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Kamandloo F, Salami M, Ghamari F, Ghaffari SB, EmamDjomeh Z, Ghasemi A, Kennedy JF. Development and evaluation of anti-reflux functional-oral suspension raft composed of sodium alginate-mung bean protein complex. Int J Biol Macromol 2024; 256:128490. [PMID: 38035967 DOI: 10.1016/j.ijbiomac.2023.128490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 11/17/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023]
Abstract
This study aimed to develop a sodium alginate (Na alginate) and mung bean protein (MBP) raft complex to improve gastric reflux symptoms. Na alginate and MBP complexes with different ratios (1:1, 2:1, and 3:1, respectively) were used for raft formulations through a wet Maillard reaction. Structural properties of raft strength, reflux resistance, intrinsic fluorescence emission spectroscopy, and Fourier transform infrared spectroscopy (FTIR) were investigated for rafts. The suspension 1:1 Na alginate/MBP with 0 h Maillard reaction time exhibited the lowest sedimentation volume among the suspensions. In contrast, 3:1 Na alginate/MBP with 6 h Maillard reaction time showed the highest sedimentation volume. Based on the results, the 3:1 Na alginate/MBP rafts had the best results, and the results were within acceptable limits. Functional properties, including antioxidant properties, the Helicobacter pylori inhibition assay, the pancreatic lipase inhibition assay, and angiotensin-converting enzyme (ACE) inhibition, were investigated for rafts. The Na alginate/MBP raft has similar characteristics to Gaviscon syrup and can be used for obesity, Helicobacter pylori infection, high blood pressure, and gastric reflux.
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Affiliation(s)
- Farzaneh Kamandloo
- Transfer Phenomena Laboratory (TPL), Department of Food Science and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Maryam Salami
- Transfer Phenomena Laboratory (TPL), Department of Food Science and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran; Functional Food Research Core (FRC), University of Tehran, Iran.
| | - Fatemeh Ghamari
- Department of Science Payame Noor University, P.O. box 19395-4697, Tehran, Iran
| | - Seyed-Behnam Ghaffari
- School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Zahra EmamDjomeh
- Transfer Phenomena Laboratory (TPL), Department of Food Science and Engineering, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran; Functional Food Research Core (FRC), University of Tehran, Iran
| | - Atiyeh Ghasemi
- Institute of Biochemistry and Biophysics, University of Tehran, Iran
| | - John F Kennedy
- Chembiotech Laboratories Ltd, Tenbury Wells, United Kingdom
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Liu J, Feng W, Huang M, Feng S, Zhang Y. Grouped Multilayer Practical Byzantine Fault Tolerance Algorithm: A Practical Byzantine Fault Tolerance Consensus Algorithm Optimized for Digital Asset Trading Scenarios. Sensors (Basel) 2023; 23:8903. [PMID: 37960601 PMCID: PMC10649370 DOI: 10.3390/s23218903] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/23/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023]
Abstract
Based on the practical Byzantine fault tolerance algorithm (PBFT), a grouped multilayer PBFT consensus algorithm (GM-PBFT) is proposed to be applied to digital asset transactions in view of the problems with excessive communication complexity and low consensus efficiency found in the current consensus mechanism for digital asset transactions. Firstly, the transaction nodes are grouped by type, and each group can handle different types of consensus requests at the same time, which improves the consensus efficiency as well as the accuracy of digital asset transactions. Second, the group develops techniques like validation, auditing, and re-election to enhance Byzantine fault tolerance by thwarting malicious node attacks. This supervisory mechanism is implemented through the Raft consensus algorithm. Finally, the consensus is stratified for the nodes in the group, and the consensus nodes in the upper layer recursively send consensus requests to the lower layer until the consensus request reaches the end layer to ensure the consistency of the block ledger in the group. Based on the results of the experiment, the approach may significantly outperform the PBFT consensus algorithm when it comes to accuracy, efficiency, and preserving the security and reliability of transactions in large-scale network node digital transaction situations.
