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Shinjyo Y, Midorikawa N, Matsumoto T, Sugaya Y, Ozawa Y, Oana A, Horie C, Yoshikawa H, Takahashi Y, Hasegawa T, Asai K. Analysis of cell death in Bacillus subtilis caused by sesquiterpenes from Chrysopogon zizanioides (L.) Roberty. J GEN APPL MICROBIOL 2022; 68:62-70. [PMID: 35418537 DOI: 10.2323/jgam.2021.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Recently, the antibacterial effects of essential oils have been investigated in addition to their therapeutic purposes. Owing to their hydrophobic nature, they are thought to perturb the integrity of the bacterial cell membrane, leading to cell death. Against such antibiotic challenges, bacteria develop mechanisms for cell envelope stress responses (CESR). In Bacillus subtilis, a gram-positive sporulating soil bacterium, the extracytoplasmic function (ECF) sigma factor-mediated response system plays a pivotal role in CESR. Among them, σM is strongly involved in response to cell envelope stress, including a shortage of available bactoprenol. Vetiver essential oil, a product of Chrysopogon zizanioides (L.) Roberty root, is also known to possess bactericidal activity. σM was exclusively and strongly induced when the cells were exposed to Vetiver extract, and depletion of multi-ECF sigma factors (ΔsigM, ΔsigW, ΔsigX, and ΔsigV) enhanced sensitivity to it. From this quadruple mutant strain, the suppressor strains, which restored resistance to the bactericidal activity of Vetiver extract, emerged, although attempts to obtain resistant strains from the wild type did not succeed. Whole-genome resequencing of the suppressor strains and genetic analysis revealed inactivation of xseB or pnpA, which code for exodeoxyribonuclease or polynucleotide phosphorylase, respectively. This allowed the quadruple mutant strain to escape from cell death caused by Vetiver extract. Composition analysis suggested that the sesquiterpene, khusimol, might contribute to the bactericidal activity of the Vetiver extract.
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Affiliation(s)
- Yu Shinjyo
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Naoya Midorikawa
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University
| | - Takashi Matsumoto
- Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture
| | - Yuki Sugaya
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Yoshiki Ozawa
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Ayumi Oana
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Chiaki Horie
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Hirofumi Yoshikawa
- Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture.,Department of Bioscience, Tokyo University of Agriculture
| | - Yasuhiro Takahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Toshio Hasegawa
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University
| | - Kei Asai
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University.,Department of Bioscience, Tokyo University of Agriculture
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Challenges and Adaptations of Life in Alkaline Habitats. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2019; 172:85-133. [DOI: 10.1007/10_2019_97] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Feng H, Wang G, Jin W, Zhang X, Huang Y, Gao A, Wu H, Wu G, Chu PK. Systematic Study of Inherent Antibacterial Properties of Magnesium-based Biomaterials. ACS APPLIED MATERIALS & INTERFACES 2016; 8:9662-9673. [PMID: 27043895 DOI: 10.1021/acsami.6b02241] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Magnesium-based materials are preferred in temporary orthopedic implants because of their biodegradability, mechanical properties, and intrinsic antibacterial properties. However, the fundamental mechanism of bacteria killing and roles of various factors are not clearly understood. In this study, we performed a systematic study of the antibacterial properties of two common Mg-based materials using a biofilm forming bacterium. Complete annihilation of the initial 3 × 10(4) bacteria is achieved with both materials in 0.1 mL LB medium in 24 h, whereas in the control, they proliferate to 10(10). The bacteria are killed more effectively in the solution than on the surface, and the bacteria killing efficiency depends more on the concentrations of the magnesium ions and hydroxyl ions than the corrosion rate. The killing process is reproduced using formula solutions, and killing is revealed to stem from the synergetic effects of alkalinity and magnesium ions instead of either one of them or Mg(OH)2 precipitate. Reactive oxygen species (ROS) are detected from the bacteria during the killing process but are not likely produced by the redox reaction directly, because they are detected at least 3 h after the reaction has commenced. The average cell size increases during the killing process, suggesting that the bacteria have difficulty with normal division which also contributes to the reduced bacteria population.
