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Barbarek SC, Shah R, Paul S, Alvarado G, Appala K, Phillips C, Henderson EC, Strandquist ET, Pokorny A, Singh VK, Gatto C, Dahl JU, Hines KM, Wilkinson BJ. Lipidomics of homeoviscous adaptation to low temperatures in Staphylococcus aureus utilizing exogenous straight-chain unsaturated fatty acids. J Bacteriol 2024:e0018724. [PMID: 38953643 DOI: 10.1128/jb.00187-24] [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: 05/16/2024] [Accepted: 06/09/2024] [Indexed: 07/04/2024] Open
Abstract
It is well established that Staphylococcus aureus can incorporate exogenous straight-chain unsaturated fatty acids (SCUFAs) into membrane phospho- and glyco-lipids from various sources in supplemented culture media and when growing in vivo during infection. Given the enhancement of membrane fluidity when oleic acid (C18:1Δ9) is incorporated into lipids, we were prompted to examine the effect of medium supplementation with C18:1Δ9 on growth at low temperatures. C18:1Δ9 supported the growth of a cold-sensitive, branched-chain fatty acid (BCFA)-deficient mutant at 12°C. Interestingly, we found similar results in the BCFA-sufficient parental strain, supported by the fact that the incorporation of C18:1Δ9 into the membrane increased membrane fluidity in both strains. We show that the incorporation of C18:1Δ9 and its elongation product C20:1Δ11 into membrane lipids was required for growth stimulation and relied on a functional FakAB incorporation system. Lipidomics analysis of the phosphatidylglycerol and diglycosyldiacylglycerol lipid classes revealed major impacts of C18:1Δ9 and temperature on lipid species. Growth at 12°C in the presence of C18:1Δ9 also led to increased production of the carotenoid pigment staphyloxanthin. The enhancement of growth by C18:1Δ9 is an example of homeoviscous adaptation to low temperatures utilizing an exogenous fatty acid. This may be significant in the growth of S. aureus at low temperatures in foods that commonly contain C18:1Δ9 and other SCUFAs in various forms. IMPORTANCE We show that Staphylococcus aureus can use its known ability to incorporate exogenous fatty acids to enhance its growth at low temperatures. Individual species of phosphatidylglycerols and diglycosyldiacylglycerols bearing one or two degrees of unsaturation derived from the incorporation of C18:1Δ9 at 12°C are described for the first time. In addition, enhanced production of the carotenoid staphyloxanthin occurs at low temperatures. The studies describe a biochemical reality underlying membrane biophysics. This is an example of homeoviscous adaptation to low temperatures utilizing exogenous fatty acids over the regulation of the biosynthesis of endogenous fatty acids. The studies have likely relevance to food safety in that unsaturated fatty acids may enhance the growth of S. aureus in the food environment.
