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Tripathy A, Priyadarsinee S, Bag N. Evaluation of functional transbilayer coupling in live cells by controlled lipid exchange and imaging fluorescence correlation spectroscopy. Methods Enzymol 2024; 700:1-32. [PMID: 38971596 DOI: 10.1016/bs.mie.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
Biophysical coupling between the inner and outer leaflets, known as inter-leaflet or transbilayer coupling, is a fundamental organizational principle in the plasma membranes of live mammalian cells. Lipid-based interactions between the two leaflets are proposed to be a primary mechanism underlying transbilayer coupling. However, there are only a few experimental evidence supporting the existence of such interactions in live cells. This is seemingly due to the lack of experimental strategies to perturb the lipid composition in one leaflet and quantitative techniques to evaluate the biophysical properties of the opposite leaflet. The existing strategies often dependent on immobilization and clustering a component in one of the leaflets and technically demanding biophysical tools to evaluate the effects on the opposing leaflet. In the recent years, the London group developed a simple but elegant method, namely methyl-alpha-cyclodextrin catalyzed lipid exchange (LEX), to efficiently exchange outer leaflet lipids with an exogenous lipid of choice. Here, we adopted this method to perturb outer leaflet lipid composition. The corresponding changes in the inner leaflet is evaluated by comparing the diffusion of lipid probes localized in this leaflet in unperturbed and perturbed conditions. We employed highly multiplexed imaging fluorescence correlation spectroscopy (ImFCS), realized in a commercially available or home-built total internal reflection fluorescence microsocope equipped with a fast and sensitive camera, to determine diffusion coefficient of the lipid probes. Using the combination of LEX and ImFCS, we directly demonstrate lipid-based transbilayer coupling that does not require immobilization of membrane components in live mast cells in resting conditions. Overall, we present a relatively straightforward experimental strategy to evaluate transbilayer coupling quantitively in live cells.
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Affiliation(s)
- Arpita Tripathy
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Sudipti Priyadarsinee
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Nirmalya Bag
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India.
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2
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Fernandez-Rojo MA, Pearen MA, Burgess AG, Ikonomopoulou MP, Hoang-Le D, Genz B, Saggiomo SL, Nawaratna SSK, Poli M, Reissmann R, Gobert GN, Deutsch U, Engelhardt B, Brooks AJ, Jones A, Arosio P, Ramm GA. The heavy subunit of ferritin stimulates NLRP3 inflammasomes in hepatic stellate cells through ICAM-1 to drive hepatic inflammation. Sci Signal 2024; 17:eade4335. [PMID: 38564492 DOI: 10.1126/scisignal.ade4335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
Serum ferritin concentrations increase during hepatic inflammation and correlate with the severity of chronic liver disease. Here, we report a molecular mechanism whereby the heavy subunit of ferritin (FTH) contributes to hepatic inflammation. We found that FTH induced activation of the NLRP3 inflammasome and secretion of the proinflammatory cytokine interleukin-1β (IL-1β) in primary rat hepatic stellate cells (HSCs) through intercellular adhesion molecule-1 (ICAM-1). FTH-ICAM-1 stimulated the expression of Il1b, NLRP3 inflammasome activation, and the processing and secretion of IL-1β in a manner that depended on plasma membrane remodeling, clathrin-mediated endocytosis, and lysosomal destabilization. FTH-ICAM-1 signaling at early endosomes stimulated Il1b expression, implying that this endosomal signaling primed inflammasome activation in HSCs. In contrast, lysosomal destabilization was required for FTH-induced IL-1β secretion, suggesting that lysosomal damage activated inflammasomes. FTH induced IL-1β production in liver slices from wild-type mice but not in those from Icam1-/- or Nlrp3-/- mice. Thus, FTH signals through its receptor ICAM-1 on HSCs to activate the NLRP3 inflammasome. We speculate that this pathway contributes to hepatic inflammation, a key process that stimulates hepatic fibrogenesis associated with chronic liver disease.
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Affiliation(s)
- Manuel A Fernandez-Rojo
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
- School of Medicine, University of Queensland, Brisbane, Herston, QLD 4006, Australia
- Hepatic Regenerative Medicine Laboratory, Madrid Institute for Advanced Studies in Food, Madrid 28049, Spain
- University of Queensland Diamantina Institute, University of Queensland, Translational Research Institute, Brisbane, QLD 4102, Australia
| | - Michael A Pearen
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
| | - Anita G Burgess
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
| | - Maria P Ikonomopoulou
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
- School of Medicine, University of Queensland, Brisbane, Herston, QLD 4006, Australia
- Translational Venomics Laboratory, Madrid Institute for Advanced Studies in Food, Madrid 28049, Spain
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
| | - Diem Hoang-Le
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
| | - Berit Genz
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
| | - Silvia L Saggiomo
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
| | | | - Maura Poli
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Regina Reissmann
- Department for BioMedical Research (DBMR), University of Bern, Freiestrasse 1, CH-3012 Bern, Switzerland
| | - Geoffrey N Gobert
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
- School of Biological Sciences, Queen's University Belfast, Belfast, UK
| | - Urban Deutsch
- Theodor Kocher Institute, University of Bern, Freiestrasse 1, CH-3012 Bern, Switzerland
| | - Britta Engelhardt
- Theodor Kocher Institute, University of Bern, Freiestrasse 1, CH-3012 Bern, Switzerland
| | - Andrew J Brooks
- University of Queensland Diamantina Institute, University of Queensland, Translational Research Institute, Brisbane, QLD 4102, Australia
| | - Alun Jones
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD 4072, Australia
| | - Paolo Arosio
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Grant A Ramm
- QIMR Berghofer Medical Research Institute, Brisbane, Herston, QLD 4006, Australia
- School of Medicine, University of Queensland, Brisbane, Herston, QLD 4006, Australia
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3
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Thakur GCN, Uday A, Jurkiewicz P. FRET-GP - A Local Measure of the Impact of Transmembrane Peptide on Lipids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:18390-18402. [PMID: 38048524 DOI: 10.1021/acs.langmuir.3c02505] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Reconstitution of a transmembrane protein in model lipid systems allows studying its structure and dynamics in isolation from the complexity of the natural environment. This approach also provides a well-defined environment for studying the interactions of proteins with lipids. In this work, we describe the FRET-GP method, which utilizes Förster resonance energy transfer (FRET) to specifically probe the nanoenvironment of a transmembrane domain. The tryptophan residues flanking this domain act as efficient FRET donors, while Laurdan acts as acceptor. The fluorescence of this solvatochromic probe is quantified using generalized polarization (GP) to report on lipid mobility in the vicinity of the transmembrane domain. We applied FRET-GP to study the transmembrane peptide WALP incorporated in liposomes. We found that the direct excitation of Laurdan to its second singlet state strongly contributes to GP values measured in FRET conditions. Removal of this parasitic contribution was essential for proper determination of GPFRET - the local analogue of classical GP parameter. The presence of WALP significantly increased both parameters but the local effects were considerably stronger (GPFRET ≫ GP). We conclude that WALP restricts lipid movement in its vicinity, inducing lateral inhomogeneity in membrane fluidity. WALP was also found to influence lipid phase transition. Our findings demonstrated that FRET-GP simultaneously provides local and global results, thereby enhancing the depth of information obtained from the measurement. We highlight the simplicity and sensitivity of the method, but also discuss its potential and limitations in studying protein-lipid interactions.
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Affiliation(s)
- Garima C N Thakur
- J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague 182 00, Czech Republic
| | - Arunima Uday
- J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague 182 00, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic, v.v.i., Prague 182 00, Czech Republic
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4
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Roversi D, Troiano C, Salnikov E, Giordano L, Riccitelli F, De Zotti M, Casciaro B, Loffredo MR, Park Y, Formaggio F, Mangoni ML, Bechinger B, Stella L. Effects of antimicrobial peptides on membrane dynamics: A comparison of fluorescence and NMR experiments. Biophys Chem 2023; 300:107060. [PMID: 37336097 DOI: 10.1016/j.bpc.2023.107060] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/25/2023] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
Abstract
Antimicrobial peptides (AMPs) represent a promising class of compounds to fight resistant infections. They are commonly thought to kill bacteria by perturbing the permeability of their cell membranes. However, bacterial killing requires a high coverage of the cell surface by bound peptides, at least in the case of cationic and amphipathic AMPs. Therefore, it is conceivable that peptide accumulation on the bacterial membranes might interfere with vital cellular functions also by perturbing bilayer dynamics, a hypothesis that has been termed "sand in the gearbox". Here we performed a systematic study of such possible effects, for two representative peptides (the cationic cathelicidin PMAP-23 and the peptaibol alamethicin), employing fluorescence and NMR spectroscopies. These approaches are commonly applied to characterize lipid order and dynamics, but sample different time-scales and could thus report on different membrane properties. In our case, fluorescence anisotropy measurements on liposomes labelled with probes localized at different depths in the bilayer showed that both peptides perturb membrane fluidity and order. Pyrene excimer-formation experiments showed a peptide-induced reduction in lipid lateral mobility. Finally, laurdan fluorescence indicated that peptide binding reduces water penetration below the headgroups region. Comparable effects were observed also in fluorescence experiments performed directly on live bacterial cells. By contrast, the fatty acyl chain order parameters detected by deuterium NMR spectroscopy remained virtually unaffected by addition of the peptides. The apparent discrepancy between the two techniques confirms previous sporadic observations and is discussed in terms of the different characteristic times of the two approaches. The perturbation of membrane dynamics in the ns timescale, indicated by the multiple fluorescence approaches reported here, could contribute to the antimicrobial activity of AMPs, by affecting the function of membrane proteins, which is strongly dependent on the physicochemical properties of the bilayer.
