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Zhang H, Zhang Y, Lu D, Chen X, Chen Y, Hu C, Guo A. MbovP0725, a secreted serine/threonine phosphatase, inhibits the host inflammatory response and affects metabolism in Mycoplasma bovis. mSystems 2024; 9:e0089123. [PMID: 38440990 PMCID: PMC11019793 DOI: 10.1128/msystems.00891-23] [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: 08/23/2023] [Accepted: 01/17/2024] [Indexed: 03/06/2024] Open
Abstract
Mycoplasma species are able to produce and release secreted proteins, such as toxins, adhesins, and virulence-related enzymes, involved in bacteria adhesion, invasion, and immune evasion between the pathogen and host. Here, we investigated a novel secreted protein, MbovP0725, from Mycoplasma bovis encoding a putative haloacid dehalogenase (HAD) hydrolase function of a key serine/threonine phosphatase depending on Mg2+ for the dephosphorylation of its substrate pNPP, and it was most active at pH 8 to 9 and temperatures around 40°C. A transposon insertion mutant strain of M. bovis HB0801 that lacked the protein MbovP0725 induced a stronger inflammatory response but with a partial reduction of adhesion ability. Using transcriptome sequencing and quantitative reverse transcription polymerase chain reaction analysis, we found that the mutant was upregulated by the mRNA expression of genes from the glycolysis pathway, while downregulated by the genes enriched in ABC transporters and acetate kinase-phosphate acetyltransferase pathway. Untargeted metabolomics showed that the disruption of the Mbov_0725 gene caused the accumulation of 9-hydroxyoctadecadienoic acids and the consumption of cytidine 5'-monophosphate, uridine monophosphate, and adenosine monophosphate. Both the exogenous and endogenous MbvoP0725 protein created by purification and transfection inhibited lipopolysaccharide (LPS)-induced IL-1β, IL-6, and TNF-α mRNA production and could also attenuate the activation of MAPK-associated pathways after LPS treatment. A pull-down assay identified MAPK p38 and ERK as potential substrates for MbovP0725. These findings define metabolism- and virulence-related roles for a HAD family phosphatase and reveal its ability to inhibit the host pro-inflammatory response. IMPORTANCE Mycoplasma bovis (M. bovis) infection is characterized by chronic pneumonia, otitis, arthritis, and mastitis, among others, and tends to involve the suppression of the immune response via multiple strategies to avoid host cell immune clearance. This study found that MbovP0725, a haloacid dehalogenase (HAD) family phosphatase secreted by M. bovis, had the ability to inhibit the host pro-inflammatory response induced by lipopolysaccharide. Transcriptomic and metabolomic analyses were used to identify MbovP0725 as an important phosphatase involved in glycolysis and nucleotide metabolism. The M. bovis transposon mutant strain T8.66 lacking MbovP0725 induced a higher inflammatory response and exhibited weaker adhesion to host cells. Additionally, T8.66 attenuated the phosphorylation of MAPK P38 and ERK and interacted with the two targets. These results suggested that MbovP0725 had the virulence- and metabolism-related role of a HAD family phosphatase, performing an anti-inflammatory response during M. bovis infection.
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Affiliation(s)
- Hui Zhang
- College of Animal & Veterinary Sciences, Key Laboratory of Animal Medicine of Sichuan Province, Southwest Minzu University, Chengdu, China
| | - Yiqiu Zhang
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Doukun Lu
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Xi Chen
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Yingyu Chen
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Changmin Hu
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
| | - Aizhen Guo
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Ruminant Bio-products of Ministry of Agriculture and Rural Affairs, Huazhong Agriculture University, Wuhan, China
- International Research Center for Animal Disease, Ministry of Science and Technology, Huazhong Agricultural University, Wuhan, China
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Zhu X, Baranowski E, Hao Z, Li X, Zhao G, Dong Y, Chen Y, Hu C, Chen H, Citti C, Wang A, Guo A. An atypical GdpP enzyme linking cyclic nucleotide metabolism to osmotic tolerance and gene regulation in Mycoplasma bovis. Front Microbiol 2023; 14:1250368. [PMID: 38098652 PMCID: PMC10720645 DOI: 10.3389/fmicb.2023.1250368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/10/2023] [Indexed: 12/17/2023] Open
Abstract
Nucleotide second messengers play an important role in bacterial adaptation to environmental changes. Recent evidence suggests that some of these regulatory molecular pathways were conserved upon the degenerative evolution of the wall-less mycoplasmas. We have recently reported the occurrence of a phosphodiesterase (PDE) in the ruminant pathogen Mycoplasma bovis, which was involved in c-di-AMP metabolism. In the present study, we demonstrate that the genome of this mycoplasma species encodes a PDE of the GdpP family with atypical DHH domains. Characterization of M. bovis GdpP (MbovGdpP) revealed a multifunctional PDE with unusual nanoRNase and single-stranded DNase activities. The alarmone ppGpp was found unable to inhibit c-di-NMP degradation by MbovGdpP but efficiently blocked its nanoRNase activity. Remarkably, MbovGdpP was found critical for the osmotic tolerance of M. bovis under K+ and Na+ conditions. Transcriptomic analyses further revealed the biological importance of MbovGdpP in tRNA biosynthesis, pyruvate metabolism, and several steps in genetic information processing. This study is an important step in understanding the role of PDE and nucleotide second messengers in the biology of a minimal bacterial pathogen.
