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Meireles D, Pombinho R, Cabanes D. Signals behind Listeria monocytogenes virulence mechanisms. Gut Microbes 2024; 16:2369564. [PMID: 38979800 PMCID: PMC11236296 DOI: 10.1080/19490976.2024.2369564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/13/2024] [Indexed: 07/10/2024] Open
Abstract
The tight and coordinated regulation of virulence gene expression is crucial to ensure the survival and persistence of bacterial pathogens in different contexts within their hosts. Considering this, bacteria do not express virulence factors homogenously in time and space, either due to their associated fitness cost or to their detrimental effect at specific infection stages. To efficiently infect and persist into their hosts, bacteria have thus to monitor environmental cues or chemical cell-to-cell signaling mechanisms that allow their transition from the external environment to the host, and therefore adjust gene expression levels, intrinsic biological activities, and appropriate behaviors. Listeria monocytogenes (Lm), a major Gram-positive facultative intracellular pathogen, stands out for its adaptability and capacity to thrive in a wide range of environments. Because of that, Lm presents itself as a significant concern in food safety and public health, that can lead to potentially life-threatening infections in humans. A deeper understanding of the intricate bacterial virulence mechanisms and the signals that control them provide valuable insights into the dynamic interplay between Lm and the host. Therefore, this review addresses the role of some crucial signals behind Lm pathogenic virulence mechanisms and explores how the ability to assimilate and interpret these signals is fundamental for pathogenesis, identifying potential targets for innovative antimicrobial strategies.
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Affiliation(s)
- Diana Meireles
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar – ICBAS, Porto, Portugal
| | - Rita Pombinho
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
| | - Didier Cabanes
- Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Group of Molecular Microbiology, IBMC, Porto, Portugal
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Zhu X, Wang S, Du Y, Liang Z, Yao H, Chen X, Wu Z. A novel aquaporin Aagp contributes to Streptococcus suis H 2O 2 efflux and virulence. Virulence 2023; 14:2249789. [PMID: 37621097 PMCID: PMC10461500 DOI: 10.1080/21505594.2023.2249789] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/05/2023] [Accepted: 08/13/2023] [Indexed: 08/26/2023] Open
Abstract
Streptococcus suis is a bacterium that can cause infections in pigs and humans. Although oxidative stress is common occurrence during bacterial growth and infection, the regulation networks of S. suis under oxidative stress remain poorly understood. To address this, we utilized RNA-Seq to reveal the transcriptional landscape of S. suis in response to H2O2 stress. We identified novel genes responsible for S. suis resistance to oxidative stress, including those involved in DNA repair or protection, and essential for the biosynthesis of amino acids and nucleic acids. In addition, we found that a novel aquaporin, Aagp, belonging to atypical aquaglyceroporins and widely distributed in diverse S. suis serotypes, plays a crucial role during H2O2 stress. By performing oxidative stress assays and measuring the intracellular H2O2 concentrations of the wild-type strain and Aagp mutants during H2O2 stress, we found that Aagp facilitated H2O2 efflux. Additionally, we found that Aagp might be involved in glycerol transport, as shown by the growth inhibition and H2O2 production in the presence of glycerol. Mice infection experiments indicated that Aagp contributed to S. suis virulence. This study contributes to understanding the mechanism of S. suis oxidative stress response, S. suis pathogenesis, and the function of aquaporins in prokaryotes.
