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Wei D, Zhan W, Gao Y, Huang L, Gong R, Wang W, Zhang R, Wu Y, Gao S, Kang T. RAB31 marks and controls an ESCRT-independent exosome pathway. Cell Res 2020; 31:157-177. [PMID: 32958903 PMCID: PMC8027411 DOI: 10.1038/s41422-020-00409-1] [Citation(s) in RCA: 221] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 08/17/2020] [Indexed: 12/16/2022] Open
Abstract
Exosomes are generated within the multivesicular endosomes (MVEs) as intraluminal vesicles (ILVs) and secreted during the fusion of MVEs with the cell membrane. The mechanisms of exosome biogenesis remain poorly explored. Here we identify that RAB31 marks and controls an ESCRT-independent exosome pathway. Active RAB31, phosphorylated by epidermal growth factor receptor (EGFR), engages flotillin proteins in lipid raft microdomains to drive EGFR entry into MVEs to form ILVs, which is independent of the ESCRT (endosomal sorting complex required for transport) machinery. Active RAB31 interacts with the SPFH domain and drives ILV formation via the Flotillin domain of flotillin proteins. Meanwhile, RAB31 recruits GTPase-activating protein TBC1D2B to inactivate RAB7, thereby preventing the fusion of MVEs with lysosomes and enabling the secretion of ILVs as exosomes. These findings establish that RAB31 has dual functions in the biogenesis of exosomes: driving ILVs formation and suppressing MVEs degradation, providing an exquisite framework to better understand exosome biogenesis.
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Affiliation(s)
- Denghui Wei
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Weixiang Zhan
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Ying Gao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Liyan Huang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Run Gong
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Wen Wang
- Department of Abdominal Oncology, The Cancer Center of the Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, Guangdong, 519000, China
| | - Ruhua Zhang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Yuanzhong Wu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Song Gao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China
| | - Tiebang Kang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, 510060, China.
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Redondo-Morata L, Losada-Pérez P, Giannotti MI. Lipid bilayers: Phase behavior and nanomechanics. CURRENT TOPICS IN MEMBRANES 2020; 86:1-55. [PMID: 33837691 DOI: 10.1016/bs.ctm.2020.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lipid membranes are involved in many physiological processes like recognition, signaling, fusion or remodeling of the cell membrane or some of its internal compartments. Within the cell, they are the ultimate barrier, while maintaining the fluidity or flexibility required for a myriad of processes, including membrane protein assembly. The physical properties of in vitro model membranes as model cell membranes have been extensively studied with a variety of techniques, from classical thermodynamics to advanced modern microscopies. Here we review the nanomechanics of solid-supported lipid membranes with a focus in their phase behavior. Relevant information obtained by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) as complementary techniques in the nano/mesoscale interface is presented. Membrane morphological and mechanical characterization will be discussed in the framework of its phase behavior, phase transitions and coexistence, in simple and complex models, and upon the presence of cholesterol.
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Affiliation(s)
- Lorena Redondo-Morata
- Center for Infection and Immunity of Lille, INSERM U1019, CNRS UMR 8204, Lille, France
| | - Patricia Losada-Pérez
- Experimental Soft Matter and Thermal Physics (EST) Group, Department of Physics, Université Libre de Bruxelles, Brussels, Belgium
| | - Marina Inés Giannotti
- Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain; Institut de Bioenginyeria de Catalunya (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Departament de Ciència de Materials i Química Física, Universitat de Barcelona, Barcelona, Spain.
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53
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Sengupta P, Lippincott-Schwartz J. Revisiting Membrane Microdomains and Phase Separation: A Viral Perspective. Viruses 2020; 12:v12070745. [PMID: 32664429 PMCID: PMC7412473 DOI: 10.3390/v12070745] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/29/2020] [Accepted: 07/07/2020] [Indexed: 12/11/2022] Open
Abstract
Retroviruses selectively incorporate a specific subset of host cell proteins and lipids into their outer membrane when they bud out from the host plasma membrane. This specialized viral membrane composition is critical for both viral survivability and infectivity. Here, we review recent findings from live cell imaging of single virus assembly demonstrating that proteins and lipids sort into the HIV retroviral membrane by a mechanism of lipid-based phase partitioning. The findings showed that multimerizing HIV Gag at the assembly site creates a liquid-ordered lipid phase enriched in cholesterol and sphingolipids. Proteins with affinity for this specialized lipid environment partition into it, resulting in the selective incorporation of proteins into the nascent viral membrane. Building on this and other work in the field, we propose a model describing how HIV Gag induces phase separation of the viral assembly site through a mechanism involving transbilayer coupling of lipid acyl chains and membrane curvature changes. Similar phase-partitioning pathways in response to multimerizing structural proteins likely help sort proteins into the membranes of other budding structures within cells.
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54
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Mir B, Goettsch C. Extracellular Vesicles as Delivery Vehicles of Specific Cellular Cargo. Cells 2020; 9:cells9071601. [PMID: 32630649 PMCID: PMC7407641 DOI: 10.3390/cells9071601] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023] Open
Abstract
Extracellular vesicles (EVs) mediate cell-to-cell communication via the transfer of biomolecules locally and systemically between organs. It has been elucidated that the specific EV cargo load is fundamental for cellular response upon EV delivery. Therefore, revealing the specific molecular machinery that functionally regulates the precise EV cargo intracellularly is of importance in understanding the role of EVs in physiology and pathophysiology and conveying therapeutic use. The purpose of this review is to summarize recent findings on the general rules, as well as specific modulator motifs governing EV cargo loading. Finally, we address available information on potential therapeutic strategies to alter cargo loading.
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55
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Henning RJ. Cardiovascular Exosomes and MicroRNAs in Cardiovascular Physiology and Pathophysiology. J Cardiovasc Transl Res 2020; 14:195-212. [PMID: 32588374 DOI: 10.1007/s12265-020-10040-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/26/2020] [Indexed: 12/16/2022]
Abstract
Cardiac exosomes mediate cell-to-cell communication, stimulate or inhibit the activities of target cells, and affect myocardial hypertrophy, injury and infarction, ventricular remodeling, angiogenesis, and atherosclerosis. The exosomes that are released in the heart from cardiomyocytes, vascular cells, fibroblasts, and resident stem cells are hypoimmunogenic, are physiologically more stable than cardiac cells, can circulate in the body, and are able to cross the blood-brain barrier. Exosomes utilize three mechanisms for cellular communication: (1) internalization by cells, (2) direct fusion to the cell membrane, and (3) receptor-ligand interactions. Cardiac exosomes transmit proteins, mRNA, and microRNAs to other cells during both physiological and pathological process. Cardiac-specific exosome miRNAs can regulate the expression of sarcomeric genes, ion channel genes, autophagy, anti-apoptotic and anti-fibrotic activity, and angiogenesis. This review discusses the role of exosomes and microRNAs in normal myocardium, myocardial injury and infarction, atherosclerosis, and the importance of circulating microRNAs as biomarkers of cardiac disease. Graphical Abstract.
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Affiliation(s)
- Robert J Henning
- University of South Florida, 13201 Bruce B. Downs Blvd., Tampa, FL, 33612-3805, USA.
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56
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Abstract
Many critical biological events, including biochemical signaling, membrane traffic, and cell motility, originate at membrane surfaces. Each such event requires that members of a specific group of proteins and lipids rapidly assemble together at a specific site on the membrane surface. Understanding the biophysical mechanisms that stabilize these assemblies is critical to decoding and controlling cellular functions. In this article, we review progress toward a quantitative biophysical understanding of the mechanisms that drive membrane heterogeneity and organization. We begin from a physical perspective, reviewing the fundamental principles and key experimental evidence behind each proposed mechanism. We then shift to a biological perspective, presenting key examples of the role of heterogeneity in biology and asking which physical mechanisms may be responsible. We close with an applied perspective, noting that membrane heterogeneity provides a novel therapeutic target that is being exploited by a growing number of studies at the interface of biology, physics, and engineering.
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Affiliation(s)
- Wade F Zeno
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Kasey J Day
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
| | - Vernita D Gordon
- Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
- Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA;
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
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Abstract
Exosomes, extracellular vesicles (EVs) of endosomal origin, emerge as master regulators of cell-to-cell signaling in physiology and disease. Exosomes are highly enriched in tetraspanins (TSPNs) and syndecans (SDCs), the latter occurring mainly in proteolytically cleaved form, as membrane-spanning C-terminal fragments of the proteins. While both protein families are membrane scaffolds appreciated for their role in exosome formation, composition, and activity, we currently ignore whether these work together to control exosome biology. Here we show that TSPN6, a poorly characterized tetraspanin, acts as a negative regulator of exosome release, supporting the lysosomal degradation of SDC4 and syntenin. We demonstrate that TSPN6 tightly associates with SDC4, the SDC4-TSPN6 association dictating the association of TSPN6 with syntenin and the TSPN6-dependent lysosomal degradation of SDC4-syntenin. TSPN6 also inhibits the shedding of the SDC4 ectodomain, mimicking the effects of matrix metalloproteinase inhibitors. Taken together, our data identify TSPN6 as a regulator of the trafficking and processing of SDC4 and highlight an important physical and functional interconnection between these membrane scaffolds for the production of exosomes. These findings clarify our understanding of the molecular determinants governing EV formation and have potentially broad impact for EV-related biomedicine.
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58
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Tiberti ML, Antonny B, Gautier R. The transbilayer distribution of polyunsaturated phospholipids determines their facilitating effect on membrane deformation. SOFT MATTER 2020; 16:1722-1730. [PMID: 31916552 DOI: 10.1039/c9sm02107h] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In the cell, membrane deformation and fission (collectively referred to as 'budding') is driven by specific protein machineries but is also influenced by lipid composition. We previously reported that phospholipids with polyunsaturated acyl chains facilitate membrane budding because they adapt their shape to membrane curvature, thereby decreasing membrane bending rigidity. The facilitating effect of polyunsaturated lipids was observed in experiments and simulations performed on membranes where the two bilayer leaflets had the same lipid composition. However, biological membranes are generally asymmetric. Here, we present coarse-grained molecular dynamics simulations on asymmetric phospholipid bilayers undergoing deformation via a pulling force along the bilayer normal. One leaflet contains monounsaturated C18:0-C18:1-phospholipids, whereas the opposite leaflet contains polyunsaturated C18:0-C22:6-phospholipids. When present in the monolayer orientated towards the pulling force and thereby in the convex face of the forming tube, C18:0-C22:6-phospholipids facilitate membrane tubulation. In contrast, C18:0-C22:6-phospholipids in the concave face of the tube have no effect. Analysis of lipid shape indicates that these contrasting effects arise from the superior ability of polyunsaturated phospholipids to swell in the convex leaflet, whereas mono and polyunsaturated phospholipids behave similarly in the concave leaflet. The leaflet-dependent effect of polyunsaturated phospholipids matches well their asymmetric distribution in biological membranes, notably in synaptic vesicles, which are produced by the fastest budding event in the body.
