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Willdigg JR, Patel Y, Arquilevich BE, Subramanian C, Frank MW, Rock CO, Helmann JD. The Bacillus subtilis cell envelope stress-inducible ytpAB operon modulates membrane properties and contributes to bacitracin resistance. J Bacteriol 2024; 206:e0001524. [PMID: 38323910 PMCID: PMC10955860 DOI: 10.1128/jb.00015-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 01/17/2024] [Indexed: 02/08/2024] Open
Abstract
Antibiotics that inhibit peptidoglycan synthesis trigger the activation of both specific and general protective responses. σM responds to diverse antibiotics that inhibit cell wall synthesis. Here, we demonstrate that cell wall-inhibiting drugs, such as bacitracin and cefuroxime, induce the σM-dependent ytpAB operon. YtpA is a predicted hydrolase previously proposed to generate the putative lysophospholipid antibiotic bacilysocin (lysophosphatidylglycerol), and YtpB is the branchpoint enzyme for the synthesis of membrane-localized C35 terpenoids. Using targeted lipidomics, we reveal that YtpA is not required for the production of lysophosphatidylglycerol. Nevertheless, ytpA was critical for growth in a mutant strain defective for homeoviscous adaptation due to a lack of genes for the synthesis of branched chain fatty acids and the Des phospholipid desaturase. Consistently, overexpression of ytpA increased membrane fluidity as monitored by fluorescence anisotropy. The ytpA gene contributes to bacitracin resistance in mutants additionally lacking the bceAB or bcrC genes, which directly mediate bacitracin resistance. These epistatic interactions support a model in which σM-dependent induction of the ytpAB operon helps cells tolerate bacitracin stress, either by facilitating the flipping of the undecaprenyl phosphate carrier lipid or by impacting the assembly or function of membrane-associated complexes involved in cell wall homeostasis.IMPORTANCEPeptidoglycan synthesis inhibitors include some of our most important antibiotics. In Bacillus subtilis, peptidoglycan synthesis inhibitors induce the σM regulon, which is critical for intrinsic antibiotic resistance. The σM-dependent ytpAB operon encodes a predicted hydrolase (YtpA) and the enzyme that initiates the synthesis of C35 terpenoids (YtpB). Our results suggest that YtpA is critical in cells defective in homeoviscous adaptation. Furthermore, we find that YtpA functions cooperatively with the BceAB and BcrC proteins in conferring intrinsic resistance to bacitracin, a peptide antibiotic that binds tightly to the undecaprenyl-pyrophosphate lipid carrier that sustains peptidoglycan synthesis.
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Affiliation(s)
| | - Yesha Patel
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | | | - Chitra Subramanian
- Department of Host Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Matthew W. Frank
- Department of Host Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Charles O. Rock
- Department of Host Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, New York, USA
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2
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Spivey WW, Rustgi S, Welti R, Roth MR, Burow MD, Bridges WC, Narayanan S. Lipid modulation contributes to heat stress adaptation in peanut. Front Plant Sci 2023; 14:1299371. [PMID: 38164249 PMCID: PMC10757947 DOI: 10.3389/fpls.2023.1299371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/28/2023] [Indexed: 01/03/2024]
Abstract
At the cellular level, membrane damage is a fundamental cause of yield loss at high temperatures (HT). We report our investigations on a subset of a peanut (Arachis hypogaea) recombinant inbred line population, demonstrating that the membrane lipid remodeling occurring at HT is consistent with homeoviscous adaptation to maintain membrane fluidity. A major alteration in the leaf lipidome at HT was the reduction in the unsaturation levels, primarily through reductions of 18:3 fatty acid chains, of the plastidic and extra-plastidic diacyl membrane lipids. In contrast, levels of 18:3-containing triacylglycerols (TGs) increased at HT, consistent with a role for TGs in sequestering fatty acids when membrane lipids undergo remodeling during plant stress. Polyunsaturated acyl chains from membrane diacyl lipids were also sequestered as sterol esters (SEs). The removal of 18:3 chains from the membrane lipids decreased the availability of susceptible molecules for oxidation, thereby minimizing oxidative damage in membranes. Our results suggest that transferring 18:3 chains from membrane diacyl lipids to TGs and SEs is a key feature of lipid remodeling for HT adaptation in peanut. Finally, QTL-seq allowed the identification of a genomic region associated with heat-adaptive lipid remodeling, which would be useful for identifying molecular markers for heat tolerance.
