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Yang GS, Wagenknecht-Wiesner A, Yin B, Suresh P, London E, Baird BA, Bag N. Lipid-driven interleaflet coupling of plasma membrane order regulates FcεRI signaling in mast cells. Biophys J 2024; 123:2256-2270. [PMID: 37533258 PMCID: PMC11331041 DOI: 10.1016/j.bpj.2023.07.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023] Open
Abstract
Interleaflet coupling-the influence of one leaflet on the properties of the opposing leaflet-is a fundamental plasma membrane organizational principle. This coupling is proposed to participate in maintaining steady-state biophysical properties of the plasma membrane, which in turn regulates some transmembrane signaling processes. A prominent example is antigen (Ag) stimulation of signaling by clustering transmembrane receptors for immunoglobulin E (IgE), FcεRI. This transmembrane signaling depends on the stabilization of ordered regions in the inner leaflet for sorting of intracellular signaling components. The resting inner leaflet has a lipid composition that is generally less ordered than the outer leaflet and that does not spontaneously phase separate in model membranes. We propose that interleaflet coupling can mediate ordering and disordering of the inner leaflet, which is poised in resting cells to reorganize upon stimulation. To test this in live cells, we first established a straightforward approach to evaluate induced changes in membrane order by measuring inner leaflet diffusion of lipid probes by imaging fluorescence correlation spectroscopy, by imaging fluorescence correlation spectroscopy (ImFCS), before and after methyl-α-cyclodexrin (mαCD)-catalyzed exchange of outer leaflet lipids (LEX) with exogenous order- or disorder-promoting phospholipids. We examined the functional impact of LEX by monitoring two Ag-stimulated responses: recruitment of cytoplasmic Syk kinase to the inner leaflet and exocytosis of secretory granules (degranulation). Based on the ImFCS data in resting cells, we observed global increase or decrease of inner leaflet order when outer leaflet is exchanged with order- or disorder-promoting lipids, respectively. We find that the degree of both stimulated Syk recruitment and degranulation correlates positively with LEX-mediated changes of inner leaflet order in resting cells. Overall, our results show that resting-state lipid ordering of the outer leaflet influences the ordering of the inner leaflet, likely via interleaflet coupling. This imposed lipid reorganization modulates transmembrane signaling stimulated by Ag clustering of IgE-FcεRI.
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Affiliation(s)
- Gil-Suk Yang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | | | - Boyu Yin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | - Pavana Suresh
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York
| | - Erwin London
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York
| | - Barbara A Baird
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | - Nirmalya Bag
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York; Department of Chemistry, Indian Institute of Technology, Kharagpur, India.
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2
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Zubia MV, Yong AJH, Holtz KM, Huang EJ, Jan YN, Jan LY. TMEM16F exacerbates tau pathology and mediates phosphatidylserine exposure in phospho-tau-burdened neurons. Proc Natl Acad Sci U S A 2024; 121:e2311831121. [PMID: 38941274 PMCID: PMC11228522 DOI: 10.1073/pnas.2311831121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 06/04/2024] [Indexed: 06/30/2024] Open
Abstract
TMEM16F is a calcium-activated phospholipid scramblase and nonselective ion channel, which allows the movement of lipids bidirectionally across the plasma membrane. While the functions of TMEM16F have been extensively characterized in multiple cell types, the role of TMEM16F in the central nervous system remains largely unknown. Here, we sought to study how TMEM16F in the brain may be involved in neurodegeneration. Using a mouse model that expresses the pathological P301S human tau (PS19 mouse), we found reduced tauopathy and microgliosis in 6- to 7-mo-old PS19 mice lacking TMEM16F. Furthermore, this reduction of pathology can be recapitulated in the PS19 mice with TMEM16F removed from neurons, while removal of TMEM16F from microglia of PS19 mice did not significantly impact tauopathy at this time point. Moreover, TMEM16F mediated aberrant phosphatidylserine exposure in neurons with phospho-tau burden. These studies raise the prospect of targeting TMEM16F in neurons as a potential treatment of neurodegeneration.
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Affiliation(s)
- Mario V Zubia
- Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | - Adeline J H Yong
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | | | - Eric J Huang
- Biomedical Sciences Graduate Program, University of California, San Francisco, CA 94143
- Department of Pathology, University of California, San Francisco, CA 94143
| | - Yuh Nung Jan
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
| | - Lily Y Jan
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
- HHMI, University of California, San Francisco, CA 94143
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3
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Mirisola MG, Longo VD. Inactivation of Ymr1, Sjl2/3 phosphatases promotes stress resistance and longevity in wild type and Ras2G19V yeast. Biomed J 2024; 47:100694. [PMID: 38154617 PMCID: PMC10950826 DOI: 10.1016/j.bj.2023.100694] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023] Open
Abstract
In Saccharomyces cerevisiae, RAt Sarcoma (Ras) activity plays a central role in mediating the effect of glucose in decreasing stress resistance and longevity, with constitutive Ras activation mutations promoting cell growth and oncogenesis. Here, we used transposon mutagenesis in yeast to identify suppressors of the constitutively active Ras2G19V, orthologue of the KRASG12C mammalian oncogene. We identified mutations in Yeast Myotubularin Related (YMR1), SynaptoJanin-Like (SJL2) and SJL3 phosphatases, which target phosphatidylinositol phosphates, as the most potent suppressors of constitutive active Ras, able to reverse its effect on stress sensitization and sufficient to extend longevity. In sjl2 mutants, the staining of Ras-GTP switched from membrane-associated to a diffuse cytoplasmic staining, suggesting that it may block Ras activity by preventing its localization. Whereas expression of the Sjl2 PI 3,4,5 phosphatase mediated stress sensitization in both the Ras2G19V and wild type backgrounds, overexpression of the phosphatidylinositol 3 kinase VPS34 (Vacuolar Protein Sorting), promoted heat shock sensitization only in the Ras2G19V background, suggesting a complex relationship between different phosphatidylinositol and stress resistance. These results provide potential targets to inhibit the growth of cancer cells with constitutive Ras activity and link the glucose-dependent yeast pro-aging Ras signaling pathway to the well-established pro-aging PhosphoInositide 3-Kinase(PI3K) pathway in worms and other species raising the possibility that the conserved longevity effect of mutations in the PI3K-AKT (AK strain Transforming) pathway may involve inhibition of Ras signaling.
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Affiliation(s)
- M G Mirisola
- SteBiCeF Department, University of Palermo, Palermo, Italy.
| | - V D Longo
- IFOM, AIRC Institute of Molecular Oncology, Milan, Italy; Longevity Institute and Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA.
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4
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Duché G, Sanderson JM. The Chemical Reactivity of Membrane Lipids. Chem Rev 2024; 124:3284-3330. [PMID: 38498932 PMCID: PMC10979411 DOI: 10.1021/acs.chemrev.3c00608] [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: 09/04/2023] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/20/2024]
Abstract
It is well-known that aqueous dispersions of phospholipids spontaneously assemble into bilayer structures. These structures have numerous applications across chemistry and materials science and form the fundamental structural unit of the biological membrane. The particular environment of the lipid bilayer, with a water-poor low dielectric core surrounded by a more polar and better hydrated interfacial region, gives the membrane particular biophysical and physicochemical properties and presents a unique environment for chemical reactions to occur. Many different types of molecule spanning a range of sizes, from dissolved gases through small organics to proteins, are able to interact with membranes and promote chemical changes to lipids that subsequently affect the physicochemical properties of the bilayer. This Review describes the chemical reactivity exhibited by lipids in their membrane form, with an emphasis on conditions where the lipids are well hydrated in the form of bilayers. Key topics include the following: lytic reactions of glyceryl esters, including hydrolysis, aminolysis, and transesterification; oxidation reactions of alkenes in unsaturated fatty acids and sterols, including autoxidation and oxidation by singlet oxygen; reactivity of headgroups, particularly with reactive carbonyl species; and E/Z isomerization of alkenes. The consequences of reactivity for biological activity and biophysical properties are also discussed.
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Affiliation(s)
- Genevieve Duché
- Génie
Enzimatique et Cellulaire, Université
Technologique de Compiègne, Compiègne 60200, France
| | - John M Sanderson
- Chemistry
Department, Durham University, Durham DH1 3LE, United Kingdom
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5
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Leomil FC, Stephan M, Pramanik S, Riske KA, Dimova R. Bilayer Charge Asymmetry and Oil Residues Destabilize Membranes upon Poration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:4719-4731. [PMID: 38373285 PMCID: PMC10919074 DOI: 10.1021/acs.langmuir.3c03370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 01/03/2024] [Accepted: 01/05/2024] [Indexed: 02/21/2024]
Abstract
Transmembrane asymmetry is ubiquitous in cells, particularly with respect to lipids, where charged lipids are mainly restricted to one monolayer. We investigate the influence of anionic lipid asymmetry on the stability of giant unilamellar vesicles (GUVs), minimal plasma membrane models. To quantify asymmetry, we apply the fluorescence quenching assay, which is often difficult to reproduce, and caution in handling the quencher is generally underestimated. We first optimize this assay and then apply it to GUVs prepared with the inverted emulsion transfer protocol by using increasing fractions of anionic lipids restricted to one leaflet. This protocol is found to produce highly asymmetric bilayers but with ∼20% interleaflet mixing. To probe the stability of asymmetric versus symmetric membranes, we expose the GUVs to porating electric pulses and monitor the fraction of destabilized vesicles. The pulses open macropores, and the GUVs either completely recover or exhibit leakage or bursting/collapse. Residual oil destabilizes porated membranes, and destabilization is even more pronounced in asymmetrically charged membranes. This is corroborated by the measured pore edge tension, which is also found to decrease with increasing charge asymmetry. Using GUVs with imposed transmembrane pH asymmetry, we confirm that poration-triggered destabilization does not depend on the approach used to generate membrane asymmetry.
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Affiliation(s)
- Fernanda
S. C. Leomil
- Max
Planck Institute of Colloids and Interfaces, 14776 Potsdam, Germany
- Departamento
de Biofísica, Universidade Federal
de São Paulo, São
Paulo 04039-032, Brazil
| | - Mareike Stephan
- Max
Planck Institute of Colloids and Interfaces, 14776 Potsdam, Germany
| | - Shreya Pramanik
- Max
Planck Institute of Colloids and Interfaces, 14776 Potsdam, Germany
| | - Karin A. Riske
- Departamento
de Biofísica, Universidade Federal
de São Paulo, São
Paulo 04039-032, Brazil
| | - Rumiana Dimova
- Max
Planck Institute of Colloids and Interfaces, 14776 Potsdam, Germany
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6
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Matsuki Y, Iwamoto M, Oiki S. Asymmetric Lipid Bilayers and Potassium Channels Embedded Therein in the Contact Bubble Bilayer. Methods Mol Biol 2024; 2796:1-21. [PMID: 38856892 DOI: 10.1007/978-1-0716-3818-7_1] [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: 06/11/2024]
Abstract
Cell membranes are highly intricate systems comprising numerous lipid species and membrane proteins, where channel proteins, lipid molecules, and lipid bilayers, as continuous elastic fabric, collectively engage in multi-modal interplays. Owing to the complexity of the native cell membrane, studying the elementary processes of channel-membrane interactions necessitates a bottom-up approach starting from forming simplified synthetic membranes. This is the rationale for establishing an in vitro membrane reconstitution system consisting of a lipid bilayer with a defined lipid composition and a channel molecule. Recent technological advancements have facilitated the development of asymmetric membranes, and the contact bubble bilayer (CBB) method allows single-channel current recordings under arbitrary lipid compositions in asymmetric bilayers. Here, we present an experimental protocol for the formation of asymmetric membranes using the CBB method. The KcsA potassium channel is a prototypical model channel with huge structural and functional information and thus serves as a reporter of membrane actions on the embedded channels. We demonstrate specific interactions of anionic lipids in the inner leaflet. Considering that the local lipid composition varies steadily in cell membranes, we `present a novel lipid perfusion technique that allows rapidly changing the lipid composition while monitoring the single-channel behavior. Finally, we demonstrate a leaflet perfusion method for modifying the composition of individual leaflets. These techniques with custom synthetic membranes allow for variable experiments, providing crucial insights into channel-membrane interplay in cell membranes.
