1
|
Rezaei R, Moazamian E, Montazeri-Najafabady N. Parasporin-4, a novel apoptosis inducer of breast cancer cells produced by Bacillus thuringiensis. Mol Biol Rep 2023; 50:4469-4480. [PMID: 37014571 DOI: 10.1007/s11033-023-08378-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/06/2023] [Indexed: 04/05/2023]
Abstract
BACKGROUND Parasporin (PS) proteins have cytocidal activity preferential for various human malignant cells. The purpose of this investigation was to see if the PS separated from B. thuringiensis strain E8 isolate had any particular cytotoxicity against breast cancer. METHODS AND RESULTS The extracted spores-crystal proteins were solubilized and digested with proteinase K. Cytotoxicity effects were analysed by MTT assay. Caspases activities were measured using ELISA. SDS-PAGE analysis was performed for determination of molecular weight of Cry protein. Identification of extracted proteins function was evaluated by MALDI-TOF MS analysis. Breast cancer cells line (MCF-7) was highly susceptible to 1 mg/mL PS and showed apoptosis characteristics, but it has no effects on the normal cells (HEK293). Apoptosis evaluation showed that caspases 1, 3, 9 and BAX were remarkably up-regulated in cancer cells, indicating the intrinsic pathway activation in these cells. PS Size was determined using SDS-PAGE in E8 isolate as 34 kDa and a 25 kDa digested peptide was identified as PS4. The function of PS4 was reported as an ABC-transporter by spectrometry. CONCLUSION The data of the present study show that PS4 is a selective cytotoxic protein against breast cancer and a molecule with a lot of potentials for next researches.
Collapse
Affiliation(s)
- Roya Rezaei
- Department of Microbiology, College of Sciences, Agriculture and Modern Technology, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Elham Moazamian
- Department of Microbiology, College of Sciences, Agriculture and Modern Technology, Shiraz Branch, Islamic Azad University, Shiraz, Iran.
| | - Nima Montazeri-Najafabady
- Shiraz Endocrine and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
2
|
Site-Directed Mutants of Parasporin PS2Aa1 with Enhanced Cytotoxic Activity in Colorectal Cancer Cell Lines. Molecules 2022; 27:molecules27217262. [DOI: 10.3390/molecules27217262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/22/2022] [Accepted: 10/24/2022] [Indexed: 11/16/2022] Open
Abstract
Parasporin 2 has cytotoxic effects against numerous colon cancer cell lines, making it a viable alternative to traditional treatments. However, its mechanism of action and receptors remain unknown. In this study, site-directed mutagenesis was used to obtain PS2Aa1 mutants with variation in domain I at positions 256 and 257. Variants 015, 002, 3-3, 3-35, and 3-45 presented G256A, G256E, G257A, G257V, and G257E substitutions, respectively. Cytotoxicity tests were performed for the cell viability of cell lines SW480, SW620, and CaCo-2. Mutants 3-3, 3-35, and 3-45 efficiently killed the cell lines. It was found that the activated forms of caspase-3 and PARP were in higher abundance as well as increased production of γH2AX when 3-35 was used to treat CaCo-2 and SW480. To assess possible membrane-binding receptors involved in the interaction, an APN receptor blocking assay showed reduced activity of some parasporins. Hence, we performed molecular docking and molecular dynamics simulations to analyze the stability of possible interactions and identify the residues that could be involved in the protein–protein interaction of PS2Aa1 and APN. We found that residues 256 and 257 facilitate the interaction. Parasporin 3-35 is promising because it has higher cytotoxicity than PS2Aa1.
Collapse
|
3
|
Genetic Modification Approaches for Parasporins Bacillus thuringiensis Proteins with Anticancer Activity. Molecules 2021; 26:molecules26247476. [PMID: 34946558 PMCID: PMC8706377 DOI: 10.3390/molecules26247476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 11/24/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a bacterium capable of producing Cry toxins, which are recognized for their bio-controlling actions against insects. However, a few Bt strains encode proteins lacking insecticidal activity but showing cytotoxic activity against different cancer cell lines and low or no cytotoxicity toward normal human cells. A subset of Cry anticancer proteins, termed parasporins (PSs), has recently arisen as a potential alternative for cancer treatment. However, the molecular receptors that allow the binding of PSs to cells and their cytotoxic mechanisms of action have not been well established. Nonetheless, their selective cytotoxic activity against different types of cancer cell lines places PSs as a promising alternative treatment modality. In this review, we provide an overview of the classification, structures, mechanisms of action, and insights obtained from genetic modification approaches for PS proteins.
Collapse
|
4
|
Isolation of new derivatives of the 20-membered macrodiolide bispolide from Kitasatospora sp. MG372-hF19. J Antibiot (Tokyo) 2021; 75:77-85. [PMID: 34873311 DOI: 10.1038/s41429-021-00492-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 11/09/2022]
Abstract
New three macrocyclic diolides, named bispolides C-E (1-3), were isolated from a fermentation broth of the actinomycete strain MG372-hF19, which produces an indole glycoside and leptomycins as we reported previously. The absolute structures of compounds 1-3 were elucidated by NMR and X-ray crystallography. Compounds 1-3 diverge from the known nine bispolides in their different alkylation patterns on the 20-membered macrocyclic diolide skeleton and the side chain in their planar structures. Furthermore, compounds 1-3 exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci and cytotoxic activity against human cancer cell lines. Among them, compound 3 has the most potent biological activities against bacteria and tumor cells. Additionally, using a membrane-potential-sensitive fluorescence probe, we found that compounds 1-3 and elaiophylin have a similar effect on membrane potential in A549 human lung cancer cells.