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Affiliation(s)
- Xifang Zhu
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
- Longhu Laboratory of Advanced Immunology, Zhengzhou, China
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | | | - Zhiyu Hao
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xixi Li
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Gang Zhao
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yaqi Dong
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yingyu Chen
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Changmin Hu
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People’s Republic of China, Wuhan, China
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
| | | | - Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
- Longhu Laboratory of Advanced Immunology, Zhengzhou, China
| | - Aizhen Guo
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People’s Republic of China, Wuhan, China
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
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3
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Burgos R, Garcia-Ramallo E, Shaw D, Lluch-Senar M, Serrano L. Development of a Serum-Free Medium To Aid Large-Scale Production of Mycoplasma-Based Therapies. Microbiol Spectr 2023; 11:e0485922. [PMID: 37097155 PMCID: PMC10269708 DOI: 10.1128/spectrum.04859-22] [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: 11/25/2022] [Accepted: 04/03/2023] [Indexed: 04/26/2023] Open
Abstract
To assist in the advancement of the large-scale production of safe Mycoplasma vaccines and other Mycoplasma-based therapies, we developed a culture medium free of animal serum and other animal components for Mycoplasma pneumoniae growth. By establishing a workflow method to systematically test different compounds and concentrations, we provide optimized formulations capable of supporting serial passaging and robust growth reaching 60 to 70% of the biomass obtained in rich medium. Global transcriptomic and proteomic analysis showed minor physiological changes upon cell culture in the animal component-free medium, supporting its suitability for the production of M. pneumoniae-based therapies. The major contributors to growth performance were found to be glucose as a carbon source, glycerol, cholesterol, and phospholipids as a source of fatty acids. Bovine serum albumin or cyclodextrin (in the animal component-free medium) were required as lipid carriers to prevent lipid toxicity. Connaught Medical Research Laboratories medium (CMRL) used to simplify medium preparation as a source of amino acids, nucleotide precursors, vitamins, and other cofactors could be substituted by cysteine. In fact, the presence of protein hydrolysates such as yeastolate or peptones was found to be essential and preferred over free amino acids, except for the cysteine. Supplementation of nucleotide precursors and vitamins is not strictly necessary in the presence of yeastolate, suggesting that this animal origin-free hydrolysate serves as an efficient source for these compounds. Finally, we adapted the serum-free medium formulation to support growth of Mycoplasma hyopneumoniae, a swine pathogen for which inactivated whole-cell vaccines are available. IMPORTANCE Mycoplasma infections have a significant negative impact on both livestock production and human health. Vaccination is often the first option to control disease and alleviate the economic impact that some Mycoplasma infections cause on milk production, weight gain, and animal health. The fastidious nutrient requirements of these bacteria, however, challenges the industrial production of attenuated or inactivated whole-cell vaccines, which depends on the use of animal serum and other animal raw materials. Apart from their clinical relevance, some Mycoplasma species have become cellular models for systems and synthetic biology, owing to the small size of their genomes and the absence of a cell wall, which offers unique opportunities for the secretion and delivery of biotherapeutics. This study proposes medium formulations free of serum and animal components with the potential of supporting large-scale production upon industrial optimization, thus contributing to the development of safe vaccines and other Mycoplasma-based therapies.
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Affiliation(s)
- Raul Burgos
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Eva Garcia-Ramallo
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Daniel Shaw
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Maria Lluch-Senar
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Pulmobiotics Ltd., Barcelona, Spain
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
| | - Luis Serrano
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- ICREA, Barcelona, Spain
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Merker Breyer G, Malvessi Cattani A, Silveira Schrank I, Maboni Siqueira F. The influence of regulatory elements on Mycoplasma hyopneumoniae 7448 transcriptional response during oxidative stress and heat shock. Mol Biol Rep 2021; 49:139-147. [PMID: 34676505 DOI: 10.1007/s11033-021-06851-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/15/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND The comprehension of genome organization and gene modulation is essential for understanding pathogens' infection mechanisms. Mycoplasma hyopneumoniae 7448 genome is organized in transcriptional units (TUs), which are flanked by regulatory elements such as putative promoters, terminators and repetitive sequences. Yet the relationship between the presence of these elements and bacterial responses during stress conditions remains unclear. Thus, in this study, in silico and RT-qPCR analyses were associated to determine the effect of regulatory elements in gene expression regulation upon heat shock and oxidative stress conditions. METHODS AND RESULTS Thirteen TU's organizational profiles were found based on promoters and terminators distribution. Differential expression in genes sharing the same TUs was observed, suggesting the activity of internal regulatory elements. Moreover, 88.8% of tested genes were differentially expressed under oxidative stress in comparison to the control condition, being 81.3% of them surrounded by their own regulatory elements. Similarly, under heat shock, 44.4% of the genes showed regulation when compared to control condition, being 75.0% of them surrounded by their own regulatory elements. CONCLUSIONS Altogether, this data suggests the activity of internal regulatory elements in gene modulation of M. hyopneumoniae 7448 transcription.
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Affiliation(s)
- Gabriela Merker Breyer
- Laboratory of Veterinary Bacteriology, Veterinary Pathology Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Amanda Malvessi Cattani
- Graduate Program in Cell and Molecular Biology, Biotechnology Center, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Irene Silveira Schrank
- Graduate Program in Cell and Molecular Biology, Biotechnology Center, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Franciele Maboni Siqueira
- Laboratory of Veterinary Bacteriology, Veterinary Pathology Department, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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5
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Yus E, Yang JS, Sogues A, Serrano L. A reporter system coupled with high-throughput sequencing unveils key bacterial transcription and translation determinants. Nat Commun 2017; 8:368. [PMID: 28848232 PMCID: PMC5573727 DOI: 10.1038/s41467-017-00239-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 06/09/2017] [Indexed: 12/24/2022] Open
Abstract
Quantitative analysis of the sequence determinants of transcription and translation regulation is relevant for systems and synthetic biology. To identify these determinants, researchers have developed different methods of screening random libraries using fluorescent reporters or antibiotic resistance genes. Here, we have implemented a generic approach called ELM-seq (expression level monitoring by DNA methylation) that overcomes the technical limitations of such classic reporters. ELM-seq uses DamID (Escherichia coli DNA adenine methylase as a reporter coupled with methylation-sensitive restriction enzyme digestion and high-throughput sequencing) to enable in vivo quantitative analyses of upstream regulatory sequences. Using the genome-reduced bacterium Mycoplasma pneumoniae, we show that ELM-seq has a large dynamic range and causes minimal toxicity. We use ELM-seq to determine key sequences (known and putatively novel) of promoter and untranslated regions that influence transcription and translation efficiency. Applying ELM-seq to other organisms will help us to further understand gene expression and guide synthetic biology. Quantitative analysis of how DNA sequence determines transcription and translation regulation is of interest to systems and synthetic biologists. Here the authors present ELM-seq, which uses Dam activity as reporter for high-throughput analysis of promoter and 5’-UTR regions.