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Affiliation(s)
- Shannon C Barbarek
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Ritika Shah
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Sharanya Paul
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Gloria Alvarado
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Keerthi Appala
- Department of Chemistry, University of Georgia, Athens, Georgia, USA
| | - Caiden Phillips
- Department of Microbiology and Immunology, Kirksville College of Osteopathic Medicine, A. T. Still University of Health Sciences, Kirksville, Missouri, USA
| | - Emma C Henderson
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Evan T Strandquist
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Antje Pokorny
- Department of Chemistry and Biochemistry, University of North Carolina-Wilmington, Wilmington, North Carolina, USA
| | - Vineet K Singh
- Department of Microbiology and Immunology, Kirksville College of Osteopathic Medicine, A. T. Still University of Health Sciences, Kirksville, Missouri, USA
| | - Craig Gatto
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Jan-Ulrik Dahl
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Kelly M Hines
- Department of Chemistry, University of Georgia, Athens, Georgia, USA
| | - Brian J Wilkinson
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
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2
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Barbarek SC, Shah R, Paul S, Alvarado G, Appala K, Henderson EC, Strandquist ET, Pokorny A, Singh VK, Gatto C, Dahl JU, Hines KM, Wilkinson BJ. Lipidomics of homeoviscous adaptation to low temperatures in Staphylococcus aureus utilizing exogenous straight-chain unsaturated fatty acids over biosynthesized endogenous branched-chain fatty acids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.02.578686. [PMID: 38352554 PMCID: PMC10862916 DOI: 10.1101/2024.02.02.578686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
It is well established that Staphylococcus aureus can incorporate exogenous straight-chain unsaturated fatty acids (SCUFAs) into membrane phospho- and glyco-lipids from various sources in supplemented culture media, and when growing in vivo in an infection. Given the enhancement of membrane fluidity when oleic acid (C18:1Δ9) is incorporated into lipids, we were prompted to examine the effect of medium supplementation with C18:1Δ9 on growth at low temperatures. C18:1Δ9 supported the growth of a cold-sensitive, branched-chain fatty acid (BCFA)-deficient mutant at 12°C. Interestingly, we found similar results in the BCFA-sufficient parental strain. We show that incorporation of C18:1Δ9 and its elongation product C20:1Δ9 into membrane lipids was required for growth stimulation and relied on a functional FakAB incorporation system. Lipidomics analysis of the phosphatidylglycerol (PG) and diglycosyldiacylglycerol (DGDG) lipid classes revealed major impacts of C18:1Δ9 and temperature on lipid species. Growth at 12°C in the presence of C18:1Δ9 also led to increased production of the carotenoid pigment staphyloxanthin; however, this was not an obligatory requirement for cold adaptation. Enhancement of growth by C18:1Δ9 is an example of homeoviscous adaptation to low temperatures utilizing an exogenous fatty acid. This may be significant in the growth of S. aureus at low temperatures in foods that commonly contain C18:1Δ9 and other SCUFAs in various forms.
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Affiliation(s)
| | - Ritika Shah
- School of Biological Sciences, Illinois State University, Normal, IL
| | - Sharanya Paul
- School of Biological Sciences, Illinois State University, Normal, IL
| | - Gloria Alvarado
- School of Biological Sciences, Illinois State University, Normal, IL
| | - Keerthi Appala
- Department of Chemistry, University of Georgia, Athens, GA
| | - Emma C. Henderson
- School of Biological Sciences, Illinois State University, Normal, IL
| | | | - Antje Pokorny
- Department of Chemistry and Biochemistry, University of North Carolina-Wilmington, Wilmington, NC
| | - Vineet K. Singh
- Department of Microbiology and Immunology, Kirksville College of Osteopathic Medicine, A. T. Still University of Health Sciences, Kirksville, MO
| | - Craig Gatto
- School of Biological Sciences, Illinois State University, Normal, IL
| | - Jan-Ulrik Dahl
- School of Biological Sciences, Illinois State University, Normal, IL
| | - Kelly M. Hines
- Department of Chemistry, University of Georgia, Athens, GA
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3
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Sugiyama S, Matsuoka D, Hara T, Sonoyama M, Matsuoka S, Murata M. Experimental and theoretical investigations into the mechanism of interactions between membrane-bound fatty acids and their binding protein: A model system to investigate the behavior of lipid acyl chains in contact with proteins. Chem Phys Lipids 2022; 247:105227. [PMID: 35932927 DOI: 10.1016/j.chemphyslip.2022.105227] [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: 05/29/2022] [Revised: 07/27/2022] [Accepted: 07/30/2022] [Indexed: 11/29/2022]
Abstract
The interaction of proteins with hydrophobic ligands in biological membranes is an important research topic in the life sciences. The hydrophobic nature of ligands, especially their lack of water solubility, often makes it difficult to experimentally investigate their interactions with proteins, thus hampering quantitative evaluation based on thermodynamic parameters. The fatty acid-binding proteins, particularly FABP3, discussed in this review can recognize fatty acids, a primary component of membrane lipids, with high affinity. The precise three-dimensional structure of fatty acids and related ligands bound in FABP3 and their interaction with the binding pocket will contribute to the understanding of accurately determining physicochemical factors that cause the expression of affinity between protein surfaces and lipids in biological membranes. During the research of FABP3, we encountered many of the problems that were widely implicated in experiments dealing with hydrophobic ligands. To address these issues, we developed experimental methodologies using X-ray crystallography, calorimetry, and surface plasmon resonance. Using these methods and computational approaches, we have obtained several insights into the interaction of hydrophobic ligands with protein binding sites. Structural and functional studies of FABP potentially lead to a better understanding of the interaction between lipids and proteins, and thus, this protein may provide one of the model systems for investigating substance transport across cell membranes and inner membrane systems.
