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Dávila MJ, Mayer C. Structural Phenomena in a Vesicle Membrane Obtained through an Evolution Experiment: A Study Based on MD Simulations. Life (Basel) 2023; 13:1735. [PMID: 37629592 PMCID: PMC10455627 DOI: 10.3390/life13081735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
The chemical evolution of biomolecules was clearly affected by the overall extreme environmental conditions found on Early Earth. Periodic temperature changes inside the Earth's crust may have played a role in the emergence and survival of functional peptides embedded in vesicular compartments. In this study, all-atom molecular dynamic (MD) simulations were used to elucidate the effect of temperature on the properties of functionalized vesicle membranes. A plausible prebiotic system was selected, constituted by a model membrane bilayer from an equimolar mixture of long-chain fatty acids and fatty amines, and an octapeptide, KSPFPFAA, previously identified as an optimized functional peptide in an evolution experiment. This peptide tends to form the largest spontaneous aggregates at higher temperatures, thereby enhancing the pore-formation process and the eventual transfer of essential molecules in a prebiotic scenario. The analyses also suggest that peptide-amphiphile interactions affect the structural properties of the membrane, with a significant increase in the degree of interdigitation at the lowest temperatures under study.
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Affiliation(s)
- María J. Dávila
- Institute of Physical Chemistry, CENIDE, University of Duisburg-Essen, 45141 Essen, Germany;
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2
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Ozu M, Galizia L, Alvear-Arias JJ, Fernández M, Caviglia A, Zimmermann R, Guastaferri F, Espinoza-Muñoz N, Sutka M, Sigaut L, Pietrasanta LI, González C, Amodeo G, Garate JA. Mechanosensitive aquaporins. Biophys Rev 2023; 15:497-513. [PMID: 37681084 PMCID: PMC10480384 DOI: 10.1007/s12551-023-01098-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/04/2023] [Indexed: 09/09/2023] Open
Abstract
Cellular systems must deal with mechanical forces to satisfy their physiological functions. In this context, proteins with mechanosensitive properties play a crucial role in sensing and responding to environmental changes. The discovery of aquaporins (AQPs) marked a significant breakthrough in the study of water transport. Their transport capacity and regulation features make them key players in cellular processes. To date, few AQPs have been reported to be mechanosensitive. Like mechanosensitive ion channels, AQPs respond to tension changes in the same range. However, unlike ion channels, the aquaporin's transport rate decreases as tension increases, and the molecular features of the mechanism are unknown. Nevertheless, some clues from mechanosensitive ion channels shed light on the AQP-membrane interaction. The GxxxG motif may play a critical role in the water permeation process associated with structural features in AQPs. Consequently, a possible gating mechanism triggered by membrane tension changes would involve a conformational change in the cytoplasmic extreme of the single file region of the water pathway, where glycine and histidine residues from loop B play a key role. In view of their transport capacity and their involvement in relevant processes related to mechanical forces, mechanosensitive AQPs are a fundamental piece of the puzzle for understanding cellular responses.
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Affiliation(s)
- Marcelo Ozu
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Luciano Galizia
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Juan José Alvear-Arias
- Interdisciplinary Center of Neurosciences of Valparaiso, University of Valparaiso, CINV, 2360102 Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Santiago, Chile
| | - Miguel Fernández
- Interdisciplinary Center of Neurosciences of Valparaiso, University of Valparaiso, CINV, 2360102 Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Santiago, Chile
| | - Agustín Caviglia
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Rosario Zimmermann
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Florencia Guastaferri
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Present Address: Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET-UNR), Rosario, Argentina
| | - Nicolás Espinoza-Muñoz
- Interdisciplinary Center of Neurosciences of Valparaiso, University of Valparaiso, CINV, 2360102 Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Santiago, Chile
| | - Moira Sutka
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lorena Sigaut
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Física, Buenos Aires, Argentina
- Instituto de Física de Buenos Aires (IFIBA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Lía Isabel Pietrasanta
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Física, Buenos Aires, Argentina
- Instituto de Física de Buenos Aires (IFIBA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Carlos González
- Millennium Nucleus in NanoBioPhysics, Santiago, Chile
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL 33136 USA
- Present Address: Molecular Bioscience Department, University of Texas, Austin, TX 78712 USA
| | - Gabriela Amodeo
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - José Antonio Garate
- Interdisciplinary Center of Neurosciences of Valparaiso, University of Valparaiso, CINV, 2360102 Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Santiago, Chile
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Bellavista, Santiago, Chile
- Centro Científico y Tecnológico de Excelencia Ciencia y Vida, Universidad San Sebastián, 7750000 Santiago, Chile
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Adams JD, Sander KB, Criddle CS, Arkin AP, Clark DS. Engineering osmolysis susceptibility in Cupriavidus necator and Escherichia coli for recovery of intracellular products. Microb Cell Fact 2023; 22:69. [PMID: 37046248 PMCID: PMC10091555 DOI: 10.1186/s12934-023-02064-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/16/2023] [Indexed: 04/14/2023] Open
Abstract
BACKGROUND Intracellular biomacromolecules, such as industrial enzymes and biopolymers, represent an important class of bio-derived products obtained from bacterial hosts. A common key step in the downstream separation of these biomolecules is lysis of the bacterial cell wall to effect release of cytoplasmic contents. Cell lysis is typically achieved either through mechanical disruption or reagent-based methods, which introduce issues of energy demand, material needs, high costs, and scaling problems. Osmolysis, a cell lysis method that relies on hypoosmotic downshock upon resuspension of cells in distilled water, has been applied for bioseparation of intracellular products from extreme halophiles and mammalian cells. However, most industrial bacterial strains are non-halotolerant and relatively resistant to hypoosmotic cell lysis. RESULTS To overcome this limitation, we developed two strategies to increase the susceptibility of non-halotolerant hosts to osmolysis using Cupriavidus necator, a strain often used in electromicrobial production, as a prototypical strain. In one strategy, C. necator was evolved to increase its halotolerance from 1.5% to 3.25% (w/v) NaCl through adaptive laboratory evolution, and genes potentially responsible for this phenotypic change were identified by whole genome sequencing. The evolved halotolerant strain experienced an osmolytic efficiency of 47% in distilled water following growth in 3% (w/v) NaCl. In a second strategy, the cells were made susceptible to osmolysis by knocking out the large-conductance mechanosensitive channel (mscL) gene in C. necator. When these strategies were combined by knocking out the mscL gene from the evolved halotolerant strain, greater than 90% osmolytic efficiency was observed upon osmotic downshock. A modified version of this strategy was applied to E. coli BL21 by deleting the mscL and mscS (small-conductance mechanosensitive channel) genes. When grown in medium with 4% NaCl and subsequently resuspended in distilled water, this engineered strain experienced 75% cell lysis, although decreases in cell growth rate due to higher salt concentrations were observed. CONCLUSIONS Our strategy is shown to be a simple and effective way to lyse cells for the purification of intracellular biomacromolecules and may be applicable in many bacteria used for bioproduction.
