
Affiliation(s)
- Omkar U Kinkar
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Arpit Prashar
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Beena Yadav
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Ashwani Kumar
- Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ashok B Hadapad
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ramesh S Hire
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| | - Ravindra D Makde
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, Maharashtra, India; Beamline Development and Application Section, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
| |
Collapse
|
3
|
Suárez-Barrera MO, Herrera-Pineda DF, Rondón-Villarreal P, Pinzón-Reyes EH, Ochoa R, Visser L, Rueda-Forero NJ. Toxic Determination of Cry11 Mutated Proteins Obtained Using Rational Design and Its Computational Analysis. Int J Mol Sci 2023; 24:ijms24109079. [PMID: 37240424 DOI: 10.3390/ijms24109079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/08/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Cry11 proteins are toxic to Aedes aegypti, the vector of dengue, chikungunya, and Zika viruses. Cry11Aa and Cry11Bb are protoxins, which when activated present their active-toxin form in two fragments between 30 and 35 kDa respectively. Previous studies conducted with Cry11Aa and Cry11Bb genes using DNA shuffling generated variant 8, which presented a deletion in the first 73 amino acids and one at position 572 and 9 substitutions including L553F and L556W. In this study, variant 8 mutants were constructed using site-directed mutagenesis, resulting in conversion of phenylalanine (F) and tryptophan (W) to leucine (L) at positions 553 and 556, respectively, producing the mutants 8F553L, 8W556L, and 8F553L/8W556L. Additionally, two mutants, A92D and C157R, derived from Cry11Bb were also generated. The proteins were expressed in the non-crystal strain BMB171 of Bacillus thuringiensis and subjected to median-lethal concentration (LC50) tests on first-instar larvae of A. aegypti. LC50 analysis showed that the 8F553L, 8W556L, 8F553L/8W556L, and C157R variants lost their toxic activity (>500 ng·mL-1), whereas the A92D protein presented a loss of toxicity of 11.4 times that of Cry11Bb. Cytotoxicity assays performed using variant 8, 8W556L and the controls Cry11Aa, Cry11Bb, and Cry-negative BMB171 on the colorectal cancer cell line SW480 reported 30-50% of cellular viability except for BMB171. Molecular dynamic simulations performed to identify whether the mutations at positions 553 and 556 were related to the stability and rigidity of the functional tertiary structure (domain III) of the Cry11Aa protein and variant 8 showed the importance of these mutations in specific regions for the toxic activity of Cry11 against A. aegypti. This generates pertinent knowledge for the design of Cry11 proteins and their biotechnological applications in vector-borne disease control and cancer cell lines.
Collapse
Affiliation(s)
- Miguel O Suárez-Barrera
- Facultad de Ciencias Médicas y de la Salud, Instituto de Investigación Masira, Universidad de Santander, Bucaramanga 680003, Colombia
- Max Planck Tandem Group in Nanobioengineering, Institute of Chemistry, Faculty of Natural and Exacts Sciences, University of Antioquia, Medellin 050010, Colombia
| | - Diego F Herrera-Pineda
- Facultad de Ciencias Médicas y de la Salud, Instituto de Investigación Masira, Universidad de Santander, Bucaramanga 680003, Colombia
| | - Paola Rondón-Villarreal
- Facultad de Ciencias Médicas y de la Salud, Instituto de Investigación Masira, Universidad de Santander, Bucaramanga 680003, Colombia
| | - Efraín Hernando Pinzón-Reyes
- Facultad de Ciencias Médicas y de la Salud, Instituto de Investigación Masira, Universidad de Santander, Bucaramanga 680003, Colombia
- Centro de Bioinformática, Simulación y Modelado (CBSM), School of Bioinformatic, Universidad de Talca, Talca 3465548, Chile
| | - Rodrigo Ochoa
- Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia, Medellin 050010, Colombia
| | - Lydia Visser
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9701 Groningen, The Netherlands
| | - Nohora Juliana Rueda-Forero
- Facultad de Ciencias Médicas y de la Salud, Instituto de Investigación Masira, Universidad de Santander, Bucaramanga 680003, Colombia
| |
Collapse
|
4
|
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: 45] [Impact Index Per Article: 15.0] [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.