Collapse
|
5
|
Pinos D, Andrés-Garrido A, Ferré J, Hernández-Martínez P. Response Mechanisms of Invertebrates to Bacillus thuringiensis and Its Pesticidal Proteins. Microbiol Mol Biol Rev 2021; 85:e00007-20. [PMID: 33504654 PMCID: PMC8549848 DOI: 10.1128/mmbr.00007-20] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Extensive use of chemical insecticides adversely affects both environment and human health. One of the most popular biological pest control alternatives is bioinsecticides based on Bacillus thuringiensis This entomopathogenic bacterium produces different protein types which are toxic to several insect, mite, and nematode species. Currently, insecticidal proteins belonging to the Cry and Vip3 groups are widely used to control insect pests both in formulated sprays and in transgenic crops. However, the benefits of B. thuringiensis-based products are threatened by insect resistance evolution. Numerous studies have highlighted that mutations in genes coding for surrogate receptors are responsible for conferring resistance to B. thuringiensis Nevertheless, other mechanisms may also contribute to the reduction of the effectiveness of B. thuringiensis-based products for managing insect pests and even to the acquisition of resistance. Here, we review the relevant literature reporting how invertebrates (mainly insects and Caenorhabditis elegans) respond to exposure to B. thuringiensis as either whole bacteria, spores, and/or its pesticidal proteins.
Collapse
Affiliation(s)
- Daniel Pinos
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| | - Ascensión Andrés-Garrido
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| | - Juan Ferré
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| | - Patricia Hernández-Martínez
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| |
Collapse
|
6
|
Zhao XD, Zhang BW, Fu LJ, Li QL, Lin Y, Yu XQ. Possible Insecticidal Mechanism of Cry41-Related Toxin against Myzus persicae by Enhancing Cathepsin B Activity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:4607-4615. [PMID: 32227950 DOI: 10.1021/acs.jafc.0c01020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cry toxins produced by Bacillus thuringiensis are well known for their high insecticidal activities against Lepidoptera, Diptera, and Coleoptera; however, their activities against Aphididae are very low. Recently, it has been reported that a Cry41-related toxin exhibited moderate activity against the aphid Myzus persicae, and thus, it is highly desirable to uncover its unique mechanism. In this paper, we report that Cathepsin B, calcium-transporting ATPase, and symbiotic bacterial-associated protein ATP-dependent-6-phosphofructokinase were pulled down from the homogenate of M. persicae as unique proteins that possibly bound to Cry41-related toxin. Cathepsin B has been reported to cleave and inactivate antiapoptotic proteins and plays a role in caspase-initiated apoptotic cascades. In this study, Cathepsin B was expressed in Escherichia coli and purified, and in vitro interaction between recombinant Cathepsin B and Cry41-related toxin was demonstrated. Interestingly, we found that addition of Cry41-related toxin obviously enhanced Cathepsin B activity. We propose a model for the mechanism of Cry41-related toxin as follows: Cry41-related toxin enters the aphid cells and enhances Cathepsin B activity, resulting in acceleration of apoptosis of aphid cells.
Collapse
Affiliation(s)
- Xiao-Di Zhao
- Fujian Provincial Key Laboratory of Biochemical Technology (Huaqiao University), Department of Bioengineering & Biotechnology, College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Bin-Wu Zhang
- Fujian Provincial Key Laboratory of Biochemical Technology (Huaqiao University), Department of Bioengineering & Biotechnology, College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Li-Jun Fu
- Fujian Key Laboratory of Ecology-toxicological Effects & Control for Emerging Contaminants, Putian University, Putian, Fujian 351100, PR China
| | - Qi-Lin Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Yi Lin
- Fujian Provincial Key Laboratory of Biochemical Technology (Huaqiao University), Department of Bioengineering & Biotechnology, College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Xiao-Qiang Yu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| |
Collapse
|
7
|
Differential proteolytic activation of the Bacillus thuringiensis Cry41Aa parasporin modulates its anticancer effect. Biochem J 2019; 476:3805-3816. [PMID: 31794004 DOI: 10.1042/bcj20190732] [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: 10/01/2019] [Revised: 11/29/2019] [Accepted: 12/03/2019] [Indexed: 11/17/2022]
Abstract
Bacillus thuringiensis (Bt) is a gram positive spore forming bacterium which produces intracellular protein crystals toxic to a wide variety of insect larvae and is the most commonly used biological pesticide worldwide. More recently, Bt crystal proteins known as parasporins have been discovered, that have no known insecticidal activity but target some human cancer cells exhibiting strong cytocidal activities with different toxicity spectra and varied activity levels. Parasporin-3, also called Cry41Aa, has only been shown to exhibit cytocidal activity towards HL-60 (Human promyelocytic leukemia cells) and HepG2 (Human liver cancer cells) cell lines after being proteolytically cleaved. In order to understand this activation mechanism various mutations were made in the N-terminal region of the protein and the toxicity against both HepG2 and HL-60 cell lines was evaluated. Our results indicate that only N-terminal cleavage is required for activation and that N-terminally deleted mutants show some toxicity without the need for proteolytic activation. Furthermore, we have shown that the level of toxicity towards the two cell lines depends on the protease used to activate the toxin. Proteinase K-activated toxin was significantly more toxic towards HepG2 and HL-60 than trypsin-activated toxin. N-terminal sequencing of activated toxins showed that this difference in toxicity is associated with a difference of just two amino acids (serine and alanine at positions 59 and 60, respectively) which we hypothesize occlude a binding motif.