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Affiliation(s)
- Eva Yus
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Doctor Aiguader 88, Barcelona, 08003, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Jae-Seong Yang
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Doctor Aiguader 88, Barcelona, 08003, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Adrià Sogues
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Doctor Aiguader 88, Barcelona, 08003, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Institut Pasteur, Unité de Microbiologie Structurale (CNRS) UMR 3528, Université Paris Diderot, 25 rue du Docteur Roux, Paris, 75724, France
| | - Luis Serrano
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Doctor Aiguader 88, Barcelona, 08003, Spain. .,Universitat Pompeu Fabra (UPF), Barcelona, Spain. .,Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys 23, Barcelona, 08010, Spain.
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6
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Torres-Puig S, Broto A, Querol E, Piñol J, Pich OQ. A novel sigma factor reveals a unique regulon controlling cell-specific recombination in Mycoplasma genitalium. Nucleic Acids Res 2015; 43:4923-36. [PMID: 25925568 PMCID: PMC4446450 DOI: 10.1093/nar/gkv422] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 04/19/2015] [Indexed: 11/22/2022] Open
Abstract
The Mycoplasma genitalium MG428 protein shows homology to members of the sigma-70 family of sigma factors. Herein, we found that MG428 activates transcription of recA, ruvA and ruvB as well as several genes with unknown function. Deletion of MG_428 or some of the up-regulated unknown genes led to severe recombination defects. Single cell analyses revealed that activation of the MG428-regulon is a rare event under laboratory growth conditions. A conserved sequence with sigma-70 promoter architecture (TTGTCA-N18/19-ATTWAT) was identified in the upstream region of all of the MG428-regulated genes or operons. Primer extension analyses demonstrated that transcription initiates immediately downstream of this sigma70-type promoter in a MG428-dependent manner. Furthermore, mutagenesis of the conserved −10 and −35 elements corroborated the requirement of these regions for promoter function. Therefore, a new mycoplasma promoter directs transcription of a unique recombination regulon. Additionally, MG428 was found to interact with the RNAP core enzyme, reinforcing the predicted role of this protein as an alternative sigma factor. Finally, our results indicate that MG428 contributes to the generation of genetic diversity in this model organism. Since recombination is an important mechanism to generate antigenic variation, MG428 emerges as a novel factor contributing to M. genitalium virulence.
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Affiliation(s)
- Sergi Torres-Puig
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular. Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Alicia Broto
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular. Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Enrique Querol
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular. Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Jaume Piñol
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular. Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Oscar Q Pich
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular. Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
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Pritchard RE, Balish MF. Mycoplasma iowae: relationships among oxygen, virulence, and protection from oxidative stress. Vet Res 2015; 46:36. [PMID: 25880161 PMCID: PMC4367981 DOI: 10.1186/s13567-015-0170-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/05/2015] [Indexed: 12/20/2022] Open
Abstract
The poultry-associated bacterium Mycoplasma iowae colonizes multiple sites in embryos, with disease or death resulting. Although M. iowae accumulates in the intestinal tract, it does not cause disease at that site, but rather only in tissues that are exposed to atmospheric O2. The activity of M. iowae catalase, encoded by katE, is capable of rapid removal of damaging H2O2 from solution, and katE confers a substantial reduction in the amount of H2O2 produced by Mycoplasma gallisepticum katE transformants in the presence of glycerol. As catalase-producing bacteria are often beneficial to hosts with inflammatory bowel disease, we explored whether M. iowae was exclusively protective against H2O2-producing bacteria in a Caenorhabditis elegans model, whether its protectiveness changed in response to O2 levels, and whether expression of genes involved in H2O2 metabolism and virulence changed in response to O2 levels. We observed that M. iowae was in fact protective against H2O2-producing Streptococcus pneumoniae, but not HCN-producing Pseudomonas aeruginosa, and that M. iowae cells grown in 1% O2 promoted survival of C. elegans to a greater extent than M. iowae cells grown in atmospheric O2. Transcript levels of an M. iowae gene encoding a homolog of Mycoplasma pneumoniae CARDS toxin were 5-fold lower in cells grown in low O2. These data suggest that reduced O2, representing the intestinal environment, triggers M. iowae to reduce its virulence capabilities, effecting a change from a pathogenic mode to a potentially beneficial one.
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Affiliation(s)
- Rachel E Pritchard
- Department of Microbiology, Miami University, Oxford, OH, 45056, USA. .,Present address: Division of Natural Sciences and Mathematics, Kentucky Wesleyan College, Owensboro, KY, 42301, USA.
| | - Mitchell F Balish
- Department of Microbiology, Miami University, Oxford, OH, 45056, USA.
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8
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Lloréns-Rico V, Lluch-Senar M, Serrano L. Distinguishing between productive and abortive promoters using a random forest classifier in Mycoplasma pneumoniae. Nucleic Acids Res 2015; 43:3442-53. [PMID: 25779052 PMCID: PMC4402517 DOI: 10.1093/nar/gkv170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 02/22/2015] [Indexed: 12/01/2022] Open
Abstract
Distinguishing between promoter-like sequences in bacteria that belong to true or abortive promoters, or to those that do not initiate transcription at all, is one of the important challenges in transcriptomics. To address this problem, we have studied the genome-reduced bacterium Mycoplasma pneumoniae, for which the RNAs associated with transcriptional start sites have been recently experimentally identified. We determined the contribution to transcription events of different genomic features: the –10, extended –10 and –35 boxes, the UP element, the bases surrounding the –10 box and the nearest-neighbor free energy of the promoter region. Using a random forest classifier and the aforementioned features transformed into scores, we could distinguish between true, abortive promoters and non-promoters with good –10 box sequences. The methods used in this characterization of promoters can be extended to other bacteria and have important applications for promoter design in bacterial genome engineering.
