101
|
Banerjee P, Wehle M, Lipowsky R, Santer M. A molecular dynamics model for glycosylphosphatidyl-inositol anchors: “flop down” or “lollipop”? Phys Chem Chem Phys 2018; 20:29314-29324. [DOI: 10.1039/c8cp04059a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Computational model for GPI anchors tested in DMPC and POPC bilayers. The free anchor rarely occurs as an erected “lollipop-like” conformation, it rather “flops down” onto the bilayer surface. Yet an attached protein (here green fluorescent protein) exhibits extensive orientational flexibility due to the phospho-ethanolamine linker.
Collapse
Affiliation(s)
- Pallavi Banerjee
- Department of Theory and Biosystems
- Max Planck Institute for Colloids and Interfaces
- 14424 Potsdam
- Germany
| | - Marko Wehle
- Department of Theory and Biosystems
- Max Planck Institute for Colloids and Interfaces
- 14424 Potsdam
- Germany
| | - Reinhard Lipowsky
- Department of Theory and Biosystems
- Max Planck Institute for Colloids and Interfaces
- 14424 Potsdam
- Germany
| | - Mark Santer
- Department of Theory and Biosystems
- Max Planck Institute for Colloids and Interfaces
- 14424 Potsdam
- Germany
| |
Collapse
|
102
|
GPI-anchored proteins are confined in subdiffraction clusters at the apical surface of polarized epithelial cells. Biochem J 2017; 474:4075-4090. [PMID: 29046391 PMCID: PMC5712066 DOI: 10.1042/bcj20170582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/19/2017] [Accepted: 10/17/2017] [Indexed: 11/28/2022]
Abstract
Spatio-temporal compartmentalization of membrane proteins is critical for the regulation of diverse vital functions in eukaryotic cells. It was previously shown that, at the apical surface of polarized MDCK cells, glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) are organized in small cholesterol-independent clusters of single GPI-AP species (homoclusters), which are required for the formation of larger cholesterol-dependent clusters formed by multiple GPI-AP species (heteroclusters). This clustered organization is crucial for the biological activities of GPI-APs; hence, understanding the spatio-temporal properties of their membrane organization is of fundamental importance. Here, by using direct stochastic optical reconstruction microscopy coupled to pair correlation analysis (pc-STORM), we were able to visualize and measure the size of these clusters. Specifically, we show that they are non-randomly distributed and have an average size of 67 nm. We also demonstrated that polarized MDCK and non-polarized CHO cells have similar cluster distribution and size, but different sensitivity to cholesterol depletion. Finally, we derived a model that allowed a quantitative characterization of the cluster organization of GPI-APs at the apical surface of polarized MDCK cells for the first time. Experimental FRET (fluorescence resonance energy transfer)/FLIM (fluorescence-lifetime imaging microscopy) data were correlated to the theoretical predictions of the model.
Collapse
|
103
|
Strutt H, Gamage J, Strutt D. Robust Asymmetric Localization of Planar Polarity Proteins Is Associated with Organization into Signalosome-like Domains of Variable Stoichiometry. Cell Rep 2017; 17:2660-2671. [PMID: 27926869 PMCID: PMC5177602 DOI: 10.1016/j.celrep.2016.11.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/21/2016] [Accepted: 11/02/2016] [Indexed: 11/18/2022] Open
Abstract
In developing epithelia, the core planar polarity proteins physically interact with each other and localize asymmetrically at opposite cell ends, forming intercellular complexes that link the polarity of neighboring cells. Using quantitative imaging to examine the composition of the core protein complex in vivo, we find that complex composition is unexpectedly plastic. The transmembrane proteins Frizzled and Flamingo form a stoichiometric nucleus in the complex, while the relative levels of the other four core proteins can vary independently. Exploring the functional consequences of this, we show that robust cell polarization is achieved over a range of complex stoichiometries but is dependent on maintaining appropriate levels of the components Frizzled and Strabismus. We propose that the core proteins assemble into signalosome-like structures, where stable association is not dependent on one-to-one interactions with binding partners, and signaling functions can act over a wide range of complex compositions.
