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Toyotake Y, Nishiyama M, Yokoyama F, Ogawa T, Kawamoto J, Kurihara T. A Novel Lysophosphatidic Acid Acyltransferase of Escherichia coli Produces Membrane Phospholipids with a cis-vaccenoyl Group and Is Related to Flagellar Formation. Biomolecules 2020; 10:E745. [PMID: 32403425 PMCID: PMC7277886 DOI: 10.3390/biom10050745] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/02/2020] [Accepted: 05/07/2020] [Indexed: 02/07/2023] Open
Abstract
Lysophosphatidic acid acyltransferase (LPAAT) introduces fatty acyl groups into the sn-2 position of membrane phospholipids (PLs). Various bacteria produce multiple LPAATs, whereas it is believed that Escherichia coli produces only one essential LPAAT homolog, PlsC-the deletion of which is lethal. However, we found that E. coli possesses another LPAAT homolog named YihG. Here, we show that overexpression of YihG in E. coli carrying a temperature-sensitive mutation in plsC allowed its growth at non-permissive temperatures. Analysis of the fatty acyl composition of PLs from the yihG-deletion mutant (∆yihG) revealed that endogenous YihG introduces the cis-vaccenoyl group into the sn-2 position of PLs. Loss of YihG did not affect cell growth or morphology, but ∆yihG cells swam well in liquid medium in contrast to wild-type cells. Immunoblot analysis showed that FliC was highly expressed in ∆yihG cells, and this phenotype was suppressed by expression of recombinant YihG in ∆yihG cells. Transmission electron microscopy confirmed that the flagellar structure was observed only in ∆yihG cells. These results suggest that YihG has specific functions related to flagellar formation through modulation of the fatty acyl composition of membrane PLs.
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Affiliation(s)
- Yosuke Toyotake
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; (Y.T.); (M.N.); (F.Y.); (T.O.); (J.K.)
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan
| | - Masayoshi Nishiyama
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; (Y.T.); (M.N.); (F.Y.); (T.O.); (J.K.)
| | - Fumiaki Yokoyama
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; (Y.T.); (M.N.); (F.Y.); (T.O.); (J.K.)
| | - Takuya Ogawa
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; (Y.T.); (M.N.); (F.Y.); (T.O.); (J.K.)
| | - Jun Kawamoto
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; (Y.T.); (M.N.); (F.Y.); (T.O.); (J.K.)
| | - Tatsuo Kurihara
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan; (Y.T.); (M.N.); (F.Y.); (T.O.); (J.K.)
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Calvez P, Jouhet J, Vié V, Durmort C, Zapun A. Lipid Phases and Cell Geometry During the Cell Cycle of Streptococcus pneumoniae. Front Microbiol 2019; 10:351. [PMID: 30936851 PMCID: PMC6432855 DOI: 10.3389/fmicb.2019.00351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 02/11/2019] [Indexed: 01/31/2023] Open
Abstract
The coexistence of different lipid phases is well-known in vitro, but evidence for their presence and function in cellular membranes remains scarce. Using a combination of fluorescent lipid probes, we observe segregation of domains that suggests the coexistence of liquid and gel phases in the membrane of Streptococcus pneumoniae, where they are localized to minimize bending stress in the ellipsoid geometry defined by the cell wall. Gel phase lipids with high bending rigidity would be spontaneously organized at the equator where curvature is minimal, thus marking the future division site, while liquid phase membrane maps onto the oblong hemispheres. In addition, the membrane-bound cell wall precursor with its particular dynamic acyl chain localizes at the division site where the membrane is highly curved. We propose a complete “chicken-and-egg” model where cell geometry determines the localization of lipid phases that positions the cell division machinery, which in turn alters the localization of lamellar phases by assembling the cell wall with a specific geometry.