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Affiliation(s)
- William W. Spivey
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, United States
| | - Sachin Rustgi
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, United States
| | - Ruth Welti
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Mary R. Roth
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Mark D. Burow
- Department of Plant and Soil Sciences, Texas Tech University, Lubbock, TX, United States
- Texas A&M AgriLife Research and Extension, Lubbock, TX, United States
| | - William C. Bridges
- School of Mathematical and Statistical Sciences, Clemson University, Clemson, SC, United States
| | - Sruthi Narayanan
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, United States
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3
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Bridier G, Olivier F, Grall J, Chauvaud L, Sejr MK, Tremblay R. Seasonal lipid dynamics of four Arctic bivalves: Implications for their physiological capacities to cope with future changes in coastal ecosystems. Ecol Evol 2023; 13:e10691. [PMID: 37928200 PMCID: PMC10620577 DOI: 10.1002/ece3.10691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 10/04/2023] [Accepted: 10/20/2023] [Indexed: 11/07/2023] Open
Abstract
The Arctic is exposed to unprecedented warming, at least three times higher than the global average, which induces significant melting of the cryosphere. Freshwater inputs from melting glaciers will subsequently affect coastal primary production and organic matter quality. However, due to a lack of basic knowledge on the physiology of Arctic organisms, it remains difficult to understand how these future trophic changes will threaten the long-term survival of benthic species in coastal habitats. This study aimed to gain new insights into the seasonal lipid dynamics of four dominant benthic bivalves (Astarte moerchi, Hiatella arctica, Musculus discors, and Mya truncata) collected before and after sea ice break-up in a high-Arctic fjord (Young Sound, NE Greenland). Total lipid content and fatty acid composition of digestive gland neutral lipids were analyzed to assess bivalve energy reserves while the fatty acid composition of gill polar lipids was determined as a biochemical indicator of interspecies variations in metabolic activity and temperature acclimation. Results showed a decrease in lipid reserves between May and August, suggesting that bivalves have only limited access to fresh organic matter until sea ice break-up. The lack of seasonal variation in the fatty acid composition of neutral lipids, especially essential ω3 fatty acids, indicates that no fatty acid transfer from the digestive glands to the gonads occurs between May and August, and therefore, no reproductive investment takes place during this period. Large interspecies differences in gill fatty acid composition were observed, which appear to be related to differences in species life span and metabolic strategies. Such differences in gill fatty acid composition of polar lipids, which generally influence metabolic rates and energy needs, may imply that not all benthic species will be equally sensitive to future changes in primary production and organic matter quality in Arctic coastal habitats.
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Affiliation(s)
- Guillaume Bridier
- Institut des Sciences de la mer de RimouskiUniversité du Québec à RimouskiRimouskiQuebecCanada
| | - Frédéric Olivier
- Biologie des Organismes et Ecosystèmes Aquatiques (BOREA) UMR 8067 MNHN, CNRS, SU, IRD 207, UCN, UAParisFrance
| | - Jacques Grall
- Laboratoire des Sciences de l'Environnement Marin (LEMAR) UMR 6539 UBO, CNRS, IRD, IfremerPlouzanéFrance
- Observatoire Marin de l'Institut Universitaire Européen de la Mer UMS 3113, Université de Bretagne OccidentalePlouzanéFrance
| | - Laurent Chauvaud
- Laboratoire des Sciences de l'Environnement Marin (LEMAR) UMR 6539 UBO, CNRS, IRD, IfremerPlouzanéFrance
| | - Mikael K. Sejr
- Arctic Research Centre and EcoscienceAarhus UniversityAarhus CDenmark
| | - Réjean Tremblay
- Institut des Sciences de la mer de RimouskiUniversité du Québec à RimouskiRimouskiQuebecCanada
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4
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Renne MF, Ernst R. Membrane homeostasis beyond fluidity: control of membrane compressibility. Trends Biochem Sci 2023; 48:963-977. [PMID: 37652754 PMCID: PMC10580326 DOI: 10.1016/j.tibs.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023]
Abstract
Biomembranes are complex materials composed of lipids and proteins that compartmentalize biochemistry. They are actively remodeled in response to physical and metabolic cues, as well as during cell differentiation and stress. The concept of homeoviscous adaptation has become a textbook example of membrane responsiveness. Here, we discuss limitations and common misconceptions revolving around it. By highlighting key moments in the life cycle of a transmembrane protein, we illustrate that membrane thickness and a finely regulated membrane compressibility are crucial to facilitate proper membrane protein insertion, function, sorting, and inheritance. We propose that the unfolded protein response (UPR) provides a mechanism for endoplasmic reticulum (ER) membrane homeostasis by sensing aberrant transverse membrane stiffening and triggering adaptive responses that re-establish membrane compressibility.