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Affiliation(s)
- Xinchi Zhu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Shuoyue Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Yu Du
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Zijing Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Huochun Yao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Xiang Chen
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
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Werum V, Ehrmann M, Vogel R, Hilgarth M. Comparative genome analysis, predicted lifestyle and antimicrobial strategies of Lactococcus carnosus and Lactococcus paracarnosus isolated from meat. Microbiol Res 2022; 258:126982. [DOI: 10.1016/j.micres.2022.126982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 02/04/2022] [Accepted: 02/08/2022] [Indexed: 12/12/2022]
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Immunoproteomic analysis of Clostridium botulinum type B secretome for identification of immunogenic proteins against botulism. Biotechnol Lett 2021; 43:1019-1036. [PMID: 33629143 PMCID: PMC7904509 DOI: 10.1007/s10529-021-03091-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 02/01/2021] [Indexed: 11/12/2022]
Abstract
Objectives To identify immunogenic proteins of C. botulinum type B secretome by immunoproteomic analysis. Results In the present study, an attempt was made to elucidate the vaccine candidates/diagnostic molecules against botulism using immuno proteomic approach. C. botulinum type B secretome was elucidated when it was grown in TPGY as well as CMM media. Predominant 51 proteins were identified in both the media using 2-DE and mass spectrometry analysis. 2D gels (CMM & TPGY) were probed with respected proteins mice antiserum and obtained 17 and 10 immunogenic proteins in TPGY as well as CMM media respectively. Hypothetical protein CLOSPO_00563, ornithine carbamoyl transferase, FlaA, molecular chaperone GroEL and secreted protease proteins were found as the common immuno dominant proteins in both media. Polyclonal Antibodies raised against C. botulinum types A and E showed cross-reactivity with secretome C. botulinum type B at the lowest dilution (1:1000) but did not show cross reactivity with highest dilution (1:30,000) with C. botulinum type B secretome. Polyclonal antibodies against C. botulinum type F secretome did not show cross reactivity with C. botulinum type B secretome. Conclusions Identified immunogenic proteins can be used as vaccine candidates and diagnostic markers for the infant and wound botulism but common immunogenic proteins may be the best vaccine candidate molecule for development of vaccine as well as diagnostic system against the infant and wound botulism. Supplementary Information The online version contains supplementary material available at 10.1007/s10529-021-03091-4.
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5
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Assoni L, Milani B, Carvalho MR, Nepomuceno LN, Waz NT, Guerra MES, Converso TR, Darrieux M. Resistance Mechanisms to Antimicrobial Peptides in Gram-Positive Bacteria. Front Microbiol 2020; 11:593215. [PMID: 33193264 PMCID: PMC7609970 DOI: 10.3389/fmicb.2020.593215] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023] Open
Abstract
With the alarming increase of infections caused by pathogenic multidrug-resistant bacteria over the last decades, antimicrobial peptides (AMPs) have been investigated as a potential treatment for those infections, directly through their lytic effect or indirectly, due to their ability to modulate the immune system. There are still concerns regarding the use of such molecules in the treatment of infections, such as cell toxicity and host factors that lead to peptide inhibition. To overcome these limitations, different approaches like peptide modification to reduce toxicity and peptide combinations to improve therapeutic efficacy are being tested. Human defense peptides consist of an important part of the innate immune system, against a myriad of potential aggressors, which have in turn developed different ways to overcome the AMPs microbicidal activities. Since the antimicrobial activity of AMPs vary between Gram-positive and Gram-negative species, so do the bacterial resistance arsenal. This review discusses the mechanisms exploited by Gram-positive bacteria to circumvent killing by antimicrobial peptides. Specifically, the most clinically relevant genera, Streptococcus spp., Staphylococcus spp., Enterococcus spp. and Gram-positive bacilli, have been explored.
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Affiliation(s)
- Lucas Assoni
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Barbara Milani
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Marianna Ribeiro Carvalho
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Lucas Natanael Nepomuceno
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Natalha Tedeschi Waz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Maria Eduarda Souza Guerra
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Thiago Rojas Converso
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Michelle Darrieux
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
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Choi S, Chung JH, Nam MH, Bang E, Hong KS, Kim YH, Seo JB, Chi SG. Elevated aldolase 1A, retrogene 1 expression induces cardiac apoptosis in rat experimental autoimmune myocarditis model. Can J Physiol Pharmacol 2020; 98:373-382. [PMID: 31999472 DOI: 10.1139/cjpp-2019-0539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Acute myocarditis is an unpredictable heart disease that is caused by inflammation-associated cell death. Although viral infection and drug exposure are known to induce acute myocarditis, the molecular basis for its development remains undefined. Using proteomics and molecular analyses in myosin-induced rat experimental autoimmune myocarditis (EAM), we identified that elevated expression of aldolase 1A, retrogene 1 (Aldoart1) is critical to induce mitochondrial dysfunction and acute myocarditis development. Here, we demonstrate that cardiac cell death is associated with increased expressions of proapoptotic genes in addition to high levels of glucose, lactate, and triglyceride in metabolite profiling. The functional protein association network analysis also suggests that Aldoart1 upregulation correlates with high levels of dihydroxyacetone kinase and triglyceride. In H9c2 cardiac cells, lipopolysaccharides (LPS) or high glucose exposure significantly increases the cytochrome c release and the conversion of pro-caspase 3 into the cleaved form of caspase 3. We also found that LPS- or glucose-induced toxicities are almost completely reversed by siRNA-mediated knockdown of Aldoartl, which consequently increases cell viability. Together, our study strongly suggests that Aldoart1 may be involved in inducing mitochondrial apoptotic processes and can be a novel therapeutic target to prevent the onset of acute myocarditis or cardiac apoptosis.