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Affiliation(s)
| | - Juliette Jouhet
- UMR 5168 CNRS, CEA, INRA, CEA Grenoble, Laboratoire de Physiologie Cellulaire Végétale, Bioscience and Biotechnologies Institute of Grenoble, Université Grenoble Alpes, Grenoble, France
| | - Véronique Vié
- Univ Rennes, CNRS, IPR-UMR 6251, ScanMat-UMS2001, Rennes, France
| | | | - André Zapun
- Univ. Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
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3
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Toyotake Y, Cho HN, Kawamoto J, Kurihara T. A novel 1-acyl-sn-glycerol-3-phosphate O-acyltransferase homolog for the synthesis of membrane phospholipids with a branched-chain fatty acyl group in Shewanella livingstonensis Ac10. Biochem Biophys Res Commun 2018; 500:704-709. [PMID: 29678574 DOI: 10.1016/j.bbrc.2018.04.140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 04/17/2018] [Indexed: 12/21/2022]
Abstract
1-Acyl-sn-glycerol-3-phosphate O-acyltransferase (PlsC) plays an essential role in the formation of phosphatidic acid, a precursor of various membrane phospholipids (PLs), in bacteria by catalyzing the introduction of an acyl group into the sn-2 position of lysophosphatidic acid. Various bacteria produce more than one PlsC. However, the physiological significance of the occurrence of multiple PlsCs is poorly understood. A psychrotrophic bacterium, Shewanella livingstonensis Ac10, which produces eicosapentaenoic acid at low temperatures, has five putative PlsCs (PlsC1-5). We previously showed that PlsC1 is responsible for the production of PLs containing an eicosapentaenoyl group. Here, we characterized another putative PlsC of this bacterium named PlsC4. We generated a plsC4-disrupted mutant and found that PLs containing 13:0 found in the parental strain were almost completely absent in the mutant. The loss of these PLs was suppressed by introduction of a plsC4-expression plasmid. PLs containing 15:0 were also drastically decreased by plsC4 disruption. Gas chromatography-mass spectrometry analysis of fatty acyl methyl esters derived from PLs of the parental strain showed that the 13:0 and 15:0 groups were an 11-methyllauroyl group and a 13-methylmyristoyl group, respectively. Phospholipase A2 treatment revealed that these fatty acyl groups were linked to the sn-2 position of PLs. Thus, PlsC4 is a new type of PlsC homolog that is responsible for the synthesis of PLs containing a branched-chain fatty acyl group at the sn-2 position and plays a clearly different role from that of PlsC1 in vivo.
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Affiliation(s)
- Yosuke Toyotake
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Hyun-Nam Cho
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Jun Kawamoto
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Tatsuo Kurihara
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
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4
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Allemann MN, Allen EE. Characterization and Application of Marine Microbial Omega-3 Polyunsaturated Fatty Acid Synthesis. Methods Enzymol 2018; 605:3-32. [DOI: 10.1016/bs.mie.2018.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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5
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Sollich M, Yoshinaga MY, Häusler S, Price RE, Hinrichs KU, Bühring SI. Heat Stress Dictates Microbial Lipid Composition along a Thermal Gradient in Marine Sediments. Front Microbiol 2017; 8:1550. [PMID: 28878741 PMCID: PMC5572230 DOI: 10.3389/fmicb.2017.01550] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 07/31/2017] [Indexed: 12/17/2022] Open
Abstract
Temperature exerts a first-order control on microbial populations, which constantly adjust the fluidity and permeability of their cell membrane lipids to minimize loss of energy by ion diffusion across the membrane. Analytical advances in liquid chromatography coupled to mass spectrometry have allowed the detection of a stunning diversity of bacterial and archaeal lipids in extreme environments such as hot springs, hydrothermal vents and deep subsurface marine sediments. Here, we investigated a thermal gradient from 18 to 101°C across a marine sediment field and tested the hypothesis that cell membrane lipids provide a major biochemical basis for the bioenergetics of archaea and bacteria under heat stress. This paper features a detailed lipidomics approach with the focus on membrane lipid structure-function. Membrane lipids analyzed here include polar lipids of bacteria and polar and core lipids of archaea. Reflecting the low permeability of their ether-linked isoprenoids, we found that archaeal polar lipids generally dominate over bacterial lipids in deep layers of the sediments influenced by hydrothermal fluids. A close examination of archaeal and bacterial lipids revealed a membrane quandary: not only low permeability, but also increased fluidity of membranes are required as a unified property of microbial membranes for energy conservation under heat stress. For instance, bacterial fatty acids were composed of longer chain lengths in concert with higher degree of unsaturation while archaea modified their tetraethers by incorporation of additional methyl groups at elevated sediment temperatures. It is possible that these configurations toward a more fluidized membrane at elevated temperatures are counterbalanced by the high abundance of archaeal glycolipids and bacterial sphingolipids, which could reduce membrane permeability through strong intermolecular hydrogen bonding. Our results provide a new angle for interpreting membrane lipid structure-function enabling archaea and bacteria to survive and grow in hydrothermal systems.