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Affiliation(s)
- Jian Liu
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (J.L.); (S.F.)
| | - Wenlong Feng
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (J.L.); (S.F.)
| | - Mengxing Huang
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (J.L.); (S.F.)
| | - Siling Feng
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (J.L.); (S.F.)
| | - Yu Zhang
- School of Computer Science and Technology, Hainan University, Haikou 570228, China;
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3
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Bandyopadhyay S, Gurjar D, Saha B, Bodhale N. Decoding the contextual duality of CD40 functions. Hum Immunol 2023; 84:590-599. [PMID: 37596136 DOI: 10.1016/j.humimm.2023.08.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 07/13/2023] [Accepted: 08/11/2023] [Indexed: 08/20/2023]
Abstract
Previously, we established that as a function of its mode of interaction with its ligand or cellular conditions such as membrane lipids, preexisting signaling intermediates activation status, a transmembrane receptor, as represented here with CD40, can induce counteractive cellular responses. Using CD40-binding peptides, recombinant mutated CD40-ligands, and an agonistic antibody, we have established the functional duality of CD40. CD40 builds up two constitutionally different signalosomes on lipid raft and non-raft membrane domains initiating two different signaling pathways. Although this initial signaling may be modified by the pre-existing signaling conditions downstream and may be subjected to feed-forward or negative signaling effects, the initial CD40-CD40L interaction plays a crucial role in the functional outcome of CD40. Herein, we have reviewed the influence of interaction between the CD40-CD40L evoking the functional duality of CD40 contingent upon different physiological states of the cells.
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Affiliation(s)
| | - Dhiraj Gurjar
- National Centre for Cell Science, Ganeshkhind, Pune 411007, India
| | - Bhaskar Saha
- National Centre for Cell Science, Ganeshkhind, Pune 411007, India
| | - Neelam Bodhale
- National Centre for Cell Science, Ganeshkhind, Pune 411007, India
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Takebayashi K, Kamimura Y, Ueda M. Field model for multistate lateral diffusion of various transmembrane proteins observed in living Dictyostelium cells. J Cell Sci 2023; 136:286715. [PMID: 36655427 PMCID: PMC10022678 DOI: 10.1242/jcs.260280] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 01/11/2023] [Indexed: 01/20/2023] Open
Abstract
The lateral diffusion of transmembrane proteins on plasma membranes is a fundamental process for various cellular functions. Diffusion properties specific for individual protein species have been extensively studied, but the common features among protein species are poorly understood. Here, we systematically studied the lateral diffusion of various transmembrane proteins in the lower eukaryote Dictyostelium discoideum cells using a hidden Markov model for single-molecule trajectories obtained experimentally. As common features, all membrane proteins that had from one to ten transmembrane regions adopted three free diffusion states with similar diffusion coefficients regardless of their structural variability. All protein species reduced their mobility similarly upon the inhibition of microtubule or actin cytoskeleton dynamics, or myosin II. The relationship between protein size and the diffusion coefficient was consistent with the Saffman-Delbrück model, meaning that membrane viscosity is a major determinant of lateral diffusion, but protein size is not. These protein species-independent properties of multistate free diffusion were explained simply and quantitatively by free diffusion on the three membrane regions with different viscosities, which is in sharp contrast to the complex diffusion behavior of transmembrane proteins in higher eukaryotes.