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Affiliation(s)
- Daniela Roversi
- Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy
| | - Cassandra Troiano
- Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy
| | - Evgeniy Salnikov
- RMN et Biophysique des membranes, Institut de Chimie de Strasbourg, CNRS/UMR 7177, Université de Strasbourg, 4, rue Blaise Pascal, Strasbourg 67000, France
| | - Lorenzo Giordano
- Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy
| | - Francesco Riccitelli
- Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy
| | - Marta De Zotti
- Department of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Bruno Casciaro
- Department of Biochemical Sciences, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy
| | - Maria Rosa Loffredo
- Department of Biochemical Sciences, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Fernando Formaggio
- Department of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Maria Luisa Mangoni
- Department of Biochemical Sciences, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy
| | - Burkhard Bechinger
- RMN et Biophysique des membranes, Institut de Chimie de Strasbourg, CNRS/UMR 7177, Université de Strasbourg, 4, rue Blaise Pascal, Strasbourg 67000, France; Institut Universitaire de France, Paris 75005, France
| | - Lorenzo Stella
- Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy.
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5
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Xu Y, Song D, Wang W, Li S, Yue T, Xia T, Shi Y. Clec12a inhibits MSU-induced immune activation through lipid raft expulsion. Life Sci Alliance 2023; 6:e202301938. [PMID: 37339805 PMCID: PMC10282328 DOI: 10.26508/lsa.202301938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/22/2023] Open
Abstract
Monosodium uric acid (MSU) crystal, the etiological agent of gout, has been shown to trigger innate immune responses via multiple pathways. It is known that MSU-induced lipid sorting on plasma membrane promotes the phosphorylation of Syk and eventually leads to the activation of phagocytes. However, whether this membrane lipid-centric mechanism is regulated by other processes is unclear. Previous studies showed that Clec12a, a member of the C-type lectin receptor family, is reported to recognize MSU and suppresses this crystalline structure-induced immune activation. How this scenario is integrated into the lipid sorting-mediated inflammatory responses by MSU, and particularly, how Clec12a intercepts lipid raft-originated signaling cascade remains to be elucidated. Here, we found that the ITIM motif of Clec12a is dispensable for its inhibition of MSU-mediated signaling; instead, the transmembrane domain of Clec12a disrupts MSU-induced lipid raft recruitment and thus attenuates downstream signals. Single amino acid mutagenesis study showed the critical role of phenylalanine in the transmembrane region for the interactions between C-type lectin receptors and lipid rafts, which is critical for the regulation of MSU-mediated lipid sorting and phagocyte activation. Overall, our study provides new insights for the molecular mechanisms of solid particle-induced immune activation and may lead to new strategies in inflammation control.
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Affiliation(s)
- Ying Xu
- Institute for Immunology, School of Medicine, Tsinghua University, Beijing, China
| | - Dingka Song
- Institute for Immunology, School of Medicine, Tsinghua University, Beijing, China
- State Key Laboratory of Oncogenes and Related Genes, Center for Single-Cell Omics, School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Wang
- Institute of Coastal Environmental Pollution Control, Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China
| | - Shixin Li
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Tongtao Yue
- Institute of Coastal Environmental Pollution Control, Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China
| | - Tie Xia
- Institute for Immunology, School of Medicine, Tsinghua University, Beijing, China
| | - Yan Shi
- Institute for Immunology, School of Medicine, Tsinghua University, Beijing, China
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute, University of Calgary, Calgary, Canada
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6
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Mitchison-Field LM, Belin BJ. Bacterial lipid biophysics and membrane organization. Curr Opin Microbiol 2023; 74:102315. [PMID: 37058914 PMCID: PMC10523990 DOI: 10.1016/j.mib.2023.102315] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 04/16/2023]
Abstract
The formation of lateral microdomains is emerging as a central organizing principle in bacterial membranes. These microdomains are targets of antibiotic development and have the potential to enhance natural product synthesis, but the rules governing their assembly are unclear. Previous studies have suggested that microdomain formation is promoted by lipid phase separation, particularly by cardiolipin (CL) and isoprenoid lipids, and there is strong evidence that CL biosynthesis is required for recruitment of membrane proteins to cell poles and division sites. New work demonstrates that additional bacterial lipids may mediate membrane protein localization and function, opening the field for mechanistic evaluation of lipid-driven membrane organization in vivo.
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Affiliation(s)
- Lorna My Mitchison-Field
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA; Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Brittany J Belin
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD, USA; Department of Biology, Johns Hopkins University, Baltimore, MD, USA.
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7
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Anselmo S, Sancataldo G, Baiamonte C, Pizzolanti G, Vetri V. Transportan 10 Induces Perturbation and Pores Formation in Giant Plasma Membrane Vesicles Derived from Cancer Liver Cells. Biomolecules 2023; 13:biom13030492. [PMID: 36979427 PMCID: PMC10046094 DOI: 10.3390/biom13030492] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/02/2023] [Accepted: 03/04/2023] [Indexed: 03/30/2023] Open
Abstract
Continuous progress has been made in the development of new molecules for therapeutic purposes. This is driven by the need to address several challenges such as molecular instability and biocompatibility, difficulties in crossing the plasma membrane, and the development of host resistance. In this context, cell-penetrating peptides (CPPs) constitute a promising tool for the development of new therapies due to their intrinsic ability to deliver therapeutic molecules to cells and tissues. These short peptides have gained increasing attention for applications in drug delivery as well as for their antimicrobial and anticancer activity but the general rules regulating the events involved in cellular uptake and in the following processes are still unclear. Here, we use fluorescence microscopy methods to analyze the interactions between the multifunctional peptide Transportan 10 (TP10) and the giant plasma membrane vesicles (GPMVs) derived from cancer cells. This aims to highlight the molecular mechanisms underlying functional interactions which bring its translocation across the membrane or cytotoxic mechanisms leading to membrane collapse and disruption. The Fluorescence Lifetime Imaging Microscopy (FLIM) method coupled with the phasor approach analysis proved to be the winning choice for following highly dynamic spatially heterogeneous events in real-time and highlighting aspects of such complex phenomena. Thanks to the presented approach, we were able to identify and monitor TP10 translocation into the lumen, internalization, and membrane-induced modifications depending on the peptide concentration regime.
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Affiliation(s)
- Sara Anselmo
- Dipartimento di Fisica e Chimica-Emilio Segré, Università degli Studi di Palermo, 90128 Palermo, Italy
| | - Giuseppe Sancataldo
- Dipartimento di Fisica e Chimica-Emilio Segré, Università degli Studi di Palermo, 90128 Palermo, Italy
| | - Concetta Baiamonte
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo, 90128 Palermo, Italy
- AteN Center-Advanced Technologies Network Center, Università degli Studi di Palermo, 90128 Palermo, Italy
| | - Giuseppe Pizzolanti
- AteN Center-Advanced Technologies Network Center, Università degli Studi di Palermo, 90128 Palermo, Italy
- Dipartimento di Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro", Università degli Studi di Palermo, 90127 Palermo, Italy
| | - Valeria Vetri
- Dipartimento di Fisica e Chimica-Emilio Segré, Università degli Studi di Palermo, 90128 Palermo, Italy
- AteN Center-Advanced Technologies Network Center, Università degli Studi di Palermo, 90128 Palermo, Italy
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8
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Fabiunke S, Fillafer C, Schneider MF. Unitary Response of Solvatochromic Dye to Pulse Excitation in Lipid and Cell Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:12408-12413. [PMID: 36154016 DOI: 10.1021/acs.langmuir.2c02261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The existence of acoustic pulse propagation in lipid monolayers at the air-water interface is well known. These pulses are controlled by the thermodynamic state of the lipid membrane. Nevertheless, the role of acoustic pulses for intra- and inter-cellular communication is still a matter of debate. Herein, we used the dye di-4-ANEPPDHQ, which is known to be sensitive to the physical state and transmembrane potential of membranes, in order to gain insights into compression waves in lipid-based membrane interfaces. The dye was incorporated into lipid monolayers made of phosphatidylserine or phosphatidylcholine at the air-water-interface. A significant blue shift of the emission spectrum was detected when the state of the monolayer was changed from the liquid-expanded (LE) to the liquid-condensed (LC) phase. This "transition sensitivity" of di-4-ANEPPDHQ was generalized in experiments with the bulk solvent dimethyl sulfoxide (DMSO). Upon crystallization of solvent, the emission spectrum also underwent a blue shift. During compression pulses in lipid monolayers, a significant fluorescence response was only observed when the main transition is crossed. The optical signature of these waves─in terms of sign and magnitude─was identical to the response of di-4-ANEPPDHQ during action potentials in neurons and excitable plant cells. These findings corroborated the suggestion that action potentials are nonlinear state changes that propagate in the cell membrane.
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Affiliation(s)
- Simon Fabiunke
- Department of Medical and Biological Physics, Technical University Dortmund, 44227 Dortmund, Germany
| | - Christian Fillafer
- Department of Medical and Biological Physics, Technical University Dortmund, 44227 Dortmund, Germany
| | - Matthias F Schneider
- Department of Medical and Biological Physics, Technical University Dortmund, 44227 Dortmund, Germany
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9
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Abstract
Phase transitions in materials are accompanied by drastic changes in their properties. Systems abruptly become softer, more conductive, have better heat storage, or support chemical reactions more efficiently. Since changes take place over small variations in external conditions (tension, temperature, pH, calcium), they appear like an on/off switch. Here, we provide experimental evidence that membrane patches of single living cells can go through a reversible phase transition. It is extremely “sharp” (highly nonlinear), and from a thermodynamic point of view we conclude it cannot only be triggered by temperature but also by pH changes (as produced by enzymes). The results strongly support the idea that phase transitions may be a tool for living systems to control their functions even specifically. The origin of nonlinear responses in cells has been suggested to be crucial for various cell functions including the propagation of the nervous impulse. In physics, nonlinear behavior often originates from phase transitions. Evidence for such transitions on the single-cell level, however, has so far not been provided, leaving the field unattended by the biological community. Here, we demonstrate that single cells of a human neuronal cell line display all optical features of a sharp, highly nonlinear phase transition within their membrane. The transition is reversible and does not originate from protein denaturation. Triggered by temperature and modified by pH here, a thermodynamic approach strongly suggests that similar nonlinear state changes can be induced by other variables such as calcium or mechanical stress. At least in lipid membranes, such state changes are accompanied by significant changes in permeability, enzyme activity, elastic, and electrical properties.