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Affiliation(s)
- Mike F Renne
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany; PZMS, Center for Molecular Signaling, Medical Faculty, Saarland University, Homburg, Germany.
| | - Robert Ernst
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany; PZMS, Center for Molecular Signaling, Medical Faculty, Saarland University, Homburg, Germany.
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5
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Pilon M, Ruiz M. PAQR proteins and the evolution of a superpower: Eating all kinds of fats: Animals rely on evolutionarily conserved membrane homeostasis proteins to compensate for dietary variation. Bioessays 2023; 45:e2300079. [PMID: 37345585 DOI: 10.1002/bies.202300079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/23/2023]
Abstract
Recently published work showed that members of the PAQR protein family are activated by cell membrane rigidity and contribute to our ability to eat a wide variety of diets. Cell membranes are primarily composed of phospholipids containing dietarily obtained fatty acids, which poses a challenge to membrane properties because diets can vary greatly in their fatty acid composition and could impart opposite properties to the cellular membranes. In particular, saturated fatty acids (SFAs) can pack tightly and form rigid membranes (like butter at room temperature) while unsaturated fatty acids (UFAs) form more fluid membranes (like vegetable oils). Proteins of the PAQR protein family, characterized by the presence of seven transmembrane domains and a cytosolic N-terminus, contribute to membrane homeostasis in bacteria, yeasts, and animals. These proteins respond to membrane rigidity by stimulating fatty acid desaturation and incorporation of UFAs into phospholipids and explain the ability of animals to thrive on diets with widely varied fat composition. Also see the video abstract here: https://youtu.be/6ckcvaDdbQg.
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Affiliation(s)
- Marc Pilon
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Mario Ruiz
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
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6
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Evans TW, Kalambokidis MJ, Jungblut AD, Millar JL, Bauersachs T, Grotheer H, Mackey TJ, Hawes I, Summons RE. Lipid Biomarkers From Microbial Mats on the McMurdo Ice Shelf, Antarctica: Signatures for Life in the Cryosphere. Front Microbiol 2022; 13:903621. [PMID: 35756013 PMCID: PMC9232131 DOI: 10.3389/fmicb.2022.903621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
Persistent cold temperatures, a paucity of nutrients, freeze-thaw cycles, and the strongly seasonal light regime make Antarctica one of Earth's least hospitable surface environments for complex life. Cyanobacteria, however, are well-adapted to such conditions and are often the dominant primary producers in Antarctic inland water environments. In particular, the network of meltwater ponds on the 'dirty ice' of the McMurdo Ice Shelf is an ecosystem with extensive cyanobacteria-dominated microbial mat accumulations. This study investigated intact polar lipids (IPLs), heterocyte glycolipids (HGs), and bacteriohopanepolyols (BHPs) in combination with 16S and 18S rRNA gene diversity in microbial mats of twelve ponds in this unique polar ecosystem. To constrain the effects of nutrient availability, temperature and freeze-thaw cycles on the lipid membrane composition, lipids were compared to stromatolite-forming cyanobacterial mats from ice-covered lakes in the McMurdo Dry Valleys as well as from (sub)tropical regions and hot springs. The 16S rRNA gene compositions of the McMurdo Ice Shelf mats confirm the dominance of Cyanobacteria and Proteobacteria while the 18S rRNA gene composition indicates the presence of Ochrophyta, Chlorophyta, Ciliophora, and other microfauna. IPL analyses revealed a predominantly bacterial community in the meltwater ponds, with archaeal lipids being barely detectable. IPLs are dominated by glycolipids and phospholipids, followed by aminolipids. The high abundance of sugar-bound lipids accords with a predominance of cyanobacterial primary producers. The phosphate-limited samples from the (sub)tropical, hot spring, and Lake Vanda sites revealed a higher abundance of aminolipids compared to those of the nitrogen-limited meltwater ponds, affirming the direct affects that N and P availability have on IPL compositions. The high abundance of polyunsaturated IPLs in the Antarctic microbial mats suggests that these lipids provide an important mechanism to maintain membrane fluidity in cold environments. High abundances of HG keto-ols and HG keto-diols, produced by heterocytous cyanobacteria, further support these findings and reveal a unique distribution compared to those from warmer climates.