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Affiliation(s)
- Jeremy David Adams
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Kyle B Sander
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Craig S Criddle
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Adam P Arkin
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Douglas S Clark
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.
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Sidarta M, Baruah L, Wenzel M. Roles of Bacterial Mechanosensitive Channels in Infection and Antibiotic Susceptibility. Pharmaceuticals (Basel) 2022; 15:ph15070770. [PMID: 35890069 PMCID: PMC9322971 DOI: 10.3390/ph15070770] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/17/2022] [Accepted: 06/19/2022] [Indexed: 02/01/2023] Open
Abstract
Bacteria accumulate osmolytes to prevent cell dehydration during hyperosmotic stress. A sudden change to a hypotonic environment leads to a rapid water influx, causing swelling of the protoplast. To prevent cell lysis through osmotic bursting, mechanosensitive channels detect changes in turgor pressure and act as emergency-release valves for the ions and osmolytes, restoring the osmotic balance. This adaptation mechanism is well-characterized with respect to the osmotic challenges bacteria face in environments such as soil or an aquatic habitat. However, mechanosensitive channels also play a role during infection, e.g., during host colonization or release into environmental reservoirs. Moreover, recent studies have proposed roles for mechanosensitive channels as determinants of antibiotic susceptibility. Interestingly, some studies suggest that they serve as entry gates for antimicrobials into cells, enhancing antibiotic efficiency, while others propose that they play a role in antibiotic-stress adaptation, reducing susceptibility to certain antimicrobials. These findings suggest different facets regarding the relevance of mechanosensitive channels during infection and antibiotic exposure as well as illustrate that they may be interesting targets for antibacterial chemotherapy. Here, we summarize the recent findings on the relevance of mechanosensitive channels for bacterial infections, including transitioning between host and environment, virulence, and susceptibility to antimicrobials, and discuss their potential as antibacterial drug targets.
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Guo Y. Detergent-free systems for structural studies of membrane proteins. Biochem Soc Trans 2021; 49:1361-1374. [PMID: 34110369 PMCID: PMC8276625 DOI: 10.1042/bst20201080] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/03/2021] [Accepted: 05/17/2021] [Indexed: 11/17/2022]
Abstract
Membrane proteins play vital roles in living organisms, serving as targets for most currently prescribed drugs. Membrane protein structural biology aims to provide accurate structural information to understand their mechanisms of action. The advance of membrane protein structural biology has primarily relied on detergent-based methods over the past several decades. However, detergent-based approaches have significant drawbacks because detergents often damage the native protein-lipid interactions, which are often crucial for maintaining the natural structure and function of membrane proteins. Detergent-free methods recently have emerged as alternatives with a great promise, e.g. for high-resolution structure determinations of membrane proteins in their native cell membrane lipid environments. This minireview critically examines the current status of detergent-free methods by a comparative analysis of five groups of membrane protein structures determined using detergent-free and detergent-based methods. This analysis reveals that current detergent-free systems, such as the styrene-maleic acid lipid particles (SMALP), the diisobutyl maleic acid lipid particles (DIBMALP), and the cycloalkane-modified amphiphile polymer (CyclAPol) technologies are not better than detergent-based approaches in terms of maintenance of native cell membrane lipids on the transmembrane domain and high-resolution structure determination. However, another detergent-free technology, the native cell membrane nanoparticles (NCMN) system, demonstrated improved maintenance of native cell membrane lipids with the studied membrane proteins, and produced particles that were suitable for high-resolution structural analysis. The ongoing development of new membrane-active polymers and their optimization will facilitate the maturation of these new detergent-free systems.
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Affiliation(s)
- Youzhong Guo
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23298-0540, USA
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Johnson SC, Veres J, Malcolm HR. Exploring the diversity of mechanosensitive channels in bacterial genomes. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:25-36. [PMID: 33244613 DOI: 10.1007/s00249-020-01478-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/08/2020] [Accepted: 11/08/2020] [Indexed: 10/22/2022]
Abstract
Mechanosensitive ion channels are responsible for touch sensation and proprioception in higher level organisms such as humans and recovery after osmotic stress in bacteria. Bacterial mechanosensitive channels are homologous to either the mechanosensitive channel of large conductance (MscL) or the mechanosensitive channel of small conductance (MscS). In the E. coli genome there are seven unique mechanosensitive channels, a single MscL homologue, and six MscS homologues. The six MscS homologues are members of the diverse MscS superfamily of ion channels, and these channels show variation on both the N and C termini when compared to E. coli MscS. In bacterial strains with phenotypic analysis of the endogenous mechanosensors, the quantity of MscS superfamily members in the genome range from 2 to 6 and all of the strains contain a copy of MscL. Here, we show an in-depth analysis of over 150 diverse bacterial genomes, encompassing nine phyla, to determine the number of genomes that contain an MscL homologue and the average number of MscS superfamily members per genome. We determined that the average genome contains 4 ± 3 MscS homologues and 67% of bacterial genomes encode for a MscL homologue.
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Affiliation(s)
- Sarah C Johnson
- Department of Chemistry, University of North Florida, Jacksonville, FL, USA
| | - Jordyn Veres
- Department of Chemistry, University of North Florida, Jacksonville, FL, USA
| | - Hannah R Malcolm
- Department of Chemistry, University of North Florida, Jacksonville, FL, USA.