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Affiliation(s)
- Kazutoshi Takebayashi
- Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan.,Center for Biosystems Dynamics Research (BDR), RIKEN, Suita, Osaka, 565-0874, Japan
| | - Yoichiro Kamimura
- Center for Biosystems Dynamics Research (BDR), RIKEN, Suita, Osaka, 565-0874, Japan
| | - Masahiro Ueda
- Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan.,Center for Biosystems Dynamics Research (BDR), RIKEN, Suita, Osaka, 565-0874, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
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Goh MWS, Tero R. Non- raft submicron domain formation in cholesterol-containing lipid bilayers induced by polyunsaturated phosphatidylethanolamine. Colloids Surf B Biointerfaces 2021; 210:112235. [PMID: 34891064 DOI: 10.1016/j.colsurfb.2021.112235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/08/2021] [Accepted: 11/16/2021] [Indexed: 12/13/2022]
Abstract
Domain formation in "HLC" ternary lipid bilayers, comprising a high transition temperature (High-Tm) lipid, a Low-Tm lipid, and cholesterol (Chol), has been extensively studied as raft-resembling systems. Recently, we reported the formation of submicron domains in an "LLC" lipid bilayer, encompassing Low-Tm phosphatidylethanolamine (PE), Low-Tm phosphatidylcholine (PC), and Chol. We hypothesized that the formation of this unique domain is driven by polyunsaturated PE. In this study, we explored the effects of the degree of PE unsaturation and the double bond distribution at the sn-position on the mechanism of formation and the composition of submicron domains. Supported lipid bilayers (SLBs), comprising PE with various degrees of unsaturation, monounsaturated PC (POPC), and Chol, were investigated using fluorescence microscopy, atomic force microscopy, and the force-distance curve measurement. The area fraction of submicron domains in PE+POPC+Chol-SLB increased with the PE concentration and degree of unsaturation of the PE acyl chain. The results indicated that the submicron domains were enriched with polyunsaturated PE and were in the liquid-disordered-like state, whereas their surrounding regions were in the liquid-ordered-like state. Segregation of polyunsaturated PE from the Chol-containing region generated submicron domains in the LLC lipid bilayer. We propose a mechanism for the formation of these submicron domains based on molecular interactions involving the hydrophobic and hydrophilic parts of the bilayer membrane.
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Sapuri-Butti AR, Wang L, Tetali SD, Rutledge JC, Parikh AN. Interactions of different lipoproteins with supported phospholipid raft membrane (SPRM) patterns to understand similar in-vivo processes. Biochim Biophys Acta Biomembr 2021; 1863:183535. [PMID: 33358851 DOI: 10.1016/j.bbamem.2020.183535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/01/2020] [Accepted: 12/11/2020] [Indexed: 11/21/2022]
Abstract
To better understand how lipoproteins interact and enter endothelium and participate in cellular processes, we investigated preferential lipid partitioning of triglyceride rich lipoproteins (TGRL), chylomicrons (CM), low density lipoproteins (LDL), very low density lipoproteins (VLDL) and their lipolysis products using supported phospholipid raft membrane (SPRM) patterns. We prepared SPRM patterns with Texas red labeled phospholipid patterns and Marina blue labeled raft patterns and added Atto-520 labeled lipoproteins (TGRL, CM, VLDL, LDL) and their lipolysis products in separate experiments and characterized these interactions using fluorescence microscopy. We observed that VLDL and LDL preferentially interacted with raft patterns. In contrast the TGRL and lipolysed products of TGRL interacted with both the patterns, slightly elevated preference for raft patterns and CM and its lipolysis products showed greater affinity to phospholipid patterns. The clear preference of VLDL and LDL for raft patterns suggests that these lipoproteins associate with cholesterol and sphingomyelin rich lipid micro-domains during their early interactions with endothelial cells, leading to atherosclerosis.
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Mohideen N, Weiner MD, Feigenson GW. Bilayer compositional asymmetry influences the nanoscopic to macroscopic phase domain size transition. Chem Phys Lipids 2020; 232:104972. [PMID: 32941827 DOI: 10.1016/j.chemphyslip.2020.104972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/18/2020] [Accepted: 09/04/2020] [Indexed: 10/23/2022]
Abstract
The eukaryotic plasma membrane (PM) exhibits lipid mixing heterogeneities known as lipid rafts. These lipid rafts, the result of liquid-liquid phase separation, can be modeled by coexisting liquid ordered (Lo) and liquid disordered (Ld) domains. Four-lipid component systems with a high-melting lipid, a nanodomain-inducing low-melting lipid, a macrodomain-inducing low-melting lipid, and cholesterol (chol) can give rise to domains of different sizes. These four-component systems have been characterized in experiments, yet there are few studies that model the asymmetric distribution of lipids actually found in the PM. We used molecular dynamics (MD) simulations to analyze the transition from nanoscopic to macroscopic domains in symmetric and in asymmetric model membranes. Using coarse-grained MD simulations, we found that asymmetry promotes macroscopic domain growth in a case where symmetric systems exhibit nanoscopic domains. Also, macroscopic domain formation in symmetric systems is highly dependent on registration of like phases in the cytoplasmic and exoplasmic leaflets. Using united-atom MD simulations, we found that symmetric Lo domains are only slightly more ordered than asymmetric Lo domains. We also found that large Lo domains in our asymmetric systems induce a slight chain ordering in the apposed cytoplasmic regions. The chol fractions of phase-separated Lo and Ld domains of the exoplasmic leaflet were unchanged whether the system was symmetric or asymmetric.