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Affiliation(s)
- Thomas W Evans
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Maria J Kalambokidis
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Anne D Jungblut
- Life Sciences Department, Natural History Museum, London, United Kingdom
| | - Jasmin L Millar
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, United Kingdom
| | - Thorsten Bauersachs
- Institute of Geosciences, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Hendrik Grotheer
- Marine Geochemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Tyler J Mackey
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Ian Hawes
- Coastal Marine Field Station, University of Waikato, Tauranga, New Zealand
| | - Roger E Summons
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
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7
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Gohrbandt M, Lipski A, Grimshaw JW, Buttress JA, Baig Z, Herkenhoff B, Walter S, Kurre R, Deckers-Hebestreit G, Strahl H. Low membrane fluidity triggers lipid phase separation and protein segregation in living bacteria. EMBO J 2022; 41:e109800. [PMID: 35037270 PMCID: PMC8886542 DOI: 10.15252/embj.2021109800] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 11/09/2022] Open
Abstract
All living organisms adapt their membrane lipid composition in response to changes in their environment or diet. These conserved membrane‐adaptive processes have been studied extensively. However, key concepts of membrane biology linked to regulation of lipid composition including homeoviscous adaptation maintaining stable levels of membrane fluidity, and gel‐fluid phase separation resulting in domain formation, heavily rely upon in vitro studies with model membranes or lipid extracts. Using the bacterial model organisms Escherichia coli and Bacillus subtilis, we now show that inadequate in vivo membrane fluidity interferes with essential complex cellular processes including cytokinesis, envelope expansion, chromosome replication/segregation and maintenance of membrane potential. Furthermore, we demonstrate that very low membrane fluidity is indeed capable of triggering large‐scale lipid phase separation and protein segregation in intact, protein‐crowded membranes of living cells; a process that coincides with the minimal level of fluidity capable of supporting growth. Importantly, the in vivo lipid phase separation is not associated with a breakdown of the membrane diffusion barrier function, thus explaining why the phase separation process induced by low fluidity is biologically reversible.
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Affiliation(s)
- Marvin Gohrbandt
- Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
| | - André Lipski
- Lebensmittelmikrobiologie und -hygiene, Institut für Ernährungs- und Lebensmittelwissenschaften, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - James W Grimshaw
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jessica A Buttress
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Zunera Baig
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Brigitte Herkenhoff
- Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
| | - Stefan Walter
- Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
| | - Rainer Kurre
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, Universität Osnabrück, Osnabrück, Germany
| | | | - Henrik Strahl
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
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8
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John Peter AT, Cheung NJ, Kornmann B. Csf1: A Putative Lipid Transport Protein Required for Homeoviscous Adaptation of the Lipidome. Contact (Thousand Oaks) 2022; 5:25152564221101974. [PMID: 37366504 PMCID: PMC10243558 DOI: 10.1177/25152564221101974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/03/2022] [Indexed: 06/28/2023]
Abstract
The non-vesicular transport of lipids between organelles mediated by lipid transport proteins (LTPs) is a key determinant of organelle biogenesis and function. Despite performing a vital function in organelle homeostasis, none of the LTP-encoding genes identified so far are truly essential, even in the simple genome of yeast, suggesting widespread redundancy. In line with this fact, it has been found that a number of LTPs have overlapping functions, making it challenging to assign unique roles for an individual LTP in lipid distribution. In our genetic screens under stringent conditions in which the distinct function of an LTP might become essential, we stumbled upon Csf1, a highly conserved protein with a Chorein-N motif found in other lipid transporters and unraveled a new function for Csf1 in lipid remodeling and homeoviscous adaptation of the lipidome. Here, we further speculate on the potential mechanisms of how the putative function of Csf1 in lipid transport could be intimately connected to its role in lipid remodeling across organelles.