Collapse
|
8
|
Aberkane L, Nacer-Khodja A, Djenane Z, Djouadi LN, Ouafek A, Bouslama L, Grib H, Mameri N, Nateche F, Djefal A. In Vitro Cytotoxicity of Parasporins from Native Algerian Bacillus thuringiensis Strains Against Laryngeal and Alveolar Cancers. Curr Microbiol 2019; 77:405-414. [PMID: 31844934 DOI: 10.1007/s00284-019-01841-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/04/2019] [Indexed: 10/25/2022]
Abstract
Parasporins (PS), a class of non-insecticidal and non-hemolytic crystal proteins of Bacillus thuringiensis (Bt), are being explored as promising anti-cancer agents due to their specific toxicity to cancer cells. This work is considered as a first initiative aiming at investigating Algerian soil Bt isolates' activity and cytotoxic potential against cancer cells. A total of 48 Bacillus spp. were isolated from different sites in Algeria. Phenotypic and biochemical tests, 16S rDNA molecular identification, and microscopic observation of crystal have confirmed the identification of Bt for ten strains. A screening for non-hemolytic crystalline proteins was performed. Extraction, purification, and activation of non-hemolytic proteins by chromatographic analysis yielded several polypeptides of different molecular weights. A purified PS1, with pro-protein of 81 kDa and several peptides with different molecular weights (18-58 kDa) after activation by trypsin, has been identified from the strain BDzG. The NH2-terminal sequence deciphered in BLAST analysis showed homology to a Bt PS1 protein. Moreover, the screening of parasporin-1 (PS1) gene has also been performed. Cytocidal activity against human epithelial type 2 (HEp2) cells, considered to originate from a human laryngeal carcinoma, was observed with an IC50 equal to 2.33 μg/ml, while moderate cytotoxicity against adenocarcinomic human alveolar basal epithelial (A549) cells has been shown with IC50 equal to 18.54 μg/ml. No cytotoxicity against normal cells was noted. Fluorescence microscopy revealed a condensed or fragmented chromatin indicating the apoptotic death of HEp2 cells. Thus, Bt PS-producer isolated from Algerian soil might have a potential to join the arsenal of natural anti-cancer drugs with high therapeutic potential.
Collapse
Affiliation(s)
- Lila Aberkane
- Medical Applications Department, Nuclear Applications Division, Nuclear Research Center of Algiers (CRNA), 02 Bd Frantz Fanon, P.O. Box 399, 16000, Algiers-Gare, Algiers, Algeria.,Environmental Engineering Department, National Polytechnic School of Algiers (ENP), 10 Rue des Frères Oudek, Hacène Badi, PO Box 182, 16200, El Harrach, Algiers, Algeria
| | - Assia Nacer-Khodja
- Medical Applications Department, Nuclear Applications Division, Nuclear Research Center of Algiers (CRNA), 02 Bd Frantz Fanon, P.O. Box 399, 16000, Algiers-Gare, Algiers, Algeria
| | - Zahia Djenane
- Laboratory of Cellular and Molecular Biology (LCMB), Microbiology Team, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene (USTHB), P.O. Box 32, El Alia, 16111, Bab Ezzouar, Algiers, Algeria
| | - Lydia Neila Djouadi
- Laboratory of Cellular and Molecular Biology (LCMB), Microbiology Team, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene (USTHB), P.O. Box 32, El Alia, 16111, Bab Ezzouar, Algiers, Algeria
| | - Abdelhakim Ouafek
- Medical Applications Department, Nuclear Applications Division, Nuclear Research Center of Algiers (CRNA), 02 Bd Frantz Fanon, P.O. Box 399, 16000, Algiers-Gare, Algiers, Algeria
| | - Lamjed Bouslama
- Laboratory of Bioactive Substances, Center of Biotechnology of Borj Cedria (CBBC), University of Tunis El Manar, P.O. Box 901, 2050, Hammam-Lif, Tunisia
| | - Hocine Grib
- Environmental Engineering Department, National Polytechnic School of Algiers (ENP), 10 Rue des Frères Oudek, Hacène Badi, PO Box 182, 16200, El Harrach, Algiers, Algeria
| | - Nabil Mameri
- Environmental Engineering Department, National Polytechnic School of Algiers (ENP), 10 Rue des Frères Oudek, Hacène Badi, PO Box 182, 16200, El Harrach, Algiers, Algeria
| | - Farida Nateche
- Laboratory of Cellular and Molecular Biology (LCMB), Microbiology Team, Faculty of Biological Sciences, University of Sciences and Technology of Houari Boumediene (USTHB), P.O. Box 32, El Alia, 16111, Bab Ezzouar, Algiers, Algeria
| | - Assia Djefal
- Medical Applications Department, Nuclear Applications Division, Nuclear Research Center of Algiers (CRNA), 02 Bd Frantz Fanon, P.O. Box 399, 16000, Algiers-Gare, Algiers, Algeria.
| |
Collapse
|
9
|
Wang Y, Guo W, Wu X, Zhang Y, Mannion C, Brouchkov A, Man YG, Chen T. Oncolytic Bacteria and their potential role in bacterium-mediated tumour therapy: a conceptual analysis. J Cancer 2019; 10:4442-4454. [PMID: 31528208 PMCID: PMC6746139 DOI: 10.7150/jca.35648] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/11/2019] [Indexed: 12/13/2022] Open
Abstract
As the human microbiota has been confirmed to be of great significance in maintaining health, the dominant bacteria in them have been applied as probiotics to treat various diseases. After the detection of bacteria in tumours, which had previously been considered a sterile region, these bacteria have been isolated and genetically modified for use in tumour therapy. In this review, we sum up the main types of bacteria used in tumour therapy and reveal the mechanisms of both wild type and engineered bacteria in eliminating tumour cells, providing potential possibilities for newly detected, genetically modified, tumour-associated bacteria in anti-tumour therapy.