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10
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Anselmo S, Sancataldo G, Mørck Nielsen H, Foderà V, Vetri V. Peptide-Membrane Interactions Monitored by Fluorescence Lifetime Imaging: A Study Case of Transportan 10. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13148-13159. [PMID: 34714654 PMCID: PMC8582253 DOI: 10.1021/acs.langmuir.1c02392] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/19/2021] [Indexed: 06/13/2023]
Abstract
The interest on detailed analysis of peptide-membrane interactions is of great interest in both fundamental and applied sciences as these may relate to both functional and pathogenic events. Such interactions are highly dynamic and spatially heterogeneous, making the investigation of the associated phenomena highly complex. The specific properties of membranes and peptide structural details, together with environmental conditions, may determine different events at the membrane interface, which will drive the fate of the peptide-membrane system. Here, we use an experimental approach based on the combination of spectroscopy and fluorescence microscopy methods to characterize the interactions of the multifunctional amphiphilic peptide transportan 10 with model membranes. Our approach, based on the use of suitable fluorescence reporters, exploits the advantages of phasor plot analysis of fluorescence lifetime imaging microscopy measurements to highlight the molecular details of occurring membrane alterations in terms of rigidity and hydration. Simultaneously, it allows following dynamic events in real time without sample manipulation distinguishing, with high spatial resolution, whether the peptide is adsorbed to or inserted in the membrane.
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Affiliation(s)
- Sara Anselmo
- Dipartimento
di Fisica e Chimica−Emilio Segré, Università degli Studi di Palermo, Viale delle Scienze ed. 18 90128, Palermo, Italy
| | - Giuseppe Sancataldo
- Dipartimento
di Fisica e Chimica−Emilio Segré, Università degli Studi di Palermo, Viale delle Scienze ed. 18 90128, Palermo, Italy
| | - Hanne Mørck Nielsen
- Department
of Pharmacy, University of Copenhagen, Universitetsparken 2 2100, Copenhagen, Denmark
| | - Vito Foderà
- Department
of Pharmacy, University of Copenhagen, Universitetsparken 2 2100, Copenhagen, Denmark
| | - Valeria Vetri
- Dipartimento
di Fisica e Chimica−Emilio Segré, Università degli Studi di Palermo, Viale delle Scienze ed. 18 90128, Palermo, Italy
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11
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Cholesterol-dependent plasma membrane order (L o) is critical for antigen-specific clonal expansion of CD4 + T cells. Sci Rep 2021; 11:13970. [PMID: 34234214 PMCID: PMC8263698 DOI: 10.1038/s41598-021-93403-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 06/23/2021] [Indexed: 12/04/2022] Open
Abstract
Early “T cell activation” events are initiated within the lipid microenvironment of the plasma membrane. Role of lipid membrane order (Lo) in spatiotemporal signaling through the antigen receptor in T cells is posited but remains unclear. We have examined the role of membrane order (Lo)/disorder (Ld) in antigen specific CD4+ T cell activation and clonal expansion by first creating membrane disorder, and then reconstituting membrane order by inserting cholesterol into the disordered plasma membrane. Significant revival of antigen specific CD4+ T cell proliferative response was observed after reconstituting the disrupted membrane order with cholesterol. These reconstitution experiments illustrate Koch’s postulate by demonstrating that cholesterol-dependent membrane order (Lo) is critical for responses generated by CD4+ T cells and point to the importance of membrane order and lipid microenvironment in signaling through T cell membrane antigen receptors.
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12
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Chmielińska A, Stepien P, Bonarek P, Girych M, Enkavi G, Rog T, Dziedzicka-Wasylewska M, Polit A. Can di-4-ANEPPDHQ reveal the structural differences between nanodiscs and liposomes? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183649. [PMID: 33991503 DOI: 10.1016/j.bbamem.2021.183649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/15/2021] [Accepted: 05/10/2021] [Indexed: 11/17/2022]
Abstract
The potential-sensitive di-4-ANEPPDHQ dye is presently gaining popularity in structural studies of the lipid bilayer. Within the bilayer, dye environmental sensitivity originates from the excitation induced charge redistribution and is usually attributed to solvent relaxation. Here, di-4-ANEPPDHQ is utilized to compare the structure of neutral and negatively charged lipid bilayers between two model systems: the nanodiscs and the liposomes. Using the well-established approach of measuring solvatochromic shifts of the steady-state spectra to study the bilayer structural changes has proved insufficient in this case. By applying an in-depth analysis of time-resolved fluorescence decays and emission spectra, we distinguished and characterized two and three distinct emissive di-4-ANEPPDHQ species in the liposomes and the nanodiscs, respectively. These emissive species were ascribed to the dual emission of the dye rather than to solvent relaxation. An additional, long-lived component present in the nanodiscs was associated with a unique domain of high order, postulated recently. Our results reveal that the di-4-ANEPPDHQ steady-state fluorescence should be interpreted with caution. With the experimental approach presented here, the di-4-ANEPPDHQ sensitivity was improved. We confirmed that the bilayer structure is, indeed, altered in the nanodiscs. Moreover, molecular dynamic simulations showed a distribution of the probe in the nanodiscs plane, which is sensitive to lipid composition. In POPC nanodiscs, probe frequently interacts with MSP, while in POPC-POPG nanodiscs, such interactions are rare. We did not observe, however, any impact of those interactions on the probe fluorescence.
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Affiliation(s)
- Anna Chmielińska
- Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Piotr Stepien
- Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Piotr Bonarek
- Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Mykhailo Girych
- Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2, 00014 Helsinki, Finland
| | - Giray Enkavi
- Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2, 00014 Helsinki, Finland
| | - Tomasz Rog
- Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2, 00014 Helsinki, Finland
| | - Marta Dziedzicka-Wasylewska
- Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Agnieszka Polit
- Faculty of Biochemistry Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
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13
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Cantu JC, Tolstykh GP, Tarango M, Beier HT, Ibey BL. Caveolin-1 is Involved in Regulating the Biological Response of Cells to Nanosecond Pulsed Electric Fields. J Membr Biol 2021; 254:141-156. [PMID: 33427940 DOI: 10.1007/s00232-020-00160-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/18/2020] [Indexed: 01/20/2023]
Abstract
Nanosecond pulsed electric fields (nsPEFs) induce changes in the plasma membrane (PM), including PM permeabilization (termed nanoporation), allowing free passage of ions into the cell and, in certain cases, cell death. Recent studies from our laboratory show that the composition of the PM is a critical determinant of PM nanoporation. Thus, we hypothesized that the biological response to nsPEF exposure could be influenced by lipid microdomains, including caveolae, which are specialized invaginations of the PM that are enriched in cholesterol and contain aggregates of important cell signaling proteins, such as caveolin-1 (Cav1). Caveolae play a significant role in cellular signal transduction, including control of calcium influx and cell death by interaction of Cav1 with regulatory signaling proteins. Present results show that depletion of Cav1 increased the influx of calcium, while Cav1 overexpression produced the opposite effect. Additionally, Cav1 is known to bind and sequester important cell signaling proteins within caveolae, rendering the binding partners inactive. Imaging of the PM after nsPEF exposure showed localized depletion of PM Cav1 and results of co-immunoprecipitation studies showed dissociation of two critical Cav1 binding partners (transient receptor potential cation channel subfamily C1 (TRPC1) and inositol trisphosphate receptor (IP3R)) after exposure to nsPEFs. Release of TRPC1 and IP3R from Cav1 would activate downstream signaling cascades, including store-operated calcium entry, which could explain the influx in calcium after nsPEF exposure. Results of the current study establish a significant relationship between Cav1 and the activation of cell signaling pathways in response to nsPEFs.
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Affiliation(s)
- Jody C Cantu
- General Dynamics Information Technology, JBSA Fort Sam Houston, 4141 Petroleum Road, Bldg. 3260, San Antonio, TX, 78234-2644, USA.
| | - Gleb P Tolstykh
- General Dynamics Information Technology, JBSA Fort Sam Houston, 4141 Petroleum Road, Bldg. 3260, San Antonio, TX, 78234-2644, USA
| | - Melissa Tarango
- General Dynamics Information Technology, JBSA Fort Sam Houston, 4141 Petroleum Road, Bldg. 3260, San Antonio, TX, 78234-2644, USA
| | - Hope T Beier
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Optical Radiation Bioeffects Branch, JBSA Fort Sam Houston, San Antonio, TX, 78234, USA
| | - Bennett L Ibey
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Bioeffects Division, Radio Frequency Bioeffects Branch, JBSA Fort Sam Houston, San Antonio, TX, 78234, USA
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14
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Melittin Induces Local Order Changes in Artificial and Biological Membranes as Revealed by Spectral Analysis of Laurdan Fluorescence. Toxins (Basel) 2020; 12:toxins12110705. [PMID: 33171598 PMCID: PMC7695215 DOI: 10.3390/toxins12110705] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/27/2020] [Accepted: 11/05/2020] [Indexed: 12/15/2022] Open
Abstract
Antimicrobial peptides (AMPs) are a class of molecules widely used in applications on eukaryotic and prokaryotic cells. Independent of the peptide target, all of them need to first pass or interact with the plasma membrane of the cells. In order to have a better image of the peptide action mechanism with respect to the particular features of the membrane it is necessary to better understand the changes induced by AMPs in the membranes. Laurdan, a lipid membrane probe sensitive to polarity changes in the environment, is used in this study for assessing changes induced by melittin, a well-known peptide, both in model and natural lipid membranes. More importantly, we showed that generalized polarization (GP) values are not always efficient or sufficient to properly characterize the changes in the membrane. We proved that a better method to investigate these changes is to use the previously described log-normal deconvolution allowing us to infer other parameters: the difference between the relative areas of elementary peak (ΔSr), and the ratio of elementary peaks areas (Rs). Melittin induced a slight decrease in local membrane fluidity in homogeneous lipid membranes. The addition of cholesterol stabilizes the membrane more in the presence of melittin. An opposite response was observed in the case of heterogeneous lipid membranes in cells, the local order of lipids being diminished. RS proved to be the most sensitive parameter characterizing the local membrane order, allowing us to distinguish among the responses to melittin of both classes of membrane we investigated (liposomes and cellular membranes). Molecular simulation of the melittin pore in homogeneous lipid bilayer suggests that lipids are more closely packed in the proximity of the melittin pore (a smaller area per lipid), supporting the experimental observation.