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9
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Chwastek G, Surma MA, Rizk S, Grosser D, Lavrynenko O, Rucińska M, Jambor H, Sáenz J. Principles of Membrane Adaptation Revealed through Environmentally Induced Bacterial Lipidome Remodeling. Cell Rep 2021; 32:108165. [PMID: 32966790 DOI: 10.1016/j.celrep.2020.108165] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/20/2020] [Accepted: 08/27/2020] [Indexed: 12/17/2022] Open
Abstract
Cells, from microbes to mammals, adapt their membrane lipid composition in response to environmental changes to maintain optimal properties. Global patterns of lipidome remodeling are poorly understood, particularly in organisms with simple lipid compositions that can provide insight into fundamental principles of membrane adaptation. Using shotgun lipidomics, we examine the simple yet, as we show here, adaptive lipidome of the plant-associated Gram-negative bacterium Methylobacterium extorquens. We observe that minimally 11 lipids account for 90% of total variability, thus constraining the upper limit of variable lipids required for an adaptive living membrane. Through lipid features analysis, we reveal that acyl chain remodeling is not evenly distributed across lipid classes, resulting in headgroup-specific effects of acyl chain variability on membrane properties. Results herein implicate headgroup-specific acyl chain remodeling as a mechanism for fine-tuning the membrane's physical state and provide a resource for using M. extorquens to explore the design principles of living membranes.
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Affiliation(s)
- Grzegorz Chwastek
- Technische Universität Dresden, B CUBE, Tatzberg 41, Dresden, Germany
| | | | - Sandra Rizk
- Technische Universität Dresden, B CUBE, Tatzberg 41, Dresden, Germany
| | - Daniel Grosser
- DZD-Paul Langerhans Institute Dresden, Fetscherstraße 74, Dresden, Germany
| | - Oksana Lavrynenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, Dresden, Germany
| | | | - Helena Jambor
- Technische Universität Dresden, Medizinische Fakultät, Fetscherstraße 74, Dresden, Germany
| | - James Sáenz
- Technische Universität Dresden, B CUBE, Tatzberg 41, Dresden, Germany.
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10
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Dymond MK. Mammalian phospholipid homeostasis: evidence that membrane curvature elastic stress drives homeoviscous adaptation in vivo. J R Soc Interface 2017; 13:rsif.2016.0228. [PMID: 27534697 DOI: 10.1098/rsif.2016.0228] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/25/2016] [Indexed: 12/23/2022] Open
Abstract
Several theories of phospholipid homeostasis have postulated that cells regulate the molecular composition of their bilayer membranes, such that a common biophysical membrane parameter is under homeostatic control. Two commonly cited theories are the intrinsic curvature hypothesis, which states that cells control membrane curvature elastic stress, and the theory of homeoviscous adaptation, which postulates cells control acyl chain packing order (membrane order). In this paper, we present evidence from data-driven modelling studies that these two theories correlate in vivo. We estimate the curvature elastic stress of mammalian cells to be 4-7 × 10(-12) N, a value high enough to suggest that in mammalian cells the preservation of membrane order arises through a mechanism where membrane curvature elastic stress is controlled. These results emerge from analysing the molecular contribution of individual phospholipids to both membrane order and curvature elastic stress in nearly 500 cellular compositionally diverse lipidomes. Our model suggests that the de novo synthesis of lipids is the dominant mechanism by which cells control curvature elastic stress and hence membrane order in vivo These results also suggest that cells can increase membrane curvature elastic stress disproportionately to membrane order by incorporating polyunsaturated fatty acids into lipids.