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Affiliation(s)
- Hongqing Feng
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Guomin Wang
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Weihong Jin
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Xuming Zhang
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Yifan Huang
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Ang Gao
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Hao Wu
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Guosong Wu
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
| | - Paul K Chu
- Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong China
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Seki T, Mineshima R, Hashimoto M, Matsumoto K, Hara H, Matsuoka S. Repression of the activities of two extracytoplasmic function σ factors, σM and σV, of Bacillus subtilis by glucolipids in Escherichia coli cells. Genes Genet Syst 2015; 90:109-14. [DOI: 10.1266/ggs.90.109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Takahiro Seki
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Ryota Mineshima
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Michihiro Hashimoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Kouji Matsumoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Satoshi Matsuoka
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
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Heterologous Expression of theOceanobacillus iheyensisSigW and Its Anti-Protein RsiW inBacillus subtilis. Biosci Biotechnol Biochem 2014; 75:966-75. [DOI: 10.1271/bbb.110035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nakao R, Takashiba S, Kosono S, Yoshida M, Watanabe H, Ohnishi M, Senpuku H. Effect of Porphyromonas gingivalis outer membrane vesicles on gingipain-mediated detachment of cultured oral epithelial cells and immune responses. Microbes Infect 2014; 16:6-16. [DOI: 10.1016/j.micinf.2013.10.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/07/2013] [Accepted: 10/08/2013] [Indexed: 01/27/2023]
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7
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Hashimoto M, Seki T, Matsuoka S, Hara H, Asai K, Sadaie Y, Matsumoto K. Induction of extracytoplasmic function sigma factors in Bacillus subtilis cells with defects in lipoteichoic acid synthesis. MICROBIOLOGY-SGM 2012; 159:23-35. [PMID: 23103977 DOI: 10.1099/mic.0.063420-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Lipoteichoic acid (LTA) is an important cell envelope component of Gram-positive bacteria. Bacillus subtilis has four homologous genes for LTA synthesis: ltaS (yflE), yfnI, yqgS and yvgJ. The products LtaS (YflE), YfnI and YqgS are bona fide LTA synthetases, whereas YvgJ functions only as an LTA primase. To clarify whether defects in LTA on the cell envelope trigger extracytoplasmic function (ECF) sigma factors, mRNA levels of the autoregulated ECF sigma factors in cells with singly and multiply deleted alleles of the ltaS homologues were examined by real-time RT-PCR. This revealed that sigM and sigX were induced in cells with a null allele of ΔltaS and ΔyfnI, respectively, and that no ECF sigma factor was induced in cells with a single null allele of ΔyqgS or ΔyvgJ. In cells with double null alleles (ΔltaS and ΔyfnI), sigW and ylaC were induced in addition to sigM and sigX. Cells with triple null alleles (ΔltaS ΔyfnI and ΔyqgS) showed a pattern of induction similar to that of the double null. In cells with quadruple null alleles, sigV and sigY were newly induced. Cells with ΔltaS had approximately 1/4 the diglucosyldiacylglycerol and over 10 times the CDP-diacylglycerol of wild-type cells. Compensatory elevation of the mRNA level of other homologues was observed (in ΔltaS cells the level of yfnI was elevated; in ΔyfnI cells that of yqgS and yvgJ was elevated; both were even higher in ΔltaS ΔyfnI cells). In ΔltaS cells, the mRNA level of yfnI was corroborated to be regulated by σ(M), which is activated in the null mutant cells. In ΔyfnI cells, the mRNA levels of yqgS and yvgJ reverted to less than those of wild-type when a defective sigX allele was introduced. Since sigX was activated in cells with ΔyfnI, this suggests that the induction of yqgS and yvgJ is dependent on σ(X). The LTAs produced by the four ltaS homologues seem to play distinct physiological roles to maintain the full function of LTA on the B. subtilis cell envelope.