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Affiliation(s)
- Seungmin Choi
- Department of Life Sciences, Korea University, Seoul 02841, Korea.,Korea Basic Science Institute, Seoul Center, Seoul 02841, Korea
| | - Joo Hee Chung
- Korea Basic Science Institute, Seoul Center, Seoul 02841, Korea
| | - Myung-Hee Nam
- Korea Basic Science Institute, Seoul Center, Seoul 02841, Korea
| | - Eunjung Bang
- Korea Basic Science Institute, Western Seoul Center, Seoul 03759, Korea
| | - Kwan Soo Hong
- Korea Basic Science Institute, Bioimaging Research Team, Cheongju 28123, Korea
| | - Yong-Hwan Kim
- Department of Biological Sciences, Delaware State University, Dover, DE 19901, USA
| | - Jong Bok Seo
- Korea Basic Science Institute, Seoul Center, Seoul 02841, Korea
| | - Sung-Gil Chi
- Department of Life Sciences, Korea University, Seoul 02841, Korea
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Sapountzis P, Zhukova M, Shik JZ, Schiott M, Boomsma JJ. Reconstructing the functions of endosymbiotic Mollicutes in fungus-growing ants. eLife 2018; 7:e39209. [PMID: 30454555 PMCID: PMC6245734 DOI: 10.7554/elife.39209] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/16/2018] [Indexed: 12/25/2022] Open
Abstract
Mollicutes, a widespread class of bacteria associated with animals and plants, were recently identified as abundant abdominal endosymbionts in healthy workers of attine fungus-farming leaf-cutting ants. We obtained draft genomes of the two most common strains harbored by Panamanian fungus-growing ants. Reconstructions of their functional significance showed that they are independently acquired symbionts, most likely to decompose excess arginine consistent with the farmed fungal cultivars providing this nitrogen-rich amino-acid in variable quantities. Across the attine lineages, the relative abundances of the two Mollicutes strains are associated with the substrate types that foraging workers offer to fungus gardens. One of the symbionts is specific to the leaf-cutting ants and has special genomic machinery to catabolize citrate/glucose into acetate, which appears to deliver direct metabolic energy to the ant workers. Unlike other Mollicutes associated with insect hosts, both attine ant strains have complete phage-defense systems, underlining that they are actively maintained as mutualistic symbionts.
