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Ito M, Morino M, Krulwich TA. Mrp Antiporters Have Important Roles in Diverse Bacteria and Archaea. Front Microbiol 2017; 8:2325. [PMID: 29218041 PMCID: PMC5703873 DOI: 10.3389/fmicb.2017.02325] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 11/10/2017] [Indexed: 11/13/2022] Open
Abstract
Mrp (Multiple resistance and pH) antiporter was identified as a gene complementing an alkaline-sensitive mutant strain of alkaliphilic Bacillus halodurans C-125 in 1990. At that time, there was no example of a multi-subunit type Na+/H+ antiporter comprising six or seven hydrophobic proteins, and it was newly designated as the monovalent cation: proton antiporter-3 (CPA3) family in the classification of transporters. The Mrp antiporter is broadly distributed among bacteria and archaea, not only in alkaliphiles. Generally, all Mrp subunits, mrpA–G, are required for enzymatic activity. Two exceptions are Mrp from the archaea Methanosarcina acetivorans and the eubacteria Natranaerobius thermophilus, which are reported to sustain Na+/H+ antiport activity with the MrpA subunit alone. Two large subunits of the Mrp antiporter, MrpA and MrpD, are homologous to membrane-embedded subunits of the respiratory chain complex I, NuoL, NuoM, and NuoN, and the small subunit MrpC has homology with NuoK. The functions of the Mrp antiporter include sodium tolerance and pH homeostasis in an alkaline environment, nitrogen fixation in Schizolobium meliloti, bile salt tolerance in Bacillus subtilis and Vibrio cholerae, arsenic oxidation in Agrobacterium tumefaciens, pathogenesis in Pseudomonas aeruginosa and Staphylococcus aureus, and the conversion of energy involved in metabolism and hydrogen production in archaea. In addition, some Mrp antiporters transport K+ and Ca2+ instead of Na+, depending on the environmental conditions. Recently, the molecular structure of the respiratory chain complex I has been elucidated by others, and details of the mechanism by which it transports protons are being clarified. Based on this, several hypotheses concerning the substrate transport mechanism in the Mrp antiporter have been proposed. The MrpA and MrpD subunits, which are homologous to the proton transport subunit of complex I, are involved in the transport of protons and their coupling cations. Herein, we outline other recent findings on the Mrp antiporter.
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Affiliation(s)
- Masahiro Ito
- Graduate School of Life Sciences, Toyo University, Gunma, Japan.,Bio-Nano Electronics Research Center, Toyo University, Kawagoe, Japan
| | - Masato Morino
- Graduate School of Life Sciences, Toyo University, Gunma, Japan.,Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Terry A Krulwich
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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Liang P, Rosas-Lemus M, Patel D, Fang X, Tuz K, Juárez O. Dynamic energy dependency of Chlamydia trachomatis on host cell metabolism during intracellular growth: Role of sodium-based energetics in chlamydial ATP generation. J Biol Chem 2017; 293:510-522. [PMID: 29123027 DOI: 10.1074/jbc.m117.797209] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 10/30/2017] [Indexed: 11/06/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular human pathogen responsible for the most prevalent sexually-transmitted infection in the world. For decades C. trachomatis has been considered an "energy parasite" that relies entirely on the uptake of ATP from the host cell. The genomic data suggest that C. trachomatis respiratory chain could produce a sodium gradient that may sustain the energetic demands required for its rapid multiplication. However, this mechanism awaits experimental confirmation. Moreover, the relationship of chlamydiae with the host cell, in particular its energy dependence, is not well understood. In this work, we are showing that C. trachomatis has an active respiratory metabolism that seems to be coupled to the sodium-dependent synthesis of ATP. Moreover, our results show that the inhibition of mitochondrial ATP synthesis at an early stage decreases the rate of infection and the chlamydial inclusion size. In contrast, the inhibition of the chlamydial respiratory chain at mid-stage of the infection cycle decreases the inclusion size but has no effect on infection rate. Remarkably, the addition of monensin, a Na+/H+ exchanger, completely halts the infection. Altogether, our data indicate that chlamydial development has a dynamic relationship with the mitochondrial metabolism of the host, in which the bacterium mostly depends on host ATP synthesis at an early stage, and at later stages it can sustain its own energy needs through the formation of a sodium gradient.