Collapse
|
5
|
Potential for Bacillus thuringiensis and Other Bacterial Toxins as Biological Control Agents to Combat Dipteran Pests of Medical and Agronomic Importance. Toxins (Basel) 2020; 12:toxins12120773. [PMID: 33291447 PMCID: PMC7762171 DOI: 10.3390/toxins12120773] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/24/2020] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
The control of dipteran pests is highly relevant to humans due to their involvement in the transmission of serious diseases including malaria, dengue fever, Chikungunya, yellow fever, zika, and filariasis; as well as their agronomic impact on numerous crops. Many bacteria are able to produce proteins that are active against insect species. These bacteria include Bacillus thuringiensis, the most widely-studied pesticidal bacterium, which synthesizes proteins that accumulate in crystals with insecticidal properties and which has been widely used in the biological control of insects from different orders, including Lepidoptera, Coleoptera, and Diptera. In this review, we summarize all the bacterial proteins, from B. thuringiensis and other entomopathogenic bacteria, which have described insecticidal activity against dipteran pests, including species of medical and agronomic importance.
Collapse
|
6
|
Florez AM, Suarez-Barrera MO, Morales GM, Rivera KV, Orduz S, Ochoa R, Guerra D, Muskus C. Toxic Activity, Molecular Modeling and Docking Simulations of Bacillus thuringiensis Cry11 Toxin Variants Obtained via DNA Shuffling. Front Microbiol 2018; 9:2461. [PMID: 30386315 PMCID: PMC6199390 DOI: 10.3389/fmicb.2018.02461] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 09/25/2018] [Indexed: 11/23/2022] Open
Abstract
The Cry11 family belongs to a large group of δ-endotoxins that share three distinct structural domains. Among the dipteran-active toxins referred to as three-domain Cry11 toxins, the Cry11Aa protein from Bacillus thuringiensis subsp. israelensis (Bti) has been the most extensively studied. Despite the potential of Bti as an effective biological control agent, the understanding of Cry11 toxins remains incomplete. In this study, five Cry11 variants obtained via DNA shuffling displayed toxic activity against Aedes aegypti and Culex quinquefasciatus. Three of these Cry11 variants (8, 23, and 79) were characterized via 3D modeling and analysis of docking with ALP1. The relevant mutations in these variants, such as deletions, insertions and point mutations, are discussed in relation to their structural domains, toxic activities and toxin-receptor interactions. Importantly, deletion of the N-terminal segment in domain I was not associated with any change in toxic activity, and domain III exhibited higher sequence variability than domains I and II. Variant 8 exhibited up to 3.78- and 6.09-fold higher toxicity to A. aegypti than Cry11Bb and Cry11Aa, respectively. Importantly, variant 79 showed an α-helix conformation at the C-terminus and formed crystals retaining toxic activity. These findings indicate that five Cry11 variants were preferentially reassembled from the cry11Aa gene during DNA shuffling. The mutations described in loop 2 and loop 3 of domain II provide valuable information regarding the activity of Cry11 toxins against A. aegypti and C. quinquefasciatus larvae and reveal new insights into the application of directed evolution strategies to study the genetic variability of specific domains in cry11 family genes.
Collapse
Affiliation(s)
- Alvaro Mauricio Florez
- RG Microbial Ecology: Metabolism, Genomics & Evolution, Microbiomas Foundation, Chía, Colombia
| | - Miguel Orlando Suarez-Barrera
- Laboratorio de Biología Molecular y Biotecnología, Universidad de Santander, Bucaramanga, Colombia.,Escuela de Medicina, Facultad de Salud, Universidad Industrial de Santander, Bucaramanga, Colombia
| | - Gloria M Morales
- Laboratorio de Biología Molecular y Biotecnología, Universidad de Santander, Bucaramanga, Colombia
| | - Karen Viviana Rivera
- Laboratorio de Biología Molecular y Biotecnología, Universidad de Santander, Bucaramanga, Colombia
| | - Sergio Orduz
- Grupo Biologa Funcional, Laboratorio de Prospección y Diseo de Biomoléculas, Escuela de Biociencias, Universidad Nacional, Sede Medellín, Colombia
| | - Rodrigo Ochoa
- Programa de Estudio y Control de Enfermedades Tropicales PECET, Unidad de Biologa Molecular y Computacional-UBMC, Universidad de Antioquía, Medellín, Colombia
| | - Diego Guerra
- Programa de Estudio y Control de Enfermedades Tropicales PECET, Unidad de Biologa Molecular y Computacional-UBMC, Universidad de Antioquía, Medellín, Colombia
| | - Carlos Muskus
- Programa de Estudio y Control de Enfermedades Tropicales PECET, Unidad de Biologa Molecular y Computacional-UBMC, Universidad de Antioquía, Medellín, Colombia
| |
Collapse
|
7
|