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Affiliation(s)
- Marion L Tiberti
- Université Côte d'Azur et CNRS, IPMC, 660 route des lucioles, 06560 Valbonne, France.
| | - Bruno Antonny
- Université Côte d'Azur et CNRS, IPMC, 660 route des lucioles, 06560 Valbonne, France.
| | - Romain Gautier
- Université Côte d'Azur et CNRS, IPMC, 660 route des lucioles, 06560 Valbonne, France.
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59
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Jefferies D, Khalid S. To infect or not to infect: molecular determinants of bacterial outer membrane vesicle internalization by host membranes. J Mol Biol 2020; 432:1251-1264. [DOI: 10.1016/j.jmb.2020.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 12/13/2019] [Accepted: 01/06/2020] [Indexed: 02/08/2023]
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60
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Skotland T, Sagini K, Sandvig K, Llorente A. An emerging focus on lipids in extracellular vesicles. Adv Drug Deliv Rev 2020; 159:308-321. [PMID: 32151658 DOI: 10.1016/j.addr.2020.03.002] [Citation(s) in RCA: 272] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/02/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023]
Abstract
Extracellular vesicles contain a lipid bilayer membrane that protects the encapsulated material, such as proteins, nucleic acids, lipids and metabolites, from the extracellular environment. These vesicles are released from cells via different mechanisms. During recent years extracellular vesicles have been studied as possible biomarkers for different diseases, as biological nanoparticles for drug delivery, and in basic studies as a tool to understand the structure of biological membranes and the mechanisms involved in vesicular trafficking. Lipids are essential molecular components of extracellular vesicles, but at the moment our knowledge about the lipid composition and the function of lipids in these vesicles is limited. However, the interest of the research community in these molecules is increasing as their role in extracellular vesicles is starting to be acknowledged. In this review, we will present the status of the field and describe what is needed to bring it forward.
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Affiliation(s)
- Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379 Oslo, Norway
| | - Krizia Sagini
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379 Oslo, Norway
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379 Oslo, Norway; Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Alicia Llorente
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, 0379 Oslo, Norway.
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61
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Pezeshkian W, Ipsen JH. Fluctuations and conformational stability of a membrane patch with curvature inducing inclusions. SOFT MATTER 2019; 15:9974-9981. [PMID: 31754667 DOI: 10.1039/c9sm01762c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Membranes with curvature inducing inclusions display a range of cooperative phenomena, which can be linked to biomembrane function, e.g. membrane tubulation, vesiculation, softening and spontaneous tension. We investigate how these phenomena are related for a fluctuating, framed membrane through analysis of a descretized membrane model by Monte Carlo simulation techniques. The membrane model is based on a dynamically triangulated surface equipped with non-interacting, up-down symmetry breaking inclusions where only terms coupled linearly to mean-curvature are maintained. We show that the lateral configurational entropy plays a key role for the mechanical properties of the semi-flexible membrane, e.g. a pronounced softening at intermediate inclusion coverages of the membrane and generation of membrane tension. Tensionless framed membranes will remain quasi-flat up to some threshold coverage, where a shape instability occurs with formation of pearling or tubular membranes, which below full coverage is associated with segregation of inclusions between the curved and flat membrane geometries. For inclusions with preference for highly curved membranes the instability appears at dilute inclusion coverages and is accompanied by strong configurational fluctuations.
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Affiliation(s)
- Weria Pezeshkian
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.
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62
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Zeno WF, Snead WT, Thatte AS, Stachowiak JC. Structured and intrinsically disordered domains within Amphiphysin1 work together to sense and drive membrane curvature. SOFT MATTER 2019; 15:8706-8717. [PMID: 31621751 PMCID: PMC6934260 DOI: 10.1039/c9sm01495k] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Cellular membranes undergo remodeling during many cellular processes including endocytosis, cytoskeletal protrusion, and organelle biogenesis. During these events, specialized proteins sense and amplify fluctuations in membrane curvature to create stably curved architectures. Amphiphysin1 is a multi-domain protein containing an N-terminal crescent-shaped BAR (Bin/Amphiphysin/Rvs) domain and a C-terminal domain that is largely disordered. When studied in isolation, the BAR domain of Amphiphysin1 senses membrane curvature and generates membrane tubules. However, the disordered domain has been largely overlooked in these studies. Interestingly, our recent work has demonstrated that the disordered domain is capable of substantially amplifying the membrane remodeling ability of the BAR domain. However, the physical mechanisms responsible for these effects are presently unclear. Here we elucidated the functional role of the disordered domain by gradually truncating it, creating a family of mutant proteins, each of which contained the BAR domain and a fraction of the disordered domain. Using quantitative fluorescence and electron microscopy, our results indicate that the disordered domain contributes to membrane remodeling by making it more difficult for the protein to bind to and assemble on flat membrane surfaces. Specifically, we found that the disordered domain began to significantly impact membrane remodeling when its projected area exceeded that of the BAR domain. Once this threshold was crossed, steric interactions with the membrane surface and with neighboring disordered domains gave rise to increased curvature sensing and membrane vesiculation, respectively. These findings provide insight into the synergy between structured and disordered domains, each of which play important biophysical roles in membrane remodeling.
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Affiliation(s)
- Wade F Zeno
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Wilton T Snead
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Ajay S Thatte
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA. and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
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63
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Extracellular Vesicles in Modifying the Effects of Ionizing Radiation. Int J Mol Sci 2019; 20:ijms20225527. [PMID: 31698689 PMCID: PMC6888126 DOI: 10.3390/ijms20225527] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 10/26/2019] [Accepted: 11/04/2019] [Indexed: 12/12/2022] Open
Abstract
Extracellular vesicles (EVs) are membrane-coated nanovesicles actively secreted by almost all cell types. EVs can travel long distances within the body, being finally taken up by the target cells, transferring information from one cell to another, thus influencing their behavior. The cargo of EVs comprises of nucleic acids, lipids, and proteins derived from the cell of origin, thereby it is cell-type specific; moreover, it differs between diseased and normal cells. Several studies have shown that EVs have a role in tumor formation and prognosis. It was also demonstrated that ionizing radiation can alter the cargo of EVs. EVs, in turn can modulate radiation responses and they play a role in radiation-induced bystander effects. Due to their biocompatibility and selective targeting, EVs are suitable nanocarrier candidates of drugs in various diseases, including cancer. Furthermore, the cargo of EVs can be engineered, and in this way they can be designed to carry certain genes or even drugs, similar to synthetic nanoparticles. In this review, we describe the biological characteristics of EVs, focusing on the recent efforts to use EVs as nanocarriers in oncology, the effects of EVs in radiation therapy, highlighting the possibilities to use EVs as nanocarriers to modulate radiation effects in clinical applications.
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Ma C, Chen H, Zhang S, Yan Y, Wu R, Wang Y, Liu Y, Yang L, Liu M. Exosomal and extracellular HMGB1 have opposite effects on SASH1 expression in rat astrocytes and glioma C6 cells. Biochem Biophys Res Commun 2019; 518:325-330. [PMID: 31421824 DOI: 10.1016/j.bbrc.2019.08.057] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 12/11/2022]
Abstract
Exosomes are a type of extracellular vesicles derived from cells and mediators of intercellular communication. Different cell types have their own unique exosomes for exchanging information. We previously found that SASH1, a tumor suppressor, was lowly expressed or absent in glioma tissues and glioma C6 cells, but the structure and function of the corresponding exosomes had been unclear. Hence, we aimed to investigate whether exosomes generated from normal glial cells and glioma cells form different protein patterns and whether those derived from normal glial cells affect SASH1 expression in glioma cells. We collected exosomes from astrocytes and C6 cells and identified their exosomal proteins through mass spectrometry. We also performed gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses, whose results showed that both the total and unique exosomal proteins from each cell type were similar. Moreover, the KEGG analysis revealed different clusters of unique exosomal proteins in glial cells and glioma cells. In the normal glial cells, the top clusters were mainly involved in processes with RNA transcripts and proteins, whereas in glioma cells the clusters were attributed to PI3K-Akt signaling, cell adhesion, and cancer-related pathways. Western blot analysis showed that HMGB1 exists in exosomes derived from cultured astrocytes, although its expression was higher in glioma C6 cells. Furthermore, we found that exosomes extracted from astrocytes could increase SASH1 expression in C6 cells (P = 0.040), whereas those derived from HMGB1-depleted astrocytes could not (P = 0.6133). The expression levels of SASH1 decreased after the addition of extracellular recombinant HMGB1 protein, whereas that of TLR4 increased. Our study is the first to demonstrate that HMGB1 plays different roles depending on its form: as an extracellular protein, HMGB1 decreases SASH1 expression, but as an exosomal protein, HMGB1 increases SASH1 expression. Nevertheless, the mechanism, which partly depends on the TLR4 pathway, behind these opposing effects requires further study. Our novel findings on the structure-dependent roles of the cytokine HMGB1 in promoting or inhibiting cancer provide a fresh insight into the interactions of cancer cells with the microenvironment.
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Affiliation(s)
- Chao Ma
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Han Chen
- Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong, China
| | - Siming Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Yingying Yan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Ronghua Wu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Yongjun Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Liu Yang
- Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong, China.