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Ancestral Reconstructions Decipher Major Adaptations of Ammonia-Oxidizing Archaea upon Radiation into Moderate Terrestrial and Marine Environments. mBio 2020; 11:mBio.02371-20. [PMID: 33051370 PMCID: PMC7554672 DOI: 10.1128/mbio.02371-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Unlike all other archaeal lineages, ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota are widespread and abundant in all moderate and oxic environments on Earth. The evolutionary adaptations that led to such unprecedented ecological success of a microbial clade characterized by highly conserved energy and carbon metabolisms have, however, remained underexplored. Here, we reconstructed the genomic content and growth temperature of the ancestor of all AOA, as well as the ancestors of the marine and soil lineages, based on 39 available complete or nearly complete genomes of AOA. Our evolutionary scenario depicts an extremely thermophilic, autotrophic, aerobic ancestor from which three independent lineages of a marine and two terrestrial groups radiated into moderate environments. Their emergence was paralleled by (i) a continuous acquisition of an extensive collection of stress tolerance genes mostly involved in redox maintenance and oxygen detoxification, (ii) an expansion of regulatory capacities in transcription and central metabolic functions, and (iii) an extended repertoire of cell appendages and modifications related to adherence and interactions with the environment. Our analysis provides insights into the evolutionary transitions and key processes that enabled the conquest of the diverse environments in which contemporary AOA are found.
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Bocchero U, Falleroni F, Mortal S, Li Y, Cojoc D, Lamb T, Torre V. Mechanosensitivity is an essential component of phototransduction in vertebrate rods. PLoS Biol 2020; 18:e3000750. [PMID: 32667916 PMCID: PMC7384764 DOI: 10.1371/journal.pbio.3000750] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/27/2020] [Accepted: 06/26/2020] [Indexed: 12/01/2022] Open
Abstract
Photoreceptors are specialized cells devoted to the transduction of the incoming visual signals. Rods are able also to shed from their tip old disks and to synthesize at the base of the outer segment (OS) new disks. By combining electrophysiology, optical tweezers (OTs), and biochemistry, we investigate mechanosensitivity in the rods of Xenopus laevis, and we show that 1) mechanosensitive channels (MSCs), transient receptor potential canonical 1 (TRPC1), and Piezo1 are present in rod inner segments (ISs); 2) mechanical stimulation—of the order of 10 pN—applied briefly to either the OS or IS evokes calcium transients; 3) inhibition of MSCs decreases the duration of photoresponses to bright flashes; 4) bright flashes of light induce a rapid shortening of the OS; and 5) the genes encoding the TRPC family have an ancient association with the genes encoding families of protein involved in phototransduction. These results suggest that MSCs play an integral role in rods’ phototransduction. It is widely thought that sensory neurons are specialized to transduce just a single sensory modality. A combination of electrophysiology, optical tweezers, and histochemistry reveals that rod photoreceptors not only express mechanosensitive channels but display mechanosensitivity, which is crucial for phototransduction.
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Affiliation(s)
- Ulisse Bocchero
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Fabio Falleroni
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Simone Mortal
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Yunzhen Li
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
| | - Dan Cojoc
- Institute of Materials, National Research Council of Italy (CNR), Trieste, Italy
| | - Trevor Lamb
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Vincent Torre
- Neurobiology Department, International School for Advanced Studies, Trieste, Italy
- Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Zhejiang, China
- Center of Systems Medicine, Chinese Academy of Medical Sciences, Suzhou Institute of Systems Medicine, Suzhou Industrial Park, Suzhou, China
- * E-mail:
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Li WL, Wang JF, Lv Y, Dong HJ, Wang LL, He T, Li QS. Improving cadmium mobilization by phosphate-solubilizing bacteria via regulating organic acids metabolism with potassium. CHEMOSPHERE 2020; 244:125475. [PMID: 31812769 DOI: 10.1016/j.chemosphere.2019.125475] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Organic acids secreted by phosphorus-solubilizing bacteria (PSB) is one of the main biological metabolites with cadmium (Cd) mobilization capacity in the conversion of insoluble precipitate forms to bioavailable forms in contaminated soil. However, the fluctuating concentrations of nutrient elements caused by agricultural activities may result in the substantial variances of carbohydrate metabolism of microorganisms involved in Cd remediation, it is therefore essential to study how metabolic strategies, especially for organic acids, affected by the environmentally friendly fertilizers, such as potassium (K). In this study, adding K+ (KCl) concentrations from 0.0 to 100.0 mg/L in medium clearly accelerated Cd mobilization from 15.9 to 35.9 mg/L via inducing the secretion of tartaric acid, 3-hydroxybutyrate, fumaric and succinic acids, increased by 10.0-, 7.5-, 4.3- and 4.1-fold changes, respectively. Current data revealed that the significant differences of metabolic pathways and genes expressions with the varied K+ concentrations included: ⅰ) K+ induces a substantial up-regulation in metabolic pathway of pyruvic acid to oxaloacetate and tartaric acids; ⅱ) the varied expression of genes involved in encoding enzymes of tricarboxylic acid cycle result in the up-regulated fumaric acid, succinic acid and 3-hydroxybutyrate; ⅲ) the expression of genes related enzyme cysteine and glutamate metabolism processes promoted with the increasing bioavailable Cd concentrations. Besides, P-type ATPase activity increased with K+ levels, indicating that H+ efflux and medium acidification were strengthened. In general, an appropriate enhancement of K based fertilizer is an effective manner for soil Cd remediation via the regulation of organic acids metabolism and H+ secretion of PSB.
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Affiliation(s)
- Wan-Li Li
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Jun-Feng Wang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Yao Lv
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Hao-Jie Dong
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Li-Li Wang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Tao He
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Qu-Sheng Li
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China.