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Affiliation(s)
- Miriam Sollich
- University of Bremen, MARUM Center for Marine Environmental SciencesBremen, Germany
| | - Marcos Y Yoshinaga
- University of Bremen, MARUM Center for Marine Environmental SciencesBremen, Germany.,Institute of Chemistry, University of São PauloSão Paulo, Brazil
| | - Stefan Häusler
- Department of Molecular Ecology, Max Planck Institute for Marine MicrobiologyBremen, Germany
| | - Roy E Price
- University of Bremen, MARUM Center for Marine Environmental SciencesBremen, Germany.,School of Marine and Atmospheric Sciences, Stony Brook University, Stony BrookNY, United States
| | - Kai-Uwe Hinrichs
- University of Bremen, MARUM Center for Marine Environmental SciencesBremen, Germany
| | - Solveig I Bühring
- University of Bremen, MARUM Center for Marine Environmental SciencesBremen, Germany
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Trifunctional lipid probes for comprehensive studies of single lipid species in living cells. Proc Natl Acad Sci U S A 2017; 114:1566-1571. [PMID: 28154130 DOI: 10.1073/pnas.1611096114] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Lipid-mediated signaling events regulate many cellular processes. Investigations of the complex underlying mechanisms are difficult because several different methods need to be used under varying conditions. Here we introduce multifunctional lipid derivatives to study lipid metabolism, lipid-protein interactions, and intracellular lipid localization with a single tool per target lipid. The probes are equipped with two photoreactive groups to allow photoliberation (uncaging) and photo-cross-linking in a sequential manner, as well as a click-handle for subsequent functionalization. We demonstrate the versatility of the design for the signaling lipids sphingosine and diacylglycerol; uncaging of the probe for these two species triggered calcium signaling and intracellular protein translocation events, respectively. We performed proteomic screens to map the lipid-interacting proteome for both lipids. Finally, we visualized a sphingosine transport deficiency in patient-derived Niemann-Pick disease type C fibroblasts by fluorescence as well as correlative light and electron microscopy, pointing toward the diagnostic potential of such tools. We envision that this type of probe will become important for analyzing and ultimately understanding lipid signaling events in a comprehensive manner.