DNA secondary structure formation by DNA shuffling of the conserved domains of the Cry protein of Bacillus thuringiensis. BMC BIOPHYSICS 2017; 10:4. [PMID: 28540040 PMCID: PMC5441083 DOI: 10.1186/s13628-017-0036-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 05/11/2017] [Indexed: 12/26/2022]
Abstract
Background The Cry toxins, or δ-endotoxins, are a diverse group of proteins produced by Bacillus thuringiensis. While DNA secondary structures are biologically relevant, it is unknown if such structures are formed in regions encoding conserved domains of Cry toxins under shuffling conditions. We analyzed 5 holotypes that encode Cry toxins and that grouped into 4 clusters according to their phylogenetic closeness. The mean number of DNA secondary structures that formed and the mean Gibbs free energy \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \left(\overline{\varDelta G}\right) $$\end{document}ΔG¯ were determined by an in silico analysis using different experimental DNA shuffling scenarios. In terms of spontaneity, shuffling efficiency was directly proportional to the formation of secondary structures but inversely proportional to ∆G. Results The results showed a shared thermodynamic pattern for each cluster and relationships among sequences that are phylogenetically close at the protein level. The regions of the cry11Aa, Ba and Bb genes that encode domain I showed more spontaneity and thus a greater tendency to form secondary structures (<∆G). In the region of domain III; this tendency was lower (>∆G) in the cry11Ba and Bb genes. Proteins that are phylogenetically closer to Cry11Ba and Cry11Bb, such as Cry2Aa and Cry18Aa, maintained the same thermodynamic pattern. More distant proteins, such as Cry1Aa, Cry1Ab, Cry30Aa and Cry30Ca, featured different thermodynamic patterns in their DNA. Conclusion These results suggest the presence of thermodynamic variations associated to the formation of secondary structures and an evolutionary relationship with regions that encode highly conserved domains in Cry proteins. The findings of this study may have a role in the in silico design of cry gene assembly by DNA shuffling techniques.
Collapse
|
8
|
Abstract
Many electrical properties of insect larval guts have been studied, but their importance for toxicity of the Cry-type toxins has never been reported in the literature. In the present work, we observed potential-dependent permeabilization of plasma membrane by several polycationic peptides derived from the Cry11Bb protoxin. The peptide BTM-P1d, all D-type amino acid analogue of the earlier reported peptide BTM-P1, demonstrated high membrane-permeabilizing activity in experiments with isolated rat liver mitochondria, RBC (red blood cells) and mitochondria in homogenates of Aedes aegypti larval guts. Two larger peptides, BTM-P2 and BTM-P3, as well as the Cry11Bb protoxin treated with the protease extract of mosquito larval guts showed similar effects. Only protease-resistant BTM-P1d, in comparison with other peptides, displayed A. aegypti larval toxicity. Taking into account the potential-dependent mechanism of membrane permeabilization by studied fragments of the Cry11Bb protoxin and the literature data related to the distribution of membrane and transepithelial potentials in the A. aegypti larval midgut, we suggest an electrical hypothesis of toxicity of the Cry toxins for mosquito larvae. According to this hypothesis, the electrical field distribution is one of the factors determining the midgut region most susceptible for insertion of activated toxins into the plasma membrane to form pores. In addition, potential-dependent penetration of short active toxin fragments into the epithelial cells could induce permeabilization of mitochondria and subsequent apoptosis or necrosis.
Collapse
|
9
|
Monnerat R, Martins E, Praça L, Dumas V, Berry C. Activity of a Brazilian strain of Bacillus thuringiensis israelensis against the cotton Boll Weevil Anthonomus grandis Boheman (Coleoptera: Tenebrionidae). NEOTROPICAL ENTOMOLOGY 2012; 41:62-7. [PMID: 23950011 DOI: 10.1007/s13744-011-0008-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 12/01/2011] [Indexed: 05/27/2023]
Abstract
A Brazilian Bacillus thuringiensis subspecies israelensis, toxic to Diptera, including mosquitoes, was found also to show toxicity to the coleopteran boll weevil Anthonomus grandis Boheman at an equivalent level to that of the standard coleopteran-active B. thuringiensis subspecies tenebrionis T08017. Recombinant B. thuringiensis strains expressing the individual Cyt1Aa, Cry4Aa, Cry4Ba and Cry11Aa toxins from this strain were assessed to evaluate their potential contribution to the activity against A. grandis, either alone or in combination. Whilst individual toxins produced mortality, none was sufficiently potent to allow calculation of LC50 values. Combinations of toxins were unable to attain the same potency as the parental B. thuringiensis subsp. israelensis, suggesting a major role for other factors produced by this strain.