Collapse
Affiliation(s)
- Helen Strutt
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Jessica Gamage
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - David Strutt
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
| |
Collapse
|
104
|
Peksel B, Gombos I, Péter M, Vigh L, Tiszlavicz Á, Brameshuber M, Balogh G, Schütz GJ, Horváth I, Vigh L, Török Z. Mild heat induces a distinct "eustress" response in Chinese Hamster Ovary cells but does not induce heat shock protein synthesis. Sci Rep 2017; 7:15643. [PMID: 29142280 PMCID: PMC5688065 DOI: 10.1038/s41598-017-15821-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/02/2017] [Indexed: 11/16/2022] Open
Abstract
The current research on cellular heat stress management focuses on the roles of heat shock proteins (HSPs) and the proteostasis network under severe stress conditions. The mild, fever-type stress and the maintenance of membrane homeostasis are less well understood. Herein, we characterized the acute effect of mild, fever-range heat shock on membrane organization, and HSP synthesis and localization in two mammalian cell lines, to delineate the role of membranes in the sensing and adaptation to heat. A multidisciplinary approach combining ultrasensitive fluorescence microscopy and lipidomics revealed the molecular details of novel cellular “eustress”, when cells adapt to mild heat by maintaining membrane homeostasis, activating lipid remodeling, and redistributing chaperone proteins. Notably, this leads to acquired thermotolerance in the complete absence of the induction of HSPs. At higher temperatures, additional defense mechanisms are activated, including elevated expression of molecular chaperones, contributing to an extended stress memory and acquired thermotolerance.
Collapse
Affiliation(s)
- Begüm Peksel
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - Imre Gombos
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - Mária Péter
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - László Vigh
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - Ádám Tiszlavicz
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - Mario Brameshuber
- Institute of Applied Physics - Biophysics, TU Wien, 1040, Vienna, Austria
| | - Gábor Balogh
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - Gerhard J Schütz
- Institute of Applied Physics - Biophysics, TU Wien, 1040, Vienna, Austria
| | - Ibolya Horváth
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - László Vigh
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary
| | - Zsolt Török
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, H-6726, Hungary.
| |
Collapse
|
105
|
Johannes L. Shiga Toxin-A Model for Glycolipid-Dependent and Lectin-Driven Endocytosis. Toxins (Basel) 2017; 9:toxins9110340. [PMID: 29068384 PMCID: PMC5705955 DOI: 10.3390/toxins9110340] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/15/2017] [Accepted: 10/20/2017] [Indexed: 12/27/2022] Open
Abstract
The cellular entry of the bacterial Shiga toxin and the related verotoxins has been scrutinized in quite some detail. This is due to their importance as a threat to human health. At the same time, the study of Shiga toxin has allowed the discovery of novel molecular mechanisms that also apply to the intracellular trafficking of endogenous proteins at the plasma membrane and in the endosomal system. In this review, the individual steps that lead to Shiga toxin uptake into cells will first be presented from a purely mechanistic perspective. Membrane-biological concepts will be highlighted that are often still poorly explored, such as fluctuation force-driven clustering, clathrin-independent membrane curvature generation, friction-driven scission, and retrograde sorting on early endosomes. It will then be explored whether and how these also apply to other pathogens, pathogenic factors, and cellular proteins. The molecular nature of Shiga toxin as a carbohydrate-binding protein and that of its cellular receptor as a glycosylated raft lipid will be an underlying theme in this discussion. It will thereby be illustrated how the study of Shiga toxin has led to the proposal of the GlycoLipid-Lectin (GL-Lect) hypothesis on the generation of endocytic pits in processes of clathrin-independent endocytosis.
Collapse
Affiliation(s)
- Ludger Johannes
- Cellular and Chemical Biology Department, Institut Curie, PSL Research University, U1143 INSERM, UMR3666 CNRS, 26 rue d'Ulm, 75248 Paris CEDEX 05, France.