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Ito T, Gong C, Kawamoto J, Kurihara T. Development of a versatile method for targeted gene deletion and insertion by using the pyrF gene in the psychrotrophic bacterium, Shewanella livingstonensis Ac10. J Biosci Bioeng 2016; 122:645-651. [PMID: 27401770 DOI: 10.1016/j.jbiosc.2016.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 05/22/2016] [Accepted: 06/07/2016] [Indexed: 11/30/2022]
Abstract
Shewanella livingstonensis Ac10, a psychrotrophic bacterium isolated from Antarctic seawater, grows well at low temperatures close to 0°C. The bacterium is useful as a host in a low-temperature protein expression system. It is also useful as a model microorganism to investigate the mechanisms of microbial cold-adaptation. Versatile genetic manipulation techniques would be useful to investigate the biology of this bacterium and to develop its applications. In this study, we developed a method for targeted gene deletion and insertion by using the gene coding for orotidine-5'-phosphate decarboxylase (pyrF), which is involved in pyrimidine synthesis. We found that S. livingstonensis Ac10 is sensitive to 5-fluoroorotic acid (5-FOA), which is converted to a highly toxic compound by the product of pyrF. A uracil-auxotrophic strain resistant to 5-FOA was constructed by deleting pyrF, thus allowing the use of a plasmid-borne copy of pyrF for selection of recombinants. We constructed the pyrF complementation suicide plasmid pKKP, which contains pyrF, the R6K replication origin, the mob site of RP4, an antibiotic marker gene, and a multiple cloning site. To demonstrate pyrF-based gene replacement, we deleted the internal region of orf5, the gene coding for an eicosapentaenoic acid (EPA) synthesis enzyme. We also successfully inserted a His6-tag-coding sequence into orf8, the gene coding for another EPA synthesis enzyme. This system allows the markerless deletion and insertion of desired sequences at specific sites in the genome, which remarkably facilitates genetic manipulation of this bacterium.
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Affiliation(s)
- Tomokazu Ito
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Chunjie Gong
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Jun Kawamoto
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Tatsuo Kurihara
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
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8
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Yoshida K, Hashimoto M, Hori R, Adachi T, Okuyama H, Orikasa Y, Nagamine T, Shimizu S, Ueno A, Morita N. Bacterial Long-Chain Polyunsaturated Fatty Acids: Their Biosynthetic Genes, Functions, and Practical Use. Mar Drugs 2016; 14:E94. [PMID: 27187420 PMCID: PMC4882568 DOI: 10.3390/md14050094] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/23/2016] [Accepted: 04/29/2016] [Indexed: 02/06/2023] Open
Abstract
The nutritional and pharmaceutical values of long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic, eicosapentaenoic and docosahexaenoic acids have been well recognized. These LC-PUFAs are physiologically important compounds in bacteria and eukaryotes. Although little is known about the biosynthetic mechanisms and functions of LC-PUFAs in bacteria compared to those in higher organisms, a combination of genetic, bioinformatic, and molecular biological approaches to LC-PUFA-producing bacteria and some eukaryotes have revealed the notably diverse organization of the pfa genes encoding a polyunsaturated fatty acid synthase complex (PUFA synthase), the LC-PUFA biosynthetic processes, and tertiary structures of the domains of this enzyme. In bacteria, LC-PUFAs appear to take part in specific functions facilitating individual membrane proteins rather than in the adjustment of the physical fluidity of the whole cell membrane. Very long chain polyunsaturated hydrocarbons (LC-HCs) such as hentriacontanonaene are considered to be closely related to LC-PUFAs in their biosynthesis and function. The possible role of LC-HCs in strictly anaerobic bacteria under aerobic and anaerobic environments and the evolutionary relationships of anaerobic and aerobic bacteria carrying pfa-like genes are also discussed.
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Affiliation(s)
- Kiyohito Yoshida
- Laboratory of Ecological Genetics, Section of Environmental Biology, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
| | - Mikako Hashimoto
- Course in Ecological Genetics, Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
| | - Ryuji Hori
- Technical Solution Center First Group, J-OIL MILLS, Inc., Chuo-ku, Tokyo 104-0044, Japan.
| | - Takumi Adachi
- Laboratory of Environmental Microbiology, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan.