Collapse
Affiliation(s)
- R Monnerat
- EMBRAPA Recursos Genéticos e Biotecnologia, Brasília, DF, Brasil.
| | | | | | | | | |
Collapse
|
10
|
Melnikov O, Baranes N, Einav M, Ben-Dov E, Manasherob R, Itsko M, Zaritsky A. Tandem repeats in a new toxin gene from Bacillus thuringiensis and in other cry11-like genes. J Mol Microbiol Biotechnol 2011; 20:204-10. [PMID: 21778765 DOI: 10.1159/000329824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A new gene, cry11Bb2 from a field isolate of Bacillus thuringiensis, was cloned for expression in Escherichia coli. The encoded protein, with a deduced molecular mass of 89.5 kDa, exhibits 97 and 79% identities with the overlap regions of Cry11Bb1 from B. thuringiensis ssp. medellin and Cry11Ba1 from ssp. jegathesan, respectively. It is however longer than Cry11Bb1 by 42 amino acids in its carboxy-terminus, of which 32 comprise 2 tandem repeats additional to the 5 existing in the latter polypeptide. Possible roles for this recurrent motif among Cry toxins and their accessory proteins, and for their encoding genes are proposed.
Collapse
Affiliation(s)
- Olga Melnikov
- Department of Life Sciences, Ben-Gurion University of the Negev, Be'er-Sheva, Israel
| | | | | | | | | | | | | |
Collapse
|
11
|
Liu XS, Dean DH. Redesigning Bacillus thuringiensis Cry1Aa toxin into a mosquito toxin. Protein Eng Des Sel 2006; 19:107-11. [PMID: 16436453 DOI: 10.1093/protein/gzj009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Bacillus thuringiensis crystal protein Cry1Aa is normally selectively active to caterpillar larvae. Through rational design, toxicity (microg/ml) to the mosquito Culex pipiens was introduced by selected deletions and substitutions of the loop residues of domain II. Toxicity to its natural target Manduca sexta was concomitantly abolished. The successful grafting of the alternate mosquito toxicity onto the original lepidopteran Cry1Aa toxin demonstrates the possibility of designing and engineering a desired toxicity into any toxin of a common scaffold by reshaping the receptor binding region with desired specificities.
Collapse
Affiliation(s)
- Xinyan Sylvia Liu
- Department of Biochemistry, The Ohio State University, Columbus, 43210-1292, USA
| | | |
Collapse
|
12
|
Lemeshko VV, Arias M, Orduz S. Mitochondria Permeabilization by a Novel Polycation Peptide BTM-P1. J Biol Chem 2005; 280:15579-86. [PMID: 15713682 DOI: 10.1074/jbc.m414064200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacillus thuringiensis subsp. medellin is known to produce the Cry11Bb protein of 94 kDa, which is toxic for mosquito larvae due to permeabilization of the plasma membrane of midgut epithelial cells. Earlier we found that a 2.8-kDa novel peptide BTM-P1, which was artificially synthesized taking into account the primary structure of Cry11Bb endotoxin, is active against several species of bacteria. In this work we show that BTM-P1 induces cyclosporin A-insensitive swelling of rat liver mitochondria in various salt solutions but not in the sucrose medium. Inorganic phosphate and Ca(2+) significantly increased this effect of the peptide. The uncoupling action of BTM-P1 on oxidative phosphorylation was stronger in the potassium-containing media and correlated with a decrease of the inner membrane potential of mitochondria. In isotonic KNO(3), KCl, or NH(4)NO(3) media, a complete drop of the inner membrane potential was observed at 1-2 microg/ml of the peptide. The peptide-induced swelling was increased by energization of mitochondria in the potassium-containing media, but it was inhibited in the NaNO(3), NH(4)NO(3), and Tris-NO(3) media. All mitochondrial effects of the peptide were completely prevented by adding a single N-terminal tryptophan residue to the peptide sequence. We suggest a mechanism of membrane permeabilization that includes a transmembrane- and surface potential-dependent insertion of the polycation peptide into the lipid bilayer and its oligomerization leading to formation of ion channels and also to the mitochondrial permeability transition pore opening in a cyclosporin A-insensitive manner.
