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Hu H, Gao Y, Li X, Chen S, Yan S, Tian X. Identification and Nematicidal Characterization of Proteases Secreted by Endophytic Bacteria Bacillus cereus BCM2. PHYTOPATHOLOGY 2020; 110:336-344. [PMID: 31524559 DOI: 10.1094/phyto-05-19-0164-r] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The endophytic bacterium Bacillus cereus BCM2 has shown great potential as a biocontrol organism against Meloidogyne incognita, which causes severe root-knot diseases in crops. In our previous study, the metabolite of BCM2 showed high nematicidal activity against the M. incognita second-stage juveniles. However, the mechanism employed by endophytic bacteria to infect and kill nematodes is still unclear. Here, we investigate both the endophytic bacterial extracellular proteins with nematicidal activity and their mechanism of killing nematodes. The first step was detecting the nematicidal activities of crude proteins. The results show that the nematode mortality rate reached 100% within 72 h, and the crude proteins damaged both the cuticle and eggshell, before finally destroying the targets. This suggests possible proteinaceous pathogeny in BCM2. Throughout the process, the fine-detail changes in the nematode cuticle and the intestinal structure were observed using scanning electron microscopy and transmission electron microscopy. These images show that BCM2 extracellular proteins did not damage the internal organization of the nematode but did severely damage its cuticle, which led to content leakage. From the crude proteins, chitosanase, alkaline serine protease, and neutral protease were purified and identified. The M. incognita-B. cereus BCM2 microenvironment simulation demonstrates that BCM2 adheres to the surface of nematodes and helps the metabolites that were produced by BCM2 to rapidly recognize and kill M. incognita. This relationship between plants, endophytic bacteria, and nematodes offers insight into the biological mechanisms that can be utilized for of nematode management.
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Affiliation(s)
- Haijing Hu
- School of Life Sciences, Nanjing University, Nanjing, 210023, People's Republic of China
| | - Yang Gao
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, School of Life Sciences, Nanjing Normal University, Nanjing, 210046, People's Republic of China
- College of Bioscience and Bioengineering, Jiangxi Agriculture University, Nanchang, 330045, People's Republic of China
| | - Xia Li
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, School of Life Sciences, Nanjing Normal University, Nanjing, 210046, People's Republic of China
| | - Shuanglin Chen
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, School of Life Sciences, Nanjing Normal University, Nanjing, 210046, People's Republic of China
| | - Shuzhen Yan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, School of Life Sciences, Nanjing Normal University, Nanjing, 210046, People's Republic of China
| | - Xinjun Tian
- School of Life Sciences, Nanjing University, Nanjing, 210023, People's Republic of China
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, People's Republic of China
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Squeglia F, Moreira M, Ruggiero A, Berisio R. The Cell Wall Hydrolytic NlpC/P60 Endopeptidases in Mycobacterial Cytokinesis: A Structural Perspective. Cells 2019; 8:cells8060609. [PMID: 31216697 PMCID: PMC6628586 DOI: 10.3390/cells8060609] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 12/11/2022] Open
Abstract
In preparation for division, bacteria replicate their DNA and segregate the newly formed chromosomes. A division septum then assembles between the chromosomes, and the mother cell splits into two identical daughters due to septum degradation. A major constituent of bacterial septa and of the whole cell wall is peptidoglycan (PGN), an essential cell wall polymer, formed by glycan chains of β−(1-4)-linked-N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc), cross-linked by short peptide stems. Depending on the amino acid located at the third position of the peptide stem, PGN is classified as either Lys-type or meso-diaminopimelic acid (DAP)-type. Hydrolytic enzymes play a crucial role in the degradation of bacterial septa to split the cell wall material shared by adjacent daughter cells to promote their separation. In mycobacteria, a key PGN hydrolase, belonging to the NlpC/P60 endopeptidase family and denoted as RipA, is responsible for the degradation of septa, as the deletion of the gene encoding for this enzyme generates abnormal bacteria with multiple septa. This review provides an update of structural and functional data highlighting the central role of RipA in mycobacterial cytokinesis and the fine regulation of its catalytic activity, which involves multiple molecular partners.