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
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Liu Y, Bai L, Guo K, Jia Y, Zhang K, Liu Q, Wang P, Wang X. Focused ultrasound-augmented targeting delivery of nanosonosensitizers from homogenous exosomes for enhanced sonodynamic cancer therapy. Theranostics 2019; 9:5261-5281. [PMID: 31410214 PMCID: PMC6691590 DOI: 10.7150/thno.33183] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/14/2019] [Indexed: 01/10/2023] Open
Abstract
Sonodynamic therapy (SDT), wherein focused ultrasound is used to guide the site-specific delivery of nano-sonosensitizers and trigger profound sono-damage, has great potential in cancer theranostics. The development of nanosensitizers with high sono-activatable efficiency and good biosafety is however challenging. Methods: In this study, we designed a functionalized smart nanosonosensitizer (EXO-DVDMS) by loading sinoporphyrin sodium (DVDMS), an excellent porphyrin sensitizer with both potential therapeutic and imaging applications, onto homotypic tumor cell-derived exosomes. Because of the high binding-affinity between DVDMS and proteins, coincubation of DVDMS and exosome would result in DVDMS attached on the surface or loaded in the core of exosomes. The prepared EXO-DVDMS was applied for ultrasound-responsive controlled release and enhanced SDT. Results: Tumor cell-derived exosomes exhibited high stability and specificity towards the homotypic tumors, along with highly controlled ultrasound-responsive drug release, and boosted reactive oxygen species (ROS) generation to augment SDT. Intriguingly, EXO-DVDMS was endocytosed by lysosomes, and the low pH in the latter triggered DVDMS relocation synergistically with the ultrasound, thereby initiating multiple cell death-signaling pathways. Furthermore, the exosomal formulation served as a functionalized nanostructure, and facilitated simultaneous imaging and tumor metastasis inhibition, that were respectively 3-folds and 10-folds higher than that of free form. Conclusions: Taken together, our findings suggest that an extracorporeal ultrasound device can non-invasively enhance homogenous tumor targeting and SDT toxicity of EXO-DVDMS, and the developed endogenous nano-sonosensitizer is a promising nanoplatform for activated cancer theranostics.
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66
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Deng H, Dutta P, Liu J. Entry modes of ellipsoidal nanoparticles on a membrane during clathrin-mediated endocytosis. SOFT MATTER 2019; 15:5128-5137. [PMID: 31190048 PMCID: PMC7570437 DOI: 10.1039/c9sm00751b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The membrane wrapping and internalization of nanoparticles, such as viruses and drug nanocarriers, through clathrin-mediated endocytosis (CME) are vitally important for intracellular transport. During CME, the shape of the particle plays crucial roles in the determination of particle-membrane interactions, but much of the previous work has been focused on spherical particles. In this work, we develop a stochastic model to study the CME of ellipsoidal particles. In our model, the deformation of the membrane and wrapping of the nanoparticles are driven by the accumulation of clathrin lattices, which is stimulated by the ligand-receptor interactions. Using our model, we systematically investigate the effect of particle shape (ellipsoids with different aspect ratios) on the CME. Our results show three entry modes: tip-first, tilted, and laying-down modes, used by ellipsoidal nanoparticles for internalization depending on the aspect ratio. Certain ellipsoids are able to take multiple entry modes for internalization. Interestingly, the prolate ellipsoid with an aspect ratio of 0.42 can be internalized with a significantly reduced number of ligand-receptor bonds. Particles which can be internalized with fewer bonds are excellent candidates for transcellular drug delivery. Moreover, our results demonstrate that internalization of ellipsoids with intermediate aspect ratios is easier than that of particles with low and high aspect ratios. Our model and simulations provide critical mechanistic insights into CME of ellipsoidal particles, and represent a viable platform for optimal design of nanoparticles for targeted drug delivery applications.
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Affiliation(s)
- Hua Deng
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99163, USA.
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67
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Zeno WF, Thatte AS, Wang L, Snead WT, Lafer EM, Stachowiak JC. Molecular Mechanisms of Membrane Curvature Sensing by a Disordered Protein. J Am Chem Soc 2019; 141:10361-10371. [PMID: 31180661 DOI: 10.1021/jacs.9b03927] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The ability of proteins to sense membrane curvature is essential for the initiation and assembly of curved membrane structures. Established mechanisms of curvature sensing rely on proteins with specific structural features. In contrast, it has recently been discovered that intrinsically disordered proteins, which lack a defined three-dimensional fold, can also be potent sensors of membrane curvature. How can an unstructured protein sense the structure of the membrane surface? Many disordered proteins that associate with membranes have two key physical features: a high degree of conformational entropy and a high net negative charge. Binding of such proteins to membrane surfaces results simultaneously in a decrease in conformational entropy and an increase in electrostatic repulsion by anionic lipids. Here we show that each of these effects gives rise to a distinct mechanism of curvature sensing. Specifically, as the curvature of the membrane increases, the steric hindrance between the disordered protein and membrane is reduced, leading to an increase in chain entropy. At the same time, increasing membrane curvature increases the average separation between anionic amino acids and lipids, creating an electrostatic preference for curved membranes. Using quantitative imaging of membrane vesicles, our results demonstrate that long disordered amino acid chains with low net charge sense curvature predominately through the entropic mechanism. In contrast, shorter, more highly charged amino acid chains rely largely on the electrostatic mechanism. These findings provide a roadmap for predicting and testing the curvature sensitivity of the large and diverse set of disordered proteins that function at cellular membranes.
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Affiliation(s)
- Wade F Zeno
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Ajay S Thatte
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Liping Wang
- Department of Biochemistry and Structural Biology , The University of Texas Health Science Center at San Antonio , San Antonio , Texas 78229 , United States
| | - Wilton T Snead
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Eileen M Lafer
- Department of Biochemistry and Structural Biology , The University of Texas Health Science Center at San Antonio , San Antonio , Texas 78229 , United States
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States.,Institute for Cellular and Molecular Biology , The University of Texas at Austin , Austin , Texas 78712 , United States
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68
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Hilgemann DW, Lin MJ, Fine M, Deisl C. On the existence of endocytosis driven by membrane phase separations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183007. [PMID: 31202864 DOI: 10.1016/j.bbamem.2019.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/31/2019] [Accepted: 06/06/2019] [Indexed: 01/15/2023]
Abstract
Large endocytic responses can occur rapidly in diverse cell types without dynamins, clathrin, or actin remodeling. Our experiments suggest that membrane phase separations are crucial with more ordered plasma membrane domains being internalized. Not only do these endocytic processes rely on coalescence of membrane domains, they are promoted by participation of membrane proteins in such domains, one important regulatory influence being palmitoylation. Membrane actin cytoskeleton in general resists membrane phase transitions, and its remodeling may play many roles. Besides membrane 'caging' and 'pinching' roles, typically ascribed to clathrin and dynamins, cytoskeleton remodeling may modify local membrane tension and buckling, as well as the presence and location of actin- and tension-free membrane patches. Endocytosis that depends on membrane phase separations becomes activated in metabolic stress and in response to Ca and PI3 kinase signaling. Internalized membrane traffics normally, and the secretory pathway eventually resupplies membrane to the plasmalemma or directs internalized membrane to other locations, including the extracellular space as exosomes. We describe here that endocytosis driven by membrane phase transitions is regulated by the same signaling mechanisms that regulate macropinocytosis, and it may play diverse roles in cells from nutrient assimilation to membrane recycling, cell migration, and the initiation of quiescent or hibernating cell states. Membrane ordering and phase separations have been shown to promote endocytosis in diverse cell types, including fibroblasts, myocytes, glial cells, and immune cells. We propose that clathrin/dynamin-independent endocytosis represents a continuum of related mechanisms with variable but universal dependence on membrane ordering and actin remodeling. This article is part of a Special Issue entitled: Molecular biophysics of membranes and membrane proteins.
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Affiliation(s)
- Donald W Hilgemann
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA.
| | - Mei-Jung Lin
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
| | - Michael Fine
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
| | - Christine Deisl
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
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69
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Nagano T, Katsurada M, Dokuni R, Hazama D, Kiriu T, Umezawa K, Kobayashi K, Nishimura Y. Crucial Role of Extracellular Vesicles in Bronchial Asthma. Int J Mol Sci 2019; 20:ijms20102589. [PMID: 31137771 PMCID: PMC6566667 DOI: 10.3390/ijms20102589] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 02/06/2023] Open
Abstract
Extracellular vesicles (EVs) are circulating vesicles secreted by various cell types. EVs are classified into three groups according to size, structural components, and generation process of vesicles: exosomes, microvesicles, and apoptotic bodies. Recently, EVs have been considered to be crucial for cell-to-cell communications and homeostasis because they contain intracellular proteins and nucleic acids. Epithelial cells from mice suffering from bronchial asthma (BA) secrete more EVs and suppress inflammation-induced EV production. Moreover, microarray analyses of bronchoalveolar lavage fluid have revealed that several microRNAs are useful novel biomarkers of BA. Mesenchymal stromal cell-derived EVs are possible candidates of novel BA therapy. In this review, we highlight the biologic roles of EVs in BA and review novel EV-targeted therapy to help understanding by clinicians and biologists.
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Affiliation(s)
- Tatsuya Nagano
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Masahiro Katsurada
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Ryota Dokuni
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Daisuke Hazama
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Tatsunori Kiriu
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Kanoko Umezawa
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Kazuyuki Kobayashi
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Yoshihiro Nishimura
- Division of Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
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70
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A lipid-based partitioning mechanism for selective incorporation of proteins into membranes of HIV particles. Nat Cell Biol 2019; 21:452-461. [PMID: 30936472 DOI: 10.1038/s41556-019-0300-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 02/18/2019] [Indexed: 12/14/2022]
Abstract
Particles that bud off from the cell surface, including viruses and microvesicles, typically have a unique membrane protein composition distinct from that of the originating plasma membrane. This selective protein composition enables viruses to evade the immune response and infect other cells. But how membrane proteins sort into budding viruses such as human immunodeficiency virus (HIV) remains unclear. Proteins could passively distribute into HIV-assembly-site membranes producing compositions resembling pre-existing plasma-membrane domains. Here, we demonstrate that proteins instead sort actively into HIV-assembly-site membranes, generating compositions enriched in cholesterol and sphingolipids that undergo continuous remodelling. Proteins are recruited into and removed from the HIV assembly site through lipid-based partitioning, initiated by oligomerization of the HIV structural protein Gag. Changes in membrane curvature at the assembly site further amplify this sorting process. Thus, a lipid-based sorting mechanism, aided by increasing membrane curvature, generates the unique membrane composition of the HIV surface.
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71
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Yushutin V, Quaini A, Majd S, Olshanskii M. A computational study of lateral phase separation in biological membranes. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3181. [PMID: 30694617 DOI: 10.1002/cnm.3181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/25/2018] [Accepted: 12/31/2018] [Indexed: 06/09/2023]
Abstract
Conservative and non-conservative phase-field models are considered for the numerical simulation of lateral phase separation and coarsening in biological membranes. An unfitted finite element method is proposed to allow for a flexible treatment of complex shapes in the absence of an explicit surface parametrization. For a set of biologically relevant shapes and parameter values, the paper compares the dynamic coarsening produced by conservative and non-conservative numerical models, its dependence on certain geometric characteristics and convergence to the final equilibrium.