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Affiliation(s)
- Yuka Matsuki
- Department of Anesthesiology and Reanimatology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Masayuki Iwamoto
- Department of Molecular Neuroscience, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Shigetoshi Oiki
- Biomedical Imaging Research Center, University of Fukui, Fukui, Japan.
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7
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Hu Y, Zhang RQ, Liu SL, Wang ZG. In-situ quantification of lipids in live cells through imaging approaches. Biosens Bioelectron 2023; 240:115649. [PMID: 37678059 DOI: 10.1016/j.bios.2023.115649] [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: 05/24/2023] [Revised: 08/03/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
Lipids are important molecules that are widely distributed within the cell, and they play a crucial role in several biological processes such as cell membrane formation, signaling, cell motility and division. Monitoring the spatiotemporal dynamics of cellular lipids in real-time and quantifying their concentrations in situ is crucial since the local concentration of lipids initiates various signaling pathways that regulate cellular processes. In this review, we first introduced the historical background of lipid quantification methods. We then delve into the current state of the art of in situ lipid quantification, including the establishment and utility of fluorescence imaging techniques based on sensors of lipid-binding domains labeled with organic dyes or fluorescent proteins, and Raman and magnetic resonance imaging (MRI) techniques that do not require lipid labeling. Next, we highlighted the biological applications of live-cell lipid quantification techniques in the study of in situ lipid distribution, lipid transformation, and lipid-mediated signaling pathways. Finally, we discussed the technical challenges and prospects for the development of lipid quantification in live cells, with the aim of promoting the development of in situ lipid quantification in live cells, which may have a profound impact on the biological and medical fields.
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Affiliation(s)
- Yusi Hu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Centre for New Organic Matter, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Centre for Analytical Sciences, College of Chemistry and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Rui-Qiao Zhang
- Qingdao Academy of Agricultural Sciences, Qingdao, 266100, China
| | - Shu-Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Centre for New Organic Matter, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Centre for Analytical Sciences, College of Chemistry and School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Zhi-Gang Wang
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Centre for New Organic Matter, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Centre for Analytical Sciences, College of Chemistry and School of Medicine, Nankai University, Tianjin, 300071, China.
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8
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Ali O, Szabó A. Review of Eukaryote Cellular Membrane Lipid Composition, with Special Attention to the Fatty Acids. Int J Mol Sci 2023; 24:15693. [PMID: 37958678 PMCID: PMC10649022 DOI: 10.3390/ijms242115693] [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] [Received: 09/18/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Biological membranes, primarily composed of lipids, envelop each living cell. The intricate composition and organization of membrane lipids, including the variety of fatty acids they encompass, serve a dynamic role in sustaining cellular structural integrity and functionality. Typically, modifications in lipid composition coincide with consequential alterations in universally significant signaling pathways. Exploring the various fatty acids, which serve as the foundational building blocks of membrane lipids, provides crucial insights into the underlying mechanisms governing a myriad of cellular processes, such as membrane fluidity, protein trafficking, signal transduction, intercellular communication, and the etiology of certain metabolic disorders. Furthermore, comprehending how alterations in the lipid composition, especially concerning the fatty acid profile, either contribute to or prevent the onset of pathological conditions stands as a compelling area of research. Hence, this review aims to meticulously introduce the intricacies of membrane lipids and their constituent fatty acids in a healthy organism, thereby illuminating their remarkable diversity and profound influence on cellular function. Furthermore, this review aspires to highlight some potential therapeutic targets for various pathological conditions that may be ameliorated through dietary fatty acid supplements. The initial section of this review expounds on the eukaryotic biomembranes and their complex lipids. Subsequent sections provide insights into the synthesis, membrane incorporation, and distribution of fatty acids across various fractions of membrane lipids. The last section highlights the functional significance of membrane-associated fatty acids and their innate capacity to shape the various cellular physiological responses.
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Affiliation(s)
- Omeralfaroug Ali
- Agrobiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary;
| | - András Szabó
- Agrobiotechnology and Precision Breeding for Food Security National Laboratory, Institute of Physiology and Animal Nutrition, Department of Animal Physiology and Health, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary;
- HUN-REN-MATE Mycotoxins in the Food Chain Research Group, Hungarian University of Agriculture and Life Sciences, Guba Sándor Str. 40, 7400 Kaposvár, Hungary
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9
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Girych M, Kulig W, Enkavi G, Vattulainen I. How Neuromembrane Lipids Modulate Membrane Proteins: Insights from G-Protein-Coupled Receptors (GPCRs) and Receptor Tyrosine Kinases (RTKs). Cold Spring Harb Perspect Biol 2023; 15:a041419. [PMID: 37487628 PMCID: PMC10547395 DOI: 10.1101/cshperspect.a041419] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Lipids play a diverse and critical role in cellular processes in all tissues. The unique lipid composition of nerve membranes is particularly interesting because it contains, among other things, polyunsaturated lipids, such as docosahexaenoic acid, which the body only gets through the diet. The crucial role of lipids in neurological processes, especially in receptor-mediated cell signaling, is emphasized by the fact that in many neuropathological diseases there are significant deviations in the lipid composition of nerve membranes compared to healthy individuals. The lipid composition of neuromembranes can significantly affect the function of receptors by regulating the physical properties of the membrane or by affecting specific interactions between receptors and lipids. In addition, it is worth noting that the ligand-binding pocket of many receptors is located inside the cell membrane, due to which lipids can even modulate the binding of ligands to their receptors. These mechanisms highlight the importance of lipids in the regulation of membrane receptor activation and function. In this article, we focus on two major protein families: G-protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs) and discuss how lipids affect their function in neuronal membranes, elucidating the basic mechanisms underlying neuronal function and dysfunction.
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Affiliation(s)
- Mykhailo Girych
- Department of Physics, University of Helsinki, FI-00014 Helsinki, Finland
| | - Waldemar Kulig
- Department of Physics, University of Helsinki, FI-00014 Helsinki, Finland
| | - Giray Enkavi
- Department of Physics, University of Helsinki, FI-00014 Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, FI-00014 Helsinki, Finland
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10
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Allender DW, Schick M. On the force between "rafts". THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:85. [PMID: 37736796 DOI: 10.1140/epje/s10189-023-00347-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/08/2023] [Indexed: 09/23/2023]
Abstract
"Rafts" in the plasma membrane are nanoscopic domains rich in sphingolipids and cholesterol. Groups of them are thought to provide stable platforms for various proteins. How several rafts can form a larger stable platform has yet to be made clear. Here, we show that in the microemulsion theory of rafts, in which they, and the sea in which they float, are characterized by a naturally occurring length, rafts separated by a sea larger than this length will attract one another, thus making the sea smaller. Similarly, if rafts are separated by a sea that is smaller than the characteristic size, they will repel one another thus allowing the sea to increase in size. Such an elastic force can clearly stabilize a platform of many rafts.
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Affiliation(s)
- D W Allender
- Department of Physics, University of Washington, Seattle, WA, USA
- Department of Physics, Kent State University, Kent, OH, USA
| | - M Schick
- Department of Physics, University of Washington, Seattle, WA, USA.
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11
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Melero A, Jiménez-Rojo N. Cracking the membrane lipid code. Curr Opin Cell Biol 2023; 83:102203. [PMID: 37437490 DOI: 10.1016/j.ceb.2023.102203] [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: 04/18/2023] [Revised: 06/01/2023] [Accepted: 06/16/2023] [Indexed: 07/14/2023]
Abstract
Why has nature acquired such a huge lipid repertoire? Although it would be theoretically possible to make a lipid bilayer fulfilling barrier functions with only one glycerophospholipid, there are diverse and numerous different lipid species. Lipids are heterogeneously distributed across the evolutionary tree with lipidomes evolving in parallel to organismal complexity. Moreover, lipids are different between organs and tissues and even within the same cell, different organelles have characteristic lipid signatures. At the molecular level, membranes are asymmetric and laterally heterogeneous. This lipid asymmetry at different scales indicates that these molecules may play very specific molecular functions in biology. Some of these roles have been recently uncovered: lipids have been shown to be essential in processes such as hypoxia and ferroptosis or in protein sorting and trafficking but many of them remain still unknown. In this review we will discuss the importance of understanding lipid diversity in biology across scales and we will share a toolbox with some of the emerging technologies that are helping us to uncover new lipid molecular functions in cell biology and, step by step, crack the membrane lipid code.
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Affiliation(s)
- Alejandro Melero
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, 1015 Lausanne, Switzerland
| | - Noemi Jiménez-Rojo
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), 48940, Leioa, Spain; Instituto Biofisika (UPV/EHU, CSIC), 48940, Leioa, Spain; Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain.
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12
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Baum JF, Uzun HD, Pomorski TG. Visualizing Loss of Plasma Membrane Lipid Asymmetry Using Annexin V Staining. Bio Protoc 2023; 13:e4754. [PMID: 37497452 PMCID: PMC10366992 DOI: 10.21769/bioprotoc.4754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/11/2023] [Accepted: 05/23/2023] [Indexed: 07/28/2023] Open
Abstract
Loss of plasma membrane lipid asymmetry contributes to many cellular functions and responses, including apoptosis, blood coagulation, and cell fusion. In this protocol, we describe the use of fluorescently labeled annexin V to detect loss of lipid asymmetry in the plasma membrane of adherent living cells by fluorescence microscopy. The approach provides a simple, sensitive, and reproducible method to detect changes in lipid asymmetry but is limited by low sample throughput. The protocol can also be adapted to other fluorescently labeled lipid-binding proteins or peptide probes. To validate the lipid binding properties of such probes, we additionally describe here the preparation and use of giant unilamellar vesicles as simple model membrane systems that have a size comparable to cells. Key features Monitoring loss of lipid asymmetry in the plasma membrane via confocal microscopy. Protocol can be applied to any type of cell that is adherent in culture, including primary cells. Assay can be adapted to other fluorescently labeled lipid-binding proteins or peptide probes. Giant unilamellar vesicles serve as a tool to validate the lipid binding properties of such probes. Graphical overview Imaging the binding of fluorescent annexin V to adherent mammalian cells and giant vesicles by confocal microscopy. Annexin V labeling is a useful method for detecting a loss of plasma membrane lipid asymmetry in cells (top image, red); DAPI can be used to identify nuclei (top image, blue). Giant vesicles are used as a tool to validate the lipid binding properties of annexin V to anionic lipids (lower image, red).