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Affiliation(s)
- Naveen Mohideen
- Cornell University Department of Physics, 117 Clark Hall, Ithaca, New York, 14853, United States; Johns Hopkins University Department of Molecular Biophysics, 101 Jenkins Hall, 3400 N. Charles Street, Baltimore, Maryland, 21218, United States.
| | - Michael D Weiner
- Cornell University Department of Physics, 117 Clark Hall, Ithaca, New York, 14853, United States; Georgia Institute of Technology Partnership for an Advanced Computing Environment, 756 W. Peachtree St. NW, Atlanta, Georgia, 30332, United States.
| | - Gerald W Feigenson
- Cornell University Department of Molecular Biology and Genetics, Room 201 215 Tower Rd. Ithaca, New York, 14853, United States.
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Mamode Cassim A, Gouguet P, Gronnier J, Laurent N, Germain V, Grison M, Boutté Y, Gerbeau-Pissot P, Simon-Plas F, Mongrand S. Plant lipids: Key players of plasma membrane organization and function. Prog Lipid Res 2018; 73:1-27. [PMID: 30465788 DOI: 10.1016/j.plipres.2018.11.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 12/29/2022]
Abstract
The plasma membrane (PM) is the biological membrane that separates the interior of all cells from the outside. The PM is constituted of a huge diversity of proteins and lipids. In this review, we will update the diversity of molecular species of lipids found in plant PM. We will further discuss how lipids govern global properties of the plant PM, explaining that plant lipids are unevenly distributed and are able to organize PM in domains. From that observation, it emerges a complex picture showing a spatial and multiscale segregation of PM components. Finally, we will discuss how lipids are key players in the function of PM in plants, with a particular focus on plant-microbe interaction, transport and hormone signaling, abiotic stress responses, plasmodesmata function. The last chapter is dedicated to the methods that the plant membrane biology community needs to develop to get a comprehensive understanding of membrane organization in plants.
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Affiliation(s)
- Adiilah Mamode Cassim
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Paul Gouguet
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Julien Gronnier
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Nelson Laurent
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France
| | - Véronique Germain
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Magali Grison
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Yohann Boutté
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France
| | - Patricia Gerbeau-Pissot
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France
| | - Françoise Simon-Plas
- Agroécologie, AgroSup Dijon, INRA, University of Bourgogne Franche-Comté, F-21000 Dijon, ERL 6003 CNRS, Dijon, France.
| | - Sébastien Mongrand
- Laboratoire de Biogenèse Membranaire (LBM), CNRS, University of Bordeaux, UMR 5200, F-33882 Villenave d'Ornon, France.
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Garcia-Castillo MD, Tran T, Bobard A, Renard HF, Rathjen SJ, Dransart E, Stechmann B, Lamaze C, Lord M, Cintrat JC, Enninga J, Tartour E, Johannes L. Retrograde transport is not required for cytosolic translocation of the B-subunit of Shiga toxin. J Cell Sci 2015; 128:2373-87. [PMID: 25977475 DOI: 10.1242/jcs.169383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/07/2015] [Indexed: 01/13/2023] Open
Abstract
Antigen-presenting cells have the remarkable capacity to transfer exogenous antigens to the cytosol for processing by proteasomes and subsequent presentation on major histocompatibility complex class-I (MHC-I) molecules, a process termed cross-presentation. This is the target of biomedical approaches that aim to trigger a therapeutic immune response. The receptor-binding B-subunit of Shiga toxin (STxB) has been developed as an antigen delivery tool for such immunotherapy applications. In this study, we have analyzed pathways and trafficking factors that are involved in this process. A covalent conjugate between STxB and saporin was generated to quantitatively sample the membrane translocation step to the cytosol in differentiated monocyte-derived THP-1 cells. We have found that retrograde trafficking to the Golgi complex was not required for STxB-saporin translocation to the cytosol or for STxB-dependent antigen cross-presentation. Depletion of endosomal Rab7 inhibited, and lowering membrane cholesterol levels favored STxB-saporin translocation. Interestingly, experiments with reducible and non-reducible linker-arm-STxB conjugates led to the conclusion that after translocation, STxB remains associated with the cytosolic membrane leaflet. In summary, we report new facets of the endosomal escape process bearing relevance to antigen cross-presentation.