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Affiliation(s)
| | - Annalisa Quaini
- Department of Mathematics, University of Houston, Houston, Texas
| | - Sheereen Majd
- Biomedical Engineering, University of Houston, Houston, Texas
| | - Maxim Olshanskii
- Department of Mathematics, University of Houston, Houston, Texas
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72
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Lázaro GR, Mukhopadhyay S, Hagan MF. Why Enveloped Viruses Need Cores-The Contribution of a Nucleocapsid Core to Viral Budding. Biophys J 2019; 114:619-630. [PMID: 29414708 DOI: 10.1016/j.bpj.2017.11.3782] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 11/11/2017] [Accepted: 11/27/2017] [Indexed: 11/17/2022] Open
Abstract
During the lifecycle of many enveloped viruses, a nucleocapsid core buds through the cell membrane to acquire an outer envelope of lipid membrane and viral glycoproteins. However, the presence of a nucleocapsid core is not required for assembly of infectious particles. To determine the role of the nucleocapsid core, we develop a coarse-grained computational model with which we investigate budding dynamics as a function of glycoprotein and nucleocapsid interactions, as well as budding in the absence of a nucleocapsid. We find that there is a transition between glycoprotein-directed budding and nucleocapsid-directed budding that occurs above a threshold strength of nucleocapsid interactions. The simulations predict that glycoprotein-directed budding leads to significantly increased size polydispersity and particle polymorphism. This polydispersity can be explained by a theoretical model accounting for the competition between bending energy of the membrane and the glycoprotein shell. The simulations also show that the geometry of a budding particle leads to a barrier to subunit diffusion, which can result in a stalled, partially budded state. We present a phase diagram for this and other morphologies of budded particles. Comparison of these structures against experiments could establish bounds on whether budding is directed by glycoprotein or nucleocapsid interactions. Although our model is motivated by alphaviruses, we discuss implications of our results for other enveloped viruses.
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Affiliation(s)
- Guillermo R Lázaro
- Martin Fisher School of Physics, Brandeis University, Waltham, Massachusetts
| | | | - Michael F Hagan
- Martin Fisher School of Physics, Brandeis University, Waltham, Massachusetts.
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73
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Banales JM, Feldstein AE, Sänger H, Lukacs-Kornek V, Szabo G, Kornek M. Extracellular Vesicles in Liver Diseases: Meeting Report from the International Liver Congress 2018. Hepatol Commun 2019; 3:305-315. [PMID: 30766966 PMCID: PMC6357829 DOI: 10.1002/hep4.1300] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 11/12/2018] [Indexed: 02/06/2023] Open
Abstract
Extracellular vesicles (EVs) are small and heterogeneous membrane‐bound structures released by cells and found in all biological fluids. They are effective intercellular communicators, acting on a number of close and/or distant target cells. EV cargo may reflect the cell of origin as well as the specific stress that induces their formation and release. They transport a variety of bioactive molecules, including messenger RNA, noncoding RNAs, proteins, lipids, and metabolites, that can be transferred among cells, regulating various cell responses. Alteration in the concentration and composition of EVs in biological fluids is a typical hallmark of pathologies in different liver diseases. Circulating EVs can serve as biomarkers or as messengers following uptake by other cells. This review is a meeting report from the International Liver Congress 2018 (European Association for the Study of the Liver) celebrated in Paris (Symposium: Extracellular vesicles and signal transmission) that discusses the role of EVs in several liver diseases, highlighting their potential value as disease biomarkers and therapeutic opportunities.
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Affiliation(s)
- Jesus M Banales
- Department of Liver and Gastrointestinal Diseases, Biodonostia Health Research Institute, Donostia University Hospital University of the Basque Country, CIBERehd, Ikerbasque San Sebastian Spain
| | - Ariel E Feldstein
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition University of California San Diego San Diego CA
| | - Hanna Sänger
- Department of Medicine II, Saarland University Medical Center Saarland University Homburg Germany
| | - Veronika Lukacs-Kornek
- Institute of Experimental Immunology University Hospital of the Rheinische Friedrich-Wilhelms-University Bonn Germany
| | - Gyongyi Szabo
- Department of Medicine University of Massachusetts Medical School Worcester MA
| | - Miroslaw Kornek
- Department of Oncology, Hematology and Rheumatology University Hospital Bonn Bonn Germany.,Department of General, Visceral, and Thoracic Surgery German Armed Forces Central Hospital Koblenz Germany
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74
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Abstract
Extracellular vesicles (EVs), and exosomes in particular, were initially considered as "garbage bags" for secretion of undesired cellular components. This view has changed considerably over the last two decades, and exosomes have now emerged as important organelles controlling cell-to-cell signaling. They are present in biological fluids and have important roles in the communication between cells in physiological and pathological processes. They are envisioned for clinical use as carriers of biomarkers, therapeutic targets, and vehicles for drug delivery. Important efforts are being made to characterize the contents of these vesicles and to understand the mechanisms that govern their biogenesis and modes of action. This chapter aims to recapitulate the place given to lipids in our understanding of exosome biology. Besides their structural role and their function as carriers, certain lipids and lipid-modifying enzymes seem to exert privileged functions in this mode of cellular communication. By extension, the use of selective "lipid inhibitors" might turn out to be interesting modulators of exosomal-based cell signaling.
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Affiliation(s)
- Antonio Luis Egea-Jimenez
- Centre de Recherche en Cancérologie de Marseille, Equipe labellisée Ligue 2018, Aix-Marseille Université, Inserm, CNRS, Institut Paoli Calmettes, Marseille, France.,Department of Human Genetics, K. U. Leuven, Leuven, Belgium
| | - Pascale Zimmermann
- Centre de Recherche en Cancérologie de Marseille, Equipe labellisée Ligue 2018, Aix-Marseille Université, Inserm, CNRS, Institut Paoli Calmettes, Marseille, France. .,Department of Human Genetics, K. U. Leuven, Leuven, Belgium.
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75
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Snead WT, Zeno WF, Kago G, Perkins RW, Richter JB, Zhao C, Lafer EM, Stachowiak JC. BAR scaffolds drive membrane fission by crowding disordered domains. J Cell Biol 2018; 218:664-682. [PMID: 30504247 PMCID: PMC6363457 DOI: 10.1083/jcb.201807119] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/12/2018] [Accepted: 11/08/2018] [Indexed: 01/01/2023] Open
Abstract
Cylindrical protein scaffolds are thought to stabilize membrane tubules, preventing membrane fission. In contrast, Snead et al. find that when scaffold proteins assemble, bulky disordered domains within them become acutely concentrated, generating steric pressure that destabilizes tubules, driving fission. Cellular membranes are continuously remodeled. The crescent-shaped bin-amphiphysin-rvs (BAR) domains remodel membranes in multiple cellular pathways. Based on studies of isolated BAR domains in vitro, the current paradigm is that BAR domain–containing proteins polymerize into cylindrical scaffolds that stabilize lipid tubules. But in nature, proteins that contain BAR domains often also contain large intrinsically disordered regions. Using in vitro and live cell assays, here we show that full-length BAR domain–containing proteins, rather than stabilizing membrane tubules, are instead surprisingly potent drivers of membrane fission. Specifically, when BAR scaffolds assemble at membrane surfaces, their bulky disordered domains become crowded, generating steric pressure that destabilizes lipid tubules. More broadly, we observe this behavior with BAR domains that have a range of curvatures. These data suggest that the ability to concentrate disordered domains is a key driver of membrane remodeling and fission by BAR domain–containing proteins.
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Affiliation(s)
- Wilton T Snead
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - Wade F Zeno
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - Grace Kago
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX.,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX
| | - Ryan W Perkins
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - J Blair Richter
- Department of Biochemistry and Structural Biology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Chi Zhao
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - Eileen M Lafer
- Department of Biochemistry and Structural Biology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX .,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX
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76
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Bieberich E. Sphingolipids and lipid rafts: Novel concepts and methods of analysis. Chem Phys Lipids 2018; 216:114-131. [PMID: 30194926 PMCID: PMC6196108 DOI: 10.1016/j.chemphyslip.2018.08.003] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/20/2018] [Accepted: 08/25/2018] [Indexed: 12/12/2022]
Abstract
About twenty years ago, the functional lipid raft model of the plasma membrane was published. It took into account decades of research showing that cellular membranes are not just homogenous mixtures of lipids and proteins. Lateral anisotropy leads to assembly of membrane domains with specific lipid and protein composition regulating vesicular traffic, cell polarity, and cell signaling pathways in a plethora of biological processes. However, what appeared to be a clearly defined entity of clustered raft lipids and proteins became increasingly fluid over the years, and many of the fundamental questions about biogenesis and structure of lipid rafts remained unanswered. Experimental obstacles in visualizing lipids and their interactions hampered progress in understanding just how big rafts are, where and when they are formed, and with which proteins raft lipids interact. In recent years, we have begun to answer some of these questions and sphingolipids may take center stage in re-defining the meaning and functional significance of lipid rafts. In addition to the archetypical cholesterol-sphingomyelin raft with liquid ordered (Lo) phase and the liquid-disordered (Ld) non-raft regions of cellular membranes, a third type of microdomains termed ceramide-rich platforms (CRPs) with gel-like structure has been identified. CRPs are "ceramide rafts" that may offer some fresh view on the membrane mesostructure and answer several critical questions for our understanding of lipid rafts.
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Affiliation(s)
- Erhard Bieberich
- Department of Physiology at the University of Kentucky, Lexington, KY, United States.
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77
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Synergy between intrinsically disordered domains and structured proteins amplifies membrane curvature sensing. Nat Commun 2018; 9:4152. [PMID: 30297718 PMCID: PMC6175956 DOI: 10.1038/s41467-018-06532-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022] Open
Abstract
The ability of proteins to sense membrane curvature is essential to cellular function. All known sensing mechanisms rely on protein domains with specific structural features such as wedge-like amphipathic helices and crescent-shaped BAR domains. Yet many proteins that contain these domains also contain large intrinsically disordered regions. Here we report that disordered domains are themselves potent sensors of membrane curvature. Comparison of Monte Carlo simulations with in vitro and live-cell measurements demonstrates that the polymer-like behavior of disordered domains found in endocytic proteins drives them to partition preferentially to convex membrane surfaces, which place fewer geometric constraints on their conformational entropy. Further, proteins containing both structured curvature sensors and disordered regions are more than twice as curvature sensitive as their respective structured domains alone. These findings demonstrate an entropic mechanism of curvature sensing that is independent of protein structure and illustrate how structured and disordered domains can synergistically enhance curvature sensitivity. Many proteins which sense membrane curvature contain intrinsically disordered domains. Here the authors use Monte Carlo simulations combined with experimental approaches and report that disordered domains are potent sensors of membrane curvature.