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Affiliation(s)
- Marcus K Dymond
- Division of Chemistry, School of Pharmacy and Biological Sciences, University of Brighton, Brighton BN2 4GL, UK
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11
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Vinçon-Laugier A, Cravo-Laureau C, Mitteau I, Grossi V. Temperature-Dependent Alkyl Glycerol Ether Lipid Composition of Mesophilic and Thermophilic Sulfate-Reducing Bacteria. Front Microbiol 2017; 8:1532. [PMID: 28848536 PMCID: PMC5552659 DOI: 10.3389/fmicb.2017.01532] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/28/2017] [Indexed: 11/13/2022] Open
Abstract
The occurrence of non-isoprenoid alkyl glycerol ether lipids in Bacteria and natural environments is increasingly being reported and the specificity and diagenetic stability of these lipids make them powerful biomarkers for biogeochemical and environmental studies. Yet the environmental controls on the biosynthesis of these peculiar membrane lipids remain poorly documented. Here, the lipid content of two mesophilic (Desulfatibacillum aliphaticivorans and Desulfatibacillum alkenivorans) and one thermophilic (Thermodesulfobacterium commune) sulfate-reducing bacteria-whose membranes are mostly composed of ether lipids-was investigated as a function of growth temperature (20-40°C and 54-84°C, respectively). For all strains, the cellular lipid content was lower at sub- or supra-optimal growth temperature, but the relative proportions of dialkyl glycerols, monoalkyl glycerols and fatty acids remained remarkably stable whatever the growth temperature. Rather than changing the proportions of the different lipid classes, the three strains responded to temperature changes by modifying the average structural composition of the alkyl and acyl chains constitutive of their membrane lipids. Major adaptive mechanisms concerned modifications of the level of branching and of the proportions of the different methyl branched lipids. Specifically, an increase in temperature induced mesophilic strains to produce less dimethyl branched dialkyl glycerols and 10-methyl branched lipids relative to linear structures, and the thermophilic strain to decrease the proportion of anteiso relative to iso methyl branched compounds. These modifications were in agreement with a regulation of the membrane fluidity. In one mesophilic and the thermophilic strains, a modification of the growth temperature further induced changes in the relative proportions of sn-2 vs sn-1 monoalkyl glycerols, suggesting an unprecedented mechanism of homeoviscous adaptation in Bacteria. Strong linear correlations observed between different ratios of alkyl glycerols and temperature allow to hypothesize the use of these specific lipids as indicators of temperature changes in the environment.
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Affiliation(s)
| | - Cristiana Cravo-Laureau
- Equipe Environnement et Microbiologie, UMR CNRS 5254, Université de Pau et des Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les MatériauxPau, France
| | - Isabelle Mitteau
- Equipe Environnement et Microbiologie, UMR CNRS 5254, Université de Pau et des Pays de l'Adour, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les MatériauxPau, France
| | - Vincent Grossi
- Laboratoire de Géologie de Lyon, UMR CNRS 5276, Université Lyon 1Villeurbanne, France
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12
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Cario A, Grossi V, Schaeffer P, Oger PM. Membrane homeoviscous adaptation in the piezo-hyperthermophilic archaeon Thermococcus barophilus. Front Microbiol 2015; 6:1152. [PMID: 26539180 PMCID: PMC4612709 DOI: 10.3389/fmicb.2015.01152] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/05/2015] [Indexed: 12/22/2022] Open
Abstract
The archaeon Thermococcus barophilus, one of the most extreme members of hyperthermophilic piezophiles known thus far, is able to grow at temperatures up to 103°C and pressures up to 80 MPa. We analyzed the membrane lipids of T. barophilus by high performance liquid chromatography–mass spectrometry as a function of pressure and temperature. In contrast to previous reports, we show that under optimal growth conditions (40 MPa, 85°C) the membrane spanning tetraether lipid GDGT-0 (sometimes called caldarchaeol) is a major membrane lipid of T. barophilus together with archaeol. Increasing pressure and decreasing temperature lead to an increase of the proportion of archaeol. Reversely, a higher proportion of GDGT-0 is observed under low pressure and high temperature conditions. Noticeably, pressure and temperature fluctuations also impact the level of unsaturation of apolar lipids having an irregular polyisoprenoid carbon skeleton (unsaturated lycopane derivatives), suggesting a structural role for these neutral lipids in the membrane of T. barophilus. Whether these apolar lipids insert in the membrane or not remains to be addressed. However, our results raise questions about the structure of the membrane in this archaeon and other Archaea harboring a mixture of di- and tetraether lipids.