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Affiliation(s)
- Shigeru Sugiyama
- Faculty of Science and Technology, Kochi University, Kochi 780-8520, Japan; JST ERATO, Lipid Active Structure Project, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Daisuke Matsuoka
- JST ERATO, Lipid Active Structure Project, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Toshiaki Hara
- JST ERATO, Lipid Active Structure Project, Osaka University, Toyonaka, Osaka 560-0043, Japan; Hamari Chemicals, Ltd. 1-19-40 Nankokita, Suminoe-ku Osaka, 2-1-26, Kitahama, Chuo-ku, Osaka 559-0034, Japan
| | - Masashi Sonoyama
- Division of Molecular Science, Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515, Japan; Gunma University Initiative for Advanced Research (GIAR), Kiryu, Gunma 376-8515, Japan; Gunma University Center for Food Science and Wellness (GUCFW), Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Shigeru Matsuoka
- JST ERATO, Lipid Active Structure Project, Osaka University, Toyonaka, Osaka 560-0043, Japan; Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan; Forefront Research Center, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Michio Murata
- JST ERATO, Lipid Active Structure Project, Osaka University, Toyonaka, Osaka 560-0043, Japan; Forefront Research Center, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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4
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Bacle A, Buslaev P, Garcia-Fandino R, Favela-Rosales F, Mendes Ferreira T, Fuchs PFJ, Gushchin I, Javanainen M, Kiirikki AM, Madsen JJ, Melcr J, Milán Rodríguez P, Miettinen MS, Ollila OHS, Papadopoulos CG, Peón A, Piggot TJ, Piñeiro Á, Virtanen SI. Inverse Conformational Selection in Lipid-Protein Binding. J Am Chem Soc 2021; 143:13701-13709. [PMID: 34465095 DOI: 10.1021/jacs.1c05549] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Interest in lipid interactions with proteins and other biomolecules is emerging not only in fundamental biochemistry but also in the field of nanobiotechnology where lipids are commonly used, for example, in carriers of mRNA vaccines. The outward-facing components of cellular membranes and lipid nanoparticles, the lipid headgroups, regulate membrane interactions with approaching substances, such as proteins, drugs, RNA, or viruses. Because lipid headgroup conformational ensembles have not been experimentally determined in physiologically relevant conditions, an essential question about their interactions with other biomolecules remains unanswered: Do headgroups exchange between a few rigid structures, or fluctuate freely across a practically continuous spectrum of conformations? Here, we combine solid-state NMR experiments and molecular dynamics simulations from the NMRlipids Project to resolve the conformational ensembles of headgroups of four key lipid types in various biologically relevant conditions. We find that lipid headgroups sample a wide range of overlapping conformations in both neutral and charged cellular membranes, and that differences in the headgroup chemistry manifest only in probability distributions of conformations. Furthermore, the analysis of 894 protein-bound lipid structures from the Protein Data Bank suggests that lipids can bind to proteins in a wide range of conformations, which are not limited by the headgroup chemistry. We propose that lipids can select a suitable headgroup conformation from the wide range available to them to fit the various binding sites in proteins. The proposed inverse conformational selection model will extend also to lipid binding to targets other than proteins, such as drugs, RNA, and viruses.