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78
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Snead WT, Stachowiak JC. A Tethered Vesicle Assay for High-Throughput Quantification of Membrane Fission. Methods Enzymol 2018; 611:559-582. [PMID: 30471700 PMCID: PMC6279246 DOI: 10.1016/bs.mie.2018.08.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Membrane fission, which divides membrane surfaces into separate compartments, is essential to diverse cellular processes including membrane trafficking and cell division. Quantitative assays are needed to elucidate the physical mechanisms by which proteins drive membrane fission. Toward this goal, several experimental tools have been developed, including visualizing fission products using electron microscopy, measuring membrane shedding from a lipid reservoir, and observing fission of individual membrane tubes pulled from giant vesicles. However, no existing assay of membrane fission provides a quantitative, high-throughput measure of the distribution of vesicle curvatures generated by fission-driving proteins. Toward addressing this challenge, here we describe a novel approach that uses confocal fluorescence imaging to quantify the diameter distribution of membrane vesicles that have been tethered to a coverslip surface following exposure to fission-driving proteins. We employ this assay to measure the progressive appearance of high curvature fission products upon exposure of vesicles to increasing protein concentration. Results from this approach are in quantitative agreement with measurements from electron microscopy, but can be collected with considerably greater throughput, enabling examination of a broad range of experimental conditions. Using the tethered vesicle approach, we have recently found that membrane-bound intrinsically disordered proteins are surprisingly potent drivers of membrane fission. The capacity to drive fission arises from steric pressure generated when disordered domains with large hydrodynamic radii bind to membranes at high local densities. More broadly, the experimental tools described here have the potential to improve our mechanistic understanding of membrane fission in diverse biophysical contexts.
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Affiliation(s)
- Wilton T Snead
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States; Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States.
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79
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Šebera J, Dubankova A, Sychrovský V, Ruzek D, Boura E, Nencka R. The structural model of Zika virus RNA-dependent RNA polymerase in complex with RNA for rational design of novel nucleotide inhibitors. Sci Rep 2018; 8:11132. [PMID: 30042483 PMCID: PMC6057956 DOI: 10.1038/s41598-018-29459-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/09/2018] [Indexed: 12/30/2022] Open
Abstract
Zika virus is a global health threat due to significantly elevated risk of fetus malformations in infected pregnant women. Currently, neither an effective therapy nor a prophylactic vaccination is available for clinical use, desperately necessitating novel therapeutics and approaches to obtain them. Here, we present a structural model of the Zika virus RNA-dependent RNA polymerase (ZIKV RdRp) in complex with template and nascent RNAs, Mg2+ ions and accessing nucleoside triphosphate. The model allowed for docking studies aimed at effective pre-screening of potential inhibitors of ZIKV RdRp. Applicability of the structural model for docking studies was illustrated with the NITD008 artificial nucleotide that is known to effectively inhibit the function of the ZIKV RdRp. The ZIKV RdRp – RNA structural model is provided for all possible variations of the nascent RNA bases pairs to enhance its general utility in docking and modelling experiments. The developed model makes the rational design of novel nucleosides and nucleotide analogues feasible and thus provides a solid platform for the development of advanced antiviral therapy.
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Affiliation(s)
- Jakub Šebera
- Gilead Sciences Research Centre at IOCB Prague, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Praha, Czech Republic
| | - Anna Dubankova
- Gilead Sciences Research Centre at IOCB Prague, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Praha, Czech Republic
| | - Vladimír Sychrovský
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Praha, Czech Republic
| | - Daniel Ruzek
- Veterinary Research Institute, Hudcova 70, CZ-62100, Brno, Czech Republic.,Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, CZ-37005, Ceske Budejovice, Czech Republic
| | - Evzen Boura
- Gilead Sciences Research Centre at IOCB Prague, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Praha, Czech Republic.
| | - Radim Nencka
- Gilead Sciences Research Centre at IOCB Prague, Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Praha, Czech Republic.
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80
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Stochastic simulations of nanoparticle internalization through transferrin receptor dependent clathrin-mediated endocytosis. Biochim Biophys Acta Gen Subj 2018; 1862:2104-2111. [PMID: 29959983 DOI: 10.1016/j.bbagen.2018.06.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/14/2018] [Accepted: 06/26/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND Receptor dependent clathrin-mediated endocytosis (CME) is one of the most important endocytic pathways for the internalization of bioparticles into cells. During CME, the ligand-receptor interactions, development of clathrin-coated pit (CCP) and membrane evolution all act together to drive the internalization of bioparticles. In this work, we develop a stochastic computational model to investigate the CME based on the Metropolis Monte Carlo simulations. METHODS The model is based on the combination of a stochastic particle binding model with a membrane model. The energetic costs of membrane bending, CCP formation and ligand-receptor interactions are systematically linked together. RESULTS We implement our model to investigate the effects of particle size, ligand density and membrane stiffness on the overall process of CME from the drug delivery perspectives. Consistent with some experiments, our results show that the intermediate particle size and ligand density favor the particle internalization. Moreover, our results show that it is easier for a particle to enter a cell with softer membrane. CONCLUSIONS The model presented here is able to provide mechanistic insights into CME and can be readily modified to include other important factors, such as actins. The predictions from the model will aid in the therapeutic design of intracellular/transcellular drug delivery and antiviral interventions.
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81
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Egea-Jimenez AL, Zimmermann P. Phospholipase D and phosphatidic acid in the biogenesis and cargo loading of extracellular vesicles. J Lipid Res 2018; 59:1554-1560. [PMID: 29853529 DOI: 10.1194/jlr.r083964] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 05/09/2018] [Indexed: 12/30/2022] Open
Abstract
Extracellular vesicles released by viable cells (exosomes and microvesicles) have emerged as important organelles supporting cell-cell communication. Because of their potential therapeutic significance, important efforts are being made toward characterizing the contents of these vesicles and the mechanisms that govern their biogenesis. It has been recently demonstrated that the lipid modifying enzyme, phospholipase D (PLD)2, is involved in exosome production and acts downstream of the small GTPase, ARF6. This review aims to recapitulate our current knowledge of the role of PLD2 and its product, phosphatidic acid, in the biogenesis of exosomes and to propose hypotheses for further investigation of a possible central role of these molecules in the biology of these organelles.
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Affiliation(s)
- Antonio Luis Egea-Jimenez
- Centre de Recherche en Cancérologie de Marseille (CRCM), Equipe labellisée LIGUE 2018, Aix-Marseille Université, Marseille F-13284, France and Inserm U1068, Institut Paoli-Calmettes, and CNRS UMR7258, Marseille F-13009, France
| | - Pascale Zimmermann
- Centre de Recherche en Cancérologie de Marseille (CRCM), Equipe labellisée LIGUE 2018, Aix-Marseille Université, Marseille F-13284, France and Inserm U1068, Institut Paoli-Calmettes, and CNRS UMR7258, Marseille F-13009, France; Department of Human Genetics, University of Leuven, B-3000 Leuven, Belgium.
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82
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Florin L, Lang T. Tetraspanin Assemblies in Virus Infection. Front Immunol 2018; 9:1140. [PMID: 29887866 PMCID: PMC5981178 DOI: 10.3389/fimmu.2018.01140] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/07/2018] [Indexed: 12/23/2022] Open
Abstract
Tetraspanins (Tspans) are a family of four-span transmembrane proteins, known as plasma membrane “master organizers.” They form Tspan-enriched microdomains (TEMs or TERMs) through lateral association with one another and other membrane proteins. If multiple microdomains associate with each other, larger platforms can form. For infection, viruses interact with multiple cell surface components, including receptors, activating proteases, and signaling molecules. It appears that Tspans, such as CD151, CD82, CD81, CD63, CD9, Tspan9, and Tspan7, coordinate these associations by concentrating the interacting partners into Tspan platforms. In addition to mediating viral attachment and entry, these platforms may also be involved in intracellular trafficking of internalized viruses and assist in defining virus assembly and exit sites. In conclusion, Tspans play a role in viral infection at different stages of the virus replication cycle. The present review highlights recently published data on this topic, with a focus on events at the plasma membrane. In light of these findings, we propose a model for how Tspan interactions may organize cofactors for viral infection into distinct molecular platforms.
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Affiliation(s)
- Luise Florin
- Department of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Thorsten Lang
- Department of Membrane Biochemistry, Life & Medical Sciences Institute, University of Bonn, Bonn, Germany
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83
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Snead WT, Stachowiak JC. Structure Versus Stochasticity-The Role of Molecular Crowding and Intrinsic Disorder in Membrane Fission. J Mol Biol 2018; 430:2293-2308. [PMID: 29627460 DOI: 10.1016/j.jmb.2018.03.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/22/2018] [Accepted: 03/26/2018] [Indexed: 01/07/2023]
Abstract
Cellular membranes must undergo remodeling to facilitate critical functions including membrane trafficking, organelle biogenesis, and cell division. An essential step in membrane remodeling is membrane fission, in which an initially continuous membrane surface is divided into multiple, separate compartments. The established view has been that membrane fission requires proteins with conserved structural features such as helical scaffolds, hydrophobic insertions, and polymerized assemblies. In this review, we discuss these structure-based fission mechanisms and highlight recent findings from several groups that support an alternative, structure-independent mechanism of membrane fission. This mechanism relies on lateral collisions among crowded, membrane-bound proteins to generate sufficient steric pressure to drive membrane vesiculation. As a stochastic process, this mechanism contrasts with the paradigm that deterministic protein structures are required to drive fission, raising the prospect that many more proteins may participate in fission than previously thought. Paradoxically, our recent work suggests that intrinsically disordered domains may be among the most potent drivers of membrane fission, owing to their large hydrodynamic radii and substantial chain entropy. This stochastic view of fission also suggests new roles for the structure-based fission proteins. Specifically, we hypothesize that in addition to driving fission directly, the canonical fission machines may facilitate the enrichment and organization of bulky disordered protein domains in order to promote membrane fission by locally amplifying protein crowding.
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Affiliation(s)
- Wilton T Snead
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.