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Affiliation(s)
- Michihiro Hashimoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
| | - Takahiro Seki
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
| | - Satoshi Matsuoka
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
| | - Kei Asai
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
| | - Yoshito Sadaie
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
| | - Kouji Matsumoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-ohkubo, Sakura-ku, Saitama-shi, Saitama-ken 338-8570, Japan
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8
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Ogawa A, Furukawa S, Fujita S, Mitobe J, Kawarai T, Narisawa N, Sekizuka T, Kuroda M, Ochiai K, Ogihara H, Kosono S, Yoneda S, Watanabe H, Morinaga Y, Uematsu H, Senpuku H. Inhibition of Streptococcus mutans biofilm formation by Streptococcus salivarius FruA. Appl Environ Microbiol 2011; 77:1572-80. [PMID: 21239559 PMCID: PMC3067281 DOI: 10.1128/aem.02066-10] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 12/30/2010] [Indexed: 11/20/2022] Open
Abstract
The oral microbial flora consists of many beneficial species of bacteria that are associated with a healthy condition and control the progression of oral disease. Cooperative interactions between oral streptococci and the pathogens play important roles in the development of dental biofilms in the oral cavity. To determine the roles of oral streptococci in multispecies biofilm development and the effects of the streptococci in biofilm formation, the active substances inhibiting Streptococcus mutans biofilm formation were purified from Streptococcus salivarius ATCC 9759 and HT9R culture supernatants using ion exchange and gel filtration chromatography. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry analysis was performed, and the results were compared to databases. The S. salivarius HT9R genome sequence was determined and used to indentify candidate proteins for inhibition. The candidates inhibiting biofilms were identified as S. salivarius fructosyltransferase (FTF) and exo-beta-d-fructosidase (FruA). The activity of the inhibitors was elevated in the presence of sucrose, and the inhibitory effects were dependent on the sucrose concentration in the biofilm formation assay medium. Purified and commercial FruA from Aspergillus niger (31.6% identity and 59.6% similarity to the amino acid sequence of FruA from S. salivarius HT9R) completely inhibited S. mutans GS-5 biofilm formation on saliva-coated polystyrene and hydroxyapatite surfaces. Inhibition was induced by decreasing polysaccharide production, which is dependent on sucrose digestion rather than fructan digestion. The data indicate that S. salivarius produces large quantities of FruA and that FruA alone may play an important role in multispecies microbial interactions for sucrose-dependent biofilm formation in the oral cavity.
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Affiliation(s)
- Ayako Ogawa
- Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
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9
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F1F0-ATP synthases of alkaliphilic bacteria: lessons from their adaptations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1362-77. [PMID: 20193659 DOI: 10.1016/j.bbabio.2010.02.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 02/22/2010] [Accepted: 02/23/2010] [Indexed: 12/14/2022]
Abstract
This review focuses on the ATP synthases of alkaliphilic bacteria and, in particular, those that successfully overcome the bioenergetic challenges of achieving robust H+-coupled ATP synthesis at external pH values>10. At such pH values the protonmotive force, which is posited to provide the energetic driving force for ATP synthesis, is too low to account for the ATP synthesis observed. The protonmotive force is lowered at a very high pH by the need to maintain a cytoplasmic pH well below the pH outside, which results in an energetically adverse pH gradient. Several anticipated solutions to this bioenergetic conundrum have been ruled out. Although the transmembrane sodium motive force is high under alkaline conditions, respiratory alkaliphilic bacteria do not use Na+- instead of H+-coupled ATP synthases. Nor do they offset the adverse pH gradient with a compensatory increase in the transmembrane electrical potential component of the protonmotive force. Moreover, studies of ATP synthase rotors indicate that alkaliphiles cannot fully resolve the energetic problem by using an ATP synthase with a large number of c-subunits in the synthase rotor ring. Increased attention now focuses on delocalized gradients near the membrane surface and H+ transfers to ATP synthases via membrane-associated microcircuits between the H+ pumping complexes and synthases. Microcircuits likely depend upon proximity of pumps and synthases, specific membrane properties and specific adaptations of the participating enzyme complexes. ATP synthesis in alkaliphiles depends upon alkaliphile-specific adaptations of the ATP synthase and there is also evidence for alkaliphile-specific adaptations of respiratory chain components.