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Affiliation(s)
- Flavia Squeglia
- Institute of Biostructures and Bioimaging (IBB), CNR, 80134 Naples, Italy.
| | - Miguel Moreira
- Institute of Biostructures and Bioimaging (IBB), CNR, 80134 Naples, Italy.
| | - Alessia Ruggiero
- Institute of Biostructures and Bioimaging (IBB), CNR, 80134 Naples, Italy.
| | - Rita Berisio
- Institute of Biostructures and Bioimaging (IBB), CNR, 80134 Naples, Italy.
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Bhat AH, Pathak D, Rao A. The alr-groEL1 operon in Mycobacterium tuberculosis: an interplay of multiple regulatory elements. Sci Rep 2017; 7:43772. [PMID: 28256563 PMCID: PMC5335608 DOI: 10.1038/srep43772] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/30/2017] [Indexed: 12/12/2022] Open
Abstract
Threonylcarbamoyladenosine is a universally conserved essential modification of tRNA that ensures translational fidelity in cellular milieu. TsaD, TsaB and TsaE are identified as tRNA-A37-threonylcarbamoyl (t6A)-transferase enzymes that have been reconstituted in vitro, in few bacteria recently. However, transcriptional organization and regulation of these genes are not known in any of these organisms. This study describes the intricate architecture of a complex multicistronic alr-groEL1 operon, harboring essential genes, namely tsaD, tsaB, tsaE, groES, groEL1, and alr (required for cell wall synthesis), and rimI encoding an N-α- acetyltransferase in Mycobacterium tuberculosis. Using northern blotting, RT-PCR and in vivo fluorescence assays, genes alr to groEL1 were found to constitute an ~6.3 kb heptacistronic operon with multiple internal promoters and an I-shaped intrinsic hairpin-like cis-regulatory element. A strong promoter PtsaD within the coding sequence of rimI gene is identified in M. tuberculosis, in addition. The study further proposes an amendment in the known bicistronic groESL1 operon annotation by providing evidence that groESL1 is co-transcribed as sub-operon of alr-groEL1 operon. The architecture of alr-groEL1 operon, conservation of the genetic context and a mosaic transcriptional profile displayed under various stress conditions convincingly suggest the involvement of this operon in stress adaptation in M. tuberculosis.
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Affiliation(s)
- Aadil H Bhat
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh-160036, India
| | - Deepika Pathak
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh-160036, India
| | - Alka Rao
- CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh-160036, India
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Teimourpour R, Sadeghian A, Meshkat Z, Esmaelizad M, Sankian M, Jabbari AR. Construction of a DNA Vaccine Encoding Mtb32C and HBHA Genes of Mycobacterium tuberculosis. Jundishapur J Microbiol 2015; 8:e21556. [PMID: 26464766 PMCID: PMC4600342 DOI: 10.5812/jjm.21556] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/14/2014] [Accepted: 10/01/2014] [Indexed: 11/23/2022] Open
Abstract
Background: Tuberculosis (TB) is a contagious disease caused by Mycobacterium tuberculosis. Development of a new vaccine for tuberculosis requires immunogenic antigens capable of inducing suitable and long-lasting T cell immunity. The emergence of multidrugs and extensively drug-resistant strains of M. tuberculosis has made it a global public health concern. Objectives: DNA vaccine is a straightforward method to introduce antigens to the host. In the present study, two immunodominant mycobacterial antigens (Mtb32C and HBHA) were isolated and cloned into pcDNA3.1 (+) to design and construct a new DNA vaccine. This vector is capable of producing new potent chimeric protein. Materials and Methods: Mtb32C (Rv0125) and heparin-binding haemagglutinin adhesion (HBHA) genes were amplified using polymerase chain reaction (PCR) of M. tuberculosis H37Rv genome and ligated into pcDNA3.1 (+). Colony-PCR and restriction enzyme analysis were used to confirm the accuracy of the cloning procedure. Results: In the current study, recombinant pcDNA3.1 (+) vector containing Mtb32C and HBHA genes was successfully constructed. The desired size of DNA fragment was observed using single and double digestion methods. Conclusions: Mtb32C and HBHA genes were successfully isolated from H37Rv genome and cloned into an eukaryotic expression vector. This vector can be considered as a vaccine to evaluate immune responses in animal models.