Collapse
Affiliation(s)
- Victor V Lemeshko
- Escuela de Física, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Medellín, AA 3840 Medellín, Colombia.
| | | | | |
Collapse
|
13
|
Ruiz LM, Segura C, Trujillo J, Orduz S. In vivo binding of the Cry11Bb toxin of Bacillus thuringiensis subsp. medellin to the midgut of mosquito larvae (Diptera: Culicidae). Mem Inst Oswaldo Cruz 2004; 99:73-9. [PMID: 15057351 DOI: 10.1590/s0074-02762004000100013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Bacillus thuringiensis subsp. medellin produces numerous proteins among which 94 kDa known as Cry11Bb, has mosquitocidal activity. The mode of action of the Cry11 proteins has been described as similar to those of the Cry1 toxins, nevertheless, the mechanism of action is still not clear. In this study we investigated the in vivo binding of the Cry11Bb toxin to the midgut of the insect species Anopheles albimanus, Aedes aegypti, and Culex quinquefasciatus by immunohistochemical analysis. Spodoptera frugiperda was included as negative control. The Cry11Bb protein was detected on the apical microvilli of the midgut epithelial cells, mostly on the posterior midgut and gastric caeca of the three mosquito species. Additionally, the toxin was detected in the Malpighian tubules of An. albimanus, Ae. aegypti, Cx. quinquefasciatus, and in the basal membrane of the epithelial cells of Ae. aegypti midgut. No toxin accumulation was observed in the peritrophic membrane of any of the mosquito species studied. These results confirm that the primary site of action of the Cry11 toxins is the apical membrane of the midgut epithelial cells of mosquito larvae.
Collapse
Affiliation(s)
- Lina María Ruiz
- Unidad de Biotecnología y Control Biológico, Corporación para Investigaciones Biológicas, Medellín, Colombia
| | | | | | | |
Collapse
|
14
|
Yamagiwa M, Ogawa R, Yasuda K, Natsuyama H, Sen K, Sakai H. Active form of dipteran-specific insecticidal protein cryllA produced by Bacillus thuringiensis subsp. israelensis. Biosci Biotechnol Biochem 2002; 66:516-22. [PMID: 12005043 DOI: 10.1271/bbb.66.516] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The nucleotide sequence of the cry11A gene from Bacillus thuringiensis subsp. israelensis strain HD522 was analyzed and the molecular characterization of CryllA toxin was done. The 70-kDa CryllA protoxin was processed in vitro into 36- and 32-kDa fragments by trypsin and into 34- and 32-kDa fragments by gut proteases from C. pipiens. These two processed fragments are associated together to form the heterodimer. The results of the binding assay with BBMV and the bioassay toward C. pipiens larvae suggested that the heterodimer was biologically as active as the non-digested CryllA toxin and the intramolecular cleavage did not promote the insecticidal activity. These results suggested that a probable complex of the 36- or 34-kDa and 32-kDa fragments was also one of the possible active forms of Cry11A, and that the biological functions of CryllA was not essentially affected by the intramolecular cleavage of the 70-kDa protein.
Collapse
Affiliation(s)
- Masashi Yamagiwa
- Department of Bioscience and Biotechnology, Okayama University, Japan
| | | | | | | | | | | |
Collapse
|
15
|
Gutierrez P, Alzate O, Orduz S. A theoretical model of the tridimensional structure of Bacillus thuringiensis subsp. medellin Cry 11Bb toxin deduced by homology modelling. Mem Inst Oswaldo Cruz 2001; 96:357-64. [PMID: 11313644 DOI: 10.1590/s0074-02762001000300013] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cry11Bb is an insecticidal crystal protein produced by Bacillus thuringiensis subsp. medellin during its stationary phase; this partial differential-endotoxin is active against dipteran insects and has great potential for mosquito borne disease control. Here, we report the first theoretical model of the tridimensional structure of a Cry11 toxin. The tridimensional structure of the Cry11Bb toxin was obtained by homology modelling on the structures of the Cry1Aa and Cry3Aa toxins. In this work we give a brief description of our model and hypothesize the residues of the Cry11Bb toxin that could be important in receptor recognition and pore formation. This model will serve as a starting point for the design of mutagenesis experiments aimed to the improvement of toxicity, and to provide a new tool for the elucidation of the mechanism of action of these mosquitocidal proteins.