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15
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Fabiunke S, Fillafer C, Paeger A, Schneider MF. Optical studies of membrane state during action potential propagation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 162:69-78. [DOI: 10.1016/j.pbiomolbio.2020.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/05/2020] [Accepted: 11/13/2020] [Indexed: 10/23/2022]
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16
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Lorent JH, Levental KR, Ganesan L, Rivera-Longsworth G, Sezgin E, Doktorova M, Lyman E, Levental I. Plasma membranes are asymmetric in lipid unsaturation, packing and protein shape. Nat Chem Biol 2020; 16:644-652. [PMID: 32367017 DOI: 10.1101/698837] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 03/27/2020] [Indexed: 05/26/2023]
Abstract
A fundamental feature of cellular plasma membranes (PMs) is an asymmetric lipid distribution between the bilayer leaflets. However, neither the detailed, comprehensive compositions of individual PM leaflets nor how these contribute to structural membrane asymmetries have been defined. We report the distinct lipidomes and biophysical properties of both monolayers in living mammalian PMs. Phospholipid unsaturation is dramatically asymmetric, with the cytoplasmic leaflet being approximately twofold more unsaturated than the exoplasmic leaflet. Atomistic simulations and spectroscopy of leaflet-selective fluorescent probes reveal that the outer PM leaflet is more packed and less diffusive than the inner leaflet, with this biophysical asymmetry maintained in the endocytic system. The structural asymmetry of the PM is reflected in the asymmetric structures of protein transmembrane domains. These structural asymmetries are conserved throughout Eukaryota, suggesting fundamental cellular design principles.
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Affiliation(s)
- J H Lorent
- McGovern Medical School, Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - K R Levental
- McGovern Medical School, Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - L Ganesan
- McGovern Medical School, Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | | | - E Sezgin
- John Radcliffe Hospital, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- SciLifeLab, Karolinska Institute, Stockholm, Sweden
| | - M Doktorova
- McGovern Medical School, Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - E Lyman
- Department of Physics and Astronomy and Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, USA
| | - I Levental
- McGovern Medical School, Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA.
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17
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Furlan AL, Laurin Y, Botcazon C, Rodríguez-Moraga N, Rippa S, Deleu M, Lins L, Sarazin C, Buchoux S. Contributions and Limitations of Biophysical Approaches to Study of the Interactions between Amphiphilic Molecules and the Plant Plasma Membrane. PLANTS 2020; 9:plants9050648. [PMID: 32443858 PMCID: PMC7285231 DOI: 10.3390/plants9050648] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/07/2020] [Accepted: 05/15/2020] [Indexed: 12/20/2022]
Abstract
Some amphiphilic molecules are able to interact with the lipid matrix of plant plasma membranes and trigger the immune response in plants. This original mode of perception is not yet fully understood and biophysical approaches could help to obtain molecular insights. In this review, we focus on such membrane-interacting molecules, and present biophysically grounded methods that are used and are particularly interesting in the investigation of this mode of perception. Rather than going into overly technical details, the aim of this review was to provide to readers with a plant biochemistry background a good overview of how biophysics can help to study molecular interactions between bioactive amphiphilic molecules and plant lipid membranes. In particular, we present the biomimetic membrane models typically used, solid-state nuclear magnetic resonance, molecular modeling, and fluorescence approaches, because they are especially suitable for this field of research. For each technique, we provide a brief description, a few case studies, and the inherent limitations, so non-specialists can gain a good grasp on how they could extend their toolbox and/or could apply new techniques to study amphiphilic bioactive compound and lipid interactions.
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Affiliation(s)
- Aurélien L. Furlan
- Laboratoire de Biophysique Moléculaire aux Interfaces, Gembloux Agro-Bio Tech, TERRA Research Center, Université de Liège, B5030 Gembloux, Belgium; (A.L.F.); (Y.L.); (M.D.); (L.L.)
| | - Yoann Laurin
- Laboratoire de Biophysique Moléculaire aux Interfaces, Gembloux Agro-Bio Tech, TERRA Research Center, Université de Liège, B5030 Gembloux, Belgium; (A.L.F.); (Y.L.); (M.D.); (L.L.)
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Picardie Jules Verne, 80039 Amiens, France; (C.B.); (N.R.-M.); (C.S.)
| | - Camille Botcazon
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Picardie Jules Verne, 80039 Amiens, France; (C.B.); (N.R.-M.); (C.S.)
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Technologie de Compiègne, 60200 Compiègne, France;
| | - Nely Rodríguez-Moraga
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Picardie Jules Verne, 80039 Amiens, France; (C.B.); (N.R.-M.); (C.S.)
| | - Sonia Rippa
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Technologie de Compiègne, 60200 Compiègne, France;
| | - Magali Deleu
- Laboratoire de Biophysique Moléculaire aux Interfaces, Gembloux Agro-Bio Tech, TERRA Research Center, Université de Liège, B5030 Gembloux, Belgium; (A.L.F.); (Y.L.); (M.D.); (L.L.)
| | - Laurence Lins
- Laboratoire de Biophysique Moléculaire aux Interfaces, Gembloux Agro-Bio Tech, TERRA Research Center, Université de Liège, B5030 Gembloux, Belgium; (A.L.F.); (Y.L.); (M.D.); (L.L.)
| | - Catherine Sarazin
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Picardie Jules Verne, 80039 Amiens, France; (C.B.); (N.R.-M.); (C.S.)
| | - Sébastien Buchoux
- Unité de Génie Enzymatique et Cellulaire, UMR 7025 CNRS/UPJV/UTC, Université de Picardie Jules Verne, 80039 Amiens, France; (C.B.); (N.R.-M.); (C.S.)
- Correspondence: ; Tel.: +33-(0)3-2282-7473
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18
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Althumairy D, Postal K, Barisas BG, Nunes GG, Roess DA, Crans DC. Polyoxometalates function as indirect activators of a G protein-coupled receptor. Metallomics 2020; 12:1044-1061. [DOI: 10.1039/d0mt00044b] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A series of multivalent polyoxovanadates were found to activate signaling of a G protein coupled receptor, the luteinizing hormone receptor.
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Affiliation(s)
- Duaa Althumairy
- Cell and Molecular Biology Program
- Colorado State University
- Fort Collins
- USA
- Department of Biological Sciences
| | - Kahoana Postal
- Department of Chemistry
- Colorado State University
- Fort Collins
- USA
- Department of Chemistry
| | - B. George Barisas
- Cell and Molecular Biology Program
- Colorado State University
- Fort Collins
- USA
- Department of Chemistry
| | - Giovana G. Nunes
- Department of Chemistry
- Universidade Federal do Paraná
- Curitiba
- Brazil
| | - Deborah A. Roess
- Cell and Molecular Biology Program
- Colorado State University
- Fort Collins
- USA
- Department of Biomedical Sciences, Colorado State University
| | - Debbie C. Crans
- Cell and Molecular Biology Program
- Colorado State University
- Fort Collins
- USA
- Department of Chemistry
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19
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Salimi H, Johnson J, Flores MG, Zhang MS, O'Malley Y, Houtman JC, Schlievert PM, Haim H. The lipid membrane of HIV-1 stabilizes the viral envelope glycoproteins and modulates their sensitivity to antibody neutralization. J Biol Chem 2019; 295:348-362. [PMID: 31757809 DOI: 10.1074/jbc.ra119.009481] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/19/2019] [Indexed: 11/06/2022] Open
Abstract
The envelope glycoproteins (Envs) of HIV-1 are embedded in the cholesterol-rich lipid membrane of the virus. Chemical depletion of cholesterol from HIV-1 particles inactivates their infectivity. We observed that diverse HIV-1 strains exhibit a range of sensitivities to such treatment. Differences in sensitivity to cholesterol depletion could not be explained by variation in Env components known to interact with cholesterol, including the cholesterol-recognition motif and cytoplasmic tail of gp41. Using antibody-binding assays, measurements of virus infectivity, and analyses of lipid membrane order, we found that depletion of cholesterol from HIV-1 particles decreases the conformational stability of Env. It enhances exposure of partially cryptic epitopes on the trimer and increases sensitivity to structure-perturbing treatments such as antibodies and cold denaturation. Substitutions in the cholesterol-interacting motif of gp41 induced similar effects as depletion of cholesterol. Surface-acting agents, which are incorporated into the virus lipid membrane, caused similar effects as disruption of the Env-cholesterol interaction. Furthermore, substitutions in gp120 that increased structural stability of Env (i.e. induced a "closed" conformation of the trimer) increased virus resistance to cholesterol depletion and to the surface-acting agents. Collectively, these results indicate a critical contribution of the viral membrane to the stability of the Env trimer and to neutralization resistance against antibodies. Our findings suggest that the potency of poorly neutralizing antibodies, which are commonly elicited in vaccinated individuals, may be markedly enhanced by altering the lipid composition of the viral membrane.
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Affiliation(s)
- Hamid Salimi
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jacklyn Johnson
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Manuel G Flores
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Michael S Zhang
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Yunxia O'Malley
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jon C Houtman
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Patrick M Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Hillel Haim
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
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20
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Effect of cholesterol on the surface polarity and hydration of lipid interphases as measured by Laurdan fluorescence: New insights. Colloids Surf B Biointerfaces 2019; 178:346-351. [DOI: 10.1016/j.colsurfb.2019.03.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/18/2019] [Accepted: 03/11/2019] [Indexed: 01/28/2023]
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21
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Laurent N, Der C, Simon-Plas F, Gerbeau-Pissot P. Cell stage appears critical for control of plasma membrane order in plant cells. PLANT SIGNALING & BEHAVIOR 2019; 14:1620058. [PMID: 31131686 PMCID: PMC6619956 DOI: 10.1080/15592324.2019.1620058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/07/2019] [Accepted: 05/10/2019] [Indexed: 05/26/2023]
Abstract
Lipids and proteins modulate both the global order of plasma membrane (PM) and its organization in distinct domains. This raises the question of the influence on PM-ordered domain formation of PM composition, which is finely controlled during cell differentiation. Labeling of plant cell PM with an environment-sensitive probe demonstrated that the level of PM order is regulated during anisotropic expansion observed during both cell regeneration from protoplasts and cell differentiation along the growing root. Indeed, PM order progressively decreased during the polarized growth of regenerated tobacco cells, without observed correlation between this parameter and the kinetics of either cell wall regeneration or cell morphology. This suggests that the dynamics of PM formation and renewal could control the PM organization, maybe by involving the secretory pathway.