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Affiliation(s)
- Roghayeh Teimourpour
- Department of Microbiology and Virology, Antimicrobial Resistance Research Center, Bu Ali Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran
| | - Ali Sadeghian
- Department of Microbiology and Virology, Antimicrobial Resistance Research Center, Bu Ali Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran
| | - Zahra Meshkat
- Department of Microbiology and Virology, Antimicrobial Resistance Research Center, Bu Ali Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran
- Corresponding author: Zahra Meshkat, Department of Microbiology and Virology, Antimicrobial Resistance Research Center, Bu Ali Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran. Tel: +98-5138002313, Fax: +98-5138002287, E-mail:
| | - Majid Esmaelizad
- Genomics and Genetic Engineering Department, Razi Vaccine and Serum Research Institute, Karaj, IR Iran
| | - Mojtaba Sankian
- Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, IR Iran
| | - Ahmad-Reza Jabbari
- Genomics and Genetic Engineering Department, Razi Vaccine and Serum Research Institute, Karaj, IR Iran
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Niu Q, Tian Y, Zhang L, Xu X, Niu X, Xia Z, Lei L, Zhang KQ, Huang X. Overexpression of the Key Virulence Proteases Bace16 and Bae16 in Bacillus nematocida B16 to Improve Its Nematocidal Activity. J Mol Microbiol Biotechnol 2012; 21:130-7. [DOI: 10.1159/000332805] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Niu Q, Huang X, Zhang L, Xu J, Yang D, Wei K, Niu X, An Z, Bennett JW, Zou C, Yang J, Zhang KQ. A Trojan horse mechanism of bacterial pathogenesis against nematodes. Proc Natl Acad Sci U S A 2010; 107:16631-6. [PMID: 20733068 PMCID: PMC2944701 DOI: 10.1073/pnas.1007276107] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the mechanisms of host-pathogen interaction can provide crucial information for successfully manipulating their relationships. Because of its genetic background and practical advantages over vertebrate model systems, the nematode Caenorhabditis elegans model has become an attractive host for studying microbial pathogenesis. Here we report a "Trojan horse" mechanism of bacterial pathogenesis against nematodes. We show that the bacterium Bacillus nematocida B16 lures nematodes by emitting potent volatile organic compounds that are much more attractive to worms than those from ordinary dietary bacteria. Seventeen B. nematocida-attractant volatile organic compounds are identified, and seven are individually confirmed to lure nematodes. Once the bacteria enter the intestine of nematodes, they secrete two proteases with broad substrate ranges but preferentially target essential intestinal proteins, leading to nematode death. This Trojan horse pattern of bacterium-nematode interaction enriches our understanding of microbial pathogenesis.