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Affiliation(s)
- Panagiotis Sapountzis
- Centre for Social Evolution, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Mariya Zhukova
- Centre for Social Evolution, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Jonathan Z Shik
- Centre for Social Evolution, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Morten Schiott
- Centre for Social Evolution, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
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8
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Koomen J, den Besten HM, Metselaar KI, Tempelaars MH, Wijnands LM, Zwietering MH, Abee T. Gene profiling-based phenotyping for identification of cellular parameters that contribute to fitness, stress-tolerance and virulence of Listeria monocytogenes variants. Int J Food Microbiol 2018; 283:14-21. [DOI: 10.1016/j.ijfoodmicro.2018.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 10/14/2022]
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9
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Crespo Tapia N, den Besten HM, Abee T. Glycerol metabolism induces Listeria monocytogenes biofilm formation at the air-liquid interface. Int J Food Microbiol 2018; 273:20-27. [DOI: 10.1016/j.ijfoodmicro.2018.03.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 03/12/2018] [Accepted: 03/13/2018] [Indexed: 11/26/2022]
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Regulation of a Glycerol-Induced Quinoprotein Alcohol Dehydrogenase by σ 54 and a LuxR-Type Regulator in Azospirillum brasilense Sp7. J Bacteriol 2017; 199:JB.00035-17. [PMID: 28439037 DOI: 10.1128/jb.00035-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/08/2017] [Indexed: 02/02/2023] Open
Abstract
Azospirillum brasilense Sp7 uses glycerol as a carbon source for growth and nitrogen fixation. When grown in medium containing glycerol as a source of carbon, it upregulates the expression of a protein which was identified as quinoprotein alcohol dehydrogenase (ExaA). Inactivation of exaA adversely affects the growth of A. brasilense on glycerol. A determination of the transcription start site of exaA revealed an RpoN-dependent -12/-24 promoter consensus. The expression of an exaA::lacZ fusion was induced maximally by glycerol and was dependent on σ54 Bioinformatic analysis of the sequence flanking the -12/-24 promoter revealed a 17-bp sequence motif with a dyad symmetry of 6 nucleotides upstream of the promoter, the disruption of which caused a drastic reduction in promoter activity. The electrophoretic mobility of a DNA fragment containing the 17-bp sequence motif was retarded by purified EraR, a LuxR-type transcription regulator that is transcribed divergently from exaA EraR also showed a positive interaction with RpoN in two-hybrid and pulldown assays.IMPORTANCE Quinoprotein alcohol dehydrogenase (ExaA) plays an important role in the catabolism of alcohols in bacteria. Although exaA expression is thought to be regulated by a two-component system consisting of EraS and EraR, the mechanism of regulation was not known. This study shows the details of the regulation of expression of the exaA gene in A. brasilense We have shown here that exaA of A. brasilense is maximally induced by glycerol and harbors a σ54-dependent promoter. The response regulator EraR binds to an inverted repeat located upstream of the exaA promoter. This study shows that a LuxR-type response regulator (EraR) binds upstream of the exaA gene and physically interacts with σ54 The unique feature of this regulation is that EraR is a LuxR-type transcription regulator that lacks the GAFTGA motif, a characteristic feature of the enhancer binding proteins that are known to interact with σ54 in other bacteria.
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Gao B, Chi L, Mahbub R, Bian X, Tu P, Ru H, Lu K. Multi-Omics Reveals that Lead Exposure Disturbs Gut Microbiome Development, Key Metabolites, and Metabolic Pathways. Chem Res Toxicol 2017; 30:996-1005. [PMID: 28234468 DOI: 10.1021/acs.chemrestox.6b00401] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lead exposure remains a global public health issue, and the recent Flint water crisis has renewed public concern about lead toxicity. The toxicity of lead has been well established in a variety of systems and organs. The gut microbiome has been shown to be highly involved in many critical physiological processes, including food digestion, immune system development, and metabolic homeostasis. However, despite the key role of the gut microbiome in human health, the functional impact of lead exposure on the gut microbiome has not been studied. The aim of this study is to define gut microbiome toxicity induced by lead exposure in C57BL/6 mice using multiomics approaches, including 16S rRNA sequencing, whole genome metagenomics sequencing, and gas chromatography-mass spectrometry (GC-MS) metabolomics. 16S rRNA sequencing revealed that lead exposure altered the gut microbiome trajectory and phylogenetic diversity. Metagenomics sequencing and metabolomics profiling showed that numerous metabolic pathways, including vitamin E, bile acids, nitrogen metabolism, energy metabolism, oxidative stress, and the defense/detoxification mechanism, were significantly disturbed by lead exposure. These perturbed molecules and pathways may have important implications for lead toxicity in the host. Taken together, these results demonstrated that lead exposure not only altered the gut microbiome community structures/diversity but also greatly affected metabolic functions, leading to gut microbiome toxicity.