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Affiliation(s)
- Amélie Bacle
- Laboratoire Coopératif "Lipotoxicity and Channelopathies - ConicMeds", Université de Poitiers, 1 rue Georges Bonnet, Poitiers 86000, France
| | - Pavel Buslaev
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, P.O. Box 35, Jyväskylä 40014, Finland.,Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Rebeca Garcia-Fandino
- Center for Research in Biological Chemistry and Molecular Materials (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela E-15782, Spain.,CIQUP, Centro de Investigao em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Fernando Favela-Rosales
- Departamento de Ciencias Básicas, Tecnológico Nacional de México - ITS Zacatecas Occidente, Sombrerete, Zacatecas 99102, México
| | - Tiago Mendes Ferreira
- NMR group - Institute for Physics, Martin Luther University Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Patrick F J Fuchs
- Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), Sorbonne Université, Paris 75005, France.,UFR Sciences du Vivant, Université de Paris, Paris 75013, France
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, Prague CZ-16610, Czech Republic
| | - Anne M Kiirikki
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Jesper J Madsen
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States.,Global and Planetary Health, College of Public Health, University of South Florida, Tampa, Florida 33612, United States
| | - Josef Melcr
- Groningen Biomolecular Sciences and Biotechnology Institute and The Zernike Institute for Advanced Materials, University of Groningen, Groningen9747 AG, The Netherlands
| | - Paula Milán Rodríguez
- Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), Sorbonne Université, Paris 75005, France
| | - Markus S Miettinen
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - O H Samuli Ollila
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Chris G Papadopoulos
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette 91198, France
| | - Antonio Peón
- CIQUP, Centro de Investigao em Química, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
| | - Thomas J Piggot
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Ángel Piñeiro
- Departamento de Física Aplicada, Facultade de Física, Universidade de Santiago de Compostela, Santiago de Compostela E-15782, Spain
| | - Salla I Virtanen
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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5
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Rasmussen T, Rasmussen A, Yang L, Kaul C, Black S, Galbiati H, Conway SJ, Miller S, Blount P, Booth IR. Interaction of the Mechanosensitive Channel, MscS, with the Membrane Bilayer through Lipid Intercalation into Grooves and Pockets. J Mol Biol 2019; 431:3339-3352. [PMID: 31173776 DOI: 10.1016/j.jmb.2019.05.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/14/2019] [Accepted: 05/29/2019] [Indexed: 10/26/2022]
Abstract
All membrane proteins have dynamic and intimate relationships with the lipids of the bilayer that may determine their activity. Mechanosensitive channels sense tension through their interaction with the lipids of the membrane. We have proposed a mechanism for the bacterial channel of small conductance, MscS, that envisages variable occupancy of pockets in the channel by lipid chains. Here, we analyze protein-lipid interactions for MscS by quenching of tryptophan fluorescence with brominated lipids. By this strategy, we define the limits of the bilayer for TM1, which is the most lipid exposed helix of this protein. In addition, we show that residues deep in the pockets, created by the oligomeric assembly, interact with lipid chains. On the cytoplasmic side, lipids penetrate as far as the pore-lining helices and lipid molecules can align along TM3b perpendicular to lipids in the bilayer. Cardiolipin, free fatty acids, and branched lipids can access the pockets where the latter have a distinct effect on function. Cholesterol is excluded from the pockets. We demonstrate that introduction of hydrophilic residues into TM3b severely impairs channel function and that even "conservative" hydrophobic substitutions can modulate the stability of the open pore. The data provide important insights into the interactions between phospholipids and MscS and are discussed in the light of recent developments in the study of Piezo1 and TrpV4.