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Affiliation(s)
- Nelson Laurent
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Christophe Der
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Françoise Simon-Plas
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Patricia Gerbeau-Pissot
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France
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22
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Nomura K, Yamaguchi T, Mori S, Fujikawa K, Nishiyama KI, Shimanouchi T, Tanimoto Y, Morigaki K, Shimamoto K. Alteration of Membrane Physicochemical Properties by Two Factors for Membrane Protein Integration. Biophys J 2019; 117:99-110. [PMID: 31164197 PMCID: PMC6626835 DOI: 10.1016/j.bpj.2019.05.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/08/2019] [Accepted: 05/14/2019] [Indexed: 12/01/2022] Open
Abstract
After a nascent chain of a membrane protein emerges from the ribosomal tunnel, the protein is integrated into the cell membrane. This process is controlled by a series of proteinaceous molecular devices, such as signal recognition particles and Sec translocons. In addition to these proteins, we discovered two endogenous components regulating membrane protein integration in the inner membrane of Escherichia coli. The integration is blocked by diacylglycerol (DAG), whereas the blocking is relieved by a glycolipid named membrane protein integrase (MPIase). Here, we investigated the influence of these integration-blocking and integration-promoting factors on the physicochemical properties of membrane lipids via solid-state NMR and fluorescence measurements. These factors did not have destructive effects on membrane morphology because the membrane maintained its lamellar structure and did not fuse in the presence of DAG and/or MPIase at their effective concentrations. We next focused on membrane flexibility. DAG did not affect the mobility of the membrane surface, whereas the sugar chain in MPIase was highly mobile and enhanced the flexibility of membrane lipid headgroups. Comparison with a synthetic MPIase analog revealed the effects of the long sugar chain on membrane properties. The acyl chain order inside the membrane was increased by DAG, whereas the increase was cancelled by the addition of MPIase. MPIase also loosened the membrane lipid packing. Focusing on the transbilayer movement, MPIase reduced the rapid flip-flop motion of DAG. On the other hand, MPIase could not compensate for the diminished lateral diffusion by DAG. These results suggest that by manipulating the membrane lipids dynamics, DAG inhibits the protein from contacting the inner membrane, whereas the flexible long sugar chain of MPIase increases the opportunity for interaction between the membrane and the protein, leading to membrane integration of the newly formed protein.
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Affiliation(s)
- Kaoru Nomura
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan.
| | - Toshiyuki Yamaguchi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Shoko Mori
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Kohki Fujikawa
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Ken-Ichi Nishiyama
- Department of Biological Chemistry and Food Sciences, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | | | - Yasushi Tanimoto
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | | | - Keiko Shimamoto
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan.
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23
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Steele HBB, Sydor MJ, Anderson DS, Holian A, Ross JBA. Using Time-Resolved Fluorescence Anisotropy of di-4-ANEPPDHQ and F2N12S to Analyze Lipid Packing Dynamics in Model Systems. J Fluoresc 2019; 29:347-352. [PMID: 30937610 DOI: 10.1007/s10895-019-02363-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/10/2019] [Indexed: 11/29/2022]
Abstract
The fluorescence probes di-4-ANEPPDHQ and F2N12S have solvochromatic emission spectra and fluorescence lifetimes that are sensitive to order within the environment of lipid membranes. We show in this communication that the time-resolved fluorescence anisotropy of these probes, analyzed either by the wobble-in-a-cone model or by the model-independent order parameter S2, provides complementary information about dynamics and lipid packing in a variety of homogeneous lipid membranes systems.
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Affiliation(s)
- Harmen B B Steele
- Department of Chemistry & Biochemistry, University of Montana, Missoula, MT, 59812, USA.,Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, MT, 59812, USA
| | - Matthew J Sydor
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Donald S Anderson
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, University of Montana, Missoula, MT, 59812, USA
| | - Andrij Holian
- Department of Biomedical and Pharmaceutical Sciences, Center for Environmental Health Sciences, University of Montana, Missoula, MT, 59812, USA
| | - J B Alexander Ross
- Department of Chemistry & Biochemistry, University of Montana, Missoula, MT, 59812, USA. .,Center for Biomolecular Structure & Dynamics, University of Montana, Missoula, MT, 59812, USA.
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24
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Almeida C, Maniti O, Di Pisa M, Swiecicki JM, Ayala-Sanmartin J. Cholesterol re-organisation and lipid de-packing by arginine-rich cell penetrating peptides: Role in membrane translocation. PLoS One 2019; 14:e0210985. [PMID: 30673771 PMCID: PMC6343925 DOI: 10.1371/journal.pone.0210985] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/06/2019] [Indexed: 11/19/2022] Open
Abstract
Cell penetrating peptides (CPPs) are able to transport hydrophilic molecules inside cells. To reach the cytosol, the peptide associated with a cargo must cross the plasma or the endosomal membrane. Different molecular mechanisms for peptide internalisation into cells have been proposed and it is becoming clear that the cellular internalisation mechanisms are different depending on the peptide sequence and structure and the target membrane. Herein, the penetration of three peptides into large unilamellar vesicles were studied: the homeodomain derived 16-residues penetratin, nona-arginine (R9), and a small peptide containing 6 arginine and 3 tryptophan residues (RW9). The membrane models were composed of phospholipids from natural sources containing different molecular species. We observed that among the three peptides, only the amphipathic peptide RW9 was able to cross the membrane vesicles in the liquid disordered state. The changes in the distribution of the previously characterized cholesterol-pyrene probe show that cholesterol-pyrene molecules dissociate from clusters upon membrane interaction with the three peptides and that the cholesterol environment becomes more disordered in the presence of RW9. Finally, we studied the effect of the peptides on lipid ordering on giant plasma membrane vesicles. The amphipathic peptides RW9 and its longer homologue RW16 induced lipid de-packing in plasma membrane vesicles. Overall, the data suggest that a disordered membrane favours the translocation of RW9, that the membrane cholesterol is redistributed during peptide interaction, and that the peptide amphipathic character is important to increase membrane fluidity and peptide membrane translocation.
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Affiliation(s)
- Claudia Almeida
- CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Laboratoire des Biomolécules, Paris, France
| | - Ofelia Maniti
- CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Laboratoire des Biomolécules, Paris, France
| | - Margherita Di Pisa
- CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Laboratoire des Biomolécules, Paris, France
| | - Jean-Marie Swiecicki
- CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Laboratoire des Biomolécules, Paris, France
| | - Jesus Ayala-Sanmartin
- CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Laboratoire des Biomolécules, Paris, France
- * E-mail:
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25
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Ma Y, Benda A, Kwiatek J, Owen DM, Gaus K. Time-Resolved Laurdan Fluorescence Reveals Insights into Membrane Viscosity and Hydration Levels. Biophys J 2018; 115:1498-1508. [PMID: 30269886 PMCID: PMC6257870 DOI: 10.1016/j.bpj.2018.08.041] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 06/27/2018] [Accepted: 08/27/2018] [Indexed: 11/24/2022] Open
Abstract
Membrane viscosity and hydration levels characterize the biophysical properties of biological membranes and are reflected in the rate and extent of solvent relaxation, respectively, of environmentally sensitive fluorophores such as Laurdan. Here, we first developed a method for a time-resolved general polarization (GP) analysis with fluorescence-lifetime imaging microscopy that captures both the extent and rate of Laurdan solvent relaxation. We then conducted time-resolved GP measurements with Laurdan-stained model membranes and cell membranes. These measurements revealed that cholesterol levels in lipid vesicles altered membrane hydration and viscosity, whereas curvature had little effect on either parameter. We also applied the method to the plasma membrane of live cells using a supercritical angle fluorescence objective, to our knowledge the first time fluorescence-lifetime imaging microscopy images were generated with supercritical angle fluorescence. Here, we found that local variations in membrane cholesterol most likely account for the heterogeneity of Laurdan lifetime in plasma membrane. In conclusion, time-resolved GP measurements provide additional insights into the biophysical properties of membranes.
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Affiliation(s)
- Yuanqing Ma
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, New South Wales, Australia
| | - Aleš Benda
- Biomedical Imaging Facility, Lowy Cancer Research Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - Joanna Kwiatek
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, New South Wales, Australia
| | - Dylan M Owen
- Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, New South Wales, Australia.
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26
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Brankatschk M, Gutmann T, Knittelfelder O, Palladini A, Prince E, Grzybek M, Brankatschk B, Shevchenko A, Coskun Ü, Eaton S. A Temperature-Dependent Switch in Feeding Preference Improves Drosophila Development and Survival in the Cold. Dev Cell 2018; 46:781-793.e4. [DOI: 10.1016/j.devcel.2018.05.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 03/17/2018] [Accepted: 08/27/2018] [Indexed: 01/01/2023]
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27
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Hernández-Villa L, Manrique-Moreno M, Leidy C, Jemioła-Rzemińska M, Ortíz C, Strzałka K. Biophysical evaluation of cardiolipin content as a regulator of the membrane lytic effect of antimicrobial peptides. Biophys Chem 2018; 238:8-15. [DOI: 10.1016/j.bpc.2018.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/05/2018] [Accepted: 04/05/2018] [Indexed: 10/17/2022]
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28
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Gomes B, Gonçalves S, Disalvo A, Hollmann A, Santos NC. Effect of 25-hydroxycholesterol in viral membrane fusion: Insights on HIV inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1171-1178. [PMID: 29408450 DOI: 10.1016/j.bbamem.2018.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 01/08/2018] [Accepted: 02/01/2018] [Indexed: 12/15/2022]
Abstract
Recently, it was demonstrated that 25-hydroxycholesterol (25HC), an oxidized cholesterol derivative, inhibits human immunodeficiency virus type 1 (HIV) entry into its target cells. However, the mechanisms involved in this action have not yet been established. The aim of this work was to study the effects of 25HC in biomembrane model systems and at the level of HIV fusion peptide (HIV-FP). Integration of different biophysical approaches was made in the context of HIV fusion process, to clarify the changes at membrane level due to the presence of 25HC that result in the suppressing of viral infection. Lipid vesicles mimicking mammalian and HIV membranes were used on spectroscopy assays and lipid monolayers in surface pressure studies. Peptide-induced lipid mixing assays were performed by Förster resonance energy transfer to calculate fusion efficiency. Liposome fusion is reduced by 50% in the presence of 25HC, comparatively to cholesterol. HIV-FP conformation was assessed by infrared assays and it relies on sterol nature. Anisotropy, surface pressure and dipole potential assays indicate that the conversion of cholesterol in 25HC leads to a loss of the cholesterol modulating effect on the membrane. With different biophysical techniques, we show that 25HC affects the membrane fusion process through the modification of lipid membrane properties, and by direct alterations on HIV-FP structure. The present data support a broad antiviral activity for 25HC.