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Zhao Y, Lv B, Sun F, Liu J, Wang Y, Gao Y, Qi F, Chang Z, Fu X. Rapid Freezing Enables Aminoglycosides To Eradicate Bacterial Persisters via Enhancing Mechanosensitive Channel MscL-Mediated Antibiotic Uptake. mBio 2020; 11:e03239-19. [PMID: 32047133 PMCID: PMC7018644 DOI: 10.1128/mbio.03239-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/06/2020] [Indexed: 12/24/2022] Open
Abstract
Bacterial persisters exhibit noninherited antibiotic tolerance and are linked to the recalcitrance of bacterial infections. It is very urgent but also challenging to develop antipersister strategies. Here, we report that 10-s freezing with liquid nitrogen dramatically enhances the bactericidal action of aminoglycoside antibiotics by 2 to 6 orders of magnitude against many Gram-negative pathogens, with weaker potentiation effects on Gram-positive bacteria. In particular, antibiotic-tolerant Escherichia coli and Pseudomonas aeruginosa persisters-which were prepared by treating exponential-phase cells with ampicillin, ofloxacin, the protonophore cyanide m-chlorophenyl hydrazone (CCCP), or bacteriostatic antibiotics-can be effectively killed. We demonstrated, as a proof of concept, that freezing potentiated the aminoglycosides' killing of P. aeruginosa persisters in a mouse acute skin wound model. Mechanistically, freezing dramatically increased the bacterial uptake of aminoglycosides regardless of the presence of CCCP, indicating that the effects are independent of the proton motive force (PMF). In line with these results, we found that the effects were linked to freezing-induced cell membrane damage and were attributable, at least partly, to the mechanosensitive ion channel MscL, which was able to directly mediate such freezing-enhanced aminoglycoside uptake. In view of these results, we propose that the freezing-induced aminoglycoside potentiation is achieved by freezing-induced cell membrane destabilization, which, in turn, activates the MscL channel, which is able to effectively take up aminoglycosides in a PMF-independent manner. Our work may pave the way for the development of antipersister strategies that utilize the same mechanism as freezing but do so without causing any injury to animal cells.IMPORTANCE Antibiotics have long been used to successfully kill bacterial pathogens, but antibiotic resistance/tolerance usually has led to the failure of antibiotic therapy, and it has become a severe threat to human health. How to improve the efficacy of existing antibiotics is of importance for combating antibiotic-resistant/tolerant pathogens. Here, we report that 10-s rapid freezing with liquid nitrogen dramatically enhanced the bactericidal action of aminoglycoside antibiotics by 2 to 6 orders of magnitude against many bacterial pathogens in vitro and also in a mouse skin wound model. In particular, such combined treatment was able to effectively kill persister cells of Escherichia coli and Pseudomonas aeruginosa, which are per se tolerant of conventional treatment with bactericidal antibiotics for several hours. We also demonstrated that freezing-induced aminoglycoside potentiation was apparently linked to freezing-induced cell membrane damage that may have activated the mechanosensitive ion channel MscL, which, in turn, was able to effectively uptake aminoglycoside antibiotics in a proton motive force-independent manner. Our report sheds light on the development of a new strategy against bacterial pathogens by combining existing antibiotics with a conventional physical treatment or with MscL agonists.
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Affiliation(s)
- Yanna Zhao
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou City, Fujian Province, China
| | - Boyan Lv
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou City, Fujian Province, China
| | - Fengqi Sun
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou City, Fujian Province, China
| | - Jiafeng Liu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Yan Wang
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou City, Fujian Province, China
| | - Yuanyuan Gao
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou City, Fujian Province, China
- Engineering Research Center of Industrial Microbiology of Ministry of Education, Fujian Normal University, Fuzhou City, Fujian Province, China
| | - Feng Qi
- Engineering Research Center of Industrial Microbiology of Ministry of Education, Fujian Normal University, Fuzhou City, Fujian Province, China
| | - Zengyi Chang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Xinmiao Fu
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou City, Fujian Province, China
- Engineering Research Center of Industrial Microbiology of Ministry of Education, Fujian Normal University, Fuzhou City, Fujian Province, China
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11
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Life with Bacterial Mechanosensitive Channels, from Discovery to Physiology to Pharmacological Target. Microbiol Mol Biol Rev 2020; 84:84/1/e00055-19. [PMID: 31941768 DOI: 10.1128/mmbr.00055-19] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
General principles in biology have often been elucidated from the study of bacteria. This is true for the bacterial mechanosensitive channel of large conductance, MscL, the channel highlighted in this review. This channel functions as a last-ditch emergency release valve discharging cytoplasmic solutes upon decreases in osmotic environment. Opening the largest gated pore, MscL passes molecules up to 30 Å in diameter; exaggerated conformational changes yield advantages for study, including in vivo assays. MscL contains structural/functional themes that recur in higher organisms and help elucidate how other, structurally more complex, channels function. These features of MscL include (i) the ability to directly sense, and respond to, biophysical changes in the membrane, (ii) an α helix ("slide helix") or series of charges ("knot in a rope") at the cytoplasmic membrane boundary to guide transmembrane movements, and (iii) important subunit interfaces that, when disrupted, appear to cause the channel to gate inappropriately. MscL may also have medical applications: the modality of the MscL channel can be changed, suggesting its use as a triggered nanovalve in nanodevices, including those for drug targeting. In addition, recent studies have shown that the antibiotic streptomycin opens MscL and uses it as one of the primary paths to the cytoplasm. Moreover, the recent identification and study of novel specific agonist compounds demonstrate that the channel is a valid drug target. Such compounds may serve as novel-acting antibiotics and adjuvants, a way of permeabilizing the bacterial cell membrane and, thus, increasing the potency of commonly used antibiotics.
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12
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King MM, Kayastha BB, Franklin MJ, Patrauchan MA. Calcium Regulation of Bacterial Virulence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:827-855. [PMID: 31646536 DOI: 10.1007/978-3-030-12457-1_33] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+) is a universal signaling ion, whose major informational role shaped the evolution of signaling pathways, enabling cellular communications and responsiveness to both the intracellular and extracellular environments. Elaborate Ca2+ regulatory networks have been well characterized in eukaryotic cells, where Ca2+ regulates a number of essential cellular processes, ranging from cell division, transport and motility, to apoptosis and pathogenesis. However, in bacteria, the knowledge on Ca2+ signaling is still fragmentary. This is complicated by the large variability of environments that bacteria inhabit with diverse levels of Ca2+. Yet another complication arises when bacterial pathogens invade a host and become exposed to different levels of Ca2+ that (1) are tightly regulated by the host, (2) control host defenses including immune responses to bacterial infections, and (3) become impaired during diseases. The invading pathogens evolved to recognize and respond to the host Ca2+, triggering the molecular mechanisms of adhesion, biofilm formation, host cellular damage, and host-defense resistance, processes enabling the development of persistent infections. In this review, we discuss: (1) Ca2+ as a determinant of a host environment for invading bacterial pathogens, (2) the role of Ca2+ in regulating main events of host colonization and bacterial virulence, and (3) the molecular mechanisms of Ca2+ signaling in bacterial pathogens.