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Affiliation(s)
- Pingdong Liang
- From the Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
| | - Mónica Rosas-Lemus
- From the Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
| | - Dhwani Patel
- From the Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
| | - Xuan Fang
- From the Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
| | - Karina Tuz
- From the Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
| | - Oscar Juárez
- From the Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois 60616
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The Biological Fight Against Pathogenic Bacteria and Protozoa. NEW WEAPONS TO CONTROL BACTERIAL GROWTH 2016. [PMCID: PMC7123701 DOI: 10.1007/978-3-319-28368-5_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The animal gastrointestinal tract is a tube with two open ends; hence, from the microbial point of view it constitutes an open system, as opposed to the circulatory system that must be a tightly closed microbial-free environment. In particular, the human intestine spans ca. 200 m2 and represents a massive absorptive surface composed of a layer of epithelial cells as well as a paracellular barrier. The permeability of this paracellular barrier is regulated by transmembrane proteins known as claudins that play a critical role in tight junctions.
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Human Bacterial Diseases from Ocean. Infect Dis (Lond) 2013. [DOI: 10.1007/978-1-4614-5719-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Exposure to solute stress affects genome-wide expression but not the polycyclic aromatic hydrocarbon-degrading activity of Sphingomonas sp. strain LH128 in biofilms. Appl Environ Microbiol 2012; 78:8311-20. [PMID: 23001650 DOI: 10.1128/aem.02516-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Members of the genus Sphingomonas are important catalysts for removal of polycyclic aromatic hydrocarbons (PAHs) in soil, but their activity can be affected by various stress factors. This study examines the physiological and genome-wide transcription response of the phenanthrene-degrading Sphingomonas sp. strain LH128 in biofilms to solute stress (invoked by 450 mM NaCl solution), either as an acute (4-h) or a chronic (3-day) exposure. The degree of membrane fatty acid saturation was increased as a response to chronic stress. Oxygen consumption in the biofilms and phenanthrene mineralization activities of biofilm cells were, however, not significantly affected after imposing either acute or chronic stress. This finding was in agreement with the transcriptomic data, since genes involved in PAH degradation were not differentially expressed in stressed conditions compared to nonstressed conditions. The transcriptomic data suggest that LH128 adapts to NaCl stress by (i) increasing the expression of genes coping with osmolytic and ionic stress such as biosynthesis of compatible solutes and regulation of ion homeostasis, (ii) increasing the expression of genes involved in general stress response, (iii) changing the expression of general and specific regulatory functions, and (iv) decreasing the expression of protein synthesis such as proteins involved in motility. Differences in gene expression between cells under acute and chronic stress suggest that LH128 goes through changes in genome-wide expression to fully adapt to NaCl stress, without significantly changing phenanthrene degrading activity.
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Mulkidjanian AY, Dibrov P, Galperin MY. The past and present of sodium energetics: may the sodium-motive force be with you. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:985-92. [PMID: 18485887 DOI: 10.1016/j.bbabio.2008.04.028] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 04/18/2008] [Accepted: 04/18/2008] [Indexed: 10/22/2022]
Abstract
All living cells routinely expel Na(+) ions, maintaining lower concentration of Na(+) in the cytoplasm than in the surrounding milieu. In the vast majority of bacteria, as well as in mitochondria and chloroplasts, export of Na(+) occurs at the expense of the proton-motive force. Some bacteria, however, possess primary generators of the transmembrane electrochemical gradient of Na(+) (sodium-motive force). These primary Na(+) pumps have been traditionally seen as adaptations to high external pH or to high temperature. Subsequent studies revealed, however, the mechanisms for primary sodium pumping in a variety of non-extremophiles, such as marine bacteria and certain bacterial pathogens. Further, many alkaliphiles and hyperthermophiles were shown to rely on H(+), not Na(+), as the coupling ion. We review here the recent progress in understanding the role of sodium-motive force, including (i) the conclusion on evolutionary primacy of the sodium-motive force as energy intermediate, (ii) the mechanisms, evolutionary advantages and limitations of switching from Na(+) to H(+) as the coupling ion, and (iii) the possible reasons why certain pathogenic bacteria still rely on the sodium-motive force.