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Affiliation(s)
- Bárbara Gomes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Anibal Disalvo
- Laboratory of Biointerfaces and Biomimetic Systems, CITSE, University of Santiago del Estero, -CONICET, 4200 Santiago del Estero, Argentina
| | - Axel Hollmann
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal; Laboratory of Biointerfaces and Biomimetic Systems, CITSE, University of Santiago del Estero, -CONICET, 4200 Santiago del Estero, Argentina; Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, University of Quilmes, B1876BXD Bernal, Argentina
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal.
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Koch G, Wermser C, Acosta IC, Kricks L, Stengel ST, Yepes A, Lopez D. Attenuating Staphylococcus aureus Virulence by Targeting Flotillin Protein Scaffold Activity. Cell Chem Biol 2017; 24:845-857.e6. [PMID: 28669526 DOI: 10.1016/j.chembiol.2017.05.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/11/2017] [Accepted: 05/30/2017] [Indexed: 01/13/2023]
Abstract
Scaffold proteins are ubiquitous chaperones that bind proteins and facilitate physical interaction of multi-enzyme complexes. Here we used a biochemical approach to dissect the scaffold activity of the flotillin-homolog protein FloA of the multi-drug-resistant human pathogen Staphylococcus aureus. We show that FloA promotes oligomerization of membrane protein complexes, such as the membrane-associated RNase Rny, which forms part of the RNA-degradation machinery called the degradosome. Cells lacking FloA had reduced Rny function and a consequent increase in the targeted sRNA transcripts that negatively regulate S. aureus toxin expression. Small molecules that altered FloA oligomerization also reduced Rny function and decreased the virulence potential of S. aureus in vitro, as well as in vivo, using invertebrate and murine infection models. Our results suggest that flotillin assists in the assembly of protein complexes involved in S. aureus virulence, and could thus be an attractive target for the development of new antimicrobial therapies.
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Affiliation(s)
- Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Charlotte Wermser
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Ivan C Acosta
- National Centre for Biotechnology (CNB), Spanish Research Council (CSIC), Darwin 3, Madrid 28049, Spain
| | - Lara Kricks
- National Centre for Biotechnology (CNB), Spanish Research Council (CSIC), Darwin 3, Madrid 28049, Spain
| | - Stephanie T Stengel
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Ana Yepes
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany; National Centre for Biotechnology (CNB), Spanish Research Council (CSIC), Darwin 3, Madrid 28049, Spain.
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30
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Strohmeier A, Först G, Tauber P, Schubert R. Membrane/Water Partition Coefficients of Bile Salts Determined Using Laurdan as a Fluorescent Probe. Biophys J 2017; 111:1714-1723. [PMID: 27760358 DOI: 10.1016/j.bpj.2016.08.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/07/2016] [Accepted: 08/15/2016] [Indexed: 11/28/2022] Open
Abstract
The interaction of liposomal membranes composed of soybean phosphatidylcholine with the bile salts (BSs) cholate (Ch), glycocholate (GC), chenodeoxycholate (CDC), and glycochenodeoxycholate (GCDC) was studied. The BSs differed with regard to their lipophilicity, pKa values, and the size of their hydrophilic moiety. Their membrane interactions were investigated using Laurdan as a membrane-anchored fluorescent dye. The apparent membrane/water partition coefficient, D, at pH 7.4 was calculated from binding plots and compared with direct binding measurements using ultracentrifugation as a reference. The Laurdan-derived LogD values at pH 7.4 were found to be 2.10 and 2.25 for the trihydroxy BSs, i.e., Ch and GC, and 2.85 and 2.75 for the dihydroxy BSs, i.e., CDC and GCDC, respectively. For the membrane-associated glycine-conjugated GC and GCDC (pKa values of ∼3.9), no differences in the Laurdan spectra of the respective BS were found at pH 6.8, 7.4, and 8.2. Unconjugated Ch and CDC (pKa values of ∼5.0) showed pronounced differences at the three pH values. Furthermore, the kinetics of membrane adsorption and transbilayer movement differed between conjugated and unconjugated BSs as determined with Laurdan-labeled liposomes.
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31
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Amaro M, Reina F, Hof M, Eggeling C, Sezgin E. Laurdan and Di-4-ANEPPDHQ probe different properties of the membrane. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2017; 50:134004. [PMID: 29449744 PMCID: PMC5802044 DOI: 10.1088/1361-6463/aa5dbc] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 01/02/2017] [Accepted: 02/02/2017] [Indexed: 05/22/2023]
Abstract
Lipid packing is a crucial feature of cellular membranes. Quantitative analysis of membrane lipid packing can be achieved using polarity sensitive probes whose emission spectrum depends on the lipid packing. However, detailed insights into the exact mechanisms that cause the changes in the spectra are necessary to interpret experimental fluorescence emission data correctly. Here, we analysed frequently used polarity sensitive probes, Laurdan and di-4-ANEPPDHQ, to test whether the underlying physical mechanisms of their spectral changes are the same and, thus, whether they report on the same physico-chemical properties of the cell membrane. Steady-state spectra as well as time-resolved emission spectra of the probes in solvents and model membranes revealed that they probe different properties of the lipid membrane. Our findings are important for the application of these dyes in cell biology.
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Affiliation(s)
- Mariana Amaro
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the C.A.S, v.v.i., Dolejskova 3, 182 23 Prague, Czechia
| | - Francesco Reina
- MRC Human Immunology Unit, OX39DS, University of Oxford, Oxford, United Kingdom
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the C.A.S, v.v.i., Dolejskova 3, 182 23 Prague, Czechia
| | - Christian Eggeling
- MRC Human Immunology Unit, OX39DS, University of Oxford, Oxford, United Kingdom
| | - Erdinc Sezgin
- MRC Human Immunology Unit, OX39DS, University of Oxford, Oxford, United Kingdom
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32
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Lopez D, Koch G. Exploring functional membrane microdomains in bacteria: an overview. Curr Opin Microbiol 2017; 36:76-84. [PMID: 28237903 DOI: 10.1016/j.mib.2017.02.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/01/2017] [Indexed: 01/08/2023]
Abstract
Recent studies show that internal organization of bacterial cells is more complex than previously appreciated. A clear example of this is the assembly of the nanoscale membrane platforms termed functional membrane microdomains. The lipid composition of these regions differs from that of the surrounding membrane; these domains confine a set of proteins involved in specific cellular processes such as protease secretion and signal transduction. It is currently thought that functional membrane microdomains act as oligomerization platforms and promote efficient oligomerization of interacting protein partners in bacterial membranes. In this review, we highlight the most noteworthy achievements, challenges and controversies of this emerging research field over the past five years.
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Affiliation(s)
- Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany; Spanish National Centre for Biotechnology (CNB), Madrid 28049, Spain.
| | - Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
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33
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Imaging Cellular Dynamics with Spectral Relaxation Imaging Microscopy: Distinct Spectral Dynamics in Golgi Membranes of Living Cells. Sci Rep 2016; 6:37038. [PMID: 27872481 PMCID: PMC5131650 DOI: 10.1038/srep37038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 10/24/2016] [Indexed: 12/03/2022] Open
Abstract
Spectral relaxation from fluorescent probes is a useful technique for determining the dynamics of condensed phases. To this end, we have developed a method based on wide-field spectral fluorescence lifetime imaging microscopy to extract spectral relaxation correlation times of fluorescent probes in living cells. We show that measurement of the phase and modulation of fluorescence from two wavelengths permit the identification and determination of excited state lifetimes and spectral relaxation correlation times at a single modulation frequency. For NBD fluorescence in glycerol/water mixtures, the spectral relaxation correlation time determined by our approach exhibited good agreement with published dielectric relaxation measurements. We applied this method to determine the spectral relaxation dynamics in membranes of living cells. Measurements of the Golgi-specific C6-NBD-ceramide probe in living HeLa cells revealed sub-nanosecond spectral dynamics in the intracellular Golgi membrane and slower nanosecond spectral dynamics in the extracellular plasma membrane. We interpret the distinct spectral dynamics as a result of structural plasticity of the Golgi membrane relative to more rigid plasma membranes. To the best of our knowledge, these results constitute one of the first measurements of Golgi rotational dynamics.