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Affiliation(s)
- Verónica Lloréns-Rico
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), Dr Aiguader 88, 08003 Barcelona, Spain Universitat Pompeu Fabra (UPF), Dr Aiguader 88, 08003 Barcelona, Spain
| | - Maria Lluch-Senar
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), Dr Aiguader 88, 08003 Barcelona, Spain Universitat Pompeu Fabra (UPF), Dr Aiguader 88, 08003 Barcelona, Spain
| | - Luis Serrano
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), Dr Aiguader 88, 08003 Barcelona, Spain Universitat Pompeu Fabra (UPF), Dr Aiguader 88, 08003 Barcelona, Spain Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys 23, 08010 Barcelona, Spain
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9
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Burgos R, Totten PA. MG428 is a novel positive regulator of recombination that triggers mgpB and mgpC gene variation in Mycoplasma genitalium. Mol Microbiol 2014; 94:290-306. [PMID: 25138908 DOI: 10.1111/mmi.12760] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2014] [Indexed: 01/01/2023]
Abstract
The human pathogen Mycoplasma genitalium employs homologous recombination to generate antigenic diversity in the immunodominant MgpB and MgpC proteins. Only recently, some of the molecular factors involved in this process have been characterized, but nothing is known about its regulation. Here, we show that M. genitalium expresses N-terminally truncated RecA isoforms via alternative translation initiation, but only the full-length protein is essential for gene variation. We also demonstrate that overexpression of MG428 positively regulates the expression of recombination genes, including recA, ruvA, ruvB and ORF2, a gene of unknown function co-transcribed with ruvAB. The co-ordinated induction of these genes correlated with an increase of mgpBC gene variation. In contrast, cells lacking MG428 were unable to generate variants despite expressing normal levels of RecA. Similarly, deletion analyses of the recA upstream region defined sequences required for gene variation without abolishing RecA expression. The requirement of these sequences is consistent with the presence of promoter elements associated with MG428-dependent recA induction. Sequences upstream of recA also influence the relative abundance of RecA isoforms, possibly through translational regulation. Overall, these results suggest that MG428 is a positive regulator of recombination and that precise control of recA expression is required to initiate mgpBC variation.
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Affiliation(s)
- Raul Burgos
- Department of Medicine, Division of Infectious Diseases, University of Washington, Seattle, WA, 98104, USA
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10
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Characterization of the operon encoding the Holliday junction helicase RuvAB from Mycoplasma genitalium and its role in mgpB and mgpC gene variation. J Bacteriol 2014; 196:1608-18. [PMID: 24532771 DOI: 10.1128/jb.01385-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mycoplasma genitalium is an emerging sexually transmitted pathogen associated with reproductive tract disease in men and women, and it can persist for months to years despite the development of a robust antibody response. Mechanisms that may contribute to persistence in vivo include phase and antigenic variation of the MgpB and MgpC adhesins. These processes occur by segmental recombination between discrete variable regions within mgpB and mgpC and multiple archived donor sequences termed MgPa repeats (MgPars). The molecular factors governing mgpB and mgpC variation are poorly understood and obscured by the paucity of recombination genes conserved in the M. genitalium genome. Recently, we demonstrated the requirement for RecA using a quantitative PCR (qPCR) assay developed to measure recombination between the mgpB and mgpC genes and MgPars. Here, we expand these studies by examining the roles of M. genitalium ruvA and ruvB homologs. Deletion of ruvA and ruvB impaired the ability to generate mgpB and mgpC phase and sequence variants, and these deficiencies could be complemented with wild-type copies, including the ruvA gene from Mycoplasma pneumoniae. In contrast, ruvA and ruvB deletions did not affect the sensitivity to UV irradiation, reinforcing our previous findings that the recombinational repair pathway plays a minor role in M. genitalium. Reverse transcription-PCR (RT-PCR) and primer extension analyses also revealed a complex transcriptional organization of the RuvAB system of M. genitalium, which is cotranscribed with two novel open reading frames (ORFs) (termed ORF1 and ORF2 herein) conserved only in M. pneumoniae. These findings suggest that these novel ORFs may play a role in recombination in these two closely related bacteria.
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11
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Shimizu K. Metabolic Regulation of a Bacterial Cell System with Emphasis on Escherichia coli Metabolism. ISRN BIOCHEMISTRY 2013; 2013:645983. [PMID: 25937963 PMCID: PMC4393010 DOI: 10.1155/2013/645983] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 10/25/2012] [Indexed: 12/19/2022]
Abstract
It is quite important to understand the overall metabolic regulation mechanism of bacterial cells such as Escherichia coli from both science (such as biochemistry) and engineering (such as metabolic engineering) points of view. Here, an attempt was made to clarify the overall metabolic regulation mechanism by focusing on the roles of global regulators which detect the culture or growth condition and manipulate a set of metabolic pathways by modulating the related gene expressions. For this, it was considered how the cell responds to a variety of culture environments such as carbon (catabolite regulation), nitrogen, and phosphate limitations, as well as the effects of oxygen level, pH (acid shock), temperature (heat shock), and nutrient starvation.