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Affiliation(s)
- Anaïs Cario
- CNRS, Laboratoire de Géologie de Lyon, Ecole Normale Supérieure de Lyon, UMR 5276, Université Claude Bernard Lyon 1 Lyon, France
| | - Vincent Grossi
- CNRS, Laboratoire de Géologie de Lyon, Ecole Normale Supérieure de Lyon, UMR 5276, Université Claude Bernard Lyon 1 Lyon, France
| | - Philippe Schaeffer
- CNRS, Laboratoire de Biogéochimie Moléculaire, Institut de Chimie de Strasbourg, Ecole de Chimie, Polymères et Matériaux, UMR 7177, Université de Strasbourg Strasbourg, France
| | - Philippe M Oger
- CNRS, Laboratoire de Géologie de Lyon, Ecole Normale Supérieure de Lyon, UMR 5276, Université Claude Bernard Lyon 1 Lyon, France
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Sweet CR, Watson RE, Landis CA, Smith JP. Temperature-Dependence of Lipid A Acyl Structure in Psychrobacter cryohalolentis and Arctic Isolates of Colwellia hornerae and Colwellia piezophila. Mar Drugs 2015; 13:4701-20. [PMID: 26264000 PMCID: PMC4557000 DOI: 10.3390/md13084701] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 07/19/2015] [Accepted: 07/20/2015] [Indexed: 12/21/2022] Open
Abstract
Lipid A is a fundamental Gram-negative outer membrane component and the essential element of lipopolysaccharide (endotoxin), a potent immunostimulatory molecule. This work describes the metabolic adaptation of the lipid A acyl structure by Psychrobacter cryohalolentis at various temperatures in its facultative psychrophilic growth range, as characterized by MALDI-TOF MS and FAME GC-MS. It also presents the first elucidation of lipid A structure from the Colwellia genus, describing lipid A from strains of Colwellia hornerae and Colwellia piezophila, which were isolated as primary cultures from Arctic fast sea ice and identified by 16S rDNA sequencing. The Colwellia strains are obligate psychrophiles, with a growth range restricted to 15 °C or less. As such, these organisms have less need for fluidity adaptation in the acyl moiety of the outer membrane, and they do not display alterations in lipid A based on growth temperature. Both Psychrobacter and Colwellia make use of extensive single-methylene variation in the size of their lipid A molecules. Such single-carbon variations in acyl size were thought to be restricted to psychrotolerant (facultative) species, but its presence in these Colwellia species shows that odd-chain acyl units and a single-carbon variation in lipid A structure are present in obligate psychrophiles, as well.
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Affiliation(s)
- Charles R Sweet
- Chemistry Department, 572M Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Rebecca E Watson
- Chemistry Department, 572M Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Corinne A Landis
- Chemistry Department, 572M Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
| | - Joseph P Smith
- Oceanography Department, 572C Holloway Road, United States Naval Academy, Annapolis, MD 21402, USA.
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14
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Abstract
Changes in temperature disrupt the fluidity of cellular membranes, which can negatively impact membrane integrity and cellular processes. Many ectotherms, including Drosophila melanogaster (Meigen), adjust the glycerophospholipid composition of their membranes to restore optimal fluidity when temperatures change, a type of trait plasticity termed homeoviscous adaptation.Existing data suggest that plasticity in the relative abundances of the glycerophospholipids phosphatidylethanolamine (PE) and phosphatidylcholine (PC) underlies cellular adaptation to temporal variability in the thermal environment. For example, laboratory populations of D. melanogaster evolved in the presence of temporally variable temperatures have greater developmental plasticity of the ratio of PE to PC (PE/PC) and greater fecundity than do populations evolved at constant temperatures.Here, we extend this work to natural populations of D. melanogaster by evaluating thermal plasticity of glycerophospholipid composition at different life stages, in genotypes isolated from Vermont, Indiana and North Carolina, USA. We also quantify the covariance between developmental and adult (reversible) plasticity, and between adult responses of the membrane to cool and warm thermal shifts.As predicted by physiological models of homeoviscous adaptation, flies from all populations decrease PE/PC and the degree of lipid unsaturation in response to warm temperatures. Furthermore, these populations have diverged in their degree of membrane plasticity. Flies from the most variable thermal environment (Vermont, USA) decrease PE/PC to a greater extent than do other populations when developed at a warm temperature, a pattern that matches our previous observation in laboratory-evolved populations. We also find that developmental plasticity and adult plasticity of PE/PC covary across genotypes, but that adult responses to cool and warm thermal shifts do not.When combined with our previous observations of laboratory-evolved populations, our findings implicate developmental plasticity of PE/PC as a mechanism of thermal adaptation in temporally variable environments. While little is known about the genetic bases of plastic responses to temperature, our observations suggest that both environmentally sensitive and environmentally specific alleles contribute to thermal adaptation of membranes, and that costs of plasticity may arise when the adult environment differs from that experienced during development.