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Affiliation(s)
- Julia F. Baum
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Huriye D. Uzun
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Thomas Günther Pomorski
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
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13
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Anari M, Montgomery MK. Phospholipid metabolism in the liver - Implications for phosphatidylserine in non-alcoholic fatty liver disease. Biochem Pharmacol 2023; 213:115621. [PMID: 37217141 DOI: 10.1016/j.bcp.2023.115621] [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] [Received: 04/03/2023] [Revised: 05/13/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023]
Abstract
Mammalian cells contain more than a thousand different glycerophospholipid species that are essential membrane components and signalling molecules, with phosphatidylserine (PS) giving membranes their negative surface charge. Depending on the tissue, PS is important in apoptosis, blood clotting, cancer pathogenesis, as well as muscle and brain function, processes that are dependent on the asymmetrical distribution of PS on the plasma membrane and/or the capacity of PS to act as anchorage for various signalling proteins. Recent studies have implicated hepatic PS in the progression of non-alcoholic fatty liver disease (NAFLD), either as beneficial in the context of suppressing hepatic steatosis and fibrosis, or on the other hand as a potential contributor to the progression of liver cancer. This review provides an extensive overview of hepatic phospholipid metabolism, including its biosynthetic pathways, intracellular trafficking and roles in health and disease, further taking a deeper dive into PS metabolism, including associate and causative evidence of the role of PS in advanced liver disease.
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Affiliation(s)
- Marziyeh Anari
- Department of Anatomy and Physiology, School of Biomedical Sciences, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Magdalene K Montgomery
- Department of Anatomy and Physiology, School of Biomedical Sciences, Faculty of Medicine Dentistry and Health Sciences, University of Melbourne, Melbourne, VIC 3010, Australia.
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14
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Frewein MPK, Piller P, Semeraro EF, Czakkel O, Gerelli Y, Porcar L, Pabst G. Distributing aminophospholipids asymmetrically across leaflets causes anomalous membrane stiffening. Biophys J 2023; 122:2445-2455. [PMID: 37120716 PMCID: PMC10322881 DOI: 10.1016/j.bpj.2023.04.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/10/2023] [Accepted: 04/25/2023] [Indexed: 05/01/2023] Open
Abstract
We studied the mechanical leaflet coupling of prototypic mammalian plasma membranes using neutron spin-echo spectroscopy. In particular, we examined a series of asymmetric phospholipid vesicles with phosphatidylcholine and sphingomyelin enriched in the outer leaflet and inner leaflets composed of phosphatidylethanolamine/phosphatidylserine mixtures. The bending rigidities of most asymmetric membranes were anomalously high, exceeding even those of symmetric membranes formed from their cognate leaflets. Only asymmetric vesicles with outer leaflets enriched in sphingolipid displayed bending rigidities in conformity with these symmetric controls. We performed complementary small-angle neutron and x-ray experiments on the same vesicles to examine possible links to structural coupling mechanisms, which would show up in corresponding changes in membrane thickness. In addition, we estimated differential stress between leaflets originating either from a mismatch of their lateral areas or spontaneous curvatures. However, no correlation with asymmetry-induced membrane stiffening was observed. To reconcile our findings, we speculate that an asymmetric distribution of charged or H-bond forming lipids may induce an intraleaflet coupling, which increases the weight of hard undulatory modes of membrane fluctuations and hence the overall membrane stiffness.
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Affiliation(s)
- Moritz P K Frewein
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; Institut Laue-Langevin, Grenoble, France; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria
| | - Paulina Piller
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria
| | - Enrico F Semeraro
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria
| | | | - Yuri Gerelli
- CNR Institute for Complex Systems, Uos Sapienza, Roma, Italy; Department of Physics, Sapienza University of Rome, Roma, Italy
| | | | - Georg Pabst
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria.
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15
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Mann D, Labudda K, Zimmermann S, Vocke KU, Gasper R, Kötting C, Hofmann E. ATP binding and ATP hydrolysis in full-length MsbA monitored via time-resolved Fourier transform infrared spectroscopy. Biol Chem 2023:hsz-2023-0122. [PMID: 37185095 DOI: 10.1515/hsz-2023-0122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 04/07/2023] [Indexed: 05/17/2023]
Abstract
The essential Escherichia coli ATPase MsbA is a lipid flippase that serves as a prototype for multi drug resistant ABC transporters. Its physiological function is the transport of lipopolisaccharides to build up the outer membranes of gram negative bacteria. Although several structural and biochemical studies of MsbA have been conducted previously, a detailed picture of the dynamic processes that link ATP hydrolysis to allocrit transport remains elusive. We report here for the first time time-resolved Fourier transform infrared (FTIR) spectroscopic measurements of the ATP binding and ATP hydrolysis reaction of full-length MsbA and determined reaction rates at 288 K of k 1 = 0.49 ± 0.28 s-1 and k 2 = 0.014 ± 0.003 s-1, respectively. We further verified these rates with photocaged NPEcgAppNHp where only nucleotide binding was observable and the negative mutant MsbA-H537A that showed slow hydrolysis (k 2 < 2 × 10-4 s-1). Besides single turnover kinetics, FTIR measurements also deliver IR signatures of all educts, products and the protein. ADP remains protein-bound after ATP hydrolysis. In addition, the spectral changes observed for the two variants MsbA-S378A and MsbA-S482A correlated with the loss of hydrogen bonding to the γ-phosphate of ATP. This study paves the way for FTIR-spectroscopic investigations of allocrite transport in full-length MsbA.
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Affiliation(s)
- Daniel Mann
- Ruhr University Bochum, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
- Forschungszentrum Jülich GmbH, Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons / ER-C-3: Structural Biology, D-52425 Jülich, Germany
- Forschungszentrum Jülich GmbH, Institute for Biological Information Processing / IBI-6 Cellular Structural Biology, D-52425 Jülich, Germany
| | - Kristin Labudda
- Ruhr University Bochum, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
- Ruhr University Bochum, Protein Crystallography, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
- Ruhr University Bochum, Center for Protein Diagnostics (PRODI), Biospectroscopy, D-44780 Bochum, Germany
| | - Sophie Zimmermann
- Ruhr University Bochum, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
- Ruhr University Bochum, Protein Crystallography, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
| | - Kai Ulrich Vocke
- Ruhr University Bochum, Protein Crystallography, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
| | - Raphael Gasper
- Ruhr University Bochum, Protein Crystallography, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
- Max Planck Institute of Molecular Physiology, Crystallography and Biophysics Facility, D-44227 Dortmund, Germany
| | - Carsten Kötting
- Ruhr University Bochum, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
- Ruhr University Bochum, Center for Protein Diagnostics (PRODI), Biospectroscopy, D-44780 Bochum, Germany
| | - Eckhard Hofmann
- Ruhr University Bochum, Protein Crystallography, Department of Biophysics, Universitätsstraße 150, D-44780 Bochum, Germany
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16
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Yasuda T, Watanabe H, Hirosawa KM, Suzuki KGN, Suga K, Hanashima S. Fluorescence Spectroscopic Analysis of Lateral and Transbilayer Fluidity of Exosome Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14695-14703. [PMID: 36421004 PMCID: PMC9731264 DOI: 10.1021/acs.langmuir.2c02258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 11/10/2022] [Indexed: 06/16/2023]
Abstract
Exosomes are small extracellular vesicles (sEVs) involved in distal cell-cell communication and cancer migration by transferring functional cargo molecules. Membrane domains similar to lipid rafts are assumed to occur in exosome membranes and are involved in interactions with target cells. However, the bilayer membrane properties of these small vesicles have not been fully investigated. Therefore, we examined the fluidity, lateral domain separation, and transbilayer asymmetry of exosome membranes using fluorescence spectroscopy. Although there were some differences between the exosomes, TMA-DPH anisotropy showing moderate lipid chain order indicated that ordered phases comprised a significant proportion of exosome membranes. Selective TEMPO quenching of the TMA-DPH fluorescence in the liquid-disordered phase indicated that 40-50% of the exosome membrane area belonged to the ordered phase based on a phase-separated model. Furthermore, NBD-PC in the outer leaflet showed longer fluorescence lifetimes than those in the inner leaflets. Therefore, the exosome membranes maintained transbilayer asymmetry with a topology similar to that of the plasma membranes. In addition, the lateral and transbilayer orders of exosome membranes obtained from different cell lines varied, probably depending on the different membrane lipid components and compositions partially derived from donor cells. As these higher membrane orders and asymmetric topologies are similar to those of cell membranes with lipid rafts, raft-like functional domains are possibly enriched on exosome membranes. These domains likely play key roles in the biological functions and cellular uptake of exosomes by facilitating selective membrane interactions with target organs.
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Affiliation(s)
- Tomokazu Yasuda
- Graduate
School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka560-0043, Japan
| | - Hirofumi Watanabe
- Graduate
School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka560-0043, Japan
| | - Koichiro M. Hirosawa
- Institute
for Glyco-core Research (iGCORE), Gifu University, 1-1 Yanagido, Gifu501-1193, Japan
| | - Kenichi G. N. Suzuki
- Institute
for Glyco-core Research (iGCORE), Gifu University, 1-1 Yanagido, Gifu501-1193, Japan
| | - Keishi Suga
- Department
of Chemical Engineering, Tohoku University, 6-6-07, Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi980-8579, Japan
| | - Shinya Hanashima
- Graduate
School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka560-0043, Japan
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17
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Hu Y, Zhang RQ, Wang ZG, Liu SL. In Situ Quantification of Lipids in Live Cells by Using Lipid-Binding Domain-Based Biosensors. Bioconjug Chem 2022; 33:2076-2087. [DOI: 10.1021/acs.bioconjchem.2c00469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yusi Hu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Centre for New Organic Matter, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Centre for Analytical Sciences, College of Chemistry and School of Medicine, Nankai University, Tianjin 300071, P. R. China
| | - Rui-Qiao Zhang
- Qingdao Academy of Agricultural Sciences, Qingdao 266100, P. R. China
| | - Zhi-Gang Wang
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Centre for New Organic Matter, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Centre for Analytical Sciences, College of Chemistry and School of Medicine, Nankai University, Tianjin 300071, P. R. China
| | - Shu-Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Centre for New Organic Matter, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Centre for Analytical Sciences, College of Chemistry and School of Medicine, Nankai University, Tianjin 300071, P. R. China
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18
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Foley SL, Hossein A, Deserno M. Fluid-gel coexistence in lipid membranes under differential stress. Biophys J 2022; 121:2997-3009. [PMID: 35859420 PMCID: PMC9463654 DOI: 10.1016/j.bpj.2022.07.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/03/2022] [Accepted: 07/12/2022] [Indexed: 11/21/2022] Open
Abstract
A widely conserved property of many biological lipid bilayers is their asymmetry. In addition to having distinct compositions on its two sides, a membrane can also exhibit different tensions in its two leaflets, a state known as differential stress. Here, we examine how this stress can influence the phase behavior of the constituent lipid monolayers of a single-component membrane. For temperatures sufficiently close to, but still above, the main transition, molecular dynamics simulations show the emergence of finite gel domains within the compressed leaflet. We describe the thermodynamics of this phenomenon by adding two empirical single-leaflet free energies for the fluid-gel transition, each evaluated at its respective asymmetry-dependent lipid density. Finite size effects arising in simulation are included in the theory through a geometry-dependent interfacial term. Our model reproduces the phase coexistence observed in simulation. It could therefore be used to connect the "hidden variable" of differential stress to experimentally observable properties of the main phase transition. These ideas could be generalized to any first-order bilayer phase transition in the presence of asymmetry, including liquid-ordered/liquid-disordered phase separation.