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84
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Abstract
Besides direct protein-protein interactions, indirect interactions mediated by membranes play an important role for the assembly and cooperative function of proteins in membrane shaping and adhesion. The intricate shapes of biological membranes are generated by proteins that locally induce membrane curvature. Indirect curvature-mediated interactions between these proteins arise because the proteins jointly affect the bending energy of the membranes. These curvature-mediated interactions are attractive for crescent-shaped proteins and are a driving force in the assembly of the proteins during membrane tubulation. Membrane adhesion results from the binding of receptor and ligand proteins that are anchored in the apposing membranes. The binding of these proteins strongly depends on nanoscale shape fluctuations of the membranes, leading to a fluctuation-mediated binding cooperativity. A length mismatch between receptor-ligand complexes in membrane adhesion zones causes repulsive curvature-mediated interactions that are a driving force for the length-based segregation of proteins during membrane adhesion.
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Affiliation(s)
- Thomas R Weikl
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany;
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85
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Bahrami AH, Weikl TR. Curvature-Mediated Assembly of Janus Nanoparticles on Membrane Vesicles. NANO LETTERS 2018; 18:1259-1263. [PMID: 29281291 DOI: 10.1021/acs.nanolett.7b04855] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Besides direct particle-particle interactions, nanoparticles adsorbed to biomembranes experience indirect interactions that are mediated by the membrane curvature arising from particle adsorption. In this Letter, we show that the curvature-mediated interactions of adsorbed Janus particles depend on the initial curvature of the membrane prior to adsorption, that is, on whether the membrane initially bulges toward or away from the particles in our simulations. The curvature-mediated interaction can be strongly attractive for Janus particles adsorbed to the outside of a membrane vesicle, which initially bulges away from the particles. For Janus particles adsorbed to the vesicle inside, in contrast, the curvature-mediated interactions are repulsive. We find that the area fraction of the adhesive Janus particle surface is an important control parameter for the curvature-mediated interaction and assembly of the particles, besides the initial membrane curvature.
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Affiliation(s)
- Amir Houshang Bahrami
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics , Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany
| | - Thomas R Weikl
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces , Science Park Golm, 14424 Potsdam, Germany
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86
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Li B, Abel SM. Shaping membrane vesicles by adsorption of a semiflexible polymer. SOFT MATTER 2018; 14:185-193. [PMID: 29143046 DOI: 10.1039/c7sm01751k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The adsorption of polymers onto fluid membranes is a problem of fundamental interest in biology and soft materials, in part because the flexibility of membranes can lead to nontrivial coupling between polymer and membrane configurations. Here, we use Monte Carlo computer simulations to study the adsorption of a semiflexible polymer onto a fluid membrane vesicle. Polymer adsorption can significantly impact both the vesicle and polymer shapes, and we identify distinct classes of configurations that emerge as a function of polymer persistence length, membrane bending rigidity, adsorption strength, and vesicle size. Large-scale deformations of the vesicle include invaginations of the membrane that internalize the polymer in a membrane bud. The buds range from disk-like shapes surrounding a collapsed polymer to tubular deformations enveloping rod-like polymers. For small vesicles, polymer adsorption also induces dumbbell-like vesicle shapes with a narrow membrane constriction circled by the polymer. Vesicles with sufficiently small or large bending rigidities adopt configurations similar to those without the polymer present. We further characterize statistical properties of the membrane and polymer configurations and identify distinct classes of polymer configurations that emerge within membrane buds. Analysis of idealized polymer-membrane configurations provides additional insight into transitions between bud shapes.
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Affiliation(s)
- Bing Li
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
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87
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Li Q, Huang Q, Huyan T, Wang Y, Huang Q, Shi J. Bifacial effects of engineering tumour cell-derived exosomes on human natural killer cells. Exp Cell Res 2017; 363:141-150. [PMID: 29269076 DOI: 10.1016/j.yexcr.2017.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 12/03/2017] [Accepted: 12/07/2017] [Indexed: 12/21/2022]
Abstract
Extracellular vesicles (EVs) are nano vesicular structures that are secreted by almost all kinds of cells. Exosomes are small EVs derived from endosomes, with a diameter between 30-100nm. Tumour-derived exosomes carry many molecules and factors from tumour cells. These exosomes are recognized and taken up by immunocytes. However, tumour-derived exosomes can not only suppress immune cell functions but also help tumours escape immune surveillance in the tumour microenvironment. The present work investigated the effect of exosomes derived from genetical modified K562 cells (GMK cells), which express IL-15, IL-18 and 4-1BBL (TNFSF9) on their surface. The results showed that these GME exosomes, carrying IL-15, IL-18 and 4-1BBL proteins similar to their host cells, could activate NK cells, increase the cytotoxicity of NK cells on some tumour cells in a short treatment (4h) and promote NK cells proliferation. However, with an extended treatment time (48h), these exosomes could inhibite the cytotoxicity of NK cells by inhibiting activated receptor expression on NK cells. These results indicated the bifacial effects of GMK exosomes on NK cells, which will be helpful to explore the possibility of using transformed exosomes as an anti-tumour immune vaccine or a therapeutic tool in future.
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Affiliation(s)
- Qi Li
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 YouyiXilu, Xi'an 710072, Shaanxi, PR China.
| | - Qiuping Huang
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 YouyiXilu, Xi'an 710072, Shaanxi, PR China
| | - Ting Huyan
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 YouyiXilu, Xi'an 710072, Shaanxi, PR China
| | - Yilin Wang
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 YouyiXilu, Xi'an 710072, Shaanxi, PR China
| | - Qingsheng Huang
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 YouyiXilu, Xi'an 710072, Shaanxi, PR China
| | - Junling Shi
- Key Laboratory for Space Bioscience and Space Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 YouyiXilu, Xi'an 710072, Shaanxi, PR China
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88
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Dubankova A, Humpolickova J, Klima M, Boura E. Negative charge and membrane-tethered viral 3B cooperate to recruit viral RNA dependent RNA polymerase 3D pol. Sci Rep 2017; 7:17309. [PMID: 29230036 PMCID: PMC5725453 DOI: 10.1038/s41598-017-17621-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 11/29/2017] [Indexed: 12/28/2022] Open
Abstract
Most single stranded plus RNA viruses hijack phosphatidylinositol 4-kinases (PI4Ks) to generate membranes highly enriched in phosphatidylinositol 4-phosphate (PI4P). These membranous compartments known as webs, replication factories or replication organelles are essential for viral replication because they provide protection from the innate intracellular immune response while serving as platforms for viral replication. Using purified recombinant proteins and biomimetic model membranes we show that the nonstructural viral 3A protein is sufficient to promote membrane hyper-phosphorylation given the proper intracellular cofactors (PI4KB and ACBD3). However, our bio-mimetic in vitro reconstitution assay revealed that rather than the presence of PI4P specifically, negative charge alone is sufficient for the recruitment of 3Dpol enzymes to the surface of the lipid bilayer. Additionally, we show that membrane tethered viral 3B protein (also known as Vpg) works in combination with the negative charge to increase the efficiency of membrane recruitment of 3Dpol.
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Affiliation(s)
- Anna Dubankova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jana Humpolickova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Klima
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Evzen Boura
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic.
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89
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Dasgupta S, Auth T, Gompper G. Nano- and microparticles at fluid and biological interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:373003. [PMID: 28608781 PMCID: PMC7104866 DOI: 10.1088/1361-648x/aa7933] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/12/2017] [Accepted: 06/13/2017] [Indexed: 05/05/2023]
Abstract
Systems with interfaces are abundant in both technological applications and biology. While a fluid interface separates two fluids, membranes separate the inside of vesicles from the outside, the interior of biological cells from the environment, and compartmentalize cells into organelles. The physical properties of interfaces are characterized by interface tension, those of membranes are characterized by bending and stretching elasticity. Amphiphilic molecules like surfactants that are added to a system with two immiscible fluids decrease the interface tension and induce a bending rigidity. Lipid bilayer membranes of vesicles can be stretched or compressed by osmotic pressure; in biological cells, also the presence of a cytoskeleton can induce membrane tension. If the thickness of the interface or the membrane is small compared with its lateral extension, both can be described using two-dimensional mathematical surfaces embedded in three-dimensional space. We review recent work on the interaction of particles with interfaces and membranes. This can be micrometer-sized particles at interfaces that stabilise emulsions or form colloidosomes, as well as typically nanometer-sized particles at membranes, such as viruses, parasites, and engineered drug delivery systems. In both cases, we first discuss the interaction of single particles with interfaces and membranes, e.g. particles in external fields, non-spherical particles, and particles at curved interfaces, followed by interface-mediated interaction between two particles, many-particle interactions, interface and membrane curvature-induced phenomena, and applications.
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Affiliation(s)
- S Dasgupta
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Institut Curie, CNRS, UMR 168, 75005 Paris, France
- Present address: Department of Physics, University of Toronto, Toronto, Ontario M5S1A7, Canada
| | - T Auth
- Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - G Gompper
- Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
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90
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Pavani KC, Alminana C, Wydooghe E, Catteeuw M, Ramírez MA, Mermillod P, Rizos D, Van Soom A. Emerging role of extracellular vesicles in communication of preimplantation embryos in vitro. Reprod Fertil Dev 2017; 29:66-83. [PMID: 28278795 DOI: 10.1071/rd16318] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In vitro, efficient communication between mammalian embryos in groups or between embryos and cocultured somatic cells implies that there is a sender, a message and a receiver that is able to decode the message. Embryos secrete a variety of autocrine and paracrine factors and, of these, extracellular vesicles have recently been implicated as putative messengers in embryo-embryo communication, as well as in communication of the embryo with the maternal tract. Extracellular vesicles (EVs) are membrane-bound vesicles that are found in biofluids and in culture media conditioned by the presence of embryos or cells. EVs carry and transfer regulatory molecules, such as microRNAs, mRNAs, lipids and proteins. We conducted a systematic search of the literature to review and present the currently available evidence regarding the possible roles of EVs in in vitro embryo communication and embryo development. It is important to note that there is limited information available on the molecular mechanisms and many of the biologically plausible functions of EVs in embryo communication have not yet been substantiated by conclusive experimental evidence. However, indirect evidence, such as the use of media conditioned by embryos or by somatic cells with improved embryo development as a result, may indicate that EVs can be an important asset for the development of tailor-made media, allowing better embryo development in vitro, even for single embryo culture.