Collapse
Affiliation(s)
- Yuqing Wang
- Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - Wenxuan Guo
- Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi 330031, PR China
| | - XiaoLi Wu
- JiangXi university of traditional Chinese medicine, College of basic medicine, Nanchang 330000, PR China
| | - Ying Zhang
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Ciaran Mannion
- Hackensack University Medical Center, Hackensack, NJ, USA
| | - Anatoli Brouchkov
- Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
- Tyumen State University, Volodarskogo 6, Tyumen 625003, Russia
| | - Yan-Gao Man
- Department of Pathology, Hackensack Meridian Health-Hackensack University Medical Center, NJ, USA
| | - Tingtao Chen
- Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi 330031, PR China
| |
Collapse
|
10
|
Crystal Protein of a Novel Bacillus thuringiensis Strain Inducing Cell Cycle Arrest and Apoptotic Cell Death in Human Leukemic Cells. Sci Rep 2019; 9:9661. [PMID: 31273223 PMCID: PMC6609778 DOI: 10.1038/s41598-019-45928-z] [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: 10/12/2018] [Accepted: 06/12/2019] [Indexed: 11/09/2022] Open
Abstract
Parasporal inclusions of a native non haemolytic Bacillus thuringiensis strain KAU 59 was screened for its cytotoxicity against human lymphocytic leukemic cell line jurkat and normal human lymphocytes. The cytotoxicity of proteinase activated and non activated solubilised parasporal inclusions against both cell lines was assessed by Cell Titer 96 Aqueous Non Radioactive Cell Proliferation Assay Kit using MTS. The 50 per cent effective concentration (EC50) values were deduced from log probit analysis at 48 h. Morphological changes associated with cytotoxicity were evaluated and molecular mechanisms of cell death were elucidated by TUNEL assay at 48 h post-inoculation. The fluorescence assisted cell sorting was done in the flow cytometer to assess the stage of cell cycle arrest. Relative quantification of caspase-3 expression in Jurkat cells treated with parasporal inclusion protein of KAU 59 was done by qRTPCR The results indicated that the protein was cytotoxic to jurkat cells at the same time non toxic to normal lymphocytes. Cytotoxicity was evident only after proteolytic activation. Apoptotic cell death was confirmed in the protein treated cells by TUNEL Assay and also up regulated caspase-3 gene expression (P < 0.001). S phase cell cycle arrest was confirmed by and fluorescence associated cell sorting.
Collapse
|
11
|
Domanska B, Fortea E, West MJ, Schwartz JL, Crickmore N. The role of membrane-bound metal ions in toxicity of a human cancer cell-active pore-forming toxin Cry41Aa from Bacillus thuringiensis. Toxicon 2019; 167:123-133. [PMID: 31181295 DOI: 10.1016/j.toxicon.2019.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/09/2019] [Accepted: 06/03/2019] [Indexed: 12/30/2022]
Abstract
Bacillus thuringiensis crystal (Cry) proteins, used for decades as insecticidal toxins, are well known to be toxic to certain insects, but not to mammals. A novel group of Cry toxins called parasporins possess a strong cytocidal activity against some human cancer cells. Cry41Aa, or parasporin3, closely resembles commercially used insecticidal toxins and yet is toxic to the human hepatic cancer cell line HepG2, disrupting membranes of susceptible cells, similar to its insecticidal counterparts. In this study, we explore the protective effect that the common divalent metal chelator EGTA exerts on Cry41Aa's activity on HepG2 cells. Our results indicate that rather than interfering with a signalling pathway as a result of chelating cations in the medium, the chelator prevented the toxin's interaction with the membrane, and thus the subsequent steps of membrane damage and p38 phosphorylation, by removing cations bound to plasma membrane components. BAPTA and DTPA also inhibited Cry41Aa toxicity but at higher concentrations. We also show for the first time that Cry41Aa induces pore formation in planar lipid bilayers. This activity is not altered by EGTA, consistent with a biological context of chelation. Salt supplementation assays identified Ca2+, Mn2+ and Zn2+ as being able to reinstate Cry41Aa activity. Our data suggest the existence of one or more metal cation-dependent receptors in the Cry41Aa mechanism of action.
Collapse
Affiliation(s)
- Barbara Domanska
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
| | - Eva Fortea
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada; Cornell Graduate School of Medical Sciences, 1300 York Avenue, New York, NY, 10065, USA
| | - Michelle J West
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Jean-Louis Schwartz
- Département de Pharmacologie et Physiologie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| |
Collapse
|
12
|
Specific Cytotoxic Effects of Parasporal Crystal Proteins Isolated from Native Saudi Arabian Bacillus thuringiensis Strains against Cervical Cancer Cells. Molecules 2019; 24:molecules24030506. [PMID: 30708936 PMCID: PMC6384957 DOI: 10.3390/molecules24030506] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 01/17/2019] [Accepted: 01/21/2019] [Indexed: 11/29/2022] Open
Abstract
Currently, global efforts are being intensified towards the discovery of local Bacillus thuringiensis (Bt) isolates with unique anticancer properties. Parasporins (PS) are a group of Bt non-insecticidal crystal proteins with potential and specific in vitro anticancer activity. However, despite the significant therapeutic potential of PS-producing Bt strains, our current knowledge on the effects of these proteins is limited. Hence, the main objective of this study was to screen Bt-derived parasporal toxins for cytotoxic activities against colon (HT-29) and cervical (HeLa) cancerous cell lines. Nine non-larvicidal and non-hemolytic Bt strains, native to Saudi Arabia, were employed for the isolation of their parasporal toxins. 16S rDNA sequencing revealed a 99.5% similarity with a reference Bt strain. While PCR screening results indicated the absence of selected Cry (Cry4A, Cry4B, Cry10 and Cry11), Cyt (Cyt1 and Cyt2) and PS (PS2, PS3 and PS4) genes, it concluded presence of the PS1 gene. SDS-PAGE analysis revealed that proteolytically-cleavaged PS protein profiles exhibit patterns resembling those observed with PS1Aa1, with major bands at 56 kDa and 17 kDa (Bt7), and 41 kDa and 16 kDa (Bt5). Solubilized and trypsinized PS proteins from all Bt strains exhibited a marked and dose-dependent cytotoxicity against HeLa cancerous cells but not against HT-29 cells. IC50 values ranged from 3.2 (Bt1) to 14.2 (Bt6) with an average of 6.8 µg/mL. The observed cytotoxicity of PS proteins against HeLa cells was specific as it was not evident against normal uterus smooth muscle cells. RT-qPCR analysis revealed the overexpression of caspase 3 and caspase 9 by 3.7, and 4.2 folds, respectively, indicative of the engagement of intrinsic pathway of apoptosis. To the best of our knowledge, this is the first report exploring and exploiting the versatile repertoire of Saudi Arabian environmental niches for the isolation of native and possibly novel Saudi Bt strains with unique and specific anticancer activity. In conclusion, native Saudi Bt-derived PS proteins might have a potential to join the arsenal of natural anticancer drugs.