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Affiliation(s)
- Maria Daniela Garcia-Castillo
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris Cedex 05 75248, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France
| | - Thi Tran
- INSERM U970, PARCC Université Paris Descartes Sorbonne Paris Cité, Paris 75006, France Hôpital Européen Georges-Pompidou, AP-HP, Service d'Immunologie Biologique, Paris Cedex 15 75908, France
| | - Alexandre Bobard
- Dynamique des Interactions Hôte Pathogène, Institut Pasteur, Paris Cedex 15 75724, France
| | - Henri-François Renard
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris Cedex 05 75248, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France
| | - Stefan J Rathjen
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris Cedex 05 75248, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France
| | - Estelle Dransart
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris Cedex 05 75248, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France
| | - Bahne Stechmann
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris Cedex 05 75248, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France
| | - Christophe Lamaze
- CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France Institut Curie - Centre de Recherche, Membrane Dynamics and Mechanics of Intracellular Signaling Group, 26 rue d'Ulm, Paris Cedex 05 75248, France
| | - Mike Lord
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK
| | | | - Jost Enninga
- Dynamique des Interactions Hôte Pathogène, Institut Pasteur, Paris Cedex 15 75724, France
| | - Eric Tartour
- INSERM U970, PARCC Université Paris Descartes Sorbonne Paris Cité, Paris 75006, France Hôpital Européen Georges-Pompidou, AP-HP, Service d'Immunologie Biologique, Paris Cedex 15 75908, France
| | - Ludger Johannes
- Institut Curie, PSL Research University, Endocytic Trafficking and Therapeutic Delivery Group, 26 rue d'Ulm, Paris Cedex 05 75248, France CNRS UMR3666, Paris 75005, France INSERM U1143, Paris 75005, France
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Abstract
The organization of eukaryotic membranes into functional domains continues to fascinate and puzzle cell biologists and biophysicists. The lipid raft hypothesis proposes that collective lipid interactions compartmentalize the membrane into coexisting liquid domains that are central to membrane physiology. This hypothesis has proven controversial because such structures cannot be directly visualized in live cells by light microscopy. The recent observations of liquid-liquid phase separation in biological membranes are an important validation of the raft hypothesis and enable application of the experimental toolbox of membrane physics to a biologically complex phase-separated membrane. This review addresses the role of giant plasma membrane vesicles (GPMVs) in refining the raft hypothesis and expands on the application of GPMVs as an experimental model to answer some of key outstanding problems in membrane biology.