| |
Collapse
|
106
|
Alvarado J, Sheinman M, Sharma A, MacKintosh FC, Koenderink GH. Force percolation of contractile active gels. SOFT MATTER 2017; 13:5624-5644. [PMID: 28812094 DOI: 10.1039/c7sm00834a] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Living systems provide a paradigmatic example of active soft matter. Cells and tissues comprise viscoelastic materials that exert forces and can actively change shape. This strikingly autonomous behavior is powered by the cytoskeleton, an active gel of semiflexible filaments, crosslinks, and molecular motors inside cells. Although individual motors are only a few nm in size and exert minute forces of a few pN, cells spatially integrate the activity of an ensemble of motors to produce larger contractile forces (∼nN and greater) on cellular, tissue, and organismal length scales. Here we review experimental and theoretical studies on contractile active gels composed of actin filaments and myosin motors. Unlike other active soft matter systems, which tend to form ordered patterns, actin-myosin systems exhibit a generic tendency to contract. Experimental studies of reconstituted actin-myosin model systems have long suggested that a mechanical interplay between motor activity and the network's connectivity governs this contractile behavior. Recent theoretical models indicate that this interplay can be understood in terms of percolation models, extended to include effects of motor activity on the network connectivity. Based on concepts from percolation theory, we propose a state diagram that unites a large body of experimental observations. This framework provides valuable insights into the mechanisms that drive cellular shape changes and also provides design principles for synthetic active materials.
Collapse
Affiliation(s)
- José Alvarado
- Systems Biophysics Department, AMOLF, 1098 XG Amsterdam, The Netherlands.
| | | | | | | | | |
Collapse
|
107
|
Chakraborty S, Chatterjee S, Barma M. Ordered phases in coupled nonequilibrium systems: Static properties. Phys Rev E 2017; 96:022127. [PMID: 28950585 DOI: 10.1103/physreve.96.022127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Indexed: 06/07/2023]
Abstract
We study a coupled driven system in which two species of particles are advected by a fluctuating potential energy landscape. While the particles follow the potential gradient, each species affects the local shape of the landscape in different ways. As a result of this two-way coupling between the landscape and the particles, the system shows interesting new phases, characterized by different sorts of long-ranged order in the particles and in the landscape. In all these ordered phases, the two particle species phase separate completely from each other, but the underlying landscape may either show complete ordering, with macroscopic regions with distinct average slopes, or may show coexistence of ordered and disordered regions, depending on the differential nature of effect produced by the particle species on the landscape. We discuss several aspects of static properties of these phases in this paper, and we discuss the dynamics of these phases in the sequel.
Collapse
Affiliation(s)
- Shauri Chakraborty
- Department of Theoretical Sciences, S.N. Bose National Centre for Basic Sciences, JD Block, Sector 3, Salt Lake, Kolkata-700106, India
| | - Sakuntala Chatterjee
- Department of Theoretical Sciences, S.N. Bose National Centre for Basic Sciences, JD Block, Sector 3, Salt Lake, Kolkata-700106, India
| | - Mustansir Barma
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Gopanpally, Hyderabad 500107, India
| |
Collapse
|
108
|
Ergodicity breaking on the neuronal surface emerges from random switching between diffusive states. Sci Rep 2017; 7:5404. [PMID: 28710444 PMCID: PMC5511290 DOI: 10.1038/s41598-017-05911-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/05/2017] [Indexed: 12/27/2022] Open
Abstract
Stochastic motion on the surface of living cells is critical to promote molecular encounters that are necessary for multiple cellular processes. Often the complexity of the cell membranes leads to anomalous diffusion, which under certain conditions it is accompanied by non-ergodic dynamics. Here, we unravel two manifestations of ergodicity breaking in the dynamics of membrane proteins in the somatic surface of hippocampal neurons. Three different tagged molecules are studied on the surface of the soma: the voltage-gated potassium and sodium channels Kv1.4 and Nav1.6 and the glycoprotein CD4. In these three molecules ergodicity breaking is unveiled by the confidence interval of the mean square displacement and by the dynamical functional estimator. Ergodicity breaking is found to take place due to transient confinement effects since the molecules alternate between free diffusion and confined motion.