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34
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Cantu JC, Tarango M, Beier HT, Ibey BL. The biological response of cells to nanosecond pulsed electric fields is dependent on plasma membrane cholesterol. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2636-2646. [DOI: 10.1016/j.bbamem.2016.07.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/09/2016] [Accepted: 07/14/2016] [Indexed: 01/06/2023]
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35
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Sandor R, Der C, Grosjean K, Anca I, Noirot E, Leborgne-Castel N, Lochman J, Simon-Plas F, Gerbeau-Pissot P. Plasma membrane order and fluidity are diversely triggered by elicitors of plant defence. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:5173-85. [PMID: 27604805 PMCID: PMC5014163 DOI: 10.1093/jxb/erw284] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Although plants are exposed to a great number of pathogens, they usually defend themselves by triggering mechanisms able to limit disease development. Alongside signalling events common to most such incompatible interactions, modifications of plasma membrane (PM) physical properties could be new players in the cell transduction cascade. Different pairs of elicitors (cryptogein, oligogalacturonides, and flagellin) and plant cells (tobacco and Arabidopsis) were used to address the issue of possible modifications of plant PM biophysical properties induced by elicitors and their links to other events of the defence signalling cascade. We observed an increase of PM order whatever the elicitor/plant cell pair used, provided that a signalling cascade was induced. Such membrane modification is dependent on the NADPH oxidase-mediated reactive oxygen species production. Moreover, cryptogein, which is the sole elicitor able to trap sterols, is also the only one able to trigger an increase in PM fluidity. The use of cryptogein variants with altered sterol-binding properties confirms the strong correlation between sterol removal from the PM and PM fluidity enhancement. These results propose PM dynamics as a player in early signalling processes triggered by elicitors of plant defence.
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Affiliation(s)
- Roman Sandor
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic
| | - Christophe Der
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Kevin Grosjean
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Iulia Anca
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Elodie Noirot
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Nathalie Leborgne-Castel
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Jan Lochman
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic
| | - Françoise Simon-Plas
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Patricia Gerbeau-Pissot
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
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Abstract
The fundamental mechanisms of protein and lipid organization at the plasma membrane have continued to engage researchers for decades. Among proposed models, one idea has been particularly successful which assumes that sterol-dependent nanoscopic phases of different lipid chain order compartmentalize proteins, thereby modulating protein functionality. This model of membrane rafts has sustainably sparked the fields of membrane biophysics and biology, and shifted membrane lipids into the spotlight of research; by now, rafts have become an integral part of our terminology to describe a variety of cell biological processes. But is the evidence clear enough to continue supporting a theoretical concept which has resisted direct proof by observation for nearly twenty years? In this essay, we revisit findings that gave rise to and substantiated the raft hypothesis, discuss its impact on recent studies, and present alternative mechanisms to account for plasma membrane heterogeneity.
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Affiliation(s)
- Eva Sevcsik
- Institute of Applied Physics, Vienna University of Technology, Vienna, Austria
| | - Gerhard J Schütz
- Institute of Applied Physics, Vienna University of Technology, Vienna, Austria
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37
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Abstract
Membrane nanodomains are dynamic liquid entities surrounded by another type of dynamic liquid. Diffusion can take place inside, around and in and out of the domains, and membrane components therefore continuously shift between domains and their surroundings. In the plasma membrane, there is the further complexity of links between membrane lipids and proteins both to the extracellular matrix and to intracellular proteins such as actin filaments. In addition, new membrane components are continuously delivered and old ones removed. On top of this, cells move. Taking all of this into account imposes great methodological challenges, and in the present chapter we discuss some methods that are currently used for membrane nanodomain studies, what information they can provide and their weaknesses.
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Abstract
An interesting concept in the organization of cellular membranes is the proposed existence of lipid rafts. Membranes of eukaryotic cells organize signal transduction proteins into membrane rafts or lipid rafts that are enriched in particular lipids such as cholesterol and are important for the correct functionality of diverse cellular processes. The assembly of lipid rafts in eukaryotes has been considered a fundamental step during the evolution of cellular complexity, suggesting that bacteria and archaea were organisms too simple to require such a sophisticated organization of their cellular membranes. However, it was recently discovered that bacteria organize many signal transduction, protein secretion, and transport processes in functional membrane microdomains, which are equivalent to the lipid rafts of eukaryotic cells. This review contains the most significant advances during the last 4 years in understanding the structural and biological role of lipid rafts in bacteria. Furthermore, this review shows a detailed description of a number of molecular and genetic approaches related to the discovery of bacterial lipid rafts as well as an overview of the group of tentative lipid-protein and protein-protein interactions that give consistency to these sophisticated signaling platforms. Additional data suggesting that lipid rafts are widely distributed in bacteria are presented in this review. Therefore, we discuss the available techniques and optimized protocols for the purification and analysis of raft-associated proteins in various bacterial species to aid in the study of bacterial lipid rafts in other laboratories that could be interested in this topic. Overall, the discovery of lipid rafts in bacteria reveals a new level of sophistication in signal transduction and membrane organization that was unexpected for bacteria and shows that bacteria are more complex than previously appreciated.
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Affiliation(s)
- Marc Bramkamp
- Department of Biology I, University of Munich (LMU), Planegg/Martinsried, Germany
| | - Daniel Lopez
- Research Center for Infectious Diseases ZINF, University of Würzburg, Würzburg, Germany
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Zhao X, Li R, Lu C, Baluška F, Wan Y. Di-4-ANEPPDHQ, a fluorescent probe for the visualisation of membrane microdomains in living Arabidopsis thaliana cells. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 87:53-60. [PMID: 25549979 DOI: 10.1016/j.plaphy.2014.12.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/21/2014] [Indexed: 05/19/2023]
Abstract
Cholesterol-enriched microdomains, also called lipid rafts, are nanoscale membrane structures with a high degree of structural order. Since these microdomains play important roles in dynamic cytological events, such as cell signalling and membrane trafficking, the detection and tracking of microdomain behaviours are crucial to studies on modern membrane physiology. Currently, observation of microdomains is mostly based on the detection of specific raft-resident constituents using artificial cross-link fluorescent probes. However, only a few microdomain-specific fluorescent dyes are available for plant cell biology studies. In this study, the photophysical properties of di-4-ANEPPDHQ were analysed. The use of confocal laser scanning microscope (CLSM)-based methods in the visualisation of microdomains in living cells of Arabidopsis thaliana was assessed. The results confirmed that the generalised polarisation (GP) method can be used to quantitatively visualise the membrane orders in live plant cells. This dye was found to have low cytotoxicity in plant root epidermal cells and root hairs. These findings suggest that di-4-ANEPPDHQ is an appropriate tool for the visualisation of microdomains in living plant cells.
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Affiliation(s)
- Xiaoyu Zhao
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
| | - Ruili Li
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
| | - Cunfu Lu
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
| | - František Baluška
- Institute of Cellular and Molecular Botany, University of Bonn, D53115, Germany.
| | - Yinglang Wan
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
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40
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Grosjean K, Mongrand S, Beney L, Simon-Plas F, Gerbeau-Pissot P. Differential effect of plant lipids on membrane organization: specificities of phytosphingolipids and phytosterols. J Biol Chem 2015; 290:5810-25. [PMID: 25575593 DOI: 10.1074/jbc.m114.598805] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than β-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains.
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Affiliation(s)
- Kevin Grosjean
- From UMR1347 Agroécologie, ERL 6300 CNRS, Université de Bourgogne, 17 Rue Sully, BP 86510, 21065 Dijon Cedex, France
| | - Sébastien Mongrand
- the Laboratoire de Biogenèse Membranaire (LBM), CNRS, UMR 5200, F-33000 Villenave d'Ornon, France, the Laboratoire de Biogenèse Membranaire (LBM), Université de Bordeaux, UMR 5200, F-33000 Villenave d'Ornon, France
| | - Laurent Beney
- the Laboratoire Procédés Alimentaires et Microbiologiques, AgroSup Dijon, F-21000 Dijon, France, and
| | - Françoise Simon-Plas
- ERL 6300 CNRS, INRA, UMR1347 Agroécologie, 17 Rue Sully, BP 86510, 21065 Dijon Cedex, France
| | - Patricia Gerbeau-Pissot
- From UMR1347 Agroécologie, ERL 6300 CNRS, Université de Bourgogne, 17 Rue Sully, BP 86510, 21065 Dijon Cedex, France,
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Maniti O, Piao HR, Ayala-Sanmartin J. Basic cell penetrating peptides induce plasma membrane positive curvature, lipid domain separation and protein redistribution. Int J Biochem Cell Biol 2014; 50:73-81. [DOI: 10.1016/j.biocel.2014.02.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/12/2014] [Accepted: 02/19/2014] [Indexed: 11/27/2022]
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Gerbeau-Pissot P, Der C, Thomas D, Anca IA, Grosjean K, Roche Y, Perrier-Cornet JM, Mongrand S, Simon-Plas F. Modification of plasma membrane organization in tobacco cells elicited by cryptogein. PLANT PHYSIOLOGY 2014; 164:273-86. [PMID: 24235133 PMCID: PMC3875808 DOI: 10.1104/pp.113.225755] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/05/2013] [Indexed: 05/07/2023]
Abstract
Lipid mixtures within artificial membranes undergo a separation into liquid-disordered and liquid-ordered phases. However, the existence of this segregation into microscopic liquid-ordered phases has been difficult to prove in living cells, and the precise organization of the plasma membrane into such phases has not been elucidated in plant cells. We developed a multispectral confocal microscopy approach to generate ratiometric images of the plasma membrane surface of Bright Yellow 2 tobacco (Nicotiana tabacum) suspension cells labeled with an environment sensitive fluorescent probe. This allowed the in vivo characterization of the global level of order of this membrane, by which we could demonstrate that an increase in its proportion of ordered phases transiently occurred in the early steps of the signaling triggered by cryptogein and flagellin, two elicitors of plant defense reactions. The use of fluorescence recovery after photobleaching revealed an increase in plasma membrane fluidity induced by cryptogein, but not by flagellin. Moreover, we characterized the spatial distribution of liquid-ordered phases on the membrane of living plant cells and monitored their variations induced by cryptogein elicitation. We analyze these results in the context of plant defense signaling, discuss their meaning within the framework of the "membrane raft" hypothesis, and propose a new mechanism of signaling platform formation in response to elicitor treatment.