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Affiliation(s)
- Kandice R Levental
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston - Medical School, Houston, TX, USA
| | - Ilya Levental
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston - Medical School, Houston, TX, USA
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11
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Curthoys NM, Parent M, Mlodzianoski M, Nelson AJ, Lilieholm J, Butler MB, Valles M, Hess ST. Dances with Membranes: Breakthroughs from Super-resolution Imaging. Curr Top Membr 2015; 75:59-123. [PMID: 26015281 PMCID: PMC5584789 DOI: 10.1016/bs.ctm.2015.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Biological membrane organization mediates numerous cellular functions and has also been connected with an immense number of human diseases. However, until recently, experimental methodologies have been unable to directly visualize the nanoscale details of biological membranes, particularly in intact living cells. Numerous models explaining membrane organization have been proposed, but testing those models has required indirect methods; the desire to directly image proteins and lipids in living cell membranes is a strong motivation for the advancement of technology. The development of super-resolution microscopy has provided powerful tools for quantification of membrane organization at the level of individual proteins and lipids, and many of these tools are compatible with living cells. Previously inaccessible questions are now being addressed, and the field of membrane biology is developing rapidly. This chapter discusses how the development of super-resolution microscopy has led to fundamental advances in the field of biological membrane organization. We summarize the history and some models explaining how proteins are organized in cell membranes, and give an overview of various super-resolution techniques and methods of quantifying super-resolution data. We discuss the application of super-resolution techniques to membrane biology in general, and also with specific reference to the fields of actin and actin-binding proteins, virus infection, mitochondria, immune cell biology, and phosphoinositide signaling. Finally, we present our hopes and expectations for the future of super-resolution microscopy in the field of membrane biology.
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Affiliation(s)
- Nikki M. Curthoys
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Matthew Parent
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | | | - Andrew J. Nelson
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Jennifer Lilieholm
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Michael B. Butler
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Matthew Valles
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
| | - Samuel T. Hess
- Department of Physics and Astronomy, University of Maine, Orono, ME, USA
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Ruysschaert JM, Lonez C. Role of lipid microdomains in TLR-mediated signalling. Biochim Biophys Acta 2015; 1848:1860-7. [PMID: 25797518 DOI: 10.1016/j.bbamem.2015.03.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/09/2015] [Accepted: 03/12/2015] [Indexed: 12/13/2022]
Abstract
Over the last twenty years, evidence has been provided that the plasma membrane is partitioned with microdomains, laterally mobile in the bilayer, providing the necessary microenvironment to specific membrane proteins for signalling pathways to be initiated. We discuss here the importance of such microdomains for Toll-like receptors (TLR) localization and function. First, lipid microdomains favour recruitment and clustering of the TLR machinery partners, i.e. receptors and co-receptors previously identified to be required for ligand recognition and signal transmission. Further, the presence of the so-called Cholesterol Recognition Amino-Acid Consensus (CRAC) sequences in the intracellular juxtamembrane domain of several Toll-like receptors suggests a direct role of cholesterol in the activation process. This article is part of a Special Issue entitled: Lipid-protein interactions.
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Affiliation(s)
- Jean-Marie Ruysschaert
- Structure and Function of Biological Membranes, Université Libre de Bruxelles, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Caroline Lonez
- Structure and Function of Biological Membranes, Université Libre de Bruxelles, Boulevard du Triomphe, 1050 Brussels, Belgium; Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom.
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Georgieva R, Chachaty C, Hazarosova R, Tessier C, Nuss P, Momchilova A, Staneva G. Docosahexaenoic acid promotes micron scale liquid-ordered domains. A comparison study of docosahexaenoic versus oleic acid containing phosphatidylcholine in raft-like mixtures. Biochim Biophys Acta 2015; 1848:1424-35. [PMID: 25767038 DOI: 10.1016/j.bbamem.2015.02.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 02/24/2015] [Accepted: 02/26/2015] [Indexed: 12/19/2022]
Abstract
The understanding of the functional role of the lipid diversity in biological membranes is a major challenge. Lipid models have been developed to address this issue by using lipid mixtures generating liquid-ordered (Lo)/liquid-disordered (Ld) immiscibility. The present study examined mixtures comprising Egg sphingomyelin (SM), cholesterol (chol) and phosphatidylcholine (PC) either containing docosahexaenoic (PDPC) or oleic acid (POPC). The mixtures were examined in terms of their capability to induce phase separation at the micron- and nano-scales. Fluorescence microscopy, electron spin resonance (ESR), X-ray diffraction (XRD) and calorimetry methods were used to analyze the lateral organization of the mixtures. Fluorescence microscopy of giant vesicles could show that the temperature of the micron-scale Lo/Ld miscibility is higher for PDPC than for POPC ternary mixtures. At 37°C, no micron-scale Lo/Ld phase separation could be identified in the POPC containing mixtures while it was evident for PDPC. In contrast, a phase separation was distinguished for both PC mixtures by ESR and XRD, indicative that PDPC and POPC mixtures differed in micron vs nano domain organization. Compared to POPC, the higher line tension of the Lo domains observed in PDPC mixtures is assumed to result from the higher difference in Lo/Ld order parameter rather than hydrophobic mismatch.