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Affiliation(s)
- Kazuyuki Shimizu
- Kyushu Institute of Technology, Fukuoka, Iizuka 820-8502, Japan
- Institute of Advanced Bioscience, Keio University, Yamagata, Tsuruoka 997-0017, Japan
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Vinuselvi P, Kim MK, Lee SK, Ghim CM. Rewiring carbon catabolite repression for microbial cell factory. BMB Rep 2012; 45:59-70. [PMID: 22360882 DOI: 10.5483/bmbrep.2012.45.2.59] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Carbon catabolite repression (CCR) is a key regulatory system found in most microorganisms that ensures preferential utilization of energy-efficient carbon sources. CCR helps microorganisms obtain a proper balance between their metabolic capacity and the maximum sugar uptake capability. It also constrains the deregulated utilization of a preferred cognate substrate, enabling microorganisms to survive and dominate in natural environments. On the other side of the same coin lies the tenacious bottleneck in microbial production of bioproducts that employs a combination of carbon sources in varied proportion, such as lignocellulose-derived sugar mixtures. Preferential sugar uptake combined with the transcriptional and/or enzymatic exclusion of less preferred sugars turns out one of the major barriers in increasing the yield and productivity of fermentation process. Accumulation of the unused substrate also complicates the downstream processes used to extract the desired product. To overcome this difficulty and to develop tailor-made strains for specific metabolic engineering goals, quantitative and systemic understanding of the molecular interaction map behind CCR is a prerequisite. Here we comparatively review the universal and strain-specific features of CCR circuitry and discuss the recent efforts in developing synthetic cell factories devoid of CCR particularly for lignocellulose- based biorefinery.
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Affiliation(s)
- Parisutham Vinuselvi
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea
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13
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Schmidl SR, Otto A, Lluch-Senar M, Piñol J, Busse J, Becher D, Stülke J. A trigger enzyme in Mycoplasma pneumoniae: impact of the glycerophosphodiesterase GlpQ on virulence and gene expression. PLoS Pathog 2011; 7:e1002263. [PMID: 21966272 PMCID: PMC3178575 DOI: 10.1371/journal.ppat.1002263] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 07/28/2011] [Indexed: 12/31/2022] Open
Abstract
Mycoplasma pneumoniae is a causative agent of atypical pneumonia. The formation of hydrogen peroxide, a product of glycerol metabolism, is essential for host cell cytotoxicity. Phosphatidylcholine is the major carbon source available on lung epithelia, and its utilization requires the cleavage of deacylated phospholipids to glycerol-3-phosphate and choline. M. pneumoniae possesses two potential glycerophosphodiesterases, MPN420 (GlpQ) and MPN566. In this work, the function of these proteins was analyzed by biochemical, genetic, and physiological studies. The results indicate that only GlpQ is an active glycerophosphodiesterase. MPN566 has no enzymatic activity as glycerophosphodiesterase and the inactivation of the gene did not result in any detectable phenotype. Inactivation of the glpQ gene resulted in reduced growth in medium with glucose as the carbon source, in loss of hydrogen peroxide production when phosphatidylcholine was present, and in a complete loss of cytotoxicity towards HeLa cells. All these phenotypes were reverted upon complementation of the mutant. Moreover, the glpQ mutant strain exhibited a reduced gliding velocity. A comparison of the proteomes of the wild type strain and the glpQ mutant revealed that this enzyme is also implicated in the control of gene expression. Several proteins were present in higher or lower amounts in the mutant. This apparent regulation by GlpQ is exerted at the level of transcription as determined by mRNA slot blot analyses. All genes subject to GlpQ-dependent control have a conserved potential cis-acting element upstream of the coding region. This element overlaps the promoter in the case of the genes that are repressed in a GlpQ-dependent manner and it is located upstream of the promoter for GlpQ-activated genes. We may suggest that GlpQ acts as a trigger enzyme that measures the availability of its product glycerol-3-phosphate and uses this information to differentially control gene expression. Mycoplasma pneumoniae serves as a model organism for bacteria with very small genomes that are nonetheless independently viable. These bacteria infect the human lung and cause an atypical pneumonia. The major virulence determinant of M. pneumoniae is hydrogen peroxide that is generated during the utilization of glycerol-3-phosphate, which might be derived from free glycerol or from the degradation of phospholipids. Indeed, lecithin is the by far most abundant carbon source on lung epithelia. In this study, we made use of the recent availability of methods to isolate mutants of M. pneumoniae and characterized the enzyme that generates glycerol-3-phosphate from deacylated lecithin (glycerophosphocholine). This enzyme, called GlpQ, is essential for the formation of hydrogen peroxide when the bacteria are incubated with glycerophosphocholine. Moreover, M. pneumoniae is unable to cause any detectable damage to the host cells in the absence of GlpQ. This underlines the important role of phospholipid metabolism for the virulence of M. pneumoniae. We observed that GlpQ in addition to its enzymatic activity is also involved in the control of expression of several genes, among them the glycerol transporter. Thus, GlpQ is central to the normal physiology and to pathogenicity of the minimal pathogen M. pneumoniae.