Collapse
|
13
|
Velásquez Cardona LF, Rojas Torres DS, Cerón Salamanca J. TOXINAS DE Bacillus thuringiensis CON ACTIVIDAD ANTICANCERÍGENA: PARASPORINAS. REVISTA COLOMBIANA DE BIOTECNOLOGÍA 2018. [DOI: 10.15446/rev.colomb.biote.v20n2.73668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Las toxinas Cry de Bacillus thuringiensis (Bt) han sido reconocidas por su acción biocontroladora contra insectos plaga. Recientemente se ha descrito que algunas cepas de Bt presentan proteínas que no presentan actividad insecticida, pero al ser enfrentadas a líneas celulares de cáncer de diferentes tipos han demostrado actividad citotóxica. Estas proteínas han sido denominadas parasporinas (PS) y surgen como una potencial alternativa para el tratamiento del cáncer debido a que presentan alta citotoxicidad hacia diferentes líneas celulares cancerígenas, y baja o nula citotoxicidad hacia células normales.
Collapse
|
14
|
A parasporin from Bacillus thuringiensis native to Peninsular India induces apoptosis in cancer cells through intrinsic pathway. J Biosci 2018. [DOI: 10.1007/s12038-018-9759-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
15
|
Soto C, Bergado G, Blanco R, Griñán T, Rodríguez H, Ros U, Pazos F, Lanio ME, Hernández AM, Álvarez C. Sticholysin II-mediated cytotoxicity involves the activation of regulated intracellular responses that anticipates cell death. Biochimie 2018; 148:18-35. [DOI: 10.1016/j.biochi.2018.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/07/2018] [Indexed: 12/12/2022]
|
16
|
Lôme V, Brunel JM, Pagès JM, Bolla JM. Multiparametric Profiling for Identification of Chemosensitizers against Gram-Negative Bacteria. Front Microbiol 2018; 9:204. [PMID: 29556218 PMCID: PMC5845390 DOI: 10.3389/fmicb.2018.00204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 01/29/2018] [Indexed: 01/22/2023] Open
Abstract
Antibiotic resistance is now a worldwide therapeutic problem. Since the beginning of anti-infectious treatment bacteria have rapidly shown an incredible ability to develop and transfer resistance mechanisms. In the last decades, the design variation of pioneer bioactive molecules has strongly improved their activity and the pharmaceutical companies partly won the race against the clock. Since the 1980s, the new classes of antibiotics that emerged were mainly directed to Gram-positive bacteria. Thus, we are now facing to multidrug-resistant Gram-negative bacteria, with no therapeutic options to deal with them. These bacteria are mainly resistant because of their double membrane that conjointly impairs antibiotic accumulation and extrudes these molecules when entered. The main challenge is to allow antibiotics to cross the impermeable envelope and reach their targets. One promising solution would be to associate, in a combination therapy, a usual antibiotic with a non-antibiotic chemosensitizer. Nevertheless, for effective drug discovery, there is a prominent lack of tools required to understand the rules of permeation and accumulation into Gram-negative bacteria. By the use of a multidrug-resistant enterobacteria, we introduce a high-content screening procedure for chemosensitizers discovery by quantitative assessment of drug accumulation, alteration of barriers, and deduction of their activity profile. We assembled and analyzed a control chemicals library to perform the proof of concept. The analysis was based on real-time monitoring of the efflux alteration and measure of the influx increase in the presence of studied compounds in an automatized bio-assay. Then, synergistic activity of compounds with an antibiotic was studied and kinetic data reduction was performed which led to the calculation of a score for each barrier to be altered.
Collapse
Affiliation(s)
- Vincent Lôme
- UMR MD1, Aix-Marseille University, IRBA, TMCD2, Facultés de Médecine et de Pharmacie, Marseille, France
| | - Jean-Michel Brunel
- Centre de Recherche en Cancérologie de Marseille (CRCM), CNRS, UMR7258, Institut Paoli Calmettes, Aix-Marseille Université, UM 105, Inserm, U1068, Faculté de Pharmacie, Marseille, France
| | - Jean-Marie Pagès
- UMR MD1, Aix-Marseille University, IRBA, TMCD2, Facultés de Médecine et de Pharmacie, Marseille, France
| | - Jean-Michel Bolla
- UMR MD1, Aix-Marseille University, IRBA, TMCD2, Facultés de Médecine et de Pharmacie, Marseille, France
| |
Collapse
|
17
|
Soberón M, Portugal L, Garcia-Gómez BI, Sánchez J, Onofre J, Gómez I, Pacheco S, Bravo A. Cell lines as models for the study of Cry toxins from Bacillus thuringiensis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 93:66-78. [PMID: 29269111 DOI: 10.1016/j.ibmb.2017.12.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/15/2017] [Accepted: 12/16/2017] [Indexed: 06/07/2023]
Abstract
Cell lines have been use extensively for the study of the mode of action of different pore forming toxins produced by different bacterial species. Bacillus thuringiensis Cry toxins are not the exception and their mechanism of action has been analyzed in different cell lines. Here we review the data obtained with different cell lines, including those that are naturally susceptible to the three domain Cry toxins (3d-Cry) and other non-susceptible cell lines that have been transformed with 3d-Cry toxin binding molecules cloned from the susceptible insects. The effects on Cry toxin action after expressing different insect gut proteins, such as glycosyl-phosphatidyl-inositol (GPI) anchored proteins (like alkaline phosphatase (ALP) aminopeptidase (APN)), or trans-membrane proteins (like cadherin (CAD) or ATP-binding cassette subfamily C member 2 (ABCC2) transporter) in cell lines showed that, with few exceptions, expression of GPI-anchored proteins do not correlated with increased susceptibility to the toxin, while the expression of CAD or ABCC2 proteins correlated with induced susceptibility to Cry toxins in the transformed cells lines. Also, that the co-expression of CAD and ABCC2 transporter induced a synergistic effect in the toxicity of 3d-Cry toxins. Overall the data show that in susceptible cell lines, the 3d-Cry toxins induce pore formation that correlates with toxicity. However, the intracellular responses remain controversial since it was shown that the same 3d-Cry toxin in different cell lines activated different responses such as adenylate cyclase-PKA death response or apoptosis. Parasporins are Cry toxins that are toxic to cancer cell lines that have structural similarities with the insecticidal Cry toxins. They belong to the 3d-Cry toxin or to MTX-like Cry toxin families but also show important differences with the insecticidal Cry proteins. Some parasporins are pore-forming toxins, and some activate apoptosis. In this review we summarized the results of the different studies about the Cry toxins mode of action using cultured cell lines and discuss their relation with the studies performed in insect larvae.