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Affiliation(s)
- R Georgieva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - C Chachaty
- Universite Pierre et Marie Curie-Paris 6, INSERM U893, CHU St. Antoine, 27 rue Chaligny, 75012 Paris, France
| | - R Hazarosova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - C Tessier
- UMR 7203, INSERM ERL 1057 - Bioactive Molecules Laboratory, Pierre et Marie Curie University, Paris, France; Department of Psychiatry, Hôpital Saint-Antoine, AP-HP, Paris, France
| | - P Nuss
- UMR 7203, INSERM ERL 1057 - Bioactive Molecules Laboratory, Pierre et Marie Curie University, Paris, France; Department of Psychiatry, Hôpital Saint-Antoine, AP-HP, Paris, France
| | - A Momchilova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria
| | - G Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.
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Ernst AM, Brügger B. Sphingolipids as modulators of membrane proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:665-70. [PMID: 24201378 DOI: 10.1016/j.bbalip.2013.10.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/22/2013] [Accepted: 10/28/2013] [Indexed: 12/13/2022]
Abstract
The diversity of the transmembranome of higher eukaryotes is matched by an enormous diversity of sphingolipid classes and molecular species. The intrinsic properties of sphingolipids are not only suited for orchestrating lateral architectures of biological membranes, but their molecular distinctions also allow for the evolution of protein motifs specifically recognising and interacting with individual lipids. Although various reports suggest a role of sphingolipids in membrane protein function, only a few cases have determined the specificity of these interactions. In this review we discuss examples of specific protein-sphingolipid interactions for which a modulator-like dependency on sphingolipids was assigned to specific proteins. These novel functions of sphingolipids in specific protein-lipid assemblies contribute to the complexity of the sphingolipid classes and other molecular species observed in animal cells. This article is part of a Special Issue entitled New Frontiers in Sphingolipid Biology.
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Asano A, Nelson-Harrington JL, Travis AJ. Phospholipase B is activated in response to sterol removal and stimulates acrosome exocytosis in murine sperm. J Biol Chem 2013; 288:28104-15. [PMID: 23943622 DOI: 10.1074/jbc.m113.450981] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Despite a strict requirement for sterol removal for sperm to undergo acrosome exocytosis (AE), the mechanisms by which changes in membrane sterols are transduced into changes in sperm fertilization competence are poorly understood. We have previously shown in live murine sperm that the plasma membrane overlying the acrosome (APM) contains several types of microdomains known as membrane rafts. When characterizing the membrane raft-associated proteomes, we identified phospholipase B (PLB), a calcium-independent enzyme exhibiting multiple activities. Here, we show that sperm surface PLB is activated in response to sterol removal. Both biochemical activity assays and immunoblots of subcellular fractions of sperm incubated with the sterol acceptor 2-hydroxypropyl-β-cyclodextrin (2-OHCD) confirmed the release of an active PLB fragment. Specific protease inhibitors prevented PLB activation, revealing a mechanistic requirement for proteolytic cleavage. Competitive inhibitors of PLB reduced the ability of sperm both to undergo AE and to fertilize oocytes in vitro, suggesting an important role in fertilization. This was reinforced by our finding that incubation either with protein concentrate released from 2-OHCD-treated sperm or with recombinant PLB peptide corresponding to the catalytic domain was able to induce AE in the absence of other stimuli. Together, these results lead us to propose a novel mechanism by which sterol removal promotes membrane fusogenicity and AE, helping confer fertilization competence. Importantly, this mechanism provides a basis for the newly emerging model of AE in which membrane fusions occur during capacitation/transit through the cumulus, prior to any physical contact between the sperm and the oocyte's zona pellucida.