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Affiliation(s)
- Krishna C Pavani
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, University of Ghent, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Carmen Alminana
- INRA, Reproductive Physiology and Behavior, UMR085, INRA, CNRS, Université de Tours, IFCE, 37380 Nouzilly, France
| | - Eline Wydooghe
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, University of Ghent, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Maaike Catteeuw
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, University of Ghent, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - Miguel A Ramírez
- Departamento de Reproduccion Animal, Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Madrid 28040, Spain
| | - Pascal Mermillod
- INRA, Reproductive Physiology and Behavior, UMR085, INRA, CNRS, Université de Tours, IFCE, 37380 Nouzilly, France
| | - Dimitrios Rizos
- Departamento de Reproduccion Animal, Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Madrid 28040, Spain
| | - Ann Van Soom
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, University of Ghent, Salisburylaan 133, B-9820 Merelbeke, Belgium
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91
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Giovannone AJ, Reales E, Bhattaram P, Fraile-Ramos A, Weimbs T. Monoubiquitination of syntaxin 3 leads to retrieval from the basolateral plasma membrane and facilitates cargo recruitment to exosomes. Mol Biol Cell 2017; 28:2843-2853. [PMID: 28814500 PMCID: PMC5638587 DOI: 10.1091/mbc.e17-07-0461] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/09/2017] [Accepted: 08/11/2017] [Indexed: 01/02/2023] Open
Abstract
Monoubiquitination of Stx3 leads to efficient endocytosis from the basolateral plasma membrane and trafficking into the multivesicular body/exosomal pathway. Stx3 plays a role in cargo recruitment into exosomes. This pathway is exploited by HCMV for virion excretion. Syntaxin 3 (Stx3), a SNARE protein located and functioning at the apical plasma membrane of epithelial cells, is required for epithelial polarity. A fraction of Stx3 is localized to late endosomes/lysosomes, although how it traffics there and its function in these organelles is unknown. Here we report that Stx3 undergoes monoubiquitination in a conserved polybasic domain. Stx3 present at the basolateral—but not the apical—plasma membrane is rapidly endocytosed, targeted to endosomes, internalized into intraluminal vesicles (ILVs), and excreted in exosomes. A nonubiquitinatable mutant of Stx3 (Stx3-5R) fails to enter this pathway and leads to the inability of the apical exosomal cargo protein GPRC5B to enter the ILV/exosomal pathway. This suggests that ubiquitination of Stx3 leads to removal from the basolateral membrane to achieve apical polarity, that Stx3 plays a role in the recruitment of cargo to exosomes, and that the Stx3-5R mutant acts as a dominant-negative inhibitor. Human cytomegalovirus (HCMV) acquires its membrane in an intracellular compartment and we show that Stx3-5R strongly reduces the number of excreted infectious viral particles. Altogether these results suggest that Stx3 functions in the transport of specific proteins to apical exosomes and that HCMV exploits this pathway for virion excretion.
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Affiliation(s)
- Adrian J Giovannone
- Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106
| | - Elena Reales
- Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106
| | - Pallavi Bhattaram
- Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106
| | - Alberto Fraile-Ramos
- Departamento de Biología Celular, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Thomas Weimbs
- Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106
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92
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Kovalev N, Inaba JI, Li Z, Nagy PD. The role of co-opted ESCRT proteins and lipid factors in protection of tombusviral double-stranded RNA replication intermediate against reconstituted RNAi in yeast. PLoS Pathog 2017; 13:e1006520. [PMID: 28759634 PMCID: PMC5552349 DOI: 10.1371/journal.ppat.1006520] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 08/10/2017] [Accepted: 07/07/2017] [Indexed: 01/28/2023] Open
Abstract
Reconstituted antiviral defense pathway in surrogate host yeast is used as an intracellular probe to further our understanding of virus-host interactions and the role of co-opted host factors in formation of membrane-bound viral replicase complexes in protection of the viral RNA against ribonucleases. The inhibitory effect of the RNA interference (RNAi) machinery of S. castellii, which only consists of the two-component DCR1 and AGO1 genes, was measured against tomato bushy stunt virus (TBSV) in wild type and mutant yeasts. We show that deletion of the co-opted ESCRT-I (endosomal sorting complexes required for transport I) or ESCRT-III factors makes TBSV replication more sensitive to the RNAi machinery in yeast. Moreover, the lack of these pro-viral cellular factors in cell-free extracts (CFEs) used for in vitro assembly of the TBSV replicase results in destruction of dsRNA replication intermediate by a ribonuclease at the 60 min time point when the CFE from wt yeast has provided protection for dsRNA. In addition, we demonstrate that co-opted oxysterol-binding proteins and membrane contact sites, which are involved in enrichment of sterols within the tombusvirus replication compartment, are required for protection of viral dsRNA. We also show that phosphatidylethanolamine level influences the formation of RNAi-resistant replication compartment. In the absence of peroxisomes in pex3Δ yeast, TBSV subverts the ER membranes, which provide as good protection for TBSV dsRNA against RNAi or ribonucleases as the peroxisomal membranes in wt yeast. Altogether, these results demonstrate that co-opted protein factors and usurped lipids are exploited by tombusviruses to build protective subcellular environment against the RNAi machinery and possibly other cellular ribonucleases. Positive-strand RNA viruses build membranous replication compartment to support their replication in the infected hosts. One of the proposed functions of the usurped subcellular membranes is to protect the viral RNA from recognition and destruction by various cellular RNA sensors and ribonucleases. To answer this fundamental question on the putative role of co-opted host factors and membranes in protecting the viral double-stranded RNA replication intermediate during replication, the authors took advantage of yeast (Saccharomyces cerevisiae), which lacks the conserved RNAi machinery, as a surrogate host for TBSV. The reconstituted RNAi machinery from S. castellii in S. cerevisiae was used as an intracellular probe to study the effect of various co-opted cellular proteins and lipids on the formation of RNAi-insensitive replication compartment. Overall, the authors demonstrate the interaction between the RNAi machinery and the viral replicase complex, and the essential roles of usurped host factors in protecting the viral dsRNA replication intermediate from RNAi-based degradation.
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Affiliation(s)
- Nikolay Kovalev
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jun-ichi Inaba
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Zhenghe Li
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
- Institute of Biotechnology, State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, P. R. China
| | - Peter D. Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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93
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Sun L, Böckmann RA. Membrane phase transition during heating and cooling: molecular insight into reversible melting. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2017; 47:151-164. [PMID: 28725998 DOI: 10.1007/s00249-017-1237-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/18/2017] [Accepted: 06/28/2017] [Indexed: 11/25/2022]
Abstract
With increasing temperature, lipid bilayers undergo a gel-fluid phase transition, which plays an essential role in many physiological phenomena. In the present work, this first-order phase transition was investigated for variable heating and cooling rates for a dipalmitoylphosphatidylcholine (DPPC) lipid bilayer by means of atomistic molecular dynamics simulations. Alternative methods to track the melting temperature [Formula: see text] are compared. The resulting [Formula: see text] is shown to be independent of the scan rate for small heating rates (0.05-0.3 K/ns) implying reversible melting, and increases for larger heating (0.3-4 K/ns) or cooling rates (2-0.1 K/ns). The reported dependency of the melting temperature on the heating rate is in perfect agreement with a two-state kinetic rate model as suggested previously. Expansion and shrinkage, as well as the dynamics of melting seeds is described. The simulations further exhibit a relative shift between melting seeds in opposing membrane leaflets as predicted from continuum elastic theory.
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Affiliation(s)
- Liping Sun
- Computational Biology, Department of Biology, Friedrich-Alexander-University of Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany
| | - Rainer A Böckmann
- Computational Biology, Department of Biology, Friedrich-Alexander-University of Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany.
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94
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Han Q, Jia B, Hong Y, Cao X, Zhai Q, Lu K, Li H, Zhu C, Fu Z, Shi Y, Lin J. Suppression of VAMP2 Alters Morphology of the Tegument and Affects Glucose uptake, Development and Reproduction of Schistosoma japonicum. Sci Rep 2017; 7:5212. [PMID: 28701752 PMCID: PMC5507895 DOI: 10.1038/s41598-017-05602-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/31/2017] [Indexed: 01/17/2023] Open
Abstract
Schistosomiasis caused by schsitosomes is a serious global public health concern. The tegument that surrounds the worm is critical to the schistosomes survival. The tegument apical membrane undergoes a continuous process of rupture and repair owing to membranous vacuoles fusing with the plasma membrane. Vesicle-associated membrane protein 2 (VAMP2), a member of soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNAREs) is required for membrane fusion. Here, we used RNA interference (RNAi) to knock down the expression of VAMP2 of Schistosoma japonicum (SjVAMP2), and both real-time PCR and western blot analysis confirmed the suppression of this molecule, as well as the suppression of the transcript levels of schistosome glucose transporters (SGTP1 and SGTP4), and insulin receptors (SjIR1 and SjIR2). SjVAMP2-suppressed worms exhibited a lower viability, and phenotypic alterations were also observed in the tegument. Moreover, the glucose consumption of SjVAMP2-suppressed worms decreased significantly in 4 and 6 days, respectively, as well as a significant reduction in egg production. We also observed a significant reduction in worm burden and hepatic eggs burden in two independent RNAi experiment in vivo, and minor pathological changes in mice treated with SjVAMP2 specific small interfering (si)RNA. These findings reveal that SjVAMP2 may play important roles in the maintenance of tegument, glucose uptake, worm development and egg production in schistosomes.
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Affiliation(s)
- Qian Han
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Bingguang Jia
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Yang Hong
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Xiaodan Cao
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Qi Zhai
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Ke Lu
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Hao Li
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Chuangang Zhu
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Zhiqiang Fu
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Yonghong Shi
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
| | - Jiaojiao Lin
- Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.