Collapse
Affiliation(s)
- Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Leivi Portugal
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Blanca-Ines Garcia-Gómez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Jorge Sánchez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Janette Onofre
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico
| | - Isabel Gómez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Sabino Pacheco
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca 62250, Morelos, Mexico.
| |
Collapse
|
18
|
The human cancer cell active toxin Cry41Aa from Bacillus thuringiensis acts like its insecticidal counterparts. Biochem J 2017; 474:1591-1602. [PMID: 28341807 DOI: 10.1042/bcj20170122] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/20/2017] [Accepted: 03/24/2017] [Indexed: 12/15/2022]
Abstract
Understanding how certain protein toxins from the normally insecticidal bacterium Bacillus thuringiensis (Bt) target human cell lines has implications for both the risk assessment of products containing these toxins and potentially for cancer therapy. This understanding requires knowledge of whether the human cell active toxins work by the same mechanism as their insecticidal counterparts or by alternative ones. The Bt Cry41Aa (also known as Parasporin3) toxin is structurally related to the toxins synthesised by commercially produced transgenic insect-resistant plants, with the notable exception of an additional C-terminal β-trefoil ricin domain. To better understand its mechanism of action, we developed an efficient expression system for the toxin and created mutations in regions potentially involved in the toxic mechanism. Deletion of the ricin domain did not significantly affect the activity of the toxin against the human HepG2 cell line, suggesting that this region was not responsible for the mammalian specificity of Cry41Aa. Various biochemical assays suggested that unlike some other human cell active toxins from Bt Cry41Aa did not induce apoptosis, but that its mechanism of action was consistent with that of a pore-forming toxin. The toxin induced a rapid and significant decrease in metabolic activity. Adenosine triphosphate depletion, cell swelling and membrane damage were also observed. An exposed loop region believed to be involved in receptor binding of insecticidal Cry toxins was shown to be important for the activity of Cry41Aa against HepG2 cells.
Collapse
|
19
|
Akiba T, Okumura S. Parasporins 1 and 2: Their structure and activity. J Invertebr Pathol 2017; 142:44-49. [DOI: 10.1016/j.jip.2016.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 09/14/2016] [Accepted: 10/17/2016] [Indexed: 11/25/2022]
|
20
|
Anti-cancer Parasporin Toxins are Associated with Different Environments: Discovery of Two Novel Parasporin 5-like Genes. Curr Microbiol 2015; 72:184-189. [PMID: 26563301 DOI: 10.1007/s00284-015-0934-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 09/14/2015] [Indexed: 12/13/2022]
Abstract
Cry toxins are primarily a family of insecticidal toxins produced by the bacterium Bacillus thuringiensis (Bt). However, some Cry toxins, called parasporins (PSs), are non-insecticidal and have been shown to differentially kill human cancer cells. Based on amino acid homology, there are currently six different classes of parasporins (PS1-6). It is not known what role parasporins play in nature, nor if certain PSs are associated with Bt found in particular environments. Herein, we present ten parasporin-containing isolates of Bt from the Caribbean island of Trinidad. Genes coding for PS1 and PS6 were found in isolates associated mainly with artificial aquatic environments (e.g., barrels with rain water), while Bt possessing two novel PS5-like genes (ps5-1 and ps5-2), were isolated from manure collected directly from the rectum of cattle. The amino acid sequences inferred from the two PS5-like genes were 51 % homologous to each other, while being only 41 or 45 % similar to PS5Aa1/Cry64Aa, the only reported member of the parasporin five class. The low level of amino acid homology between the two PS5-like genes and PS5Aa1 indicate that the two PS5-like genes may represent a new class of parasporins, or greatly expand the level of diversity within the current parasporin 5 class.
Collapse
|
21
|
Brasseur K, Auger P, Asselin E, Parent S, Côté JC, Sirois M. Parasporin-2 from a New Bacillus thuringiensis 4R2 Strain Induces Caspases Activation and Apoptosis in Human Cancer Cells. PLoS One 2015; 10:e0135106. [PMID: 26263002 PMCID: PMC4532506 DOI: 10.1371/journal.pone.0135106] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/16/2015] [Indexed: 01/04/2023] Open
Abstract
In previous studies, parasporin-2Aa1, originally isolated from Bacillus thuringiensis strain A1547, was shown to be cytotoxic against specific human cancer cells but the mechanisms of action were not studied. In the present study, we found that proteinase K activated parasporin-2Aa1 protein isolated from a novel B. thuringiensis strain, 4R2, was specifically cytotoxic to endometrial, colon, liver, cervix, breast and prostate cancer. It showed no toxicity against normal cells. Upon treatment with proteinase K-activated parasporin-2Aa1, morphological changes were observed and western blot analysis revealed the cleavage of poly (ADP-Ribose) polymerase, caspase-3 and caspase-9 in cancer cell lines exclusively, indicative of programmed cell death, apoptosis. Flow cytometry analyses,using propidium iodide and annexin V, as well as a caspases 3/7 assay confirmed apoptosis induction. Further analyses were performed to study survival pathways, including AKT, XIAP, ERK1/2 and PAR-4, a known inducer of apoptosis. These results indicate that parasporin-2Aa1 is a selective cytotoxic protein that induces apoptosis in various human cancer cell lines from diverse tissues.