Collapse
|
109
|
Akin EJ, Solé L, Johnson B, Beheiry ME, Masson JB, Krapf D, Tamkun MM. Single-Molecule Imaging of Nav1.6 on the Surface of Hippocampal Neurons Reveals Somatic Nanoclusters. Biophys J 2017; 111:1235-1247. [PMID: 27653482 DOI: 10.1016/j.bpj.2016.08.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/09/2016] [Accepted: 08/15/2016] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium (Nav) channels are responsible for the depolarizing phase of the action potential in most nerve cells, and Nav channel localization to the axon initial segment is vital to action potential initiation. Nav channels in the soma play a role in the transfer of axonal output information to the rest of the neuron and in synaptic plasticity, although little is known about Nav channel localization and dynamics within this neuronal compartment. This study uses single-particle tracking and photoactivation localization microscopy to analyze cell-surface Nav1.6 within the soma of cultured hippocampal neurons. Mean-square displacement analysis of individual trajectories indicated that half of the somatic Nav1.6 channels localized to stable nanoclusters ∼230 nm in diameter. Strikingly, these domains were stabilized at specific sites on the cell membrane for >30 min, notably via an ankyrin-independent mechanism, indicating that the means by which Nav1.6 nanoclusters are maintained in the soma is biologically different from axonal localization. Nonclustered Nav1.6 channels showed anomalous diffusion, as determined by mean-square-displacement analysis. High-density single-particle tracking of Nav channels labeled with photoactivatable fluorophores in combination with Bayesian inference analysis was employed to characterize the surface nanoclusters. A subpopulation of mobile Nav1.6 was observed to be transiently trapped in the nanoclusters. Somatic Nav1.6 nanoclusters represent a new, to our knowledge, type of Nav channel localization, and are hypothesized to be sites of localized channel regulation.
Collapse
Affiliation(s)
- Elizabeth J Akin
- Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, Colorado; Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, Colorado; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Laura Solé
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Ben Johnson
- Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, Colorado; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Mohamed El Beheiry
- Physico-Chimie Curie, Institut Curie, Paris Sciences Lettres, CNRS UMR 168, Université Pierre et Marie Curie, Paris, France
| | - Jean-Baptiste Masson
- Institut Pasteur, Decision and Bayesian Computation, Centre National de la Recherche Scientifique (CNRS) UMR 3525, Paris, France; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Diego Krapf
- School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado; Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado.
| | - Michael M Tamkun
- Cell and Molecular Biology Graduate Program, Colorado State University, Fort Collins, Colorado; Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, Colorado; Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado.
| |
Collapse
|
110
|
|
111
|
Abstract
The central mechanism for the transmission of the prion protein misfolding is the structural conversion of the normal cellular prion protein to the pathogenic misfolded prion protein, by the interaction with misfolded prion protein. This process might be enhanced due to the homo-dimerization/oligomerization of normal prion protein. However, the behaviors of normal prion protein in the plasma membrane have remained largely unknown. Here, using single fluorescent-molecule imaging, we found that both prion protein and Thy1, a control glycosylphosphatidylinositol-anchored protein, exhibited very similar intermittent transient immobilizations lasting for a few seconds within an area of 24.2 and 3.5 nm in diameter in CHO-K1 and hippocampal neurons cultured for 1- and 2-weeks, respectively. Prion protein molecules were immobile during 72% of the time, approximately 1.4× more than Thy1, due to prion protein’s higher immobilization frequency. When mobile, prion protein diffused 1.7× slower than Thy1. Prion protein’s slower diffusion might be caused by its transient interaction with other prion protein molecules, whereas its brief immobilization might be due to temporary association with prion protein clusters. Prion protein molecules might be newly recruited to prion protein clusters all the time, and simultaneously, prion protein molecules in the cluster might be departing continuously. Such dynamic interactions of normal prion protein molecules would strongly enhance the spreading of misfolded prion protein.
Collapse
|
112
|
Tsuji T, Fujimoto M, Tatematsu T, Cheng J, Orii M, Takatori S, Fujimoto T. Niemann-Pick type C proteins promote microautophagy by expanding raft-like membrane domains in the yeast vacuole. eLife 2017; 6:e25960. [PMID: 28590904 PMCID: PMC5462540 DOI: 10.7554/elife.25960] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 05/16/2017] [Indexed: 11/13/2022] Open
Abstract
Niemann-Pick type C is a storage disease caused by dysfunction of NPC proteins, which transport cholesterol from the lumen of lysosomes to the limiting membrane of that compartment. Using freeze fracture electron microscopy, we show here that the yeast NPC orthologs, Ncr1p and Npc2p, are essential for formation and expansion of raft-like domains in the vacuolar (lysosome) membrane, both in stationary phase and in acute nitrogen starvation. Moreover, the expanded raft-like domains engulf lipid droplets by a microautophagic mechanism. We also found that the multivesicular body pathway plays a crucial role in microautophagy in acute nitrogen starvation by delivering sterol to the vacuole. These data show that NPC proteins promote microautophagy in stationary phase and under nitrogen starvation conditions, likely by increasing sterol in the limiting membrane of the vacuole.