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Affiliation(s)
- Michelle M King
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Biraj B Kayastha
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Michael J Franklin
- Department of Microbiology and Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
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13
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Willson BJ, Chapman LNM, Thomas GH. Evolutionary dynamics of membrane transporters and channels: enhancing function through fusion. Curr Opin Genet Dev 2019; 58-59:76-86. [DOI: 10.1016/j.gde.2019.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 02/05/2023]
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14
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Mesgari-Shadi A, Sarrafzadeh MH, Barar J, Omidi Y. Cost-effective batch production process of scFv antibody in Escherichia coli. Hum Antibodies 2018. [PMID: 29526846 DOI: 10.3233/hab-180333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cost-effective production of antibody (Ab) fragments is of great interests of many pharmaceutical industries, in large part due to their high usages in research, diagnosis and therapy. Thus, the production of Abs necessitates accomplishment of the optimal strategies. OBJECTIVE In this study, based on the induction start time using arabinose, we implemented a novel strategy for the cost-effective production of single chain variable fragment (scFv) in Escherichia coli (E. coli). METHODS Complex and minimum media were used to investigate the batch fermentation in 50 mL batch tubes to find the optimum conditions for the production of a scFv in the Escherichia coli HB2151. RESULTS Arabinose was used as an appropriate economical alternative of isopropyl β-D-1-thiogalactopyranoside (IPTG) for the production of scFv antibody. The optimum concentration of arabinose as an inducer was 0.1% (w/w), while below this point the scFv production yield (YP/X) decreased significantly. The start time of the induction of E. coli HB2151 cells was adjusted to the stationary phase of the growth, and the results showed higher specific scFv production yields up to 0.9 mg scFv/g biomass in the minimum media. The optimum induction duration times for the complex and minimum media were about 12 and 24 hours, respectively. CONCLUSIONS We propose this method to possibly be used for the large-scale production of recombinant proteins/peptides such as scFv and Fab antibodies.
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Affiliation(s)
- Ali Mesgari-Shadi
- School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran.,Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Jaleh Barar
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yadollah Omidi
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
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15
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Nakayama Y, Komazawa K, Bavi N, Hashimoto KI, Kawasaki H, Martinac B. Evolutionary specialization of MscCG, an MscS-like mechanosensitive channel, in amino acid transport in Corynebacterium glutamicum. Sci Rep 2018; 8:12893. [PMID: 30150671 PMCID: PMC6110860 DOI: 10.1038/s41598-018-31219-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/14/2018] [Indexed: 11/09/2022] Open
Abstract
MscCG, a mechanosensitive channel of Corynebacterium glutamicum provides a major export mechanism for glutamate in this Gram-positive bacterium, which has for many years been used for industrial production of glutamate and other amino acids. The functional characterization of MscCG is therefore, of great significance to understand its conductive properties for different amino acids. Here we report the first successful giant spheroplast preparation of C. glutamicum amenable to the patch clamp technique, which enabled us to investigate mechanosensitive channel activities of MscCG in the native membrane of this bacterium. Single channel recordings from these spheroplasts revealed the presence of three types of mechanosensitive channels, MscCG, MscCG2, and CgMscL, which differ largely from each other in their conductance and mechanosensitivity. MscCG has a relatively small conductance of ~340 pS followed by an intermediate MscCG2 conductance of ~1.0 nS and comparably very large conductance of 3.7 nS exhibited by CgMscL. By applying Laplace's law, we determined that very moderate membrane tension of ~5.5 mN/m was required for half activation of MscCG compared to ~12 mN/m required for half activation of both MscCG2 and CgMscL. Furthermore, by combining the micropipette aspiration technique with molecular dynamics simulations we measured mechanical properties of the C. glutamicum membrane, whose area elasticity module of KA ≈ 15 mN/m is characteristic of a very soft membrane compared to the three times larger area expansion modulus of KA ≈ 44 mN/m of the more elastic E. coli membrane. Moreover, we demonstrate that the "soft" properties of the C. glutamicum membrane have a significant impact on the MscCG gating characterized by a strong voltage-dependent hysteresis in the membrane of C. glutamicum compared to a complete absence of the hysteresis in the E. coli cell membrane. We thus propose that MscCG has evolved and adapted as an MscS-like channel to the mechanical properties of the C. glutamicum membrane enabling the channel to specialize in transport of amino acids such as glutamate, which are major osmolytes helping the bacterial cells survive extreme osmotic stress.
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Affiliation(s)
- Yoshitaka Nakayama
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Kosuke Komazawa
- Department of Green and Sustainable Chemistry, Tokyo Denki University, 5 Asahi-cho, Senju, Adachi-ku, Tokyo, 120-8551, Japan
| | - Navid Bavi
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, Faculty of Medicine, The University of New South Wales, Darlinghurst, NSW, 2010, Australia.,Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, 60637, USA
| | - Ken-Ichi Hashimoto
- Department of Green and Sustainable Chemistry, Tokyo Denki University, 5 Asahi-cho, Senju, Adachi-ku, Tokyo, 120-8551, Japan
| | - Hisashi Kawasaki
- Department of Green and Sustainable Chemistry, Tokyo Denki University, 5 Asahi-cho, Senju, Adachi-ku, Tokyo, 120-8551, Japan
| | - Boris Martinac
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia. .,St Vincent's Clinical School, Faculty of Medicine, The University of New South Wales, Darlinghurst, NSW, 2010, Australia.
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16
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Maksaev G, Shoots JM, Ohri S, Haswell ES. Nonpolar residues in the presumptive pore-lining helix of mechanosensitive channel MSL10 influence channel behavior and establish a nonconducting function. PLANT DIRECT 2018; 2:e00059. [PMID: 30506019 PMCID: PMC6261518 DOI: 10.1002/pld3.59] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Mechanosensitive (MS) ion channels provide a universal mechanism for sensing and responding to increased membrane tension. MscS-like (MSL) 10 is a relatively well-studied MS ion channel from Arabidopsis thaliana that is implicated in cell death signaling. The relationship between the amino acid sequence of MSL10 and its conductance, gating tension, and opening and closing kinetics remains unstudied. Here, we identify several nonpolar residues in the presumptive pore-lining transmembrane helix of MSL10 (TM6) that contribute to these basic channel properties. F553 and I554 are essential for wild type channel conductance and the stability of the open state. G556, a glycine residue located at a predicted kink in TM6, is essential for channel conductance. The increased tension sensitivity of MSL10 compared to close homolog MSL8 may be attributed to F563, but other channel characteristics appear to be dictated by more global differences in structure. Finally, MSL10 F553V and MSL10 G556V provided the necessary tools to establish that MSL10's ability to trigger cell death is independent of its ion channel function.