Collapse
Affiliation(s)
- Kevin Brasseur
- Research Group in Molecular Oncology and Endocrinology, Department of Medical Biology, Université du Québec à Trois-Rivières, 3351, Boul. Des Forges, CP 500, Trois-Rivières, Québec, Canada G9A 5H7
| | - Pascal Auger
- Research Group in Molecular Oncology and Endocrinology, Department of Medical Biology, Université du Québec à Trois-Rivières, 3351, Boul. Des Forges, CP 500, Trois-Rivières, Québec, Canada G9A 5H7
| | - Eric Asselin
- Research Group in Molecular Oncology and Endocrinology, Department of Medical Biology, Université du Québec à Trois-Rivières, 3351, Boul. Des Forges, CP 500, Trois-Rivières, Québec, Canada G9A 5H7
| | - Sophie Parent
- Research Group in Molecular Oncology and Endocrinology, Department of Medical Biology, Université du Québec à Trois-Rivières, 3351, Boul. Des Forges, CP 500, Trois-Rivières, Québec, Canada G9A 5H7
| | - Jean-Charles Côté
- Agriculture and Agri-Food Canada, Research Centre, 430, Boul. Gouin, Saint-Jean-sur-Richelieu, Québec, Canada J3B 3E6
| | - Marc Sirois
- Research Group in Molecular Oncology and Endocrinology, Department of Medical Biology, Université du Québec à Trois-Rivières, 3351, Boul. Des Forges, CP 500, Trois-Rivières, Québec, Canada G9A 5H7
- * E-mail:
| |
Collapse
|
22
|
Xu C, Wang BC, Yu Z, Sun M. Structural insights into Bacillus thuringiensis Cry, Cyt and parasporin toxins. Toxins (Basel) 2014; 6:2732-70. [PMID: 25229189 PMCID: PMC4179158 DOI: 10.3390/toxins6092732] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/26/2014] [Accepted: 08/28/2014] [Indexed: 11/30/2022] Open
Abstract
Since the first X-ray structure of Cry3Aa was revealed in 1991, numerous structures of B. thuringiensis toxins have been determined and published. In recent years, functional studies on the mode of action and resistance mechanism have been proposed, which notably promoted the developments of biological insecticides and insect-resistant transgenic crops. With the exploration of known pore-forming toxins (PFTs) structures, similarities between PFTs and B. thuringiensis toxins have provided great insights into receptor binding interactions and conformational changes from water-soluble to membrane pore-forming state of B. thuringiensis toxins. This review mainly focuses on the latest discoveries of the toxin working mechanism, with the emphasis on structural related progress. Based on the structural features, B. thuringiensis Cry, Cyt and parasporin toxins could be divided into three categories: three-domain type α-PFTs, Cyt toxin type β-PFTs and aerolysin type β-PFTs. Structures from each group are elucidated and discussed in relation to the latest data, respectively.
Collapse
Affiliation(s)
- Chengchen Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Bi-Cheng Wang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| | - Ziniu Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| |
Collapse
|
23
|
Argôlo-Filho RC, Loguercio LL. Bacillus thuringiensis Is an Environmental Pathogen and Host-Specificity Has Developed as an Adaptation to Human-Generated Ecological Niches. INSECTS 2013; 5:62-91. [PMID: 26462580 PMCID: PMC4592628 DOI: 10.3390/insects5010062] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 12/03/2013] [Accepted: 12/13/2013] [Indexed: 11/16/2022]
Abstract
Bacillus thuringiensis (Bt) has been used successfully as a biopesticide for more than 60 years. More recently, genes encoding their toxins have been used to transform plants and other organisms. Despite the large amount of research on this bacterium, its true ecology is still a matter of debate, with two major viewpoints dominating: while some understand Bt as an insect pathogen, others see it as a saprophytic bacteria from soil. In this context, Bt's pathogenicity to other taxa and the possibility that insects may not be the primary targets of Bt are also ideas that further complicate this scenario. The existence of conflicting research results, the difficulty in developing broader ecological and genetics studies, and the great genetic plasticity of this species has cluttered a definitive concept. In this review, we gathered information on the aspects of Bt ecology that are often ignored, in the attempt to clarify the lifestyle, mechanisms of transmission and target host range of this bacterial species. As a result, we propose an integrated view to account for Bt ecology. Although Bt is indeed a pathogenic bacterium that possesses a broad arsenal for virulence and defense mechanisms, as well as a wide range of target hosts, this seems to be an adaptation to specific ecological changes acting on a versatile and cosmopolitan environmental bacterium. Bt pathogenicity and host-specificity was favored evolutionarily by increased populations of certain insect species (or other host animals), whose availability for colonization were mostly caused by anthropogenic activities. These have generated the conditions for ecological imbalances that favored dominance of specific populations of insects, arachnids, nematodes, etc., in certain areas, with narrower genetic backgrounds. These conditions provided the selective pressure for development of new hosts for pathogenic interactions, and so, host specificity of certain strains.
Collapse
Affiliation(s)
- Ronaldo Costa Argôlo-Filho
- Department of Biological Sciences, State University of Santa Cruz (UESC), Rod, Ilhéus-Itabuna, Km-16, Ilhéus-BA 45662-900, Brazil.
| | - Leandro Lopes Loguercio
- Department of Biological Sciences, State University of Santa Cruz (UESC), Rod, Ilhéus-Itabuna, Km-16, Ilhéus-BA 45662-900, Brazil.
| |
Collapse
|
24
|
Parasporin 1Ac2, a novel cytotoxic crystal protein isolated from Bacillus thuringiensis B0462 strain. Curr Microbiol 2013; 66:475-80. [PMID: 23306354 DOI: 10.1007/s00284-013-0301-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 12/22/2012] [Indexed: 10/27/2022]
Abstract
Two novel parasporin (PS) genes were cloned from Bacillus thuringiensis B0462 strain. One was 100 % identical even in nucleotide sequence level with that of parasporin-1Aa (PS1Aa1) from B. thuringiensis A1190 strain. The other (PS1Ac2) showed significant homology (99 % identity) to that of PS1Ac1 from B. thuringiensis 87-29 strain. The 15 kDa (S(113)-R(250)) and 60 kDa (I(251)-S(777)) fragments consisting of an active form of PS1Ac2 were expressed as His-tag fusion. Upon purification under denaturing condition and refolding, the recombinant polypeptides were applied to cancer cells to analyze their cytotoxicities. 3-(4,5-Dimethyl-2-thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide assay revealed that either of 15 or 60 kDa polypeptide exhibited no cytotoxicity to HeLa cells, but they became cytotoxic upon mixed together. Our results suggested that PS1Ac2 was responsible for the cytotoxicity of B. thuringiensis B0462 strain, and that the formation of hetero-dimer of 15 and 60 kDa polypeptide was required for their cytotoxicity.