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Affiliation(s)
- Atsushi Asano
- From the Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853
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Gallego M, Alday A, Alonso H, Casis O. Adrenergic regulation of cardiac ionic channels: role of membrane microdomains in the regulation of kv4 channels. Biochim Biophys Acta 2013; 1838:692-9. [PMID: 23811359 DOI: 10.1016/j.bbamem.2013.06.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 06/13/2013] [Accepted: 06/17/2013] [Indexed: 11/18/2022]
Abstract
The heart must constantly adapt its activity to the needs of the body. In any potentially dangerous or physically demanding situation the activated sympathetic nervous system leads a very fast cardiac response. Under these circumstances, α1-adrenergic receptors activate intracellular signaling pathways that finally phosphorylate the caveolae-located subpopulation of Kv4 channels and reduce the transient outward K(+) current (Ito) amplitude. This reduction changes the shape of the cardiac action potential and makes the plateau phase to start at higher voltages. This means that there are more calcium ions entering the myocyte and the result is an increase in the strength of the contraction. However, an excessive reduction of Ito could dangerously prolong action potential duration and this could cause arrhythmias when the heart rate is high. This excessive current reduction does not occur because there is a second population of Ito channels located in non-caveolar membrane rafts that are not accessible for α1-AR mediated regulation. Thus, the location of the components of a given transduction signaling pathway in membrane domains determines the correct and safe behavior of the heart. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
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Affiliation(s)
- Mónica Gallego
- Lascaray Research Center, University of the Basque Country (UPV/EHU), Av. Miguel de Unamuno 3, 01006 Vitoria, Spain; Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain.
| | - Aintzane Alday
- Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain.
| | - Hiart Alonso
- Lascaray Research Center, University of the Basque Country (UPV/EHU), Av. Miguel de Unamuno 3, 01006 Vitoria, Spain; Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain.
| | - Oscar Casis
- Lascaray Research Center, University of the Basque Country (UPV/EHU), Av. Miguel de Unamuno 3, 01006 Vitoria, Spain; Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain.
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Krishnan G, Chatterjee N. Detergent resistant membrane fractions are involved in calcium signaling in Müller glial cells of retina. Int J Biochem Cell Biol 2013; 45:1758-66. [PMID: 23732110 DOI: 10.1016/j.biocel.2013.05.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/20/2013] [Accepted: 05/21/2013] [Indexed: 12/23/2022]
Abstract
Compartmentalization of the plasma membrane into lipid microdomains promotes efficient cellular processes by increasing local molecular concentrations. Calcium signaling, either as transients or propagating waves require integration of complex macromolecular machinery. Calcium waves represent a form of intercellular signaling in the central nervous system and the retina. We hypothesized that the mechanism for calcium waves would require effector proteins to aggregate at the plasma membrane in lipid microdomains. The current study shows that in Müller glia of the retina, proteins involved in calcium signaling aggregate in detergent resistant membranes identifying rafts and respond by redistributing on stimulation. We have investigated Purinoreceptor-1 (P2Y1), Ryanodine receptor (RyR), and Phospholipase C (PLC-β1). P2Y1, RyR and PLC-β1, redistribute from caveolin-1 and flotillin-1 positive fractions on stimulation with the agonists, ATP, 2MeS-ATP and Thapsigargin, an inhibitor of sarcoplasmic-endoplasmic reticulum Ca-ATPase (SERCA). Redistribution is absent on treatment with cyclopiazonic acid, another SERCA inhibitor. Disruption of rafts by removing cholesterol cause proteins involved in this machinery to redistribute and change agonist-induced calcium signaling. Cholesterol depletion from raft lead to increase in time to peak of calcium levels in agonist-evoked calcium signals in all instances, as seen by live imaging. This study emphasizes the necessity of a sub-population of proteins to cluster in specialized lipid domains. The requirement for such an organization at the raft-like microdomains may have implications on intercellular communication in the retina. Such concerted interaction at the rafts can regulate calcium dynamics and could add another layer of complexity to calcium signaling in cells.
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Affiliation(s)
- Gopinath Krishnan
- Department of L & T Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Chennai 600006, India
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