- Bioproduction Research Institute, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology (AIST), Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan.
| | - Hidetoshi Okuyama
- Laboratory of Environmental Molecular Biology, Section of Environmental Biology, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-0810, Japan.
| | - Yoshitake Orikasa
- Department Food Science, Obihiro University Agriculture Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Tadashi Nagamine
- ROM Co. Ltd., Togashi Bld., Chuo-ku, Sapporo, Hokkaido 060-0062, Japan.
| | - Satoru Shimizu
- Horonobe Research Institute for the Subsurface Environment, Northern Advancement Centre for Science and Technology, 5-3, Sakae-machi, Horonobe, Teshio-gun, Hokkaido 098-3221, Japan.
| | - Akio Ueno
- Horonobe Research Institute for the Subsurface Environment, Northern Advancement Centre for Science and Technology, 5-3, Sakae-machi, Horonobe, Teshio-gun, Hokkaido 098-3221, Japan.
| | - Naoki Morita
- Laboratory of Environmental Microbiology, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan.
- Bioproduction Research Institute, Department of Life Science and Biotechnology, National Institute of Advanced Industrial Science and Technology (AIST), Toyohira-ku, Sapporo, Hokkaido 062-8517, Japan.
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Matsumoto K, Hara H, Fishov I, Mileykovskaya E, Norris V. The membrane: transertion as an organizing principle in membrane heterogeneity. Front Microbiol 2015; 6:572. [PMID: 26124753 PMCID: PMC4464175 DOI: 10.3389/fmicb.2015.00572] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/25/2015] [Indexed: 01/05/2023] Open
Abstract
The bacterial membrane exhibits a significantly heterogeneous distribution of lipids and proteins. This heterogeneity results mainly from lipid-lipid, protein-protein, and lipid-protein associations which are orchestrated by the coupled transcription, translation and insertion of nascent proteins into and through membrane (transertion). Transertion is central not only to the individual assembly and disassembly of large physically linked groups of macromolecules (alias hyperstructures) but also to the interactions between these hyperstructures. We review here these interactions in the context of the processes in Bacillus subtilis and Escherichia coli of nutrient sensing, membrane synthesis, cytoskeletal dynamics, DNA replication, chromosome segregation, and cell division.
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Affiliation(s)
- Kouji Matsumoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, SaitamaJapan
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, SaitamaJapan
| | - Itzhak Fishov
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-ShevaIsrael
| | - Eugenia Mileykovskaya
- Department of Biochemistry and Molecular Biology, University of Texas Medical School at HoustonHouston, TX, USA
| | - Vic Norris
- Laboratory of Microbiology Signals and Microenvironment EA 4312, Department of Science, University of Rouen, Mont-Saint-AignanFrance
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Kurihara T, Kawamoto J. [Chemical approach to analyze the physiological function of phospholipids with polyunsaturated fatty acyl chain]. YAKUGAKU ZASSHI 2014; 134:507-13. [PMID: 24694811 DOI: 10.1248/yakushi.13-00251-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) occur in biological membranes as acyl groups of phospholipids and exhibit remarkable physiological activities. In human, they have various beneficial effects on health such as protective effects against cardiovascular disease, inflammation, and cancer. We have been studying their physiological functions in bacteria, which have a much simpler membrane structure than eukaryotes. We found that the cell division of a marine bacterium, Shewanella livingstonensis Ac10, is inhibited and shows growth retardation by disruption of its EPA biosynthesis genes. We synthesized a fluorescent analog of EPA-containing phospholipids (EPA-PLs) as a chemical probe to analyze their subcellular distribution and found that it is localized at the center of the cell undergoing cell division. This localization was shown to depend on the structure of the hydrocarbon chain of the phospholipids. We also examined the effects of EPA-PLs on the folding of Omp74, a major membrane protein of this bacterium, by using liposomes and found that EPA-PLs facilitated the folding process. The results imply that EPA-PLs function as a chemical chaperone in the folding of membrane proteins. These findings would contribute to understanding of the physiological function of phospholipids with polyunsaturated fatty acyl chains in various biological membranes.