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Affiliation(s)
- Tim Rasmussen
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Akiko Rasmussen
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Limin Yang
- Department of Physiology, U.T. Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9040, USA.
| | - Corinna Kaul
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK
| | - Susan Black
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Heloisa Galbiati
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Stuart J Conway
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
| | - Samantha Miller
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Paul Blount
- Department of Physiology, U.T. Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390-9040, USA.
| | - Ian Rylance Booth
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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6
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Pezeshkian W, Khandelia H, Marsh D. Lipid Configurations from Molecular Dynamics Simulations. Biophys J 2018; 114:1895-1907. [PMID: 29694867 PMCID: PMC5937052 DOI: 10.1016/j.bpj.2018.02.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 02/09/2018] [Accepted: 02/13/2018] [Indexed: 01/10/2023] Open
Abstract
The extent to which current force fields faithfully reproduce conformational properties of lipids in bilayer membranes, and whether these reflect the structural principles established for phospholipids in bilayer crystals, are central to biomembrane simulations. We determine the distribution of dihedral angles in palmitoyl-oleoyl phosphatidylcholine from molecular dynamics simulations of hydrated fluid bilayer membranes. We compare results from the widely used lipid force field of Berger et al. with those from the most recent C36 release of the CHARMM force field for lipids. Only the CHARMM force field produces the chain inequivalence with sn-1 as leading chain that is characteristic of glycerolipid packing in fluid bilayers. The exposure and high partial charge of the backbone carbonyls in Berger lipids leads to artifactual binding of Na+ ions reported in the literature. Both force fields predict coupled, near-symmetrical distributions of headgroup dihedral angles, which is compatible with models of interconverting mirror-image conformations used originally to interpret NMR order parameters. The Berger force field produces rotamer populations that correspond to the headgroup conformation found in a phosphatidylcholine lipid bilayer crystal, whereas CHARMM36 rotamer populations are closer to the more relaxed crystal conformations of phosphatidylethanolamine and glycerophosphocholine. CHARMM36 alone predicts the correct relative signs of the time-average headgroup order parameters, and reasonably reproduces the full range of NMR data from the phosphate diester to the choline methyls. There is strong motivation to seek further experimental criteria for verifying predicted conformational distributions in the choline headgroup, including the 31P chemical shift anisotropy and 14N and CD3 NMR quadrupole splittings.
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Affiliation(s)
- Weria Pezeshkian
- MEMPHYS-Centre for Biomembrane Physics, University of Southern Denmark, Odense M, Denmark
| | - Himanshu Khandelia
- MEMPHYS-Centre for Biomembrane Physics, University of Southern Denmark, Odense M, Denmark
| | - Derek Marsh
- MEMPHYS-Centre for Biomembrane Physics, University of Southern Denmark, Odense M, Denmark; Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
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7
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Hegedüs C, Telbisz Á, Hegedűs T, Sarkadi B, Özvegy-Laczka C. Lipid regulation of the ABCB1 and ABCG2 multidrug transporters. Adv Cancer Res 2015; 125:97-137. [PMID: 25640268 DOI: 10.1016/bs.acr.2014.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This chapter deals with the interactions of two medically important multidrug ABC transporters (MDR-ABC), ABCB1 and ABCG2, with lipid molecules. Both ABCB1 and ABCG2 are capable of transporting a wide range of hydrophobic drugs and xenobiotics and are involved in cancer chemotherapy resistance. Therefore, the exploration of their mechanism of action has major therapeutic consequences. As discussed here in detail, both ABCB1 and ABCG2 are significantly affected by various lipid compounds especially those residing in their close proximity in the plasma membrane. ABCB1 is capable of transporting lipids and lipid derivatives, and thus may alter the general membrane composition by "flopping" membrane lipid constituents, while there is no such information regarding ABCG2. Still, both ABCB1 and ABCG2 show complex interactions with a variety of lipid molecules, and the transporters are significantly modulated by cholesterol and cholesterol derivatives at the posttranslational level. In this chapter, we explore the molecular details of the direct transporter-lipid interactions, the potential role of lipid-sensor domains within the proteins, as well as the application of experimental site-directed mutagenesis, detailed structural studies, and in silico modeling for examining these interactions. We also discuss the regulation of ABCB1 and ABCG2 expression at the transcriptional level, occurring through nuclear receptors involved in lipid sensing. The better understanding of lipid interactions with these medically important MDR-ABC transporters may significantly improve further drug development and clinical treatment options.