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Affiliation(s)
- Sebastian R. Schmidl
- Department of General Microbiology, Georg-August-University Göttingen, Göttingen, Germany
| | - Andreas Otto
- Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany
| | - Maria Lluch-Senar
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jaume Piñol
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Julia Busse
- Department of General Microbiology, Georg-August-University Göttingen, Göttingen, Germany
| | - Dörte Becher
- Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany
| | - Jörg Stülke
- Department of General Microbiology, Georg-August-University Göttingen, Göttingen, Germany
- * E-mail:
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14
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Moitinho-Silva L, Heineck BL, Reolon LA, Paes JA, Klein CS, Rebelatto R, Schrank IS, Zaha A, Ferreira HB. Mycoplasma hyopneumoniae type I signal peptidase: expression and evaluation of its diagnostic potential. Vet Microbiol 2011; 154:282-91. [PMID: 21831542 DOI: 10.1016/j.vetmic.2011.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 06/09/2011] [Accepted: 07/12/2011] [Indexed: 01/21/2023]
Abstract
Type I signal peptidase (SPase I) is a membrane-anchored protease of the general secretory pathway, which is encoded by the sipS gene in Mycoplasma hyopneumoniae, the etiological agent of porcine enzootic pneumonia (PEP). In this study, the expression of the M. hyopneumoniae SPase I (MhSPase I) was analyzed in virulent and avirulent strains, and the recombinant protein (rMhSPase I), expressed in Escherichia coli, was evaluated regarding its potential as an immunodiagnostic antigen. It was demonstrated that the sipS coding DNA sequence (CDS) is most likely part of an operon, being co-transcribed along with four other CDSs. Quantitative reverse transcriptase PCR and immunoblot assays showed that MhSPase I is expressed by all three strains analyzed, with no transcriptional difference, but with evidence of a higher protein level in a pathogenic strain (7422), in comparison to another pathogenic (7448) and a non-pathogenic (J) strain. rMhSPase I was strongly immunogenic for mice, and the MhSPase I antigenicity was confirmed. Polyclonal serum anti-rMhSPase I presented no detectable cross-reaction with Mycoplasma flocculare and Mycoplasma hyorhinis. Moreover, phylogenetic analysis demonstrated a low conservation between MhSPase I and orthologous proteins from other porcine respiratory disease complex-related bacteria, Firmicutes and other Mycoplasma species. The potential of an rMhSPase I-based ELISA for PEP immunodiagnosis was demonstrated. Overall, we investigated the expression of sipS and the encoded MhSPase I in three M. hyopneumoniae strains and showed that this protein is a good antigen for use in PEP serodiagnosis and possibly vaccination, as well as a potential target for antibiotic development.
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Affiliation(s)
- Lucas Moitinho-Silva
- Laboratório de Genômica Estrutural e Funcional, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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15
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Zhang W, Baseman JB. Transcriptional regulation of MG_149, an osmoinducible lipoprotein gene from Mycoplasma genitalium. Mol Microbiol 2011; 81:327-39. [PMID: 21692875 DOI: 10.1111/j.1365-2958.2011.07717.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transcriptional regulation remains poorly understood in Mycoplasma genitalium, the smallest self-replicating cell and the causative agent of a spectrum of urogenital diseases. Previously, we reported that MG_149, a lipoprotein-encoding gene, was highly induced under physiological hyperosmolarity conditions. In this study we further analysed MG_149 transcription with a focus on the identification of promoter elements and regulatory mechanisms. We established MG_149 as a genuine osmoinducible gene that exhibited the highest transcript abundance compared with other lipoprotein genes. Using genetic approaches, we demonstrated that the -10 region of the MG_149 promoter was essential for osmoinduction. Moreover, we showed that MG_149 osmoinduction was regulated by DNA supercoiling, as the presence of novobiocin decreased MG_149 expression in a dose-dependent manner. Taken together, these results indicate that DNA supercoiling participates in controlling MG_149 expression during in vivo-like conditions.
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Affiliation(s)
- Wenbo Zhang
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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16
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Kannan TR, Musatovova O, Balasubramanian S, Cagle M, Jordan JL, Krunkosky TM, Davis A, Hardy RD, Baseman JB. Mycoplasma pneumoniae Community Acquired Respiratory Distress Syndrome toxin expression reveals growth phase and infection-dependent regulation. Mol Microbiol 2010; 76:1127-41. [PMID: 20199607 PMCID: PMC2883071 DOI: 10.1111/j.1365-2958.2010.07092.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Mycoplasma pneumoniae causes acute and chronic respiratory infections, including tracheobronchitis and community acquired pneumonia, and is linked to asthma and an array of extra-pulmonary disorders. Recently, we identified an ADP-ribosylating and vacuolating toxin of M. pneumoniae, designated Community Acquired Respiratory Distress Syndrome (CARDS) toxin. In this study we analysed CARDS toxin gene (annotated mpn372) transcription and identified its promoter. We also compared CARDS toxin mRNA and protein profiles in M. pneumoniae during distinct in vitro growth phases. CARDS toxin mRNA expression was maximal, but at low levels, during early exponential growth and declined sharply during mid-to-late log growth phases, which was in direct contrast to other mycoplasma genes examined. Between 7% and 10% of CARDS toxin was localized to the mycoplasma membrane at mid-exponential growth, which was reinforced by immunogold electron microscopy. No CARDS toxin was released into the medium. Upon M. pneumoniae infection of mammalian cells, increased expression of CARDS toxin mRNA was observed when compared with SP-4 broth-grown cultures. Further, confocal immunofluorescence microscopy revealed that M. pneumoniae readily expressed CARDS toxin during infection of differentiated normal human bronchial epithelial cells. Analysis of M. pneumoniae-infected mouse lung tissue revealed high expression of CARDS toxin per mycoplasma cell when compared with M. pneumoniae cells grown in SP-4 medium alone. Taken together, these studies indicate that CARDS toxin expression is carefully controlled by environmental cues that influence its transcription and translation. Further, the acceleration of CARDS toxin synthesis and accumulation in vivo is consistent with its role as a bona fide virulence determinant.
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Affiliation(s)
- T R Kannan
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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17
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Schmidl SR, Gronau K, Pietack N, Hecker M, Becher D, Stülke J. The phosphoproteome of the minimal bacterium Mycoplasma pneumoniae: analysis of the complete known Ser/Thr kinome suggests the existence of novel kinases. Mol Cell Proteomics 2010; 9:1228-42. [PMID: 20097688 DOI: 10.1074/mcp.m900267-mcp200] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mycoplasma pneumoniae belongs to the Mollicutes, the group of organisms with the smallest genomes that are capable of host-independent life. These bacteria show little regulation in gene expression, suggesting an important role for the control of protein activities. We have studied protein phosphorylation in M. pneumoniae to identify phosphorylated proteins. Two-dimensional gel electrophoresis and mass spectrometry allowed the detection of 63 phosphorylated proteins, many of them enzymes of central carbon metabolism and proteins related to host cell adhesion. We identified 16 phosphorylation sites, among them 8 serine and 8 threonine residues, respectively. A phosphoproteome analysis with mutants affected in the two annotated protein kinase genes or in the single known protein phosphatase gene suggested that only one protein (HPr) is phosphorylated by the HPr kinase, HPrK, whereas four adhesion-related or surface proteins were targets of the protein kinase C, PrkC. A comparison with the phosphoproteomes of other bacteria revealed that protein phosphorylation is evolutionarily only poorly conserved. Only one single protein with an identified phosphorylation site, a phosphosugar mutase (ManB in M. pneumoniae), is phosphorylated on a conserved serine residue in all studied organisms from archaea and bacteria to man. We demonstrate that this protein undergoes autophosphorylation. This explains the strong conservation of this phosphorylation event. For most other proteins, even if they are phosphorylated in different species, the actual phosphorylation sites are different. This suggests that protein phosphorylation is a form of adaptation of the bacteria to the specific needs of their particular ecological niche.