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Affiliation(s)
- Qiuhong Niu
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
- School of Life Science and Technology, Nanyang Normal University, Nanyang City, Henan 473061, People's Republic of China
| | - Xiaowei Huang
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Lin Zhang
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
| | - Dongmei Yang
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Kangbi Wei
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Xuemei Niu
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Zhiqiang An
- University of Texas Health Science Center, Houston, TX 77030; and
| | | | - Chenggang Zou
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Jinkui Yang
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
| | - Ke-Qin Zhang
- Laboratory for Conservation and Utilization of Bio-Resources and
- Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan 650091, People's Republic of China
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Ribeiro-Guimarães ML, Marengo EB, Tempone AJ, Amaral JJ, Klitzke CF, Silveira EKXD, Portaro FCV, Pessolani MCV. Cloning, expression and characterisation of an HtrA-like serine protease produced in vivo by Mycobacterium leprae. Mem Inst Oswaldo Cruz 2010; 104:1132-8. [PMID: 20140374 DOI: 10.1590/s0074-02762009000800010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Accepted: 11/30/2009] [Indexed: 11/22/2022] Open
Abstract
Members of the high temperature requirement A (HtrA) family of chaperone proteases have been shown to play a role in bacterial pathogenesis. In a recent report, we demonstrated that the gene ML0176, which codes for a predicted HtrA-like protease, a gene conserved in other species of mycobacteria, is transcribed by Mycobacterium leprae in human leprosy lesions. In the present study, the recombinant ML0176 protein was produced and its enzymatic properties investigated. M. lepraerecombinant ML0176 was able to hydrolyse a variety of synthetic and natural peptides. Similar to other HtrA proteins, this enzyme displayed maximum proteolytic activity at temperatures above 40 degrees C and was completely inactivated by aprotinin, a protease inhibitor with high selectivity for serine proteases. Finally, analysis of M. leprae ML0176 specificity suggested a broader cleavage preference than that of previously described HtrAs homologues. In summary, we have identified an HtrA-like protease in M. lepraethat may constitute a potential new target for the development of novel prophylactic and/or therapeutic strategies against mycobacterial infections.
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Ohol YM, Goetz DH, Chan K, Shiloh MU, Craik CS, Cox JS. Mycobacterium tuberculosis MycP1 protease plays a dual role in regulation of ESX-1 secretion and virulence. Cell Host Microbe 2010; 7:210-20. [PMID: 20227664 PMCID: PMC3121311 DOI: 10.1016/j.chom.2010.02.006] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 12/05/2009] [Accepted: 02/09/2010] [Indexed: 11/19/2022]
Abstract
Mycobacterium tuberculosis uses the ESX-1 secretion system to deliver virulence proteins during infection of host cells. Here we report a mechanism of posttranscriptional control of ESX-1 mediated by MycP1, a M. tuberculosis serine protease. We show that MycP1 is required for ESX-1 secretion but that, unexpectedly, genetic inactivation of MycP1 protease activity increases secretion of ESX-1 substrates. We demonstrate that EspB, an ESX-1 substrate required for secretion, is a target of MycP1 in vitro and in vivo. During macrophage infection, an inactive MycP1 protease mutant causes hyperactivation of ESX-1-stimulated innate signaling pathways. MycP1 is required for growth in mice during acute infection, while loss of its protease activity leads to attenuated virulence during chronic infection. As the key ESX-1 substrates ESAT-6 and CFP-10 are highly immunogenic, fine-tuning of their secretion by MycP1 may balance virulence and immune detection and be essential for successful maintenance of long-term M. tuberculosis infection.
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Affiliation(s)
- Yamini M Ohol
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
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Ribeiro-Guimarães ML, Pessolani MCV. Comparative genomics of mycobacterial proteases. Microb Pathog 2007; 43:173-8. [PMID: 17611072 DOI: 10.1016/j.micpath.2007.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 05/05/2007] [Accepted: 05/12/2007] [Indexed: 11/22/2022]
Abstract
Although proteases are recognized as important virulent factors in pathogenic microorganisms, little information is available so far regarding the potential role of these enzymes in diseases caused by mycobacteria. Here we use bioinformatic tools to compare the protease-coding genes present in the genome of Mycobacterium leprae, Mycobacterium tuberculosis, Mycobacterium bovis and Mycobacterium avium paratuberculosis. This analysis allowed a review of the nomenclature of the protease family present in mycobacteria. A special attention was devoted to the 'decaying genome' of M. leprae where a relatively high level of conservation of protease-coding genes was observed when compared to other genes families. A total of 39 genes out of the 49 found in M. bovis were identified in M. leprae. Of relevance, a core of well-conserved 38 protease genes shared by the four species was defined. This set of proteases is probably essential for survival in the host and disease outcome and may constitute novel targets for drug development leading to a more effective control of mycobacterial diseases.
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Affiliation(s)
- Michelle Lopes Ribeiro-Guimarães
- Laboratory of Cellular Microbiology, Department of Mycobacterioses, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brasil 4365, Manguinhos, 21040-900 Rio de Janeiro, RJ, Brazil
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