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95
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Xu K, Nagy PD. Sterol Binding by the Tombusviral Replication Proteins Is Essential for Replication in Yeast and Plants. J Virol 2017; 91:e01984-16. [PMID: 28100609 PMCID: PMC5355592 DOI: 10.1128/jvi.01984-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/10/2017] [Indexed: 12/24/2022] Open
Abstract
Membranous structures derived from various organelles are important for replication of plus-stranded RNA viruses. Although the important roles of co-opted host proteins in RNA virus replication have been appreciated for a decade, the equally important functions of cellular lipids in virus replication have been gaining full attention only recently. Previous work with Tomato bushy stunt tombusvirus (TBSV) in model host yeast has revealed essential roles for phosphatidylethanolamine and sterols in viral replication. To further our understanding of the role of sterols in tombusvirus replication, in this work we showed that the TBSV p33 and p92 replication proteins could bind to sterols in vitro The sterol binding by p33 is supported by cholesterol recognition/interaction amino acid consensus (CRAC) and CARC-like sequences within the two transmembrane domains of p33. Mutagenesis of the critical Y amino acids within the CRAC and CARC sequences blocked TBSV replication in yeast and plant cells. We also showed the enrichment of sterols in the detergent-resistant membrane (DRM) fractions obtained from yeast and plant cells replicating TBSV. The DRMs could support viral RNA synthesis on both the endogenous and exogenous templates. A lipidomic approach showed the lack of enhancement of sterol levels in yeast and plant cells replicating TBSV. The data support the notion that the TBSV replication proteins are associated with sterol-rich detergent-resistant membranes in yeast and plant cells. Together, the results obtained in this study and the previously published results support the local enrichment of sterols around the viral replication proteins that is critical for TBSV replication.IMPORTANCE One intriguing aspect of viral infections is their dependence on efficient subcellular assembly platforms serving replication, virion assembly, or virus egress via budding out of infected cells. These assembly platforms might involve sterol-rich membrane microdomains, which are heterogeneous and highly dynamic nanoscale structures usurped by various viruses. Here, we demonstrate that TBSV p33 and p92 replication proteins can bind to sterol in vitro Mutagenesis analysis of p33 within the CRAC and CARC sequences involved in sterol binding shows the important connection between the abilities of p33 to bind to sterol and to support TBSV replication in yeast and plant cells. Together, the results further strengthen the model that cellular sterols are essential as proviral lipids during viral replication.
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Affiliation(s)
- Kai Xu
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
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96
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Szatmári T, Kis D, Bogdándi EN, Benedek A, Bright S, Bowler D, Persa E, Kis E, Balogh A, Naszályi LN, Kadhim M, Sáfrány G, Lumniczky K. Extracellular Vesicles Mediate Radiation-Induced Systemic Bystander Signals in the Bone Marrow and Spleen. Front Immunol 2017; 8:347. [PMID: 28396668 PMCID: PMC5366932 DOI: 10.3389/fimmu.2017.00347] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/10/2017] [Indexed: 12/02/2022] Open
Abstract
Radiation-induced bystander effects refer to the induction of biological changes in cells not directly hit by radiation implying that the number of cells affected by radiation is larger than the actual number of irradiated cells. Recent in vitro studies suggest the role of extracellular vesicles (EVs) in mediating radiation-induced bystander signals, but in vivo investigations are still lacking. Here, we report an in vivo study investigating the role of EVs in mediating radiation effects. C57BL/6 mice were total-body irradiated with X-rays (0.1, 0.25, 2 Gy), and 24 h later, EVs were isolated from the bone marrow (BM) and were intravenously injected into unirradiated (so-called bystander) animals. EV-induced systemic effects were compared to radiation effects in the directly irradiated animals. Similar to direct radiation, EVs from irradiated mice induced complex DNA damage in EV-recipient animals, manifested in an increased level of chromosomal aberrations and the activation of the DNA damage response. However, while DNA damage after direct irradiation increased with the dose, EV-induced effects peaked at lower doses. A significantly reduced hematopoietic stem cell pool in the BM as well as CD4+ and CD8+ lymphocyte pool in the spleen was detected in mice injected with EVs isolated from animals irradiated with 2 Gy. These EV-induced alterations were comparable to changes present in the directly irradiated mice. The pool of TLR4-expressing dendritic cells was different in the directly irradiated mice, where it increased after 2 Gy and in the EV-recipient animals, where it strongly decreased in a dose-independent manner. A panel of eight differentially expressed microRNAs (miRNA) was identified in the EVs originating from both low- and high-dose-irradiated mice, with a predicted involvement in pathways related to DNA damage repair, hematopoietic, and immune system regulation, suggesting a direct involvement of these pathways in mediating radiation-induced systemic effects. In conclusion, we proved the role of EVs in transmitting certain radiation effects, identified miRNAs carried by EVs potentially responsible for these effects, and showed that the pattern of changes was often different in the directly irradiated and EV-recipient bystander mice, suggesting different mechanisms.
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Affiliation(s)
- Tünde Szatmári
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Dávid Kis
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Enikő Noémi Bogdándi
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Anett Benedek
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Scott Bright
- Genomic Instability Group, Department of Biological and Medical Sciences, Oxford Brookes University , Oxford , UK
| | - Deborah Bowler
- Genomic Instability Group, Department of Biological and Medical Sciences, Oxford Brookes University , Oxford , UK
| | - Eszter Persa
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Enikő Kis
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Andrea Balogh
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Lívia N Naszályi
- Research Group for Molecular Biophysics, Hungarian Academy of Sciences, Semmelweis University , Budapest , Hungary
| | - Munira Kadhim
- Genomic Instability Group, Department of Biological and Medical Sciences, Oxford Brookes University , Oxford , UK
| | - Géza Sáfrány
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
| | - Katalin Lumniczky
- Division of Radiation Medicine, National Public Health Centre, National Research Directorate for Radiobiology and Radiohygiene , Budapest , Hungary
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97
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Fernandez-Trillo F, Grover LM, Stephenson-Brown A, Harrison P, Mendes PM. Vesicles in Nature and the Laboratory: Elucidation of Their Biological Properties and Synthesis of Increasingly Complex Synthetic Vesicles. Angew Chem Int Ed Engl 2017; 56:3142-3160. [DOI: 10.1002/anie.201607825] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 10/12/2016] [Indexed: 12/19/2022]
Affiliation(s)
| | - Liam M. Grover
- School of Chemical Engineering; University of Birmingham; Edgbaston Birmingham B15 2TT UK
| | - Alex Stephenson-Brown
- School of Chemical Engineering; University of Birmingham; Edgbaston Birmingham B15 2TT UK
| | - Paul Harrison
- Institute of Inflammation and Ageing (IIA); University of Birmingham; Edgbaston Birmingham B15 2TT UK
| | - Paula M. Mendes
- School of Chemical Engineering; University of Birmingham; Edgbaston Birmingham B15 2TT UK
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98
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Fernandez-Trillo F, Grover LM, Stephenson-Brown A, Harrison P, Mendes PM. Vesikel in der Natur und im Labor: die Aufklärung der biologischen Eigenschaften und die Synthese zunehmend komplexer synthetischer Vesikel. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201607825] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | - Liam M. Grover
- School of Chemical Engineering; University of Birmingham; Edgbaston Birmingham B15 2TT Großbritannien
| | - Alex Stephenson-Brown
- School of Chemical Engineering; University of Birmingham; Edgbaston Birmingham B15 2TT Großbritannien
| | - Paul Harrison
- Institute of Inflammation and Ageing (IIA); University of Birmingham; Edgbaston Birmingham B15 2TT Großbritannien
| | - Paula M. Mendes
- School of Chemical Engineering; University of Birmingham; Edgbaston Birmingham B15 2TT Großbritannien
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99
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Cordonnier M, Chanteloup G, Isambert N, Seigneuric R, Fumoleau P, Garrido C, Gobbo J. Exosomes in cancer theranostic: Diamonds in the rough. Cell Adh Migr 2017; 11:151-163. [PMID: 28166442 DOI: 10.1080/19336918.2016.1250999] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
During the last 10 years, exosomes, which are small vesicles of 50-200 nm diameter of endosomal origin, have aroused a great interest in the scientific and clinical community for their roles in intercellular communication in almost all physiological and pathological processes. Most cells can potentially release these nanovesicles that share with the parent cell a similar lipid bilayer with transmembrane proteins and a panel of enclosed soluble proteins such as heat shock proteins and genetic material, thus acting as potential nanoshuttles of biomarkers. Exosomes surface proteins allow their targeting and capture by recipient cells, while the exosomes' content can modify the physiological state of recipient cells. Tumor derived exosomes by interacting with other cells of the tumor microenvironment modulate tumor progression, angiogenic switch, metastasis, and immune escape. Targeting tumor-derived exosomes might be an interesting approach in cancer therapy. Furthermore, because a key issue to improve cancer patients' outcome relies on earlier cancer diagnosis (metastases, as opposed to the primary tumor, are responsible for most cancer deaths) exosomes have been put forward as promising biomarker candidates for cancer diagnosis and prognosis. This review summarizes the roles of exosomes in cancer and clinical interest, focusing on the importance of exosomal heat shock proteins (HSP). The challenges of clinical translation of HSP-exosomes as therapeutic targets and biomarkers for early cancer detection are also discussed.
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Affiliation(s)
- Marine Cordonnier
- a INSERM, UMR 866, Laboratoire d'Excellence LipSTIC , Dijon , France.,b University of Burgundy, Faculty of Medicine and Pharmacy , Dijon , France
| | - Gaëtan Chanteloup
- a INSERM, UMR 866, Laboratoire d'Excellence LipSTIC , Dijon , France.,b University of Burgundy, Faculty of Medicine and Pharmacy , Dijon , France
| | - Nicolas Isambert
- a INSERM, UMR 866, Laboratoire d'Excellence LipSTIC , Dijon , France.,b University of Burgundy, Faculty of Medicine and Pharmacy , Dijon , France.,c Department of Medical Oncology , Georges-François Leclerc Centre , Dijon , France
| | - Renaud Seigneuric
- a INSERM, UMR 866, Laboratoire d'Excellence LipSTIC , Dijon , France.,b University of Burgundy, Faculty of Medicine and Pharmacy , Dijon , France
| | - Pierre Fumoleau
- c Department of Medical Oncology , Georges-François Leclerc Centre , Dijon , France
| | - Carmen Garrido
- a INSERM, UMR 866, Laboratoire d'Excellence LipSTIC , Dijon , France.,b University of Burgundy, Faculty of Medicine and Pharmacy , Dijon , France.,c Department of Medical Oncology , Georges-François Leclerc Centre , Dijon , France.,d Equipe Labellisée par la Ligue Nationale Contre le Cancer , Paris , France
| | - Jessica Gobbo
- a INSERM, UMR 866, Laboratoire d'Excellence LipSTIC , Dijon , France.,b University of Burgundy, Faculty of Medicine and Pharmacy , Dijon , France.,c Department of Medical Oncology , Georges-François Leclerc Centre , Dijon , France
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100
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Wei C, Plucinski A, Nuasaen S, Tripathi A, Tangboriboonrat P, Tauer K. Swelling-Induced Deformation of Spherical Latex Particles. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b02379] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chunxiang Wei
- Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany
| | | | - Sukanya Nuasaen
- Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany
| | - Amit Tripathi
- Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany
| | - Pramuan Tangboriboonrat
- P.
Tangboriboonrat Department of Chemistry, Faculty of Science, Mahidol University, Rama 6 Road, Phyathai, Bangkok 10400, Thailand
| | - Klaus Tauer
- Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany
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