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Affiliation(s)
- Grigory Maksaev
- Department of Biology and Center for Engineering MechanoBiologyWashington University in Saint LouisSaint LouisMissouri
- Present address:
Department of Cell Biology and Physiology and Center for the Investigation of Membrane Excitability DiseasesWashington University School of MedicineSaint LouisMO
| | - Jennette M. Shoots
- Department of Biology and Center for Engineering MechanoBiologyWashington University in Saint LouisSaint LouisMissouri
| | - Simran Ohri
- Department of Biology and Center for Engineering MechanoBiologyWashington University in Saint LouisSaint LouisMissouri
| | - Elizabeth S. Haswell
- Department of Biology and Center for Engineering MechanoBiologyWashington University in Saint LouisSaint LouisMissouri
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17
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Identification and Characterization of the Neisseria gonorrhoeae MscS-Like Mechanosensitive Channel. Infect Immun 2018; 86:IAI.00090-18. [PMID: 29581189 DOI: 10.1128/iai.00090-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/15/2018] [Indexed: 12/25/2022] Open
Abstract
Mechanosensitive channels are ubiquitous in bacteria and provide an essential mechanism to survive sudden exposure to a hypo-osmotic environment by the sensing and release of increased turgor pressure. No mechanosensitive channels have thus far been identified and characterized for the human-specific bacterial pathogen Neisseria gonorrhoeae In this study, we identified and characterized the N. gonorrhoeae MscS-like mechanosensitive channel (Ng-MscS). Electrophysiological analyses by the patch clamp method showed that Ng-MscS is stretch activated and contains pressure-dependent gating properties. Further mutagenesis studies of critical residues forming the hydrophobic vapor lock showed that gain-of-function mutations in Ng-MscS inhibited bacterial growth. Subsequent analysis of the function of Ng-MscS in N. gonorrhoeae by osmotic down-shock assays revealed that the survival of Ng-mscS deletion mutants was significantly reduced compared with that of wild-type strains, while down-shock survival was restored upon the ectopic complementation of mscS Finally, to investigate whether Ng-MscS is important for N. gonorrhoeae during infections, competition assays were performed by using a murine vaginal tract infection model. Ng-mscS deletion mutants were outcompeted by N. gonorrhoeae wild-type strains for colonization and survival in this infection model, highlighting that Ng-MscS contributes to in vivo colonization and survival. Therefore, Ng-MscS might be a promising target for the future development of novel antimicrobials.
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18
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Hug I, Deshpande S, Sprecher KS, Pfohl T, Jenal U. Second messenger-mediated tactile response by a bacterial rotary motor. Science 2018; 358:531-534. [PMID: 29074777 DOI: 10.1126/science.aan5353] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 09/15/2017] [Indexed: 01/26/2023]
Abstract
When bacteria encounter surfaces, they respond with surface colonization and virulence induction. The mechanisms of bacterial mechanosensation and downstream signaling remain poorly understood. Here, we describe a tactile sensing cascade in Caulobacter crescentus in which the flagellar motor acts as sensor. Surface-induced motor interference stimulated the production of the second messenger cyclic diguanylate by the motor-associated diguanylate cyclase DgcB. This led to the allosteric activation of the glycosyltransferase HfsJ to promote rapid synthesis of a polysaccharide adhesin and surface anchoring. Although the membrane-embedded motor unit was essential for surface sensing, mutants that lack external flagellar structures were hypersensitive to mechanical stimuli. Thus, the bacterial flagellar motor acts as a tetherless sensor reminiscent of mechanosensitive channels.
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Affiliation(s)
- Isabelle Hug
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Switzerland
| | - Siddharth Deshpande
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056, Switzerland
| | - Kathrin S Sprecher
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Switzerland
| | - Thomas Pfohl
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056, Switzerland
| | - Urs Jenal
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Switzerland.
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19
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A Single Mechanosensitive Channel Protects Francisella tularensis subsp. holarctica from Hypoosmotic Shock and Promotes Survival in the Aquatic Environment. Appl Environ Microbiol 2018; 84:AEM.02203-17. [PMID: 29269496 DOI: 10.1128/aem.02203-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/15/2017] [Indexed: 01/01/2023] Open
Abstract
Francisella tularensis subsp. holarctica is found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protect F. tularensis subsp. holarctica from hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however, FtMscS was required to survive the transition from the host niche to freshwater. The deletion of FtMscS did not alter the sensitivity of F. tularensis subsp. holarctica to detergents, H2O2, or antibiotics, suggesting that the role of FtMscS is specific to protection from hypoosmotic shock. The deletion of FtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.IMPORTANCE The contamination of freshwater by Francisella tularensis subsp. holarctica has resulted in a number of outbreaks of tularemia. Invariably, the contamination originates from the carcasses or excreta of infected animals and thus involves an abrupt osmotic downshock as the bacteria enter freshwater. How F. tularensis survives this drastic change in osmolarity has not been clear, but here we report that a single mechanosensitive channel protects the bacterium from osmotic downshock. This channel is functional despite lacking much of the cytoplasmic vestibule domain that is present in better-studied organisms such as Escherichia coli; this report builds on previous studies that have suggested that parts of this domain are dispensable for downshock protection. These findings extend our understanding of the aquatic cycle and ecological persistence of F. tularensis, with further implications for mechanosensitive channel biology.
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20
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Abstract
Mechanosensitive (MS) channels protect bacteria against hypo-osmotic shock and fulfil additional functions. Hypo-osmotic shock leads to high turgor pressure that can cause cell rupture and death. MS channels open under these conditions and release unspecifically solutes and consequently the turgor pressure. They can recognise the raised pressure via the increased tension in the cell membrane. Currently, a better understanding how MS channels can sense tension on molecular level is developing because the interaction of the lipid bilayer with the channel is being investigated in detail. The MS channel of large conductance (MscL) and of small conductance (MscS) have been distinguished and studied in molecular detail. In addition, larger channels were found that contain a homologous region corresponding to MscS so that MscS represents a family of channels. Often several members of this family are present in a species. The importance of this family is underlined by the fact that members can be found not only in bacteria but also in higher organisms. While MscL and MscS have been studied for years in particular by electrophysiology, mutagenesis, molecular dynamics, X-ray crystallography and other biophysical techniques, only recently more details are emerging about other members of the MscS-family.