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Affiliation(s)
- Samuel L Foley
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Amirali Hossein
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania; Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania.
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19
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Buyan A, Allender DW, Corry B, Schick M. Lipid redistribution in the highly curved footprint of Piezo1. Biophys J 2022:S0006-3495(22)00595-1. [PMID: 35927961 DOI: 10.1016/j.bpj.2022.07.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 04/06/2022] [Accepted: 07/18/2022] [Indexed: 11/15/2022] Open
Abstract
We investigate the effects on the distribution of lipids in the plasma membrane that are caused by the insertion of a protein, Piezo1, that significantly distorts the membrane toward the cytosol. From coarse-grained molecular dynamics simulations, we find that the major effects occur in the outer, extracellular, leaflet. The mol fraction of cholesterol increases significantly in the curved region of the membrane close to Piezo1, while those of phosphatidylcholine and of sphingomyelin decrease. In the inner leaflet, mol fractions of cholesterol and of phosphatidylethanolamine decrease slightly as the protein is approached, while that of phosphatidylserine increases slightly. The mol fraction of phosphatidylcholine decreases markedly as the protein is approached. Most of these results are understood in the context of a theoretical model that utilizes two elements; (i) a coupling between the leaflets' actual curvatures and their compositionally-dependent spontaneous curvatures and, (ii) the dependence of the spontaneous curvatures not only on the mol fractions of the phospholipids, but also on the effect that cholesterol has on the spontaneous curvatures of the phospholipids.
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Affiliation(s)
- Amanda Buyan
- Research School of Biology, The Australian National University, Acton, Australia
| | - D W Allender
- Department of Physics, University of Washington, Seattle WA; Department of Physics, Kent State University, Kent OH
| | - Ben Corry
- Research School of Biology, The Australian National University, Acton, Australia
| | - M Schick
- Department of Physics, University of Washington, Seattle WA
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20
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Li C, Wang Y, Xing Y, Han J, Zhang Y, Zhang A, Hu J, Hua Y, Bai Y. Regulation of microglia phagocytosis and potential involvement of exercise. Front Cell Neurosci 2022; 16:953534. [PMID: 35959472 PMCID: PMC9357882 DOI: 10.3389/fncel.2022.953534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/29/2022] [Indexed: 12/11/2022] Open
Abstract
Microglia are considered the main phagocytic cells in the central nervous system, remodeling neural circuits by pruning synapses during development. Microglial phagocytosis is also a crucial process in maintaining adult brain homeostasis and clearing potential toxic factors, which are recognized to be associated with neurodegenerative and neuroinflammatory disorders. For example, microglia can engulf amyloid-β plaques, myelin debris, apoptotic cells, and extracellular harmful substances by expressing a variety of specific receptors on the cell surface or by reprogramming intracellular glucose and lipid metabolism processes. Furthermore, physical exercise has been implicated to be one of the non-pharmaceutical treatments for various nervous system diseases, which is closely related to neuroplasticity and microglia functions including proliferation, activation, and phagocytosis. This review focuses on the central regulatory mechanisms related to microglia phagocytosis and the potential role of exercise training in this process.
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Affiliation(s)
- Congqin Li
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yong Wang
- Department of Neurology, Minhang Hospital, Fudan University, Shanghai, China
| | - Ying Xing
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing Han
- State Key Laboratory of Medical Neurobiology, Department of Integrative Medicine and Neurobiology, Brain Science Collaborative Innovation Center, School of Basic Medical Sciences, Institutes of Brain Science, Fudan Institutes of Integrative Medicine, Fudan University, Shanghai, China
| | - Yuqian Zhang
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Anjing Zhang
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jian Hu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yan Hua
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yulong Bai
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Disorders, Huashan Hospital, Fudan University, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Yulong Bai
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21
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Kehlenbeck DM, Traore DAK, Josts I, Sander S, Moulin M, Haertlein M, Prevost S, Forsyth VT, Tidow H. Cryo-EM structure of MsbA in saposin-lipid nanoparticles (Salipro) provides insights into nucleotide coordination. FEBS J 2022; 289:2959-2970. [PMID: 34921499 DOI: 10.1111/febs.16327] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/05/2021] [Accepted: 12/16/2021] [Indexed: 01/28/2023]
Abstract
The ATP-binding cassette transporter MsbA is a lipid flippase, translocating lipid A, glycolipids, and lipopolysaccharides from the inner to the outer leaflet of the inner membrane of Gram-negative bacteria. It has been used as a model system for time-resolved structural studies as several MsbA structures in different states and reconstitution systems (detergent/nanodiscs/peptidiscs) are available. However, due to the limited resolution of the available structures, detailed structural information on the bound nucleotides has remained elusive. Here, we have reconstituted MsbA in saposin A-lipoprotein nanoparticles (Salipro) and determined the structure of ADP-vanadate-bound MsbA by single-particle cryo-electron microscopy to 3.5 Å resolution. This procedure has resulted in significantly improved resolution and enabled us to model all side chains and visualise detailed ADP-vanadate interactions in the nucleotide-binding domains. The approach may be applicable to other dynamic membrane proteins.
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Affiliation(s)
- Dominique-Maurice Kehlenbeck
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR), Germany.,Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Germany.,Life Sciences Group, Institut Laue-Langevin, Grenoble, France.,Partnership for Structural Biology (PSB), Grenoble, France
| | - Daouda A K Traore
- Life Sciences Group, Institut Laue-Langevin, Grenoble, France.,Partnership for Structural Biology (PSB), Grenoble, France.,Faculty of Natural Sciences, Keele University, UK.,Faculté des Sciences et Techniques, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Bamako, Mali
| | - Inokentijs Josts
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR), Germany.,Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Germany
| | - Simon Sander
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR), Germany.,Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Germany
| | - Martine Moulin
- Life Sciences Group, Institut Laue-Langevin, Grenoble, France.,Partnership for Structural Biology (PSB), Grenoble, France
| | - Michael Haertlein
- Life Sciences Group, Institut Laue-Langevin, Grenoble, France.,Partnership for Structural Biology (PSB), Grenoble, France
| | - Sylvain Prevost
- Large Scale Structures Group, Institut Laue-Langevin, Grenoble, France
| | - V Trevor Forsyth
- Life Sciences Group, Institut Laue-Langevin, Grenoble, France.,Partnership for Structural Biology (PSB), Grenoble, France.,Faculty of Natural Sciences, Keele University, UK
| | - Henning Tidow
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR), Germany
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22
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Frewein MPK, Piller P, Semeraro EF, Batchu KC, Heberle FA, Scott HL, Gerelli Y, Porcar L, Pabst G. Interdigitation-Induced Order and Disorder in Asymmetric Membranes. J Membr Biol 2022; 255:407-421. [PMID: 35471665 PMCID: PMC9581838 DOI: 10.1007/s00232-022-00234-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/26/2022] [Indexed: 12/31/2022]
Abstract
We studied the transleaflet coupling of compositionally asymmetric liposomes in the fluid phase. The vesicles were produced by cyclodextrin-mediated lipid exchange and contained dipalmitoyl phosphatidylcholine (DPPC) in the inner leaflet and different mixed-chain phosphatidylcholines (PCs) as well as milk sphingomyelin (MSM) in the outer leaflet. In order to jointly analyze the obtained small-angle neutron and X-ray scattering data, we adapted existing models of trans-bilayer structures to measure the overlap of the hydrocarbon chain termini by exploiting the contrast of the terminal methyl ends in X-ray scattering. In all studied systems, the bilayer-asymmetry has large effects on the lipid packing density. Fully saturated mixed-chain PCs interdigitate into the DPPC-containing leaflet and evoke disorder in one or both leaflets. The long saturated acyl chains of MSM penetrate even deeper into the opposing leaflet, which in turn has an ordering effect on the whole bilayer. These results are qualitatively understood in terms of a balance of entropic repulsion of fluctuating hydrocarbon chain termini and van der Waals forces, which is modulated by the interdigitation depth. Monounsaturated PCs in the outer leaflet also induce disorder in DPPC despite vestigial or even absent interdigitation. Instead, the transleaflet coupling appears to emerge here from a matching of the inner leaflet lipids to the larger lateral lipid area of the outer leaflet lipids.
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Affiliation(s)
- Moritz P K Frewein
- Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010, Graz, Austria.,Institut Laue-Langevin, 38042, Grenoble, France.,BioTechMed Graz, 8010, Graz, Austria.,Field of Excellence BioHealth, 8010, Graz, Austria
| | - Paulina Piller
- Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010, Graz, Austria.,BioTechMed Graz, 8010, Graz, Austria.,Field of Excellence BioHealth, 8010, Graz, Austria
| | - Enrico F Semeraro
- Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010, Graz, Austria.,BioTechMed Graz, 8010, Graz, Austria.,Field of Excellence BioHealth, 8010, Graz, Austria
| | | | | | - Haden L Scott
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN, 37996, USA.,Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Yuri Gerelli
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, 60131, Ancona, Italy
| | | | - Georg Pabst
- Institute of Molecular Biosciences, University of Graz, NAWI Graz, 8010, Graz, Austria. .,BioTechMed Graz, 8010, Graz, Austria. .,Field of Excellence BioHealth, 8010, Graz, Austria.
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23
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Dieudonné T, Herrera SA, Laursen MJ, Lejeune M, Stock C, Slimani K, Jaxel C, Lyons JA, Montigny C, Pomorski TG, Nissen P, Lenoir G. Autoinhibition and regulation by phosphoinositides of ATP8B1, a human lipid flippase associated with intrahepatic cholestatic disorders. eLife 2022; 11:75272. [PMID: 35416773 PMCID: PMC9045818 DOI: 10.7554/elife.75272] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 04/12/2022] [Indexed: 11/24/2022] Open
Abstract
P4-ATPases flip lipids from the exoplasmic to the cytosolic leaflet, thus maintaining lipid asymmetry in eukaryotic cell membranes. Mutations in several human P4-ATPase genes are associated with severe diseases, for example in ATP8B1 causing progressive familial intrahepatic cholestasis, a rare inherited disorder progressing toward liver failure. ATP8B1 forms a binary complex with CDC50A and displays a broad specificity to glycerophospholipids, but regulatory mechanisms are unknown. Here, we report functional studies and the cryo-EM structure of the human lipid flippase ATP8B1-CDC50A at 3.1 Å resolution. We find that ATP8B1 is autoinhibited by its N- and C-terminal tails, which form extensive interactions with the catalytic sites and flexible domain interfaces. Consistently, ATP hydrolysis is unleashed by truncation of the C-terminus, but also requires phosphoinositides, most markedly phosphatidylinositol-3,4,5-phosphate (PI(3,4,5)P3), and removal of both N- and C-termini results in full activation. Restored inhibition of ATP8B1 truncation constructs with a synthetic peptide mimicking the C-terminal segment further suggests molecular communication between N- and C-termini in the autoinhibition and demonstrates that the regulatory mechanism can be interfered with by exogenous compounds. A recurring (G/A)(Y/F)AFS motif of the C-terminal segment suggests that this mechanism is employed widely across P4-ATPase lipid flippases in plasma membrane and endomembranes.