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Effects of high hydrostatic pressure on coastal bacterial community abundance and diversity. Appl Environ Microbiol 2014; 80:5992-6003. [PMID: 25063663 DOI: 10.1128/aem.02109-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Hydrostatic pressure is an important parameter influencing the distribution of microbial life in the ocean. In this study, the response of marine bacterial populations from surface waters to pressures representative of those under deep-sea conditions was examined. Southern California coastal seawater collected 5 m below the sea surface was incubated in microcosms, using a range of temperatures (16 to 3°C) and hydrostatic pressure conditions (0.1 to 80 MPa). Cell abundance decreased in response to pressure, while diversity increased. The morphology of the community also changed with pressurization to a predominant morphotype of small cocci. The pressure-induced community changes included an increase in the relative abundance of Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, and Flavobacteria largely at the expense of Epsilonproteobacteria. Culturable high-pressure-surviving bacteria were obtained and found to be phylogenetically similar to isolates from cold and/or deep-sea environments. These results provide novel insights into the response of surface water bacteria to changes in hydrostatic pressure.
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Doughty DM, Dieterle M, Sessions AL, Fischer WW, Newman DK. Probing the subcellular localization of hopanoid lipids in bacteria using NanoSIMS. PLoS One 2014; 9:e84455. [PMID: 24409299 PMCID: PMC3883690 DOI: 10.1371/journal.pone.0084455] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/22/2013] [Indexed: 01/14/2023] Open
Abstract
The organization of lipids within biological membranes is poorly understood. Some studies have suggested lipids group into microdomains within cells, but the evidence remains controversial due to non-native imaging techniques. A recently developed NanoSIMS technique indicated that sphingolipids group into microdomains within membranes of human fibroblast cells. We extended this NanoSIMS approach to study the localization of hopanoid lipids in bacterial cells by developing a stable isotope labeling method to directly detect subcellular localization of specific lipids in bacteria with ca. 60 nm resolution. Because of the relatively small size of bacterial cells and the relative abundance of hopanoid lipids in membranes, we employed a primary 2H-label to maximize our limit of detection. This approach permitted the analysis of multiple stable isotope labels within the same sample, enabling visualization of subcellular lipid microdomains within different cell types using a secondary label to mark the growing end of the cell. Using this technique, we demonstrate subcellular localization of hopanoid lipids within alpha-proteobacterial and cyanobacterial cells. Further, we provide evidence of hopanoid lipid domains in between cells of the filamentous cyanobacterium Nostoc punctiforme. More broadly, our method provides a means to image lipid microdomains in a wide range of cell types and test hypotheses for their functions in membranes.
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Affiliation(s)
- David M. Doughty
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
- Howard Hughes Medical Institute, Pasadena, California, United States of America
| | - Michael Dieterle
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - Alex L. Sessions
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
| | - Woodward W. Fischer
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (WWF); (DKN)
| | - Dianne K. Newman
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, United States of America
- Howard Hughes Medical Institute, Pasadena, California, United States of America
- * E-mail: (WWF); (DKN)
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13
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Boekema EJ, Scheffers DJ, van Bezouwen LS, Bolhuis H, Folea IM. Focus on membrane differentiation and membrane domains in the prokaryotic cell. J Mol Microbiol Biotechnol 2013; 23:345-56. [PMID: 23920497 DOI: 10.1159/000351361] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A summary is presented of membrane differentiation in the prokaryotic cell, with an emphasis on the organization of proteins in the plasma/cell membrane. Many species belonging to the Eubacteria and Archaea have special membrane domains and/or membrane proliferation, which are vital for different cellular processes. Typical membrane domains are found in bacteria where a specific membrane protein is abundantly expressed. Lipid rafts form another example. Despite the rareness of conventional organelles as found in eukaryotes, some bacteria are known to