Collapse
Affiliation(s)
- Takuma Tsuji
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Megumi Fujimoto
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tsuyako Tatematsu
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Jinglei Cheng
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Minami Orii
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sho Takatori
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Toyoshi Fujimoto
- Department of Molecular Cell Biology and Anatomy, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|
113
|
Sezgin E, Levental I, Mayor S, Eggeling C. The mystery of membrane organization: composition, regulation and roles of lipid rafts. Nat Rev Mol Cell Biol 2017; 18:361-374. [PMID: 28356571 PMCID: PMC5500228 DOI: 10.1038/nrm.2017.16] [Citation(s) in RCA: 1272] [Impact Index Per Article: 181.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cellular plasma membranes are laterally heterogeneous, featuring a variety of distinct subcompartments that differ in their biophysical properties and composition. A large number of studies have focused on understanding the basis for this heterogeneity and its physiological relevance. The membrane raft hypothesis formalized a physicochemical principle for a subtype of such lateral membrane heterogeneity, in which the preferential associations between cholesterol and saturated lipids drive the formation of relatively packed (or ordered) membrane domains that selectively recruit certain lipids and proteins. Recent studies have yielded new insights into this mechanism and its relevance in vivo, owing primarily to the development of improved biochemical and biophysical technologies.
Collapse
Affiliation(s)
- Erdinc Sezgin
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
| | - Ilya Levental
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, 6431 Fannin Street, Houston, Texas 77030, USA
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bellary Road, Bangalore 560065, India
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
| |
Collapse
|
114
|
Deshpande SA, Pawar AB, Dighe A, Athale CA, Sengupta D. Role of spatial inhomogenity in GPCR dimerisation predicted by receptor association–diffusion models. Phys Biol 2017; 14:036002. [DOI: 10.1088/1478-3975/aa6b68] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
115
|
Gross P, Kumar KV, Grill SW. How Active Mechanics and Regulatory Biochemistry Combine to Form Patterns in Development. Annu Rev Biophys 2017; 46:337-356. [DOI: 10.1146/annurev-biophys-070816-033602] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Peter Gross
- BIOTEC, Technische Universität Dresden, 01307 Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
| | - K. Vijay Kumar
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560089, India
| | - Stephan W. Grill
- BIOTEC, Technische Universität Dresden, 01307 Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany
| |
Collapse
|
116
|
Sizes of lipid domains: What do we know from artificial lipid membranes? What are the possible shared features with membrane rafts in cells? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:789-802. [DOI: 10.1016/j.bbamem.2017.01.030] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/21/2017] [Accepted: 01/26/2017] [Indexed: 12/13/2022]
|
117
|
Ma Y, Yamamoto Y, Nicovich PR, Goyette J, Rossy J, Gooding JJ, Gaus K. A FRET sensor enables quantitative measurements of membrane charges in live cells. Nat Biotechnol 2017; 35:363-370. [DOI: 10.1038/nbt.3828] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 02/15/2017] [Indexed: 02/07/2023]
|
118
|
Simón L, Funes AK, Yapur MA, Cabrillana ME, Monclus MA, Boarelli PV, Vincenti AE, Saez Lancellotti TE, Fornés MW. Manchette-acrosome disorders during spermiogenesis and low efficiency of seminiferous tubules in hypercholesterolemic rabbit model. PLoS One 2017; 12:e0172994. [PMID: 28241054 PMCID: PMC5328279 DOI: 10.1371/journal.pone.0172994] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/13/2017] [Indexed: 12/31/2022] Open
Abstract
Hypercholesterolemia is a marker for several adult chronic diseases. Recently we demonstrated that sub/infertility is also associated to Hypercholesterolemia in rabbits. Seminal alterations included: abnormal sperm morphology, decreased sperm number and declined percentage of motile sperm, among others. In this work, our objective was to evaluate the effects of hypercholesterolemia on testicular efficiency and spermiogenesis, as the latter are directly related to sperm number and morphology respectively. Tubular efficiency was determined by comparing total number of spermatogenic cells with each cell type within the proliferation/differentiation compartments. We found lower testicular efficiency related to both a decrease in spermatogonial cells and an increase in germ cell apoptosis in hypercholesterolemic rabbits. On the other hand, spermiogenesis-the last step of spermatogenesis involved in sperm shaping-was detaily analyzed, particularly the acrosome-nucleus-manchette complex. The manchette is a microtubular-based temporary structure responsible in sperm cell elongation. We analyzed the contribution of actin filaments and raft microdomains in the arrangement of the manchette. Under fluorescence microscopy, spermatocyte to sperm cell development was followed in cells isolated from V to VIII tubular stages. In cells from hypercholesterolemic rabbits, abnormal development of acrosome, nucleus and inaccurate tail implantation were associated with actin-alpha-tubulin-GM1 sphingolipid altered distribution. Morphological alterations were also observed at electron microscopy. We demonstrated for the first time that GM1-enriched microdomains together with actin filaments and microtubules are involved in allowing the correct anchoring of the manchette complex. In conclusion, cholesterol enriched diets promote male fertility alterations by affecting critical steps in sperm development: spermatogenesis and spermiogenesis. It was also demonstrated that hypercholesterolemic rabbit model is a useful tool to study serum cholesterol increment linked to sub/infertility.
Collapse
Affiliation(s)
- Layla Simón
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
- Instituto de investigaciones. Facultad de Ciencias Médicas. Universidad del Aconcagua. Mendoza, Argentina
| | - Abi K. Funes
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
| | - Martín A. Yapur
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
| | - María E. Cabrillana
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
- Instituto de investigaciones. Facultad de Ciencias Médicas. Universidad del Aconcagua. Mendoza, Argentina
| | - María A. Monclus
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
- Instituto de investigaciones. Facultad de Ciencias Médicas. Universidad del Aconcagua. Mendoza, Argentina
| | - Paola V. Boarelli
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
- Instituto de investigaciones. Facultad de Ciencias Médicas. Universidad del Aconcagua. Mendoza, Argentina
| | - Amanda E. Vincenti
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
| | - Tania E. Saez Lancellotti
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
- Instituto de investigaciones. Facultad de Ciencias Médicas. Universidad del Aconcagua. Mendoza, Argentina
| | - Miguel W. Fornés
- Laboratorio de Investigaciones Andrológicas de Mendoza (LIAM). Instituto y Área de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo y Centro Científico Tecnológico (CCT), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina
- Instituto de investigaciones. Facultad de Ciencias Médicas. Universidad del Aconcagua. Mendoza, Argentina
- * E-mail:
| |
Collapse
|
119
|
Husain K, Rao M. Emergent Structures in an Active Polar Fluid: Dynamics of Shape, Scattering, and Merger. PHYSICAL REVIEW LETTERS 2017; 118:078104. [PMID: 28256860 DOI: 10.1103/physrevlett.118.078104] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Indexed: 06/06/2023]
Abstract
Spatially localized defect structures emerge spontaneously in a hydrodynamic description of an active polar fluid comprising polar "actin" filaments and "myosin" motor proteins that (un)bind to filaments and exert active contractile stresses. These emergent defect structures are characterized by distinct textures and can be either static or mobile-we derive effective equations of motion for these "extended particles" and analyze their shape, kinetics, interactions, and scattering. Depending on the impact parameter and propulsion speed, these active defects undergo elastic scattering or merger. Our results are relevant for the dynamics of actomyosin-dense structures at the cell cortex, reconstituted actomyosin complexes, and 2D active colloidal gels.
Collapse
Affiliation(s)
- Kabir Husain
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore 560 065, India
| | - Madan Rao
- Simons Centre for the Study of Living Machines, National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore 560 065, India
| |
Collapse
|
120
|
Astrocyte-to-neuron communication through integrin-engaged Thy-1/CBP/Csk/Src complex triggers neurite retraction via the RhoA/ROCK pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:243-254. [DOI: 10.1016/j.bbamcr.2016.11.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/27/2016] [Accepted: 11/07/2016] [Indexed: 12/22/2022]
|
121
|
Stone MB, Shelby SA, Núñez MF, Wisser K, Veatch SL. Protein sorting by lipid phase-like domains supports emergent signaling function in B lymphocyte plasma membranes. eLife 2017; 6. [PMID: 28145867 PMCID: PMC5373823 DOI: 10.7554/elife.19891] [Citation(s) in RCA: 138] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/31/2017] [Indexed: 12/19/2022] Open
Abstract
Diverse cellular signaling events, including B cell receptor (BCR) activation, are hypothesized to be facilitated by domains enriched in specific plasma membrane lipids and proteins that resemble liquid-ordered phase-separated domains in model membranes. This concept remains controversial and lacks direct experimental support in intact cells. Here, we visualize ordered and disordered domains in mouse B lymphoma cell membranes using super-resolution fluorescence localization microscopy, demonstrate that clustered BCR resides within ordered phase-like domains capable of sorting key regulators of BCR activation, and present a minimal, predictive model where clustering receptors leads to their collective activation by stabilizing an extended ordered domain. These results provide evidence for the role of membrane domains in BCR signaling and a plausible mechanism of BCR activation via receptor clustering that could be generalized to other signaling pathways. Overall, these studies demonstrate that lipid mediated forces can bias biochemical networks in ways that broadly impact signal transduction. DOI:http://dx.doi.org/10.7554/eLife.19891.001 Membranes made of molecules called lipids surround every living cell to protect the cell's contents. Cells also communicate with the outside environment via their membranes. Proteins in the membrane receive information from the environment and trigger signaling pathways inside the cell to relay this information to the center of cell. The way in which proteins are organized on the membrane has a major influence on their signaling activity. Some areas of the membrane are more crowded with certain lipids and signaling proteins than others. Lipid and protein molecules of particular types can come together and form distinct areas called “ordered” and “disordered” domains. The lipids in ordered domains are more tightly packed than disordered domains and it is thought that this difference allows domains to selectively exclude or include certain proteins. Ordered domains are also known as "lipid rafts". Lipid rafts and disordered domains may help cells to control the activities of signaling pathways, however, technical limitations have made it difficult to study the roles of these domains. The membranes surrounding immune cells called B cells contain a protein called the B cell receptor, which engages with proteins from microbes and other foreign invaders. When the B cell receptor binds to a foreign protein it forms clusters with other B cell receptors and becomes active, triggering a signaling pathway that leads to immune responses. Stone, Shelby et al. examined lipid rafts and disordered domains in B cells from mice using a technique called super-resolution fluorescence microscopy. The results show that clusters of B cell receptors are present within lipid rafts. These clusters made the lipid rafts larger and more stable. A protein that is needed during the early stages of B cell receptor signaling was also found in the same lipid rafts. Another protein that terminates signaling was excluded because it prefers disordered domains. Together, this provides a local environment in certain areas of the membrane that favors receptor activity and supports the subsequent immune response. Future work is needed to understand how cells control the make-up of lipids and proteins within their membranes, and how defects in this regulation can alter signaling activity and lead to disease. DOI:http://dx.doi.org/10.7554/eLife.19891.002
Collapse
Affiliation(s)
- Matthew B Stone
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Sarah A Shelby
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Marcos F Núñez
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Kathleen Wisser
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| | - Sarah L Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, United States
| |
Collapse
|
122
|
Visualization of BRI1 and SERK3/BAK1 Nanoclusters in Arabidopsis Roots. PLoS One 2017; 12:e0169905. [PMID: 28114413 PMCID: PMC5256950 DOI: 10.1371/journal.pone.0169905] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 12/23/2016] [Indexed: 01/06/2023] Open
Abstract
Brassinosteroids (BRs) are plant hormones that are perceived at the plasma membrane (PM) by the ligand binding receptor BRASSINOSTEROID-INSENSITIVE1 (BRI1) and the co-receptor SOMATIC EMBRYOGENESIS RECEPTOR LIKE KINASE 3/BRI1 ASSOCIATED KINASE 1 (SERK3/BAK1). To visualize BRI1-GFP and SERK3/BAK1-mCherry in the plane of the PM, variable-angle epifluorescence microscopy (VAEM) was employed, which allows selective illumination of a thin surface layer. VAEM revealed an inhomogeneous distribution of BRI1-GFP and SERK3/BAK1-mCherry at the PM, which we attribute to the presence of distinct nanoclusters. Neither the BRI1 nor the SERK3/BAK1 nanocluster density is affected by depletion of endogenous ligands or application of exogenous ligands. To reveal interacting populations of receptor complexes, we utilized selective-surface observation—fluorescence lifetime imaging microscopy (SSO-FLIM) for the detection of Förster resonance energy transfer