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Affiliation(s)
- Thibaud Dieudonné
- Institute for Integrative Biology of the Cell, Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Sara Abad Herrera
- Department of Molecular Biochemistry, Ruhr University Bochum, Bochum, Germany
| | | | - Maylis Lejeune
- Institute for Integrative Biology of the Cell, Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Charlott Stock
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Kahina Slimani
- Institute for Integrative Biology of the Cell, Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Christine Jaxel
- Institute for Integrative Biology of the Cell, Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Joseph A Lyons
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Cédric Montigny
- Institute for Integrative Biology of the Cell, Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | | | - Poul Nissen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Guillaume Lenoir
- Institute for Integrative Biology of the Cell, Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
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24
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Crowley J, Withana M, Deplazes E. The interaction of steroids with phospholipid bilayers and membranes. Biophys Rev 2022; 14:163-179. [PMID: 35340606 PMCID: PMC8921366 DOI: 10.1007/s12551-021-00918-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 11/18/2021] [Indexed: 12/13/2022] Open
Abstract
Steroids are critical for various physiological processes and used to treat inflammatory conditions. Steroids act by two distinct pathways. The genomic pathway is initiated by the steroid binding to nuclear receptors while the non-genomic pathway involves plasma membrane receptors. It has been proposed that steroids might also act in a more indirect mechanism by altering biophysical properties of membranes. Yet, little is known about the effect of steroids on membranes, and steroid-membrane interactions are complex and challenging to characterise. The focus of this review is to outline what is currently known about the interactions of steroids with phospholipid bilayers and illustrate the complexity of these systems using cortisone and progesterone as the main examples. The combined findings from current work demonstrate that the hydrophobicity and planarity of the steroid core does not provide a consensus for steroid-membrane interactions. Even small differences in the substituents on the steroid core can result in significant changes in steroid-membrane interactions. Furthermore, steroid-induced changes in phospholipid bilayer properties are often dependent on steroid concentration and lipid composition. This complexity means that currently there is insufficient information to establish a reliable structure-activity relationship to describe the effect of steroids on membrane properties. Future work should address the challenge of connecting the findings from studying the effect of steroids on phospholipid bilayers to cell membranes. Insights from steroid-membrane interactions will benefit our understanding of normal physiology and assist drug development.
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Affiliation(s)
- Jackson Crowley
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007 Australia
| | - Minduli Withana
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007 Australia
| | - Evelyne Deplazes
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007 Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD 4072 Australia
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25
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Allender DW, Schick M. A Theoretical Basis for Nanodomains. J Membr Biol 2022; 255:451-460. [PMID: 35084528 DOI: 10.1007/s00232-021-00213-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/22/2021] [Indexed: 01/06/2023]
Abstract
We review the current theories of nanodomain, or "raft," formation. We emphasize that the idea that they are co-exisiting Lo and Ld phases is fraught with difficulties, as is the closely related idea that they are due to critical fluctuations. We then review an alternate theory that the plasma membrane is a two-dimensional microemulsion, and that the mechanism that drives to zero the line tension between Lo and Ld phases is the coupling of height and composition fluctuations. The theory yields rafts of SM and cholesterol in the outer leaf and POPS and POPC in the inner leaf. The "sea" between rafts consists of POPC in the outer leaf and POPE and cholesterol in the inner leaf. The characteristic size of the domain structures is tens of nanometers.
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Affiliation(s)
- D W Allender
- Department of Physics, University of Washington, Seattle, Washington, USA.,Department of Physics, Kent State University, Kent, OH, USA
| | - M Schick
- Department of Physics, University of Washington, Seattle, Washington, USA.
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26
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Barrantes FJ. Fluorescence sensors for imaging membrane lipid domains and cholesterol. CURRENT TOPICS IN MEMBRANES 2021; 88:257-314. [PMID: 34862029 DOI: 10.1016/bs.ctm.2021.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Lipid membrane domains are supramolecular lateral heterogeneities of biological membranes. Of nanoscopic dimensions, they constitute specialized hubs used by the cell as transient signaling platforms for a great variety of biologically important mechanisms. Their property to form and dissolve in the bulk lipid bilayer endow them with the ability to engage in highly dynamic processes, and temporarily recruit subpopulations of membrane proteins in reduced nanometric compartments that can coalesce to form larger mesoscale assemblies. Cholesterol is an essential component of these lipid domains; its unique molecular structure is suitable for interacting intricately with crevices and cavities of transmembrane protein surfaces through its rough β face while "talking" to fatty acid acyl chains of glycerophospholipids and sphingolipids via its smooth α face. Progress in the field of membrane domains has been closely associated with innovative improvements in fluorescence microscopy and new fluorescence sensors. These advances enabled the exploration of the biophysical properties of lipids and their supramolecular platforms. Here I review the rationale behind the use of biosensors over the last few decades and their contributions towards elucidation of the in-plane and transbilayer topography of cholesterol-enriched lipid domains and their molecular constituents. The challenges introduced by super-resolution optical microscopy are discussed, as well as possible scenarios for future developments in the field, including virtual ("no staining") staining.
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Affiliation(s)
- Francisco J Barrantes
- Biomedical Research Institute (BIOMED), Catholic University of Argentina (UCA)-National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.
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27
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Boccaccio A, Picco C, Di Zanni E, Scholz-Starke J. Phospholipid scrambling by a TMEM16 homolog of Arabidopsis thaliana. FEBS J 2021; 289:2578-2592. [PMID: 34775680 PMCID: PMC9299152 DOI: 10.1111/febs.16279] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/15/2021] [Accepted: 11/12/2021] [Indexed: 12/20/2022]
Abstract
Membrane asymmetry is important for cellular physiology and established by energy‐dependent unidirectional lipid translocases, which have diverse physiological functions in plants. By contrast, the role of phospholipid scrambling (PLS), the passive bidirectional lipid transfer leading to the break‐down of membrane asymmetry, is currently still unexplored. The Arabidopsis thaliana genome contains a single gene (At1g73020) with homology to the eukaryotic TMEM16 family of Ca2+‐activated phospholipid scramblases. Here, we investigated the protein function of this Arabidopsis homolog. Fluorescent AtTMEM16 fusions localized to the ER both in transiently expressing Arabidopsis protoplasts and HEK293 cells. A putative scrambling domain (SCRD) was identified on the basis of sequence conservation and conferred PLS to transfected HEK293 cells, when grafted into the backbone of the non‐scrambling plasma membrane‐localized TMEM16A chloride channel. Finally, AtTMEM16 ‘gain‐of‐function’ variants gave rise to cellular phenotypes typical of aberrant scramblase activity, which were reversed by the additional introduction of a ‘loss‐of‐function’ mutation into the SCRD. In conclusion, our data suggest AtTMEM16 works as an ER‐resident lipid scramblase in Arabidopsis.
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Affiliation(s)
- Anna Boccaccio
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Genova, Italy
| | - Cristiana Picco
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Genova, Italy
| | - Eleonora Di Zanni
- Institute of Biophysics, Consiglio Nazionale delle Ricerche, Genova, Italy
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28
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Abe M, Makino A, Murate M, Hullin-Matsuda F, Yanagawa M, Sako Y, Kobayashi T. PMP2/FABP8 induces PI(4,5)P 2-dependent transbilayer reorganization of sphingomyelin in the plasma membrane. Cell Rep 2021; 37:109935. [PMID: 34758297 DOI: 10.1016/j.celrep.2021.109935] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 08/20/2021] [Accepted: 10/13/2021] [Indexed: 12/11/2022] Open
Abstract
Sphingomyelin (SM) is a mammalian lipid mainly distributed in the outer leaflet of the plasma membrane (PM). We show that peripheral myelin protein 2 (PMP2), a member of the fatty-acid-binding protein (FABP) family, can localize at the PM and controls the transbilayer distribution of SM. Genetic screening with genome-wide small hairpin RNA libraries identifies PMP2 as a protein involved in the transbilayer movement of SM. A biochemical assay demonstrates that PMP2 is a phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-binding protein. PMP2 induces the tubulation of model membranes in a PI(4,5)P2-dependent manner, accompanied by the modification of the transbilayer membrane distribution of lipids. In the PM of PMP2-overexpressing cells, inner-leaflet SM is increased whereas outer-leaflet SM is reduced. PMP2 is a causative protein of Charcot-Marie-Tooth disease (CMT). A mutation in PMP2 associated with CMT increases its affinity for PI(4,5)P2, inducing membrane tubulation and the subsequent transbilayer movement of lipids.
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Affiliation(s)
- Mitsuhiro Abe
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
| | - Asami Makino
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Motohide Murate
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
| | - Françoise Hullin-Matsuda
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Université de Lyon, CarMeN Laboratory, INSERM U1060, INRAE U1397, Université Claude Bernard Lyon 1, 69495 Pierre-Benite, France
| | - Masataka Yanagawa
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Toshihide Kobayashi
- Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Cellular Informatics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France.
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29
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Wong HY, Langlotz M, Gan-Schreier H, Xu W, Staffer S, Tuma-Kellner S, Liebisch G, Merle U, Chamulitrat W. Constitutive oxidants from hepatocytes of male iPLA2β-null mice increases the externalization of phosphatidylethanolamine on plasma membrane. Free Radic Res 2021; 55:625-633. [PMID: 34696671 DOI: 10.1080/10715762.2021.1987426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
We have found that group VIA calcium-independent phospholipase A2 (iPLA2β) has specificity for hydrolysis of phosphatidylethanolamine (PE) in mouse livers. Phospholipids (PLs) are transported to plasma membrane and some PLs including PE are externalized to maintain membrane PL asymmetry. Here we demonstrated that hepatocytes of iPLA2β-null (KO) mice showed an increase in PE containing palmitate and oleate. We aimed to examine whether externalization of PE on the outer leaflets could be affected by iPLA2β deficiency and its modulation by reactive oxygen species (ROS) or apoptosis. As duramycin has high affinity to PE, we used duramycin conjugated with biotin (DLB) and streptavidin 488 as a probe for detection of externalized PE. Compared to WT, naïve KO hepatocytes showed an increase in both PE externalization and ROS generation. These events were observed in male but not in female KO mice. Hydrogen peroxide or menadione treatment enhanced PE externalization to the same extent for both male/female WT and KO hepatocytes. By indirect immunofluorescence, DLB-streptavidin staining was observed as small punctuated spots on the cell surface of menadione-treated KO hepatocytes. Unlike the reported PS externalization, CD95/FasL treatment did not lead to any increase in PE externalization, and iPLA2β deficiency-dependent PE externalization was also not correlated with apoptosis. Thus, constitutive (but not induced) ROS generation in iPLA2β-deficient hepatocytes leads to PE externalization observed only in male mice. Such PE externalization may imply detrimental effects regarding further oxidation of PE fatty acids and the binding with pathogens on the outer leaflets of hepatocyte plasma membrane.