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Affiliation(s)
- Sebastian R Schmidl
- Department of General Microbiology, Georg-August-Universität Göttingen, Grisebachstrasse 8, D-37077 Göttingen, Germany
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18
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Yus E, Maier T, Michalodimitrakis K, van Noort V, Yamada T, Chen WH, Wodke JAH, Güell M, Martínez S, Bourgeois R, Kühner S, Raineri E, Letunic I, Kalinina OV, Rode M, Herrmann R, Gutiérrez-Gallego R, Russell RB, Gavin AC, Bork P, Serrano L. Impact of genome reduction on bacterial metabolism and its regulation. Science 2009; 326:1263-8. [PMID: 19965476 DOI: 10.1126/science.1177263] [Citation(s) in RCA: 217] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To understand basic principles of bacterial metabolism organization and regulation, but also the impact of genome size, we systematically studied one of the smallest bacteria, Mycoplasma pneumoniae. A manually curated metabolic network of 189 reactions catalyzed by 129 enzymes allowed the design of a defined, minimal medium with 19 essential nutrients. More than 1300 growth curves were recorded in the presence of various nutrient concentrations. Measurements of biomass indicators, metabolites, and 13C-glucose experiments provided information on directionality, fluxes, and energetics; integration with transcription profiling enabled the global analysis of metabolic regulation. Compared with more complex bacteria, the M. pneumoniae metabolic network has a more linear topology and contains a higher fraction of multifunctional enzymes; general features such as metabolite concentrations, cellular energetics, adaptability, and global gene expression responses are similar, however.
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Affiliation(s)
- Eva Yus
- Centre for Genomic Regulation (CRG) and Universitat Pompeu Fabra, Avenida Dr. Aiguader 88, 08003 Barcelona, Spain
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19
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Comparative proteomic analysis of pathogenic and non-pathogenic strains from the swine pathogen Mycoplasma hyopneumoniae. Proteome Sci 2009; 7:45. [PMID: 20025764 PMCID: PMC2804596 DOI: 10.1186/1477-5956-7-45] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Accepted: 12/21/2009] [Indexed: 11/29/2022] Open
Abstract
Background Mycoplasma hyopneumoniae is a highly infectious swine pathogen and is the causative agent of enzootic pneumonia (EP). Following the previous report of a proteomic survey of the pathogenic 7448 strain of swine pathogen, Mycoplasma hyopneumoniae, we performed comparative protein profiling of three M. hyopneumoniae strains, namely the non-pathogenic J strain and the two pathogenic strains 7448 and 7422. Results In 2DE comparisons, we were able to identify differences in expression levels for 67 proteins, including the overexpression of some cytoadherence-related proteins only in the pathogenic strains. 2DE immunoblot analyses allowed the identification of differential proteolytic cleavage patterns of the P97 adhesin in the three strains. For more comprehensive protein profiling, an LC-MS/MS strategy was used. Overall, 35% of the M. hyopneumoniae genome coding capacity was covered. Partially overlapping profiles of identified proteins were observed in the strains with 81 proteins identified only in one strain and 54 proteins identified in two strains. Abundance analysis of proteins detected in more than one strain demonstrates the relative overexpression of 64 proteins, including the P97 adhesin in the pathogenic strains. Conclusions Our results indicate the physiological differences between the non-pathogenic strain, with its non-infective proliferate lifestyle, and the pathogenic strains, with its constitutive expression of adhesins, which would render the bacterium competent for adhesion and infection prior to host contact.
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20
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Breton M, Sagné E, Duret S, Béven L, Citti C, Renaudin J. First report of a tetracycline-inducible gene expression system for mollicutes. MICROBIOLOGY-SGM 2009; 156:198-205. [PMID: 19797362 DOI: 10.1099/mic.0.034074-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Inducible promoter systems are powerful tools for studying gene function in prokaryotes but have never been shown to function in mollicutes. In this study we evaluated the efficacy of the tetracycline-inducible promoter Pxyl/tetO(2) from Bacillus subtilis in controlling gene expression in two mollicutes, the plant pathogen Spiroplasma citri and the animal pathogen Mycoplasma agalactiae. An S. citri plasmid carrying the spiralin gene under the control of the xyl/tetO(2) tetracycline-inducible promoter and the TetR repressor gene under the control of a constitutive spiroplasmal promoter was introduced into the spiralin-less S. citri mutant GII3-9a3. In the absence of tetracycline, expression of TetR almost completely abolished expression of spiralin from the xyl/tetO(2) promoter. Adding tetracycline (>50 ng ml(-1)) to the medium induced high-level expression of spiralin. Interestingly, inducible expression of spiralin was also detected in vivo: in S. citri-infected leafhoppers fed on tetracycline-containing medium and in S. citri-infected plants watered with tetracycline. A similar construct was introduced into the M. agalactiae chromosome through transposition. Tetracycline-induced expression of spiralin proved the TetR-Pxyl/tetO(2) system to be functional in the ruminant pathogen, suggesting that this tetracycline-inducible promoter system might be of general use in mollicutes.