have an intricate internal cell membrane organization. Membrane proliferation can be divided into curvature and invaginations which can lead to internal compartmentalization. This study discusses some of the clearest examples of bacteria with such domains and internal membranes. The need for membrane specialization is highest among the heterogeneous group of bacteria which harvest light energy, such as photosynthetic bacteria and halophilic archaea. Most of the highly specialized membranes and domains, such as the purple membrane, chromatophore and chlorosome, are found in these autotrophic organisms. Otherwise the need for membrane differentiation is lower and variable, except for those structures involved in cell division. Microscopy techniques have given essential insight into bacterial membrane morphology. As microscopy will further contribute to the unraveling of membrane organization in the years to come, past and present technology in electron microscopy and light microscopy is discussed. Electron microscopy was the first to unravel bacterial morphology because it can directly visualize membranes with inserted proteins, which no other technique can do. Electron microscopy techniques developed in the 1950s and perfected in the following decades involve the thin sectioning and freeze fractioning of cells. Several studies from the golden age of these techniques show amazing examples of cell membrane morphology. More recently, light microscopy in combination with the use of fluorescent dyes has become an attractive technique for protein localization with the natural membrane. However, the resolution problem in light microscopy remains and overinterpretation of observed phenomena is a pitfall. Thus, light microscopy as a stand-alone technique is not sufficient to prove, for instance, the long-range helical distribution of proteins in membrane such as MinD spirals in Bacillus subtilis. Electron tomography is an emerging electron microscopy technique that can provide three-dimensional reconstructions of small, nonchemically fixed bacteria. It will become a useful tool for studying prokaryotic membranes in more detail and is expected to collect information complementary to those of advanced light microscopy. Together, microscopy techniques can meet the challenge of the coming years: to specify membrane structures in more detail and to bring them to the level of specific protein-protein interactions.
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Affiliation(s)
- Egbert J Boekema
- Department of Electron Microscopy, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, NL–9747 AG Groningen, The Netherlands.
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Fishov I, Norris V. Membrane heterogeneity created by transertion is a global regulator in bacteria. Curr Opin Microbiol 2012. [DOI: 10.1016/j.mib.2012.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Dai XZ, Kawamoto J, Sato SB, Esaki N, Kurihara T. Eicosapentaenoic acid facilitates the folding of an outer membrane protein of the psychrotrophic bacterium, Shewanella livingstonensis Ac10. Biochem Biophys Res Commun 2012; 425:363-7. [PMID: 22842563 DOI: 10.1016/j.bbrc.2012.07.097] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 07/19/2012] [Indexed: 10/28/2022]
Abstract
Polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), are found in various cold-adapted microorganisms. We previously demonstrated that EPA-containing phospholipids (EPA-PLs) synthesized by the psychrotrophic bacterium Shewanella livingstonensis Ac10 support cell division, membrane biogenesis, and the production of membrane proteins at low temperatures. In this article, we demonstrate the effects of EPA-PLs on the folding and conformational transition of Omp74, a major outer membrane cold-inducible protein in this bacterium. Omp74 from an EPA-less mutant migrated differently from that of the parent strain on SDS-polyacrylamide gel, suggesting that EPA-PLs affect the conformation of Omp74 in vivo. To examine the effects of EPA-PLs on Omp74 protein folding, in vitro refolding of recombinant Omp74 was carried out with liposomes composed of 1,2-dipalmitoleoyl-sn-glycero-3-phosphoglycerol and 1,2-dipalmitoleoyl-sn-glycero-3-phosphoethanolamine (1:1 molar ratio) with or without EPA-PLs as guest lipids. SDS-PAGE analysis of liposome-reconstituted Omp74 revealed more rapid folding in the presence of EPA-PLs. CD spectroscopy of Omp74 folding kinetics at 4 °C showed that EPA-PLs accelerated β-sheet formation. These results suggest that EPA-PLs act as chemical chaperones, accelerating membrane insertion and secondary structure formation of Omp74 at low temperatures.
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Affiliation(s)
- Xian-Zhu Dai
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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