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Affiliation(s)
| | - Monika Langlotz
- Center for Molecular Biology, University of Heidelberg, Heidelberg, Germany
| | | | - Weihong Xu
- Heidelberg University Hospital, Heidelberg, Germany
| | | | | | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University Regensburg, Regensburg, Germany
| | - Uta Merle
- Heidelberg University Hospital, Heidelberg, Germany
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30
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Lipid Self-Assemblies under the Atomic Force Microscope. Int J Mol Sci 2021; 22:ijms221810085. [PMID: 34576248 PMCID: PMC8467407 DOI: 10.3390/ijms221810085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/26/2021] [Accepted: 08/27/2021] [Indexed: 12/13/2022] Open
Abstract
Lipid model membranes are important tools in the study of biophysical processes such as lipid self-assembly and lipid–lipid interactions in cell membranes. The use of model systems to adequate and modulate complexity helps in the understanding of many events that occur in cellular membranes, that exhibit a wide variety of components, including lipids of different subfamilies (e.g., phospholipids, sphingolipids, sterols…), in addition to proteins and sugars. The capacity of lipids to segregate by themselves into different phases at the nanoscale (nanodomains) is an intriguing feature that is yet to be fully characterized in vivo due to the proposed transient nature of these domains in living systems. Model lipid membranes, instead, have the advantage of (usually) greater phase stability, together with the possibility of fully controlling the system lipid composition. Atomic force microscopy (AFM) is a powerful tool to detect the presence of meso- and nanodomains in a lipid membrane. It also allows the direct quantification of nanomechanical resistance in each phase present. In this review, we explore the main kinds of lipid assemblies used as model membranes and describe AFM experiments on model membranes. In addition, we discuss how these assemblies have extended our knowledge of membrane biophysics over the last two decades, particularly in issues related to the variability of different model membranes and the impact of supports/cytoskeleton on lipid behavior, such as segregated domain size or bilayer leaflet uncoupling.
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31
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Zhang R, Wu S, Ding Q, Fan Q, Dai Y, Guo S, Ye Y, Li C, Zhou M. Recent advances in cell membrane-camouflaged nanoparticles for inflammation therapy. Drug Deliv 2021; 28:1109-1119. [PMID: 34121563 PMCID: PMC8205088 DOI: 10.1080/10717544.2021.1934188] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
During inflammation, inflammatory cells are rapidly recruited to sites of infection or injury, where they cross physiological barriers around the infected site and further infiltrate into the tissues. Other cells, such as erythrocytes, endothelial cells and stem cells, also play prominent roles in host defense and tissue repair. In recent years, nanotechnology has been exploited to deliver drugs to sites of inflammation. For example, nanoparticles camouflaged with a cell membrane are a novel drug-delivery platform that can interact with the immune system and that show great potential for treating inflammation. Encapsulating drugs inside plasma membranes derived from various cells involved in inflammatory processes can be effective against inflammation. This review describes the preparation, characterization, and properties of various types of cell membrane-camouflaged biomimetic nanoparticles. It also summarizes preclinical research into their efficacy against inflammation.
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Affiliation(s)
- Rongtao Zhang
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China.,School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Siqiong Wu
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China.,School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Qian Ding
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China.,School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Qingze Fan
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yan Dai
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Shiwei Guo
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yun Ye
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Chunhong Li
- Department of Pharmaceutical Sciences, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Meiling Zhou
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, China
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32
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Buwaneka P, Ralko A, Liu SL, Cho W. Evaluation of the available cholesterol concentration in the inner leaflet of the plasma membrane of mammalian cells. J Lipid Res 2021; 62:100084. [PMID: 33964305 PMCID: PMC8178126 DOI: 10.1016/j.jlr.2021.100084] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/21/2021] [Accepted: 04/27/2021] [Indexed: 12/11/2022] Open
Abstract
Cholesterol is an essential component of the mammalian plasma membrane involved in diverse cellular processes. Our recent quantitative imaging analysis using ratiometric cholesterol sensors showed that the available cholesterol concentration in the inner leaflet of the plasma membrane (IPM) is low in unstimulated cells and increased in a stimulus-specific manner to trigger cell signaling events. However, the transbilayer distribution of cholesterol in the plasma membrane of mammalian cells remains controversial. Here we report a systematic and rigorous evaluation of basal IPM cholesterol levels in a wide range of mammalian cells with different properties employing cholesterol sensors derived from the D4 domain of the Perfringolysin O toxin and a sterol-transfer protein, Osh4. Results consistently showed that, although basal IPM cholesterol levels vary significantly among cells, they remain significantly lower than cholesterol levels in the outer leaflets. We found that IPM cholesterol levels were particularly low in all tested primary cells. These results support the universality of the low basal IPM cholesterol concentration under physiological conditions. We also report here the presence of sequestered IPM cholesterol pools, which may become available to cytosolic proteins under certain physiological conditions. We hypothesize that these pools may partly account for the low basal level of available IPM cholesterol. In conclusion, we provide new experimental data that confirm the asymmetric transbilayer distribution of the plasma membrane cholesterol, which may contribute to regulation of various cellular signaling processes at the plasma membrane.
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Affiliation(s)
- Pawanthi Buwaneka
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Arthur Ralko
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Shu-Lin Liu
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Wonhwa Cho
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA.
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33
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Gruenberg J. Life in the lumen: The multivesicular endosome. Traffic 2021; 21:76-93. [PMID: 31854087 PMCID: PMC7004041 DOI: 10.1111/tra.12715] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 12/12/2022]
Abstract
The late endosomes/endo‐lysosomes of vertebrates contain an atypical phospholipid, lysobisphosphatidic acid (LBPA) (also termed bis[monoacylglycero]phosphate [BMP]), which is not detected elsewhere in the cell. LBPA is abundant in the membrane system present in the lumen of this compartment, including intralumenal vesicles (ILVs). In this review, the current knowledge on LBPA and LBPA‐containing membranes will be summarized, and their role in the control of endosomal cholesterol will be outlined. Some speculations will also be made on how this system may be overwhelmed in the cholesterol storage disorder Niemann‐Pick C. Then, the roles of intralumenal membranes in endo‐lysosomal dynamics and functions will be discussed in broader terms. Likewise, the mechanisms that drive the biogenesis of intralumenal membranes, including ESCRTs, will also be discussed, as well as their diverse composition and fate, including degradation in lysosomes and secretion as exosomes. This review will also discuss how intralumenal membranes are hijacked by pathogenic agents during intoxication and infection, and what is the biochemical composition and function of the intra‐endosomal lumenal milieu. Finally, this review will allude to the size limitations imposed on intralumenal vesicle functions and speculate on the possible role of LBPA as calcium chelator in the acidic calcium stores of endo‐lysosomes.
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Affiliation(s)
- Jean Gruenberg
- Biochemistry Department, University of Geneva, Geneva, Switzerland
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34
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The transport mechanism of P4 ATPase lipid flippases. Biochem J 2021; 477:3769-3790. [PMID: 33045059 DOI: 10.1042/bcj20200249] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/02/2020] [Accepted: 09/16/2020] [Indexed: 12/18/2022]
Abstract
P4 ATPase lipid flippases are ATP-driven transporters that translocate specific lipids from the exoplasmic to the cytosolic leaflet of biological membranes, thus establishing a lipid gradient between the two leaflets that is essential for many cellular processes. While substrate specificity, subcellular and tissue-specific expression, and physiological functions have been assigned to a number of these transporters in several organisms, the mechanism of lipid transport has been a topic of intense debate in the field. The recent publication of a series of structural models based on X-ray crystallography and cryo-EM studies has provided the first glimpse into how P4 ATPases have adapted the transport mechanism used by the cation-pumping family members to accommodate a substrate that is at least an order of magnitude larger than cations.
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35
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Elucidation of underlying molecular mechanism of 5-Fluorouracil chemoresistance and its restoration using fish oil in experimental colon carcinoma. Mol Cell Biochem 2021; 476:1517-1527. [PMID: 33392922 DOI: 10.1007/s11010-020-03999-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/20/2020] [Indexed: 02/07/2023]
Abstract
Latest strategies for cancer treatment primarily focus on the use of chemosensitizers to enhance therapeutic outcome. N-3 PUFAs have emerged as the strongest candidate for the prevention of colorectal cancer (CRC). Our previous studies have demonstrated that fish oil (FO) rich in n-3 PUFAs not only increased therapeutic potential of 5-Fluorouracil(5-FU) in colon cancer but also ameliorated its toxicity. Henceforth, the present study is designed to elucidate mechanistic insights of FO as a chemosensitizer to circumvent drug resistance in experimental colon carcinoma. The colon cancer was induced by 1,2-dimethylhydrazine(DMH)/dextran sulfate sodium(DSS) in male Balb/c mice and these animals were treated with 5-FU(12.5 mg/kg b.w.), FO(0.2 ml), or 5-FU + FO(12.5 mg/kg b.w + 0.2 ml) orally for 14 days. The molecular mechanism of overcoming 5-FU resistance using FO in colon cancer was delineated by estimating expression of cancer stem cell markers using flowcytometric method and drug transporters by immunohistochemistry and immunoblotting. Additionally, distribution profile of 5-FU and its cytotoxic metabolite, 5-FdUMP at target(colon), and non-target sites (serum, kidney, liver, spleen) was assessed using high-performance liquid chromatography(HPLC) method. The observations revealed that expression of CSCs markers was remarkably reduced after using fish oil along with 5-FU in carcinogen-treated animals. Interestingly, the use of FO alongwith 5-FU also significantly declined the expression of drug transporters (ABCB1,ABCC5) and consequently resulted in an increased cellular uptake of 5-FU and its metabolite, 5-FdUMP at target site (colon). It could be possibly associated with change in permeability of cell membrane owing to the alteration in membrane fluidity. The present study revealed the mechanistic insights of FO as a MDR revertant which successfully restored 5-FU-mediated chemoresistance in experimental colon carcinoma.