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Affiliation(s)
- Bei Gao
- Department of Environmental Health Science, University of Georgia , Athens, Georgia 30602, United States
| | - Liang Chi
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | - Ridwan Mahbub
- Department of Environmental Health Science, University of Georgia , Athens, Georgia 30602, United States
| | - Xiaoming Bian
- Department of Environmental Health Science, University of Georgia , Athens, Georgia 30602, United States
| | - Pengcheng Tu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | - Hongyu Ru
- Department of Population Health and Pathobiology, North Carolina State University , Raleigh, North Carolina 27607, United States
| | - Kun Lu
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
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Williams TJ, Allen M, Tschitschko B, Cavicchioli R. Glycerol metabolism of haloarchaea. Environ Microbiol 2016; 19:864-877. [PMID: 27768817 DOI: 10.1111/1462-2920.13580] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Haloarchaea are heterotrophic members of the Archaea that thrive in hypersaline environments, often feeding off the glycerol that is produced as an osmolyte by eucaryotic Dunaliella during primary production. In this study we analyzed glycerol metabolism genes in closed genomes of haloarchaea and examined published data describing the growth properties of haloarchaea and experimental data for the enzymes involved. By integrating the genomic data with knowledge from the literature, we derived an understanding of the ecophysiology and evolutionary properties of glycerol catabolic pathways in haloarchaea.
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Affiliation(s)
- Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, New South Wales, Australia
| | - Michelle Allen
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, New South Wales, Australia
| | - Bernhard Tschitschko
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, New South Wales, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, New South Wales, Australia
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Kentache T, Milohanic E, Cao TN, Mokhtari A, Aké FM, Ma Pham QM, Joyet P, Deutscher J. Transport and Catabolism of Pentitols by Listeria monocytogenes. J Mol Microbiol Biotechnol 2016; 26:369-380. [PMID: 27553222 DOI: 10.1159/000447774] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 06/22/2016] [Indexed: 11/19/2022] Open
Abstract
Transposon insertion into Listeria monocytogenes lmo2665, which encodes an EIIC of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), was found to prevent D-arabitol utilization. We confirm this result with a deletion mutant and show that Lmo2665 is also required for D-xylitol utilization. We therefore called this protein EIICAxl. Both pentitols are probably catabolized via the pentose phosphate pathway (PPP) because lmo2665 belongs to an operon, which encodes the three PTSAxl components, two sugar-P dehydrogenases, and most PPP enzymes. The two dehydrogenases oxidize the pentitol-phosphates produced during PTS-catalyzed transport to the PPP intermediate xylulose-5-P. L. monocytogenes contains another PTS, which exhibits significant sequence identity to PTSAxl. Its genes are also part of an operon encoding PPP enzymes. Deletion of the EIIC-encoding gene (lmo0508) affected neither D-arabitol nor D-xylitol utilization, although D-arabitol induces the expression of this operon. Both operons are controlled by MtlR/LicR-type transcription activators (Lmo2668 and Lmo0501, respectively). Phosphorylation of Lmo0501 by the soluble PTSAxl components probably explains why D-arabitol also induces the second pentitol operon. Listerial virulence genes are submitted to strong repression by PTS sugars, such as glucose. However, D-arabitol inhibited virulence gene expression only at high concentrations, probably owing to its less efficient utilization compared to glucose.
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Affiliation(s)
- Takfarinas Kentache
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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The bacterial phosphoenolpyruvate:carbohydrate phosphotransferase system: regulation by protein phosphorylation and phosphorylation-dependent protein-protein interactions. Microbiol Mol Biol Rev 2015; 78:231-56. [PMID: 24847021 DOI: 10.1128/mmbr.00001-14] [Citation(s) in RCA: 276] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The bacterial phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) carries out both catalytic and regulatory functions. It catalyzes the transport and phosphorylation of a variety of sugars and sugar derivatives but also carries out numerous regulatory functions related to carbon, nitrogen, and phosphate metabolism, to chemotaxis, to potassium transport, and to the virulence of certain pathogens. For these different regulatory processes, the signal is provided by the phosphorylation state of the PTS components, which varies according to the availability of PTS substrates and the metabolic state of the cell. PEP acts as phosphoryl donor for enzyme I (EI), which, together with HPr and one of several EIIA and EIIB pairs, forms a phosphorylation cascade which allows phosphorylation of the cognate carbohydrate bound to the membrane-spanning EIIC. HPr of firmicutes and numerous proteobacteria is also phosphorylated in an ATP-dependent reaction catalyzed by the bifunctional HPr kinase/phosphorylase. PTS-mediated regulatory mechanisms are based either on direct phosphorylation of the target protein or on phosphorylation-dependent interactions. For regulation by PTS-mediated phosphorylation, the target proteins either acquired a PTS domain by fusing it to their N or C termini or integrated a specific, conserved PTS regulation domain (PRD) or, alternatively, developed their own specific sites for PTS-mediated phosphorylation. Protein-protein interactions can occur with either phosphorylated or unphosphorylated PTS components and can either stimulate or inhibit the function of the target proteins. This large variety of signal transduction mechanisms allows the PTS to regulate numerous proteins and to form a vast regulatory network responding to the phosphorylation state of various PTS components.