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Affiliation(s)
- Csilla Hegedüs
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ágnes Telbisz
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Tamás Hegedűs
- MTA-SE Molecular Biophysics Research Group of the Hungarian Academy of Sciences, Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Balázs Sarkadi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; MTA-SE Molecular Biophysics Research Group of the Hungarian Academy of Sciences, Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Csilla Özvegy-Laczka
- MTA-SE Molecular Biophysics Research Group of the Hungarian Academy of Sciences, Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
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8
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Cross TA, Murray DT, Watts A. Helical membrane protein conformations and their environment. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2013; 42:731-55. [PMID: 23996195 PMCID: PMC3818118 DOI: 10.1007/s00249-013-0925-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 07/25/2013] [Accepted: 08/12/2013] [Indexed: 02/02/2023]
Abstract
Evidence that membrane proteins respond conformationally and functionally to their environment is growing. Structural models, by necessity, have been characterized in preparations where the protein has been removed from its native environment. Different structural methods have used various membrane mimetics that have recently included lipid bilayers as a more native-like environment. Structural tools applied to lipid bilayer-embedded integral proteins are informing us about important generic characteristics of how membrane proteins respond to the lipid environment as compared with their response to other nonlipid environments. Here, we review the current status of the field, with specific reference to observations of some well-studied α-helical membrane proteins, as a starting point to aid the development of possible generic principles for model refinement.
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Affiliation(s)
- Timothy A. Cross
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Dylan T. Murray
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Anthony Watts
- Biomembrane structure Unit, Biochemistry Department, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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Fantini J, Barrantes FJ. How cholesterol interacts with membrane proteins: an exploration of cholesterol-binding sites including CRAC, CARC, and tilted domains. Front Physiol 2013; 4:31. [PMID: 23450735 PMCID: PMC3584320 DOI: 10.3389/fphys.2013.00031] [Citation(s) in RCA: 326] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 02/08/2013] [Indexed: 12/20/2022] Open
Abstract
The plasma membrane of eukaryotic cells contains several types of lipids displaying high biochemical variability in both their apolar moiety (e.g., the acyl chain of glycerolipids) and their polar head (e.g., the sugar structure of glycosphingolipids). Among these lipids, cholesterol is unique because its biochemical variability is almost exclusively restricted to the oxidation of its polar −OH group. Although generally considered the most rigid membrane lipid, cholesterol can adopt a broad range of conformations due to the flexibility of its isooctyl chain linked to the polycyclic sterane backbone. Moreover, cholesterol is an asymmetric molecule displaying a planar α face and a rough β face. Overall, these structural features open up a number of possible interactions between cholesterol and membrane lipids and proteins, consistent with the prominent regulatory functions that this unique lipid exerts on membrane components. The aim of this review is to describe how cholesterol interacts with membrane lipids and proteins at the molecular/atomic scale, with special emphasis on transmembrane domains of proteins containing either the consensus cholesterol-binding motifs CRAC and CARC or a tilted peptide. Despite their broad structural diversity, all these domains bind cholesterol through common molecular mechanisms, leading to the identification of a subset of amino acid residues that are overrepresented in both linear and three-dimensional membrane cholesterol-binding sites.
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Affiliation(s)
- Jacques Fantini
- EA-4674, Interactions Moléculaires et Systèmes Membranaires, Aix-Marseille Université Marseille, France
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10
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