Collapse
Affiliation(s)
- P Gutierrez
- Unidad de Biotecnología y Control Biológico, Corporación para Investigaciones Biológica, Medellin, Colombia
| | | | | |
Collapse
|
16
|
Charles JF, Nielsen-LeRoux C. Mosquitocidal bacterial toxins: diversity, mode of action and resistance phenomena. Mem Inst Oswaldo Cruz 2001; 95 Suppl 1:201-6. [PMID: 11142715 DOI: 10.1590/s0074-02762000000700034] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bacteria active against dipteran larvae (mosquitoes and black flies) include a wide variety of Bacillus thuringiensis and B. sphaericus strains, as well as isolates of Brevibacillus laterosporus and Clostridium bifermentans. All display different spectra and levels of activity correlated with the nature of the toxins, mainly produced during the sporulation process. This paper describes the structure and mode of action of the main mosquitocidal toxins, in relationship with their potential use in mosquito and/or black fly larvae control. Investigations with laboratory and field colonies of mosquitoes that have become highly resistant to the B. sphaericus Bin toxin have shown that several mechanisms of resistance are involved, some affecting the toxin/receptor binding step, others unknown.
Collapse
Affiliation(s)
- J F Charles
- Bactéries et Champignons Entomopathogènes, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris, France.
| | | |
Collapse
|
17
|
Segura C, Guzman F, Patarroyo ME, Orduz S. Activation pattern and toxicity of the Cry11Bb1 toxin of Bacillus thuringiensis subsp. medellin. J Invertebr Pathol 2000; 76:56-62. [PMID: 10963404 DOI: 10.1006/jipa.2000.4945] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bacillus thuringiensis protoxins undergo proteolytic processing in the midgut of susceptible insects to become active. The ability to process the Cry11Bb1 protoxin by trypsin and Culex quinquefasciatus larval gut extracts was tested. The protease activity indicated by the appearance of proteolytic products increased with an increment in pH, with the highest activity being observed at pH 10.6. A time course study showed the proteolysis of the 94-kDa Cry11Bb protein ending with the production of fragments of relative molecular mass of 30 and 35 kDa within 5 min. In vitro, gut proteases extract cleaved the solubilized toxin between Ser59 and Ile60 and between Ala395 and Asn396, generating a 30-kDa N-terminal and a 35-kDa C-terminal fragment, respectively. Similarly, mosquito larvae processed in vivo the parasporal inclusions, generating the same fragments as those observed in vitro. The Cry11Bb1 protoxin activated with trypsin or gut proteases showed larvicidal activity against C. quinquefasciatus first instar larvae. The data suggest that gut proteases participate in the activation of CryllBbl protoxin, generating at least two different fragments on which the activity could reside.
Collapse
Affiliation(s)
- C Segura
- Unidad de Biotecnología y Control Biológico, Corporación para Investigaciones Biológicas, Medellin, Colombia
| | | | | | | |
Collapse
|
18
|
Servant P, Rosso ML, Hamon S, Poncet S, Del cluse A, Rapoport G. Production of Cry11A and Cry11Ba toxins in Bacillus sphaericus confers toxicity towards Aedes aegypti and resistant Culex populations. Appl Environ Microbiol 1999; 65:3021-6. [PMID: 10388698 PMCID: PMC91451 DOI: 10.1128/aem.65.7.3021-3026.1999] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cry11A from Bacillus thuringiensis subsp. israelensis and Cry11Ba from Bacillus thuringiensis subsp. jegathesan were introduced, separately and in combination, into the chromosome of Bacillus sphaericus 2297 by in vivo recombination. Two loci on the B. sphaericus chromosome were chosen as target sites for recombination: the binary toxin locus and the gene encoding the 36-kDa protease that may be responsible for the cleavage of the Mtx protein. Disruption of the protease gene did not increase the larvicidal activity of the recombinant strain against Aedes aegypti and Culex pipiens. Synthesis of the Cry11A and Cry11Ba toxins made the recombinant strains toxic to A. aegypti larvae to which the parental strain was not toxic. The strain containing Cry11Ba was more toxic than strains containing the added Cry11A or both Cry11A and Cry11Ba. The production of the two toxins together with the binary toxin did not significantly increase the toxicity of the recombinant strain to susceptible C. pipiens larvae. However, the production of Cry11A and/or Cry11Ba partially overcame the resistance of C. pipiens SPHAE and Culex quinquefasciatus GeoR to B. sphaericus strain 2297.
Collapse
Affiliation(s)
- P Servant
- Unité de Biochimie Microbienne, URA 1300 du Centre National de la Recherche Scientifique, Institut Pasteur, 75724 Paris, France.
| | | | | | | | | | | |
Collapse
|