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Comparative proteomic analysis of Streptomyces lividans Wild-Type and ppk mutant strains reveals the importance of storage lipids for antibiotic biosynthesis. Appl Environ Microbiol 2013; 79:5907-17. [PMID: 23872561 DOI: 10.1128/aem.02280-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Streptomyces lividans TK24 is a strain that naturally produces antibiotics at low levels, but dramatic overproduction of antibiotics occurs upon interruption of the ppk gene. However, the role of the Ppk enzyme in relation to the regulation of antibiotic biosynthesis remains poorly understood. In order to gain a better understanding of the phenotype of the ppk mutant, the proteomes of the wild-type (wt) and ppk mutant strains, grown for 96 h on R2YE medium limited in phosphate, were analyzed. Intracellular proteins were separated on two-dimensional (2D) gels, spots were quantified, and those showing a 3-fold variation or more were identified by mass spectrometry. The expression of 12 proteins increased and that of 29 decreased in the ppk mutant strain. Our results suggested that storage lipid degradation rather than hexose catabolism was taking place in the mutant. In order to validate this hypothesis, the triacylglycerol contents of the wt and ppk mutant strains of S. lividans as well as that of Streptomyces coelicolor M145, a strain that produces antibiotics at high levels and is closely related to S. lividans, were assessed using electron microscopy and thin-layer chromatography. These studies highlighted the large difference in triacylglycerol contents of the three strains and confirmed the hypothetical link between storage lipid metabolism and antibiotic biosynthesis in Streptomyces.
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Utilization of D-ribitol by Lactobacillus casei BL23 requires a mannose-type phosphotransferase system and three catabolic enzymes. J Bacteriol 2013; 195:2652-61. [PMID: 23564164 DOI: 10.1128/jb.02276-12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lactobacillus casei strains 64H and BL23, but not ATCC 334, are able to ferment D-ribitol (also called D-adonitol). However, a BL23-derived ptsI mutant lacking enzyme I of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) was not able to utilize this pentitol, suggesting that strain BL23 transports and phosphorylates D-ribitol via a PTS. We identified an 11-kb region in the genome sequence of L. casei strain BL23 (LCABL_29160 to LCABL_29270) which is absent from strain ATCC 334 and which contains the genes for a GlpR/IolR-like repressor, the four components of a mannose-type PTS, and six metabolic enzymes potentially involved in D-ribitol metabolism. Deletion of the gene encoding the EIIB component of the presumed ribitol PTS indeed prevented D-ribitol fermentation. In addition, we overexpressed the six catabolic genes, purified the encoded enzymes, and determined the activities of four of them. They encode a D-ribitol-5-phosphate (D-ribitol-5-P) 2-dehydrogenase, a D-ribulose-5-P 3-epimerase, a D-ribose-5-P isomerase, and a D-xylulose-5-P phosphoketolase. In the first catabolic step, the protein D-ribitol-5-P 2-dehydrogenase uses NAD(+) to oxidize D-ribitol-5-P formed during PTS-catalyzed transport to D-ribulose-5-P, which, in turn, is converted to D-xylulose-5-P by the enzyme D-ribulose-5-P 3-epimerase. Finally, the resulting D-xylulose-5-P is split by D-xylulose-5-P phosphoketolase in an inorganic phosphate-requiring reaction into acetylphosphate and the glycolytic intermediate D-glyceraldehyde-3-P. The three remaining enzymes, one of which was identified as D-ribose-5-P-isomerase, probably catalyze an alternative ribitol degradation pathway, which might be functional in L. casei strain 64H but not in BL23, because one of the BL23 genes carries a frameshift mutation.
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