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21
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Plattner H, Verkhratsky A. Inseparable tandem: evolution chooses ATP and Ca2+ to control life, death and cellular signalling. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0419. [PMID: 27377729 DOI: 10.1098/rstb.2015.0419] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 01/01/2023] Open
Abstract
From the very dawn of biological evolution, ATP was selected as a multipurpose energy-storing molecule. Metabolism of ATP required intracellular free Ca(2+) to be set at exceedingly low concentrations, which in turn provided the background for the role of Ca(2+) as a universal signalling molecule. The early-eukaryote life forms also evolved functional compartmentalization and vesicle trafficking, which used Ca(2+) as a universal signalling ion; similarly, Ca(2+) is needed for regulation of ciliary and flagellar beat, amoeboid movement, intracellular transport, as well as of numerous metabolic processes. Thus, during evolution, exploitation of atmospheric oxygen and increasingly efficient ATP production via oxidative phosphorylation by bacterial endosymbionts were a first step for the emergence of complex eukaryotic cells. Simultaneously, Ca(2+) started to be exploited for short-range signalling, despite restrictions by the preset phosphate-based energy metabolism, when both phosphates and Ca(2+) interfere with each other because of the low solubility of calcium phosphates. The need to keep cytosolic Ca(2+) low forced cells to restrict Ca(2+) signals in space and time and to develop energetically favourable Ca(2+) signalling and Ca(2+) microdomains. These steps in tandem dominated further evolution. The ATP molecule (often released by Ca(2+)-regulated exocytosis) rapidly grew to be the universal chemical messenger for intercellular communication; ATP effects are mediated by an extended family of purinoceptors often linked to Ca(2+) signalling. Similar to atmospheric oxygen, Ca(2+) must have been reverted from a deleterious agent to a most useful (intra- and extracellular) signalling molecule. Invention of intracellular trafficking further increased the role for Ca(2+) homeostasis that became critical for regulation of cell survival and cell death. Several mutually interdependent effects of Ca(2+) and ATP have been exploited in evolution, thus turning an originally unholy alliance into a fascinating success story.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Alexei Verkhratsky
- Faculty of Biological Sciences, University of Manchester, Manchester M13 9PT, UK Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
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22
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Chemical and mechanical stimuli act on common signal transduction and cytoskeletal networks. Proc Natl Acad Sci U S A 2016; 113:E7500-E7509. [PMID: 27821730 DOI: 10.1073/pnas.1608767113] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Signal transduction pathways activated by chemoattractants have been extensively studied, but little is known about the events mediating responses to mechanical stimuli. We discovered that acute mechanical perturbation of cells triggered transient activation of all tested components of the chemotactic signal transduction network, as well as actin polymerization. Similarly to chemoattractants, the shear flow-induced signal transduction events displayed features of excitability, including the ability to mount a full response irrespective of the length of the stimulation and a refractory period that is shared with that generated by chemoattractants. Loss of G protein subunits, inhibition of multiple signal transduction events, or disruption of calcium signaling attenuated the response to acute mechanical stimulation. Unlike the response to chemoattractants, an intact actin cytoskeleton was essential for reacting to mechanical perturbation. These results taken together suggest that chemotactic and mechanical stimuli trigger activation of a common signal transduction network that integrates external cues to regulate cytoskeletal activity and drive cell migration.
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23
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Cox CD, Bavi N, Martinac B. Origin of the Force: The Force-From-Lipids Principle Applied to Piezo Channels. CURRENT TOPICS IN MEMBRANES 2016; 79:59-96. [PMID: 28728824 DOI: 10.1016/bs.ctm.2016.09.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Piezo channels are a ubiquitously expressed, principal type of molecular force sensor in eukaryotes. They enable cells to decode a myriad of physical stimuli and are essential components of numerous mechanosensory processes. Central to their physiological role is the ability to change conformation in response to mechanical force. Here we discuss the evolutionary origin of Piezo in relation to other MS channels in addition to the force that gates Piezo channels. In particular, we discuss whether Piezo channels are inherently mechanosensitive in accordance with the force-from-lipid paradigm which has been firmly established for bacterial MS channels and two-pore domain K+ (K2P) channels. We also discuss the evidence supporting a reliance on or direct interaction with structural scaffold proteins of the cytoskeleton and extracellular matrix according to the force-from-filament principle. In doing so, we explain the false dichotomy that these distinctions represent. We also discuss the possible unifying models that shed light on channel mechanosensitivity at the molecular level.
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Affiliation(s)
- C D Cox
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia; University of New South Wales, Darlinghurst, NSW, Australia
| | - N Bavi
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia; University of New South Wales, Darlinghurst, NSW, Australia
| | - B Martinac
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia; University of New South Wales, Darlinghurst, NSW, Australia
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24
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Widderich N, Czech L, Elling FJ, Könneke M, Stöveken N, Pittelkow M, Riclea R, Dickschat JS, Heider J, Bremer E. Strangers in the archaeal world: osmostress-responsive biosynthesis of ectoine and hydroxyectoine by the marine thaumarchaeon Nitrosopumilus maritimus. Environ Microbiol 2016; 18:1227-48. [PMID: 26636559 DOI: 10.1111/1462-2920.13156] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/19/2015] [Accepted: 11/27/2015] [Indexed: 11/29/2022]
Abstract
Ectoine and hydroxyectoine are compatible solutes widely synthesized by members of the Bacteria to cope with high osmolarity surroundings. Inspection of 557 archaeal genomes revealed that only 12 strains affiliated with the Nitrosopumilus, Methanothrix or Methanobacterium genera harbour ectoine/hydroxyectoine gene clusters. Phylogenetic considerations suggest that these Archaea have acquired these genes through horizontal gene transfer events. Using the Thaumarchaeon 'Candidatus Nitrosopumilus maritimus' as an example, we demonstrate that the transcription of its ectABCD genes is osmotically induced and functional since it leads to the production of both ectoine and hydroxyectoine. The ectoine synthase and the ectoine hydroxylase were biochemically characterized, and their properties resemble those of their counterparts from Bacteria. Transcriptional analysis of osmotically stressed 'Ca. N. maritimus' cells demonstrated that they possess an ectoine/hydroxyectoine gene cluster (hyp-ectABCD-mscS) different from those recognized previously since it contains a gene for an MscS-type mechanosensitive channel. Complementation experiments with an Escherichia coli mutant lacking all known mechanosensitive channel proteins demonstrated that the (Nm)MscS protein is functional. Hence, 'Ca. N. maritimus' cells cope with high salinity not only through enhanced synthesis of osmostress-protective ectoines but they already prepare themselves simultaneously for an eventually occurring osmotic down-shock by enhancing the production of a safety-valve (NmMscS).