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Affiliation(s)
| | - Christophe Der
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Dominique Thomas
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Iulia-Andra Anca
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Kevin Grosjean
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Yann Roche
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Jean-Marie Perrier-Cornet
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Sébastien Mongrand
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
| | - Françoise Simon-Plas
- Université de Bourgogne (P.G.-P., C.D., D.T., K.G.), and Institut National de la Recherche Agronomique (I.-A.A., Y.R., F.S.-P.), Unité Mixte de Recherche 1347 Agroécologie, Equipe de Recherche Labelisée 6300 Centre National de la Recherche Scientifique, BP 86510, F–21000 Dijon, France
- AgroSup Dijon, Laboratoire Procédés Alimentaires et Microbiologiques, F–21000 Dijon, France (J.-M.P.-C.); and
- Centre National de la Recherche Scientifique, Laboratoire de Biogenèse Membranaire, Unité Mixte de Recherche 5200, Université Victor Segalen, Institut National de la Recherche Agronomique Bordeaux Aquitaine, BP 81, F–33883 Villenave d’Ornon, France (S.M.)
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Kamerbeek C, Borroni V, Pediconi M, Sato S, Kobayashi T, Barrantes F. Antibody-induced acetylcholine receptor clusters inhabit liquid-ordered and liquid-disordered domains. Biophys J 2013; 105:1601-11. [PMID: 24094401 PMCID: PMC3822676 DOI: 10.1016/j.bpj.2013.08.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 08/09/2013] [Accepted: 08/21/2013] [Indexed: 11/24/2022] Open
Abstract
The distribution of nicotinic acetylcholine receptor (AChR) clusters at the cell membrane was studied in CHO-K1/A5 cells using fluorescence microscopy. Di-4-ANEPPDHQ, a fluorescent probe that differentiates between liquid-ordered (Lo) and liquid-disordered (Ld) phases in model membranes, was used in combination with monoclonal anti-AChR antibody labeling of live cells, which induces AChR clustering. The so-called generalized polarization (GP) of di-4-ANEPPDHQ was measured in regions of the cell-surface membrane associated with or devoid of antibody-induced AChR clusters, respectively. AChR clusters were almost equally distributed between Lo and Ld domains, independently of receptor surface levels and agonist (carbamoylcholine and nicotine) or antagonist (α-bungarotoxin) binding. Cholesterol depletion diminished the cell membrane mean di-4-ANEPPDHQ GP and the number of AChR clusters associated with Ld membrane domains increased concomitantly. Depolymerization of the filamentous actin cytoskeleton by Latrunculin A had the opposite effect, with more AChR clusters associated with Lo domains. AChR internalized via small vesicles having lower GP and lower cholesterol content than the surface membrane. Upon cholesterol depletion, only 12% of the AChR-containing vesicles costained with the fluorescent cholesterol analog fPEG-cholesterol, i.e., AChR endocytosis was essentially dissociated from that of cholesterol. In conclusion, the distribution of AChR submicron-sized clusters at the cell membrane appears to be regulated by cholesterol content and cytoskeleton integrity.
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Affiliation(s)
| | - Virginia Borroni
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Bahía Blanca, Argentina
| | - María F. Pediconi
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Bahía Blanca, Argentina
| | | | | | - Francisco J. Barrantes
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Bahía Blanca, Argentina
- Laboratory of Molecular Neurobiology, Institute for Biomedical Research UCA-CONICET, Faculty of Medical Sciences, Catholic University of Argentina, Buenos Aires, Argentina
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Brignac-Huber LM, Reed JR, Eyer MK, Backes WL. Relationship between CYP1A2 localization and lipid microdomain formation as a function of lipid composition. Drug Metab Dispos 2013; 41:1896-905. [PMID: 23963955 DOI: 10.1124/dmd.113.053611] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cytochrome P450 (P450) function requires the interaction of P450 and NADPH-cytochrome P450 reductase (CPR) in membranes, and is frequently studied using reconstituted systems composed solely of phosphatidylcholine. There is increasing evidence that other endoplasmic reticulum (ER) lipids can affect P450 structure, activity, and interactions with CPR. Some of these lipid effects have been attributed to the formation of organized liquid-ordered (l(o)) domains. The goal of this study was to determine if l(o) domains were formed in P450 reconstituted systems mimicking the ER membrane. CYP1A2, when incorporated in "ER-like" lipid vesicles, displayed detergent insolubility after treatment with Brij 98 and centrifugation in a sucrose gradient. Lipid probes were employed to identify domain formation in both ER-like vesicles and model membranes known to form l(o) domains. Changes in fluorescence resonance energy transfer (FRET) using an established donor/acceptor FRET pair in both ER-like and model l(o)-forming systems demonstrated the coexistence of l(o)- and liquid-disordered domains as a function of cholesterol and sphingomyelin content. Similarly, 6-dodecanoyl-2-dimethylaminonaphthalene (laurdan), a probe that reports on membrane organization, showed that cholesterol and sphingomyelin increased membrane order. Finally, brominated-phosphatidylcholine allowed for monitoring of the location of both CPR and CYP1A2 within the l(o) regions of ER-like systems. Taken together, the results demonstrate that ER-like vesicles generate microdomains, and both CYP1A2 and CPR predominantly localize into l(o) membrane regions. Probe fluorescent responses suggest that lipid microdomains form in these vesicles whether or not enzymes are included in the reconstituted systems. Thus, it does not appear that the proteins are critical for stabilizing l(o) domains.
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Affiliation(s)
- Lauren M Brignac-Huber
- Department of Pharmacology and Experimental Therapeutics, Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, New Orleans, Louisiana
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45
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Marty NJ, Holman CL, Abdullah N, Johnson CP. The C2 domains of otoferlin, dysferlin, and myoferlin alter the packing of lipid bilayers. Biochemistry 2013; 52:5585-92. [PMID: 23859474 DOI: 10.1021/bi400432f] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ferlins are large multi-C2 domain membrane proteins involved in membrane fusion and fission events. In this study, we investigate the effects of binding of the C2 domains of otoferlin, dysferlin, and myoferlin on the structure of lipid bilayers. Fluorescence measurements indicate that multi-C2 domain constructs of myoferlin, dysferlin, and otoferlin change the lipid packing of both small unilamellar vesicles and giant plasma membrane vesicles. The activities of these proteins were enhanced in the presence of calcium and required negatively charged lipids like phosphatidylserine or phosphatidylglycerol for activity. Experiments with individual domains uncovered functional differences between the C2A domain of otoferlin and those of dysferlin and myoferlin, and truncation studies suggest that the effects of each subsequent C2 domain on lipid ordering appear to be additive. Finally, we demonstrate that the activities of these proteins on membranes are insensitive to high salt concentrations, suggesting a nonelectrostatic component to the interaction between ferlin C2 domains and lipid bilayers. Together, the data indicate that dysferlin, otoferlin, and myoferlin do not merely passively adsorb to membranes but actively sculpt lipid bilayers, which would result in highly curved or distorted membrane regions that could facilitate membrane fusion, membrane fission, or recruitment of other membrane-trafficking proteins.
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Affiliation(s)
- Naomi J Marty
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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46
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Modification of the Lipid Phase of Biological and Model Membranes by Bilberry Leaf Extract. FOOD BIOPHYS 2013. [DOI: 10.1007/s11483-013-9309-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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47
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Bach JN, Bramkamp M. Flotillins functionally organize the bacterial membrane. Mol Microbiol 2013; 88:1205-17. [PMID: 23651456 DOI: 10.1111/mmi.12252] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2013] [Indexed: 01/24/2023]
Abstract
Proteins and lipids are heterogeneously distributed in biological membranes. The correct function of membrane proteins depends on spatiotemporal organization into defined membrane areas, called lipid domains or rafts. Lipid microdomains are therefore thought to assist compartmentalization of membranes. However, how lipid and protein assemblies are organized and whether proteins are actively involved in these processes remains poorly understood. We now have identified flotillins to be responsible for lateral segregation of defined membrane domains in the model organism Bacillus subtilis. We show that flotillins form large, dynamic assemblies that are able to influence membrane fluidity and prevent condensation of Laurdan stained membrane regions. Absence of flotillins in vivo leads to coalescence of distinct domains of high membrane order and, hence, loss of flotillins in the bacterial plasma-membrane reduces membrane heterogeneity. We show that flotillins interact with various proteins involved in protein secretion, cell wall metabolism, transport and membrane-related signalling processes. Importantly, maintenance of membrane heterogeneity is critical for vital cellular processes such as protein secretion.
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Affiliation(s)
- Juri Niño Bach
- Department of Biology I, Ludwig-Maximilians-University, Munich, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany
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Sezgin E, Chwastek G, Aydogan G, Levental I, Simons K, Schwille P. Photoconversion of Bodipy-Labeled Lipid Analogues. Chembiochem 2013; 14:695-8. [DOI: 10.1002/cbic.201300038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Indexed: 11/10/2022]
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49
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Dinic J, Ashrafzadeh P, Parmryd I. Actin filaments attachment at the plasma membrane in live cells cause the formation of ordered lipid domains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1102-11. [DOI: 10.1016/j.bbamem.2012.12.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 12/03/2012] [Accepted: 12/04/2012] [Indexed: 11/29/2022]
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50
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Owen DM, Rentero C, Magenau A, Abu-Siniyeh A, Gaus K. Quantitative imaging of membrane lipid order in cells and organisms. Nat Protoc 2011; 7:24-35. [PMID: 22157973 DOI: 10.1038/nprot.2011.419] [Citation(s) in RCA: 304] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
It is now recognized that lipids and proteins in cellular membranes are not homogenously distributed. A high degree of membrane order is the biophysical hallmark of cholesterol-enriched lipid rafts, which may induce the lateral sorting of proteins within the membrane. Here we describe a quantitative fluorescence microscopy technique for imaging localized lipid environments and measuring membrane lipid order in live and fixed cells, as well as in intact tissues. The method is based on the spectral ratiometric imaging of the polarity-sensitive membrane dyes Laurdan and di-4-ANEPPDHQ. Laurdan typically requires multiphoton excitation, making it suitable for the imaging of tissues such as whole, living zebrafish embryos, whereas di-4-ANEPPDHQ imaging can be achieved with standard confocal microscopes. This approach, which takes around 4 h, directly examines the organization of cellular membranes and is distinct from alternative approaches that infer membrane order by measuring probe partitioning or dynamics.
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Affiliation(s)
- Dylan M Owen
- Centre for Vascular Research, University of New South Wales, Sydney, Australia.
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