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Kurz M, Brünig ANS, Galinski EA. NhaD type sodium/proton-antiporter of Halomonas elongata: a salt stress response mechanism in marine habitats? SALINE SYSTEMS 2006; 2:10. [PMID: 16872527 PMCID: PMC1552076 DOI: 10.1186/1746-1448-2-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 07/27/2006] [Indexed: 02/04/2023]
Abstract
Background Sodium/proton-antiporters (Nha) are known to play an important role in pH- and Na+-homeostasis. In microorganisms several types with different capacity, affinity and selectivity for Na+ and Li+ exist. The homeostasis system of E. coli, NhaA and NhaB, is well researched, but the function of other types of Na+/H+-antiporters like NhaD is yet to be fully understood. Since several antiporters play an important role at various points in the physiology of higher organisms, one can speculate that the main functions of some of those procaryotic antiporters differ from pH- and Na+-homeostasis. Results This study investigates the function and regulation of a gene encoding for a NhaD type antiporter which was discovered in the halophilic eubacterium Halomonas elongata. The deduced primary amino acid sequence of the abovementioned gene showed more than 60% identity to known antiporters of the NhaD type from Alkalimonas amylolytica, Shewanella oneidensis and several other marine organisms of the γ-Proteobacteria. Evidence was found for a dual regulation of H. elongata NhaD expression. The gene was cloned and expressed in E. coli. Antiporter deficient NaCl and LiCl sensitive E. coli mutants EP432 and KNabc were partially complemented by a plasmid carrying the H. elongata nhaD gene. Surprisingly the LiCl sensitivity of E. coli strain DH5α having a complete homeostasis system was increased when NhaD was co-expressed. Conclusion Since NhaD is an antiporter known so far only from halophilic or haloalcaliphilic Proteobacteria one can speculate that this type of antiporter provides a special mechanism for adaptation to marine habitats. As was already speculated – though without supporting data – and substantiated in this study this might be active Na+-import for osmoregulatory purposes.
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Affiliation(s)
- Matthias Kurz
- Institut für Mikrobiologie und Biotechnologie, Rheinische Friedrich Wilhelms-Universität Bonn, Meckenheimer Allee, Bonn, Germany
| | - Anika NS Brünig
- Institut für Mikrobiologie und Biotechnologie, Rheinische Friedrich Wilhelms-Universität Bonn, Meckenheimer Allee, Bonn, Germany
| | - Erwin A Galinski
- Institut für Mikrobiologie und Biotechnologie, Rheinische Friedrich Wilhelms-Universität Bonn, Meckenheimer Allee, Bonn, Germany
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Faruque SM, Biswas K, Udden SMN, Ahmad QS, Sack DA, Nair GB, Mekalanos JJ. Transmissibility of cholera: in vivo-formed biofilms and their relationship to infectivity and persistence in the environment. Proc Natl Acad Sci U S A 2006; 103:6350-5. [PMID: 16601099 PMCID: PMC1458881 DOI: 10.1073/pnas.0601277103] [Citation(s) in RCA: 217] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The factors that enhance the waterborne spread of bacterial epidemics and sustain the epidemic strain in nature are unclear. Although the epidemic diarrheal disease cholera is known to be transmitted by water contaminated with pathogenic Vibrio cholerae, routine isolation of pathogenic strains from aquatic environments is challenging. Here, we show that conditionally viable environmental cells (CVEC) of pathogenic V. cholerae that resist cultivation by conventional techniques exist in surface water as aggregates (biofilms) of partially dormant cells. Such CVEC can be recovered as fully virulent bacteria by inoculating the water into rabbit intestines. Furthermore, when V. cholerae shed in stools of cholera patients are inoculated in environmental water samples in the laboratory, the cells exhibit characteristics similar to CVEC, suggesting that CVEC are the infectious form of V. cholerae in water and that CVEC in nature may have been derived from human cholera stools. We also observed that stools from cholera patients contain a heterogeneous mixture of biofilm-like aggregates and free-swimming planktonic cells of V. cholerae. Estimation of the relative infectivity of these different forms of V. cholerae cells suggested that the enhanced infectivity of V. cholerae shed in human stools is largely due to the presence of clumps of cells that disperse in vivo, providing a high dose of the pathogen. The results of this study support a model of cholera transmission in which in vivo-formed biofilms contribute to enhanced infectivity and environmental persistence of pathogenic V. cholerae.
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Affiliation(s)
- Shah M. Faruque
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
- To whom correspondence may be addressed. E-mail:
, , or
| | - Kuntal Biswas
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - S. M. Nashir Udden
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - Qazi Shafi Ahmad
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - David A. Sack
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
| | - G. Balakrish Nair
- *Molecular Genetics Laboratory, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka-1212, Bangladesh; and
- To whom correspondence may be addressed. E-mail:
, , or
| | - John J. Mekalanos
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115
- To whom correspondence may be addressed. E-mail:
, , or
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