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Affiliation(s)
- Marc Breton
- Université de Bordeaux 2, UMR 1090 Génomique Diversité Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Evelyne Sagné
- Université de Toulouse, ENVT, UMR 1225 Interactions hôtes agents pathogènes, F-31076 Toulouse, France.,INRA, UMR 1225 Interactions hôtes agents pathogènes, F-31076 Toulouse, France
| | - Sybille Duret
- Université de Bordeaux 2, UMR 1090 Génomique Diversité Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Laure Béven
- Université de Bordeaux 2, UMR 1090 Génomique Diversité Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
| | - Christine Citti
- Université de Toulouse, ENVT, UMR 1225 Interactions hôtes agents pathogènes, F-31076 Toulouse, France.,INRA, UMR 1225 Interactions hôtes agents pathogènes, F-31076 Toulouse, France
| | - Joël Renaudin
- Université de Bordeaux 2, UMR 1090 Génomique Diversité Pouvoir Pathogène, F-33883 Villenave d'Ornon, France.,INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, F-33883 Villenave d'Ornon, France
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21
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Abstract
Glycerol is one of the few carbon sources that can be utilized by Mycoplasma pneumoniae. Glycerol metabolism involves uptake by facilitated diffusion, phosphorylation, and the oxidation of glycerol 3-phosphate to dihydroxyacetone phosphate, a glycolytic intermediate. We have analyzed the expression of the genes involved in glycerol metabolism and observed constitutive expression irrespective of the presence of glycerol or preferred carbon sources. Similarly, the enzymatic activity of glycerol kinase is not modulated by HPr-dependent phosphorylation. This lack of regulation is unique among the bacteria for which glycerol metabolism has been studied so far. Two types of enzymes catalyze the oxidation of glycerol 3-phosphate: oxidases and dehydrogenases. Here, we demonstrate that the enzyme encoded by the M. pneumoniae glpD gene is a glycerol 3-phosphate oxidase that forms hydrogen peroxide rather than NADH(2). The formation of hydrogen peroxide by GlpD is crucial for cytotoxic effects of M. pneumoniae. A glpD mutant exhibited a significantly reduced formation of hydrogen peroxide and a severely reduced cytotoxicity. Attempts to isolate mutants affected in the genes of glycerol metabolism revealed that only the glpD gene, encoding the glycerol 3-phosphate oxidase, is dispensable. In contrast, the glpF and glpK genes, encoding the glycerol facilitator and the glycerol kinase, respectively, are essential in M. pneumoniae. Thus, the enzymes of glycerol metabolism are crucial for the pathogenicity of M. pneumoniae but also for other essential, yet-to-be-identified functions in the M. pneumoniae cell.
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22
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Görke B, Stülke J. Carbon catabolite repression in bacteria: many ways to make the most out of nutrients. Nat Rev Microbiol 2008; 6:613-24. [PMID: 18628769 DOI: 10.1038/nrmicro1932] [Citation(s) in RCA: 1084] [Impact Index Per Article: 67.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Most bacteria can selectively use substrates from a mixture of different carbon sources. The presence of preferred carbon sources prevents the expression, and often also the activity, of catabolic systems that enable the use of secondary substrates. This regulation, called carbon catabolite repression (CCR), can be achieved by different regulatory mechanisms, including transcription activation and repression and control of translation by an RNA-binding protein, in different bacteria. Moreover, CCR regulates the expression of virulence factors in many pathogenic bacteria. In this Review, we discuss the most recent findings on the different mechanisms that have evolved to allow bacteria to use carbon sources in a hierarchical manner.
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Affiliation(s)
- Boris Görke
- Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University Göttingen, Grisebachstr 8, D-37077 Göttingen, Germany
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23
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Hallamaa KM, Tang SL, Ficorilli N, Browning GF. Differential expression of lipoprotein genes in Mycoplasma pneumoniae after contact with human lung epithelial cells, and under oxidative and acidic stress. BMC Microbiol 2008; 8:124. [PMID: 18647421 PMCID: PMC2515320 DOI: 10.1186/1471-2180-8-124] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 07/23/2008] [Indexed: 11/16/2022] Open
Abstract
Background Mycoplasma pneumoniae is a human pathogen that is a common cause of community-acquired pneumonia. It harbours a large number of lipoprotein genes, most of which are of unknown function. Because of their location on the cell surface, these proteins are likely to be involved in the bacterial response to environmental changes, or in the initial stages of infection. The aim of this study was to determine if genes encoding surface lipoproteins are differentially expressed after contact with a human cell line, or after exposure to oxidative or acidic stress. Results Using qRT-PCR assays, we observed that the expression of a number of lipoprotein genes was up-regulated when M. pneumoniae was placed in contact with human cells. In contrast, lipoprotein expression was generally down-regulated or unchanged when exposed to either hydrogen peroxide or low pH (5.5). When exposed to low pH, the mRNA levels of four polycistronically transcribed genes in Lipoprotein Multigene Family 6 formed a gradient of decreasing quantity with increasing distance from a predicted promoter. Conclusion The demonstrated transcriptional changes provide evidence for the functionality of these mostly unassigned genes and indicate that they are regulated in response to changes in environmental conditions. In addition we have shown that the members of Lipoprotein Gene Family 6 may be expressed polycistronically.
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Affiliation(s)
- Katri M Hallamaa
- Department of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia.
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Expression of Mycoplasma proteins carrying an affinity tag in M. pneumoniae allows rapid purification and circumvents problems related to the aberrant genetic code. Appl Environ Microbiol 2007; 73:7799-801. [PMID: 17933931 DOI: 10.1128/aem.01861-07] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Mycoplasma pneumoniae and several other mollicutes, the UGA opal codon specifies tryptophan rather than a translation stop. This often makes it difficult to express Mycoplasma proteins in heterologous hosts. In this work, we demonstrate that mollicute proteins can be fused to an affinity tag and be expressed directly in M. pneumoniae. The protein can then be purified by affinity chromatography and be used for biochemical or any other desired analysis.
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