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10
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Liu J, Fujisawa M, Hicks DB, Krulwich TA. Characterization of the Functionally Critical AXAXAXA and PXXEXXP Motifs of the ATP Synthase c-Subunit from an Alkaliphilic Bacillus. J Biol Chem 2009; 284:8714-25. [PMID: 19176524 DOI: 10.1074/jbc.m808738200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The membrane-embedded rotor in the F(0) sector of proton-translocating ATP synthases is formed from hairpin-like c-subunits that are protonated and deprotonated during energization of ATP synthesis. This study focuses on two c-subunit motifs that are unique to synthases of extremely alkaliphilic Bacillus species. One motif is the AXAXAXA sequence found in the N-terminal helix-1 instead of the GXGXGXG of non-alkaliphiles. Quadruple A-->G chromosomal mutants of alkaliphilic Bacillus pseudofirmus OF4 retain 50% of the wild-type hydrolytic activity (ATPase) but <18% of the ATP synthase capacity at high pH. Consistent with a structural impact of the four alanine replacements, the mutant ATPase activity showed enhanced inhibition by dicyclohexylcarbodiimide, which blocks the helix-2 carboxylate. Single, double, or triple A-->G mutants exhibited more modest defects, as monitored by malate growth. The key carboxylate is in the second motif, which is P(51)XXE(54)XXP in extreme alkaliphiles instead of the (A/G)XX(E/D)XXP found elsewhere. Mutation of Pro(51) to alanine had been shown to severely reduce malate growth and ATP synthesis at high pH. Here, two Pro(51) to glycine mutants of different severities retained ATP synthase capacity but exhibited growth deficits and proton leakiness. A Glu(54) to Asp(54) change increased proton leakiness and reduced malate growth 79-90%. The Pro(51) and the Glu(54) mutants were both more dicyclohexylcarbodiimide-sensitive than wild type. The results highlight the requirement for c-subunit adaptations to achieve alkaliphile ATP synthesis with minimal cytoplasmic proton loss and suggest partial suppression of some mutations by changes outside the atp operon.
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Affiliation(s)
- Jun Liu
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029, USA
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Hashimoto M, Takahashi H, Hara Y, Hara H, Asai K, Sadaie Y, Matsumoto K. Induction of extracytoplasmic function sigma factors in Bacillus subtilis cells with membranes of reduced phosphatidylglycerol content. Genes Genet Syst 2009; 84:191-8. [DOI: 10.1266/ggs.84.191] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Michihiro Hashimoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Hiroaki Takahashi
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Yoshinori Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Kei Asai
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Yoshito Sadaie
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
| | - Kouji Matsumoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University
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12
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Opr86 is essential for viability and is a potential candidate for a protective antigen against biofilm formation by Pseudomonas aeruginosa. J Bacteriol 2008; 190:3969-78. [PMID: 18390657 DOI: 10.1128/jb.02004-07] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that is one of the most refractory to therapy when it forms biofilms in the airways of cystic fibrosis patients. To date, studies regarding the production of an immunogenic and protective antigen to inhibit biofilm formation by P. aeruginosa have been superficial. The previously uncharacterized outer membrane protein (OMP) Opr86 (PA3648) of P. aeruginosa is a member of the Omp85 family, of which homologs have been found in all gram-negative bacteria. Here we verify the availability of Opr86 as a protective antigen to inhibit biofilm formation by P. aeruginosa PAO1 and several other isolates. A mutant was constructed in which Opr86 expression could be switched on or off through a tac promoter-controlled opr86 gene. The result, consistent with previous Omp85 studies, showed that Opr86 is essential for viability and plays a role in OMP assembly. Depletion of Opr86 resulted in streptococci-like morphological changes and liberation of excess membrane vesicles. A polyclonal antibody against Opr86 which showed reactivity to PAO1 cells was obtained. The antibody inhibited biofilm formation by PAO1 and the other clinical strains tested. Closer examination of early attachment revealed that cells treated with the antibody were unable to attach to the surface. Our data suggest that Opr86 is a critical OMP and a potential candidate as a protective antigen against biofilm formation by P. aeruginosa.