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36
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Madu AJ, Ugwu AO, Efobi C. Hyperhaemolytic Syndrome in Sickle Cell Disease: Clearing the Cobwebs. Med Princ Pract 2021; 30:236-243. [PMID: 33176303 PMCID: PMC8280419 DOI: 10.1159/000512945] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 11/10/2020] [Indexed: 12/23/2022] Open
Abstract
Sickle cell disease (SCD) presents with a dynamic background of haemolysis and deepening anaemia. This increases the demand for transfusion if any additional strain on haemopoiesis is encountered due to any other physiological or pathological causes. Patients with cerebrovascular accidents are placed on chronic blood transfusion; those with acute sequestration and acute chest syndrome are likewise managed with blood transfusion. These patients are prone to develop complications of blood transfusion including alloimmunization and hyperhaemolytic syndrome (HHS). This term is used to describe haemolysis of both transfused and "own" red cells occurring during or post-transfusion in sickle cell patients. Hyperhaemolysis results in worsening post-transfusion haemoglobin due attendant haemolysis of both transfused and autologous red cells. The mechanism underlying this rare and usually fatal complication of SCD has been thought to be secondary to changes in the red cell membrane with associated immunological reactions against exposed cell membrane phospholipids. The predisposition to HHS in sickle cell is also varied and the search for a prediction pattern or value has been evasive. This review discusses the pathogenesis, risk factors and treatment of HHS, elaborating on what is known of this rare condition.
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Affiliation(s)
- Anazoeze Jude Madu
- Department of Haematology and Immunology, University of Nigeria Ituku-Ozalla Campus, Ituku-Ozalla, Nigeria,
| | - Angela Ogechukwu Ugwu
- Department of Haematology and Immunology, University of Nigeria Ituku-Ozalla Campus, Ituku-Ozalla, Nigeria
| | - Chilota Efobi
- Department of Haematology, Nnamdi Azikiwe University, Nnewi, Nigeria
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37
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Foley S, Deserno M. Stabilizing Leaflet Asymmetry under Differential Stress in a Highly Coarse-Grained Lipid Membrane Model. J Chem Theory Comput 2020; 16:7195-7206. [PMID: 33126796 DOI: 10.1021/acs.jctc.0c00862] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a version of the coarse-grained Cooke lipid model, modified to simulate asymmetric lipid membranes. It is inspired by a method employed by Wang et al. [ Commun. Comput. Phys. 2013, 13, 1093-1106] for artificially penalizing lipid flip-flop but copes more robustly with differential stress, at the cost of one additional bead per lipid and the concomitant increase in computational overhead. Bilayer asymmetry ultimately breaks down beyond a system size dependent critical differential stress, which can be predicted from a simple analytical model. We remeasure many important material parameters for the new model and find it to be consistent with typical fluid lipid membranes. Maintaining a stable stress asymmetry has many applications, and we give two examples: (i) connecting monolayer stress to lipid number asymmetry in order to directly measure the monolayer area modulus and (ii) finding its strain-dependent higher-order correction by monitoring the equilibrium bilayer area.
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Affiliation(s)
- Samuel Foley
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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38
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Jones AJY, Gabriel F, Tandale A, Nietlispach D. Structure and Dynamics of GPCRs in Lipid Membranes: Physical Principles and Experimental Approaches. Molecules 2020; 25:E4729. [PMID: 33076366 PMCID: PMC7587580 DOI: 10.3390/molecules25204729] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/11/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
Over the past decade, the vast amount of information generated through structural and biophysical studies of GPCRs has provided unprecedented mechanistic insight into the complex signalling behaviour of these receptors. With this recent information surge, it has also become increasingly apparent that in order to reproduce the various effects that lipids and membranes exert on the biological function for these allosteric receptors, in vitro studies of GPCRs need to be conducted under conditions that adequately approximate the native lipid bilayer environment. In the first part of this review, we assess some of the more general effects that a membrane environment exerts on lipid bilayer-embedded proteins such as GPCRs. This is then followed by the consideration of more specific effects, including stoichiometric interactions with specific lipid subtypes. In the final section, we survey a range of different membrane mimetics that are currently used for in vitro studies, with a focus on NMR applications.
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Affiliation(s)
| | | | | | - Daniel Nietlispach
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK; (A.J.Y.J.); (F.G.); (A.T.)
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39
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Frøsig MM, Costa SR, Liesche J, Østerberg JT, Hanisch S, Nintemann S, Sørensen H, Palmgren M, Pomorski TG, López-Marqués RL. Pseudohyphal growth in Saccharomyces cerevisiae involves protein kinase-regulated lipid flippases. J Cell Sci 2020; 133:jcs235994. [PMID: 32661085 DOI: 10.1242/jcs.235994] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 07/01/2020] [Indexed: 12/15/2022] Open
Abstract
Lipid flippases of the P4 ATPase family establish phospholipid asymmetry in eukaryotic cell membranes and are involved in many essential cellular processes. The yeast Saccharomyces cerevisiae contains five P4 ATPases, among which Dnf3p is poorly characterized. Here, we demonstrate that Dnf3p is a flippase that catalyzes translocation of major glycerophospholipids, including phosphatidylserine, towards the cytosolic membrane leaflet. Deletion of the genes encoding Dnf3p and the distantly related P4 ATPases Dnf1p and Dnf2p results in yeast mutants with aberrant formation of pseudohyphae, suggesting that the Dnf1p-Dnf3p proteins have partly redundant functions in the control of this specialized form of polarized growth. Furthermore, as previously demonstrated for Dnf1 and Dnf2p, the phospholipid flipping activity of Dnf3p is positively regulated by flippase kinase 1 (Fpk1p) and Fpk2p. Phylogenetic analyses demonstrate that Dnf3p belongs to a subfamily of P4 ATPases specific for fungi and are likely to represent a hallmark of fungal evolution.
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Affiliation(s)
- Merethe Mørch Frøsig
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Sara Rute Costa
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Johannes Liesche
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Jeppe Thulin Østerberg
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Susanne Hanisch
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Sebastian Nintemann
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Helle Sørensen
- Data Science Lab, Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark
| | - Michael Palmgren
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
| | - Thomas Günther Pomorski
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
- Department of Molecular Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Rosa L López-Marqués
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK - 1871 Frederiksberg C, Denmark
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40
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Lipid asymmetry of a model mitochondrial outer membrane affects Bax-dependent permeabilization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183241. [DOI: 10.1016/j.bbamem.2020.183241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/16/2020] [Accepted: 02/12/2020] [Indexed: 11/24/2022]
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41
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In Vitro Assays: Friends or Foes of Cell-Penetrating Peptides. Int J Mol Sci 2020; 21:ijms21134719. [PMID: 32630650 PMCID: PMC7369778 DOI: 10.3390/ijms21134719] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/24/2020] [Accepted: 07/01/2020] [Indexed: 12/20/2022] Open
Abstract
The cell membrane is a complex and highly regulated system that is composed of lipid bilayer and proteins. One of the main functions of the cell membrane is the regulation of cell entry. Cell-penetrating peptides (CPPs) are defined as peptides that can cross the plasma membrane and deliver their cargo inside the cell. The uptake of a peptide is determined by its sequence and biophysicochemical properties. At the same time, the uptake mechanism and efficiency are shown to be dependent on local peptide concentration, cell membrane lipid composition, characteristics of the cargo, and experimental methodology, suggesting that a highly efficient CPP in one system might not be as productive in another. To better understand the dependence of CPPs on the experimental system, we present a review of the in vitro assays that have been employed in the literature to evaluate CPPs and CPP-cargos. Our comprehensive review suggests that utilization of orthogonal assays will be more effective for deciphering the true ability of CPPs to translocate through the membrane and enter the cell cytoplasm.
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42
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Kara S, Amon L, Lühr JJ, Nimmerjahn F, Dudziak D, Lux A. Impact of Plasma Membrane Domains on IgG Fc Receptor Function. Front Immunol 2020; 11:1320. [PMID: 32714325 PMCID: PMC7344230 DOI: 10.3389/fimmu.2020.01320] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/26/2020] [Indexed: 12/13/2022] Open
Abstract
Lipid cell membranes not only represent the physical boundaries of cells. They also actively participate in many cellular processes. This contribution is facilitated by highly complex mixtures of different lipids and incorporation of various membrane proteins. One group of membrane-associated receptors are Fc receptors (FcRs). These cell-surface receptors are crucial for the activity of most immune cells as they bind immunoglobulins such as immunoglobulin G (IgG). Based on distinct mechanisms of IgG binding, two classes of Fc receptors are now recognized: the canonical type I FcγRs and select C-type lectin receptors newly referred to as type II FcRs. Upon IgG immune complex induced cross-linking, these receptors are known to induce a multitude of cellular effector responses in a cell-type dependent manner, including internalization, antigen processing, and presentation as well as production of cytokines. The response is also determined by specific intracellular signaling domains, allowing FcRs to either positively or negatively modulate immune cell activity. Expression of cell-type specific combinations and numbers of receptors therefore ultimately sets a threshold for induction of effector responses. Mechanistically, receptor cross-linking and localization to lipid rafts, i.e., organized membrane microdomains enriched in intracellular signaling proteins, were proposed as major determinants of initial FcR activation. Given that immune cell membranes might also vary in their lipid compositions, it is reasonable to speculate, that the cell membrane and especially lipid rafts serve as an additional regulator of FcR activity. In this article, we aim to summarize the current knowledge on the interplay of lipid rafts and IgG binding FcRs with a focus on the plasma membrane composition and receptor localization in immune cells, the proposed mechanisms underlying this localization and consequences for FcR function with respect to their immunoregulatory capacity.
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Affiliation(s)
- Sibel Kara
- Department of Biology, Institute of Genetics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Lukas Amon
- Laboratory of Dendritic Cell Biology, Department of Dermatology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Jennifer J Lühr
- Laboratory of Dendritic Cell Biology, Department of Dermatology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Division of Nano-Optics, Max-Planck Institute for the Science of Light, Erlangen, Germany
| | - Falk Nimmerjahn
- Department of Biology, Institute of Genetics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Medical Immunology Campus Erlangen (MICE), Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Deutsches Zentrum Immuntherapie (DZI), Erlangen, Germany
| | - Diana Dudziak
- Laboratory of Dendritic Cell Biology, Department of Dermatology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Medical Immunology Campus Erlangen (MICE), Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Deutsches Zentrum Immuntherapie (DZI), Erlangen, Germany.,Comprehensive Cancer Center Erlangen-European Metropolitan Area of Nürnberg (CCC ER-EMN), Erlangen, Germany
| | - Anja Lux
- Department of Biology, Institute of Genetics, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.,Medical Immunology Campus Erlangen (MICE), Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
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Radyukhin VA, Baratova LA. Molecular Mechanisms of Raft Organization in Biological Membranes. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162020030164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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44
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Bozelli JC, Yune J, Dang X, Narayana JL, Wang G, Epand RM. Membrane activity of two short Trp-rich amphipathic peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183280. [PMID: 32220553 DOI: 10.1016/j.bbamem.2020.183280] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/09/2020] [Accepted: 03/18/2020] [Indexed: 12/13/2022]
Abstract
Short linear antimicrobial peptides are attractive templates for developing new antibiotics. Here, it is described a study of the interaction between two short Trp-rich peptides, horine and verine-L, and model membranes. Isothermal titration calorimetry studies showed that the affinity of these peptides towards large unilamellar vesicles (LUV) having a lipid composition mimicking the lipid composition of S. aureus membranes is ca. 30-fold higher than that towards E. coli mimetics. The former interaction is driven by enthalpy and entropy, while the latter case is driven by entropy, suggesting differences in the forces that play a role in the binding to the two types of model membranes. Upon membrane binding the peptides acquired different conformations according to circular dichroism (CD) studies; however, in both cases CD studies indicated stacked W-residues. Peptide-induced membrane permeabilization, lipid flip-flop, molecular packing at the membrane-water interface, and lateral lipid segregation were observed in all cases. However, the extent of these peptide-induced changes on membrane properties was always higher in S. aureus than E. coli mimetics. Both peptides seem to act via a similar mechanism of membrane permeabilization of S. aureus membrane mimetics, while their mechanisms seem to differ in the case of E. coli. This may be the result of differences in both the peptides´ structure and the membrane lipid composition between both types of bacteria.