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Affiliation(s)
- Nils Widderich
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University, Karl-von-Frisch Str. 8, D-35043, Marburg, Germany
| | - Laura Czech
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University, Karl-von-Frisch Str. 8, D-35043, Marburg, Germany
| | - Felix J Elling
- Organic Geochemistry Group, MARUM - Center for Marine Environmental Sciences, University of Bremen, PO Box 330 440, D-28334, Bremen, Germany
| | - Martin Könneke
- Organic Geochemistry Group, MARUM - Center for Marine Environmental Sciences, University of Bremen, PO Box 330 440, D-28334, Bremen, Germany
| | - Nadine Stöveken
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University, Karl-von-Frisch Str. 8, D-35043, Marburg, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerwein-Str. 6, D-35043, Marburg, Germany
| | - Marco Pittelkow
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University, Karl-von-Frisch Str. 8, D-35043, Marburg, Germany
| | - Ramona Riclea
- Kekulé-Institut for Organic Chemistry and Biochemistry, Friedrich-Wilhelms-University Bonn, Gerhard-Domagk Str. 1, D-53121, Bonn, Germany.,Institute of Organic Chemistry, TU Braunschweig, Hagenring 30, D-38106, Braunschweig, Germany
| | - Jeroen S Dickschat
- Kekulé-Institut for Organic Chemistry and Biochemistry, Friedrich-Wilhelms-University Bonn, Gerhard-Domagk Str. 1, D-53121, Bonn, Germany.,Institute of Organic Chemistry, TU Braunschweig, Hagenring 30, D-38106, Braunschweig, Germany
| | - Johann Heider
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University, Karl-von-Frisch Str. 8, D-35043, Marburg, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerwein-Str. 6, D-35043, Marburg, Germany
| | - Erhard Bremer
- Laboratory for Molecular Microbiology, Department of Biology, Philipps-University, Karl-von-Frisch Str. 8, D-35043, Marburg, Germany.,LOEWE-Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerwein-Str. 6, D-35043, Marburg, Germany
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25
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Rasmussen T, Rasmussen A, Singh S, Galbiati H, Edwards MD, Miller S, Booth IR. Properties of the Mechanosensitive Channel MscS Pore Revealed by Tryptophan Scanning Mutagenesis. Biochemistry 2015; 54:4519-30. [PMID: 26126964 PMCID: PMC4519979 DOI: 10.1021/acs.biochem.5b00294] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Bacterial mechanosensitive channels
gate when the transmembrane
turgor rises to levels that compromise the structural integrity of
the cell wall. Gating creates a transient large diameter pore that
allows hydrated solutes to pass from the cytoplasm at rates close
to those of diffusion. In the closed conformation, the channel limits
transmembrane solute movement, even that of protons. In the MscS crystal
structure (Protein Data Bank entry 2oau), a narrow, hydrophobic opening is visible
in the crystal structure, and it has been proposed that a vapor lock
created by the hydrophobic seals, L105 and L109, is the barrier to
water and ions. Tryptophan scanning mutagenesis has proven to be a
highly valuable tool for the analysis of channel structure. Here Trp
residues were introduced along the pore-forming TM3a helix and in
selected other parts of the protein. Mutants were investigated for
their expression, stability, and activity and as fluorescent probes
of the physical properties along the length of the pore. Most Trp
mutants were expressed at levels similar to that of the parent (MscS
YFF) and were stable as heptamers in detergent in the presence and
absence of urea. Fluorescence data suggest a long hydrophobic region
with low accessibility to aqueous solvents, extending from L105/L109
to G90. Steady-state fluorescence anisotropy data are consistent with
significant homo-Förster resonance energy transfer between
tryptophan residues from different subunits within the narrow pore.
The data provide new insights into MscS structure and gating.
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Affiliation(s)
- Tim Rasmussen
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Akiko Rasmussen
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Shivani Singh
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Heloisa Galbiati
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Michelle D Edwards
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Samantha Miller
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Ian R Booth
- †School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom.,‡Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
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26
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Bachin D, Nazarenko LV, Mironov KS, Pisareva T, Allakhverdiev SI, Los DA. Mechanosensitive ion channel MscL controls ionic fluxes during cold and heat stress in Synechocystis. FEMS Microbiol Lett 2015; 362:fnv090. [DOI: 10.1093/femsle/fnv090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2015] [Indexed: 12/25/2022] Open
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27
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Battle AR, Ridone P, Bavi N, Nakayama Y, Nikolaev YA, Martinac B. Lipid-protein interactions: Lessons learned from stress. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1744-56. [PMID: 25922225 DOI: 10.1016/j.bbamem.2015.04.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 04/13/2015] [Accepted: 04/18/2015] [Indexed: 12/11/2022]
Abstract
Biological membranes are essential for normal function and regulation of cells, forming a physical barrier between extracellular and intracellular space and cellular compartments. These physical barriers are subject to mechanical stresses. As a consequence, nature has developed proteins that are able to transpose mechanical stimuli into meaningful intracellular signals. These proteins, termed Mechanosensitive (MS) proteins provide a variety of roles in response to these stimuli. In prokaryotes these proteins form transmembrane spanning channels that function as osmotically activated nanovalves to prevent cell lysis by hypoosmotic shock. In eukaryotes, the function of MS proteins is more diverse and includes physiological processes such as touch, pain and hearing. The transmembrane portion of these channels is influenced by the physical properties such as charge, shape, thickness and stiffness of the lipid bilayer surrounding it, as well as the bilayer pressure profile. In this review we provide an overview of the progress to date on advances in our understanding of the intimate biophysical and chemical interactions between the lipid bilayer and mechanosensitive membrane channels, focusing on current progress in both eukaryotic and prokaryotic systems. These advances are of importance due to the increasing evidence of the role the MS channels play in disease, such as xerocytosis, muscular dystrophy and cardiac hypertrophy. Moreover, insights gained from lipid-protein interactions of MS channels are likely relevant not only to this class of membrane proteins, but other bilayer embedded proteins as well. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- A R Battle
- Menzies Health Institute Queensland and School of Pharmacy, Griffith University, Gold Coast Campus, QLD 4222, Australia
| | - P Ridone
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - N Bavi
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia
| | - Y Nakayama
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Y A Nikolaev
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia
| | - B Martinac
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW, Australia.
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