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Glycosylation of the OMP85 homolog of Porphyromonas gingivalis and its involvement in biofilm formation. Biochem Biophys Res Commun 2008; 365:784-9. [DOI: 10.1016/j.bbrc.2007.11.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Accepted: 11/09/2007] [Indexed: 01/18/2023]
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14
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Kajiyama Y, Otagiri M, Sekiguchi J, Kosono S, Kudo T. Complex formation by the mrpABCDEFG gene products, which constitute a principal Na+/H+ antiporter in Bacillus subtilis. J Bacteriol 2007; 189:7511-4. [PMID: 17693497 PMCID: PMC2168430 DOI: 10.1128/jb.00968-07] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bacillus subtilis Mrp (also referred to as Sha) is a particularly unusual Na(+)/H(+) antiporter encoded by mrpABCDEFG. Using His tagging of Mrp proteins, we showed complex formation by the mrpABCDEFG gene products by pull-down and blue native polyacrylamide gel electrophoresis analyses. This is the first molecular evidence that the Mrp is a multicomponent antiporter in the cation-proton antiporter 3 family.
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Affiliation(s)
- Yusuke Kajiyama
- Environmental Molecular Biology Lab, RIKEN, Wako, Saitama, Japan
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Padan E, Bibi E, Ito M, Krulwich TA. Alkaline pH homeostasis in bacteria: new insights. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1717:67-88. [PMID: 16277975 PMCID: PMC3072713 DOI: 10.1016/j.bbamem.2005.09.010] [Citation(s) in RCA: 488] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2005] [Revised: 08/19/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Abstract
The capacity of bacteria to survive and grow at alkaline pH values is of widespread importance in the epidemiology of pathogenic bacteria, in remediation and industrial settings, as well as in marine, plant-associated and extremely alkaline ecological niches. Alkali-tolerance and alkaliphily, in turn, strongly depend upon mechanisms for alkaline pH homeostasis, as shown in pH shift experiments and growth experiments in chemostats at different external pH values. Transcriptome and proteome analyses have recently complemented physiological and genetic studies, revealing numerous adaptations that contribute to alkaline pH homeostasis. These include elevated levels of transporters and enzymes that promote proton capture and retention (e.g., the ATP synthase and monovalent cation/proton antiporters), metabolic changes that lead to increased acid production, and changes in the cell surface layers that contribute to cytoplasmic proton retention. Targeted studies over the past decade have followed up the long-recognized importance of monovalent cations in active pH homeostasis. These studies show the centrality of monovalent cation/proton antiporters in this process while microbial genomics provides information about the constellation of such antiporters in individual strains. A comprehensive phylogenetic analysis of both eukaryotic and prokaryotic genome databases has identified orthologs from bacteria to humans that allow better understanding of the specific functions and physiological roles of the antiporters. Detailed information about the properties of multiple antiporters in individual strains is starting to explain how specific monovalent cation/proton antiporters play dominant roles in alkaline pH homeostasis in cells that have several additional antiporters catalyzing ostensibly similar reactions. New insights into the pH-dependent Na(+)/H(+) antiporter NhaA that plays an important role in Escherichia coli have recently emerged from the determination of the structure of NhaA. This review highlights the approaches, major findings and unresolved problems in alkaline pH homeostasis, focusing on the small number of well-characterized alkali-tolerant and extremely alkaliphilic bacteria.