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Affiliation(s)
- José C Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 4K1, Canada
| | - Jenny Yune
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 4K1, Canada
| | - Xiangli Dang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Jayaram Lakshmaiah Narayana
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Guangshun Wang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 4K1, Canada.
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45
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Gupta A, Korte T, Herrmann A, Wohland T. Plasma membrane asymmetry of lipid organization: fluorescence lifetime microscopy and correlation spectroscopy analysis. J Lipid Res 2020; 61:252-266. [PMID: 31857388 PMCID: PMC6997606 DOI: 10.1194/jlr.d119000364] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/03/2019] [Indexed: 02/06/2023] Open
Abstract
A fundamental feature of the eukaryotic cell membrane is the asymmetric arrangement of lipids in its two leaflets. A cell invests significant energy to maintain this asymmetry and uses it to regulate important biological processes, such as apoptosis and vesiculation. The dynamic coupling of the inner or cytoplasmic and outer or exofacial leaflets is a challenging open question in membrane biology. Here, we combined fluorescence lifetime imaging microscopy (FLIM) with imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) to differentiate the dynamics and organization of the two leaflets of live mammalian cells. We characterized the biophysical properties of fluorescent analogs of phosphatidylcholine, sphingomyelin, and phosphatidylserine in the plasma membrane of two mammalian cell lines (CHO-K1 and RBL-2H3). Because of their specific transverse membrane distribution, these probes allowed leaflet-specific investigation of the plasma membrane. We compared the results of the two methods having different temporal and spatial resolution. Fluorescence lifetimes of fluorescent lipid analogs were in ranges characteristic for the liquid ordered phase in the outer leaflet and for the liquid disordered phase in the inner leaflet. The observation of a more fluid inner leaflet was supported by free diffusion in the inner leaflet, with high average diffusion coefficients. The liquid ordered phase in the outer leaflet was accompanied by slower diffusion and diffusion with intermittent transient trapping. Our results show that the combination of FLIM and ITIR-FCS with specific fluorescent lipid analogs is a powerful tool for investigating lateral and transbilayer characteristics of plasma membrane in live cell lines.
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Affiliation(s)
- Anjali Gupta
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences National University of Singapore, Singapore
| | - Thomas Korte
- Institute for Biology/Biophysics, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Herrmann
- Institute for Biology/Biophysics, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences National University of Singapore, Singapore
- Department of Chemistry, National University of Singapore, Singapore
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46
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Allender DW, Giang H, Schick M. Model Plasma Membrane Exhibits a Microemulsion in Both Leaves Providing a Foundation for "Rafts". Biophys J 2020; 118:1019-1031. [PMID: 32023433 DOI: 10.1016/j.bpj.2020.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 12/02/2019] [Accepted: 01/03/2020] [Indexed: 12/22/2022] Open
Abstract
We consider a model lipid plasma membrane, one that describes the outer leaf as consisting of sphingomyelin, phosphatidylcholine, and cholesterol and the inner leaf of phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and cholesterol. Their relative compositions are taken from experiment; the cholesterol freely interchanges between leaves. Fluctuations in local composition are coupled to fluctuations in the local membrane curvature, as in the Leibler-Andelman mechanism. Structure factors of components in both leaves display a peak at nonzero wavevector. This indicates that the disordered fluid membrane is characterized by structure of the corresponding wavelength. The scale is given by membrane properties: its bending modulus and its surface tension, which arises from the membrane's connections to the cytoskeleton. From measurements on the plasma membrane, this scale is on the order of 100 nm. We find that the membrane can be divided into two different kinds of domains that differ not only in their composition but also in their curvature. The first domain in the outer, exoplasmic leaf is rich in cholesterol and sphingomyelin, whereas the inner, cytoplasmic leaf is rich in phosphatidylserine and phosphatidylcholine. The second kind of domain is rich in phosphatidylcholine in the outer leaf and in cholesterol and phosphatidylethanolamine in the inner leaf. The theory provides a tenable basis for the origin of structure in the plasma membrane and an illuminating picture of the organization of lipids therein.
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Affiliation(s)
- David W Allender
- Department of Physics, University of Washington, Seattle, Washington; Department of Physics, Kent State University, Kent, Ohio
| | - Ha Giang
- Department of Physics, University of Washington, Seattle, Washington; Viettel Aerospace Institute, Hanoi, Vietnam
| | - M Schick
- Department of Physics, University of Washington, Seattle, Washington.
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Labyrinthopeptins Exert Broad-Spectrum Antiviral Activity through Lipid-Binding-Mediated Virolysis. J Virol 2020; 94:JVI.01471-19. [PMID: 31666384 DOI: 10.1128/jvi.01471-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/23/2019] [Indexed: 12/31/2022] Open
Abstract
To counteract the serious health threat posed by known and novel viral pathogens, drugs that target a variety of viruses through a common mechanism have attracted recent attention due to their potential in treating (re)emerging infections, for which direct-acting antivirals are not available. We found that labyrinthopeptins A1 and A2, the prototype congeners of carbacyclic lanthipeptides, inhibit the proliferation of diverse enveloped viruses, including dengue virus, Zika virus, West Nile virus, hepatitis C virus, chikungunya virus, Kaposi's sarcoma-associated herpesvirus, cytomegalovirus, and herpes simplex virus, in the low micromolar to nanomolar range. Mechanistic studies on viral particles revealed that labyrinthopeptins induce a virolytic effect through binding to the viral membrane lipid phosphatidylethanolamine (PE). These effects are enhanced by a combined equimolar application of both labyrinthopeptins, and a clear synergism was observed across a concentration range corresponding to 10% to 90% inhibitory concentrations of the compounds. Time-resolved experiments with large unilamellar vesicles (LUVs) reveal that membrane lipid raft compositions (phosphatidylcholine [PC]/PE/cholesterol/sphingomyelin at 17:10:33:40) are particularly sensitive to labyrinthopeptins in comparison to PC/PE (90:10) LUVs, even though the overall PE amount remains constant. Labyrinthopeptins exhibited low cytotoxicity and had favorable pharmacokinetic properties in mice (half-life [t 1/2] = 10.0 h), which designates them promising antiviral compounds acting by an unusual viral lipid targeting mechanism.IMPORTANCE For many viral infections, current treatment options are insufficient. Because the development of each antiviral drug is time-consuming and expensive, the prospect of finding broad-spectrum antivirals that can fight multiple, diverse viruses-well-known viruses as well as (re)emerging species-has gained attention, especially for the treatment of viral coinfections. While most known broad-spectrum agents address processes in the host cell, we found that targeting lipids of the free virus outside the host cell with the natural products labyrinthopeptin A1 and A2 is a viable strategy to inhibit the proliferation of a broad range of viruses from different families, including chikungunya virus, dengue virus, Zika virus, Kaposi's sarcoma-associated herpesvirus, and cytomegalovirus. Labyrinthopeptins bind to viral phosphatidylethanolamine and induce virolysis without exerting cytotoxicity on host cells. This represents a novel and unusual mechanism to tackle medically relevant viral infections.
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48
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Investigation of substrate specificity of sialidases with membrane mimetic glycoconjugates. Glycoconj J 2019; 37:175-185. [PMID: 31802374 DOI: 10.1007/s10719-019-09895-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/20/2019] [Accepted: 11/06/2019] [Indexed: 01/17/2023]
Abstract
Sialidases or neuraminidases play important roles in various physiological and pathological processes by cleaving terminal sialic acids (Sias) (desialylation) from the glycans of both glycoproteins and glycolipids. To understand the biological significance of desialylation by sialidases, it is important to investigate enzyme specificity with native substrate in biological membrane of cells. Herein, we report a membrane-mimicking system with liposome ganglioside conjugates containing different lipids for evaluating substrate specificity of sialidase and the lipid effect on the enzyme activity. Briefly, liposomes of phosphatidylcholine (PC) and cholesterol with ganglioside (GM3 or GM1) along with different percentage of phosphatidylserine (PS) or phosphatidylethanolamine (PE) were prepared and characterized. Their desialylation profiles with Arthrobacter ureafaciens (bacterial) sialidase and H1N1 (influenza viral) sialidase were quantified by HPLC method. A diversity of substrate preference was found for both bacterial and viral sialidase to the liposome ganglioside conjugate platform. The apparent Km and Vmax were dependent on the type of lipid. These results indicate that the intrinsic characteristics of the membrane-like system affect the sialidase specificity and activity. This biomimetic substrate provides a better tool for unravelling the substrate specificity and the biological function of sialidases and for screening of functional sialidase inhibitors as well.
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49
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Siggel M, Bhaskara RM, Hummer G. Phospholipid Scramblases Remodel the Shape of Asymmetric Membranes. J Phys Chem Lett 2019; 10:6351-6354. [PMID: 31566982 DOI: 10.1021/acs.jpclett.9b02531] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The cell membrane and many organellar membranes are asymmetric and highly curved. In experiments, it is challenging to reconstitute and characterize membranes that differ in the lipid composition of their leaflets. Here we use molecular dynamics simulations to study the large-scale membrane shape changes associated with lipid shuttling between asymmetric leaflets. We exploit leaflet asymmetry to create a stable, near-spherical vesicle bud connected to a flat bilayer under periodic boundary conditions. Then we demonstrate how the lipid scramblase nhTMEM16 relaxes the lipid-number asymmetry. By mediating the flipping of lipids, this transmembrane protein dissipates the mechanochemical gradient between the leaflets and drives a large-scale membrane reorganization, converting the vesicle bud into a flat membrane. Our procedure to exploit bilayer asymmetry for simulations of highly curved membranes can be used to study the function of other lipid transporters and membrane-shaping proteins.
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Affiliation(s)
- Marc Siggel
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , Max-von-Laue Str. 3 , 60438 Frankfurt am Main , Germany
| | - Ramachandra M Bhaskara
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , Max-von-Laue Str. 3 , 60438 Frankfurt am Main , Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , Max-von-Laue Str. 3 , 60438 Frankfurt am Main , Germany
- Institute of Biophysics , Goethe University Frankfurt , 60438 Frankfurt am Main , Germany
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50
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Zhang S, Lin X. Lipid Acyl Chain cis Double Bond Position Modulates Membrane Domain Registration/Anti-Registration. J Am Chem Soc 2019; 141:15884-15890. [DOI: 10.1021/jacs.9b06977] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Siya Zhang
- Institute of Nanotechnology for Single Cell Analysis (INSCA), Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China
- State Key Laboratory of Medical Molecular Biology, School of Basic Medicine, Peking Union Medical College and Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Xubo Lin
- Institute of Nanotechnology for Single Cell Analysis (INSCA), Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, China
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
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