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Affiliation(s)
- Brandon S Cooper
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Loubna A Hammad
- METACyt Biochemical Analysis Center, Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Kristi L Montooth
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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15
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Vidovic S, Korber DR. Escherichia coli O157: Insights into the adaptive stress physiology and the influence of stressors on epidemiology and ecology of this human pathogen. Crit Rev Microbiol 2014; 42:83-93. [PMID: 24601836 DOI: 10.3109/1040841x.2014.889654] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Escherichia coli O157, a foodborne pathogen of major concern for public health, has been associated with numerous outbreaks of haemorrhagic colitis and hemolytic uremic syndrome worldwide. Human infection with E. coli O157 has been primarily associated with the food-chain transmission route. This transmission route commonly elicits a multi-faceted adaptive stress response of E. coli O157 for an extended period of time prior to human infection. Several recent research articles have indicated that E. coli O157:H7 has evolved unique survival characteristics which can affect the epidemiology and ecology of this zoonotic pathogen. This review article summarizes the recent knowledge of the molecular responses of E. coli O157 to the most common stressors found within the human food chain, and further emphasizes the influence of these stressors on the epidemiology and ecology of E. coli O157.
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Affiliation(s)
- Sinisa Vidovic
- a Department of Food and Bioproducts Sciences , University of Saskatchewan , Saskatchewan , Canada
| | - Darren R Korber
- a Department of Food and Bioproducts Sciences , University of Saskatchewan , Saskatchewan , Canada
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Czarnoleski M, Cooper BS, Kierat J, Angilletta MJ. Flies developed small bodies and small cells in warm and in thermally fluctuating environments. ACTA ACUST UNITED AC 2013; 216:2896-901. [PMID: 23619414 DOI: 10.1242/jeb.083535] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although plasma membranes benefit cells by regulating the flux of materials to and from the environment, these membranes cost energy to maintain. Because smaller cells provide relatively more membrane area for transport, ectotherms that develop in warm environments should consist of small cells despite the energetic cost. Effects of constant temperatures on cell size qualitatively match this prediction, but effects of thermal fluctuations on cell size are unknown. Thermal fluctuations could favour either small or large cells; small cells facilitate transport during peaks in metabolic demand whereas large cells minimize the resources needed for homeoviscous adaptation. To explore this problem, we examined effects of thermal fluctuations during development on the size of epidermal cells in the wings of Drosophila melanogaster. Flies derived from a temperate population were raised at two mean temperatures (18 and 25°C), with either no variation or a daily variation of ±4°C. Flies developed faster at a mean temperature of 25°C. Thermal fluctuations sped development, but only at 18°C. An increase in the mean and variance of temperature caused flies to develop smaller cells and wings. Thermal fluctuations reduced the size of males at 18°C and the size of females at 25°C. The thorax, the wings and the cells decreased with an increase in the mean and in the variance of temperature, but the response of cells was the strongest. Based on this pattern, we hypothesize that development of the greater area of membranes under thermal fluctuations provides a metabolic advantage that outweighs the greater energetic cost of remodelling membranes.
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Affiliation(s)
- Marcin Czarnoleski
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
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Nozawa Y. Adaptive regulation of membrane lipids and fluidity during thermal acclimation in Tetrahymena. Proc Jpn Acad Ser B Phys Biol Sci 2011; 87:450-462. [PMID: 21986311 PMCID: PMC3313689 DOI: 10.2183/pjab.87.450] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 07/21/2011] [Indexed: 05/30/2023]
Abstract
The free-living eukaryotic protozoan Tetrahymena is a potentially useful model for the thermoadaptive membrane regulation because of easy growth in the axenic culture, systematic isolation of subcellular organelles, and quick response to temperature stress. Exposure of Tetrahymena cells to the cold temperature induces marked alterations in the lipid composition and the physical properties (fluidity) of various membranes. The increase in fatty acid unsaturation of membrane phospholipids is required to preserve the proper fluidity. In this homeoviscous adaptive response, acyl-CoA desaturase plays a pivotal role and its activity is regulated by induction of the enzyme via transcriptional activation.
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Affiliation(s)
- Yoshinori Nozawa
- Department of Health and Food Sciences, Tokai Gakuin University, Kakamigahara, Japan.
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