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Affiliation(s)
- Etana Padan
- Alexander Silberman Institute of Life Sciences, Hebrew University, Jerusalem 91904, Israel.
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Kosono S, Haga K, Tomizawa R, Kajiyama Y, Hatano K, Takeda S, Wakai Y, Hino M, Kudo T. Characterization of a multigene-encoded sodium/hydrogen antiporter (sha) from Pseudomonas aeruginosa: its involvement in pathogenesis. J Bacteriol 2005; 187:5242-8. [PMID: 16030218 PMCID: PMC1196046 DOI: 10.1128/jb.187.15.5242-5248.2005] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sha (also known as Mrp/Mnh/Pha) is a Na+/H+ antiporter encoded by a cluster of six or seven genes that probably form a multisubunit transport complex. The Sha system is important for the homeostasis of H+, Na+, and other monovalent cations and plays a critical role in various functions, including alkaliphily, sporulation, and symbiosis. Here, we characterized the sha homologue genes from the opportunistic pathogen Pseudomonas aeruginosa, which exist as a cluster of six genes (PA1054 to PA1059). The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na+/H+ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na+/H+ antiporters, indicating that genes PA1054 to PA1059 are responsible for Na+/H+ antiport activity. We disrupted PA1054 (a shaA homologue gene) and determined its effect on Na+ tolerance during growth, Na+ efflux, and pathogenicity in mice. Disruption of PA1054 resulted in severe Na+ sensitivity during growth and decreased Na+ efflux activity. In mice, the deletion mutant of PA1054 also exhibited an attenuated virulence in systemic, pulmonary, and urinary tract infections and also a decrease in colonization of the infected organs. From these results, we conclude that the genes PA1054 to PA1059 encode a Na+/H+ antiporter that is largely responsible for Na+ extrusion in P. aeruginosa and has a role in the infection of the pathogen. We propose to designate PA1054 to PA1059 as the sha (sodium hydrogen antiporter) genes, shaABCDEFG.
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Affiliation(s)
- Saori Kosono
- Environmental Molecular Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
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Swartz TH, Ikewada S, Ishikawa O, Ito M, Krulwich TA. The Mrp system: a giant among monovalent cation/proton antiporters? Extremophiles 2005; 9:345-54. [PMID: 15980940 DOI: 10.1007/s00792-005-0451-6] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Accepted: 04/08/2005] [Indexed: 10/25/2022]
Abstract
Mrp systems are a novel and broadly distributed type of monovalent cation/proton antiporter of bacteria and archaea. Monovalent cation/proton antiporters are membrane transport proteins that catalyze efflux of cytoplasmic sodium, potassium or lithium ions in exchange for external hydrogen ions (protons). Other known monovalent cation antiporters are single gene products, whereas Mrp systems have been proposed to function as hetero-oligomers. A mrp operon typically has six or seven genes encoding hydrophobic proteins all of which are required for optimal Mrp-dependent sodium-resistance. There is little sequence similarity of Mrp proteins to other antiporters but three of these proteins have significant sequence similarity to membrane embedded subunits of ion-translocating electron transport complexes. Mrp antiporters have essential roles in the physiology of alkaliphilic and neutralophilic Bacillus species, nitrogen-fixing Sinorhizobium meliloti and in the pathogen Staphylococcus aureus, although these bacteria contain multiple monovalent cation/proton antiporters. The wide distribution of Mrp systems leads to the anticipation of important roles in an even wider variety of pathogens, extremophiles and environmentally important organisms. Here, the distribution, established physiological roles and catalytic activities of Mrp systems are reviewed, hypotheses regarding their complexity are discussed and major open questions about their function are highlighted.
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Affiliation(s)
- Talia H Swartz
- Department of Pharmacology & Biological Chemistry, Mount Sinai School of Medicine, New York, NY 10029, USA
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