Collapse
|
25
|
Vachon V, Laprade R, Schwartz JL. Current models of the mode of action of Bacillus thuringiensis insecticidal crystal proteins: A critical review. J Invertebr Pathol 2012; 111:1-12. [DOI: 10.1016/j.jip.2012.05.001] [Citation(s) in RCA: 283] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/01/2012] [Accepted: 05/03/2012] [Indexed: 12/29/2022]
|
26
|
Okumura S, Saitoh H, Ishikawa T, Inouye K, Mizuki E. Mode of action of parasporin-4, a cytocidal protein from Bacillus thuringiensis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1476-82. [DOI: 10.1016/j.bbamem.2010.11.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 11/02/2010] [Accepted: 11/03/2010] [Indexed: 12/28/2022]
|
27
|
Yin J, Ding X, Xia L, Yu Z, Lv Y, Hu S, Huang S, Cao Z, Xiao X. Transcription of gene in an acrystalliferous strain of Bacillus thuringiensis XBU001 positively regulated by the metalloprotease camelysin gene at the onset of stationary phase. FEMS Microbiol Lett 2011; 318:92-100. [PMID: 21332578 DOI: 10.1111/j.1574-6968.2011.02247.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The calY gene, encoding metalloprotease camelysin in the Bacillus thuringiensis acrystalliferous strain XBU001, was amplified and sequenced. The camelysin from the calY sequence was 199 amino acids in size (c. 22 000 Da). The temperature-sensitive plasmid pKESX was used to construct a metalloprotease camelysin-deficient strain of B. thuringiensis. The calY gene was replaced by an erythromycin-resistant gene in KCTF. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and MS analysis showed that the metalloprotease InhA was not expressed after knocking out the gene calY. The temperature-sensitive plasmid pKPC was used to construct a metalloprotease camelysin complementation strain KCTFC. The InhA protein was found in KCTFC. Analysis of the expression of InhA in the wild-type strain KCTF12, camelysin-deficient and complementation strains indicated that inhA expression depended on camelysin. Although camelysin did not directly regulate the expression of the InhA through binding to the promoter of the inhA, the results suggest that camelysin can positively regulate the expression of the InhA protein.
Collapse
Affiliation(s)
- Jia Yin
- Key Laboratory of Microbial Molecular Biology of Hunan Province, College of Life Science, Hunan Normal University, Changsha, China
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Parasporins from a Caribbean Island: evidence for a globally dispersed Bacillus thuringiensis strain. Curr Microbiol 2011; 62:1643-8. [PMID: 21380719 DOI: 10.1007/s00284-011-9905-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 02/17/2011] [Indexed: 10/18/2022]
Abstract
Parasporins represent a new functional class of Cry (crystal protein) toxins produced by the bacterium Bacillus thuringiensis (Bt). Unlike Cry toxins that demonstrate activity mainly against some insect cells, parasporins are characterized as being non-hemolytic, yet capable of preferentially killing some human cancer cells. Globally, six different parasporin types, PS1-PS6, based on protein sequence homology, have been identified in only four countries (Japan, Vietnam, India, and Canada). Herein we report the results of a screening study of 160 Bt isolates collected from the Caribbean island of Trinidad. One isolate (strain 64-1-94) was shown to kill human cancer cells and to contain one ps6 and two ps1 parasporin genes. The two ps1 genes were located approximately 6 kb apart from each other, sharing a similar spatial arrangement, and high sequence homology, with two plasmid-located ps1 genes, ps1Aa6 and ps1Ad1, recently isolated from a Japanese strain. Evidence is also presented that a parasporin gene reported previously for a Canadian strain, ps1Aa2, is most likely derived from a recombination event between these same two genes found in the Trinidadian and Japanese strains. Notably, all three strains share a ps6 parasporin gene, presumably located on a separate plasmid. These data suggest that the global population of ps1 genes may be have originated from a single pair of parasporin genes. Given the large geographical distance between the collection sites, which are located on both continental land masses and islands at sea, ps1 genes are able to retain a remarkable level of homology not easily explained.
Collapse
|
29
|
Cancino-Rodezno A, Porta H, Soberón M, Bravo A. Defense and death responses to pore forming toxins. Biotechnol Genet Eng Rev 2009; 26:65-82. [DOI: 10.5661/bger-26-65] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
30
|
Abe Y, Shimada H, Kitada S. Raft-targeting and oligomerization of Parasporin-2, a bacillus thuringiensis crystal protein with anti-tumour activity. J Biochem 2007; 143:269-75. [PMID: 18006515 DOI: 10.1093/jb/mvm220] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Parasporin-2 is a newly classified Bacillus thuringiensis crystal toxin with strong cytocidal activities toward human liver and colon cancer cells. Similar to other insecticidal B. thuringiensis crystal toxins, parasporin-2 shows target specificity and damages the cellular membrane. However, the mode of parasporin-2 actions toward the cell membrane remains unknown. Here, we show that this anti-tumour crystal toxin targets lipid rafts and assembles into oligomeric complexes in the membrane of human hepatocyte cancer (HepG2) cells. Upon incubation with HepG2 cells, peripheral membrane-bound toxins, which were recovered in a low-density detergent-resistant membrane fraction, i.e. with lipid rafts, were transformed into heat-stable SDS-resistant membrane-embedded oligomers (approximately 200 kDa). The toxin oligomerization was dependent on temperature and coupled with cell lysis. The toxin oligomerization also occurred in a cell-free membrane system and was required for binding to membrane proteins, the lipid bilayer and cholesterols. These results indicate that parasporin-2 is an oligomerizing and pore-forming toxin that accumulates in lipid rafts.
Collapse
Affiliation(s)
- Yuichi Abe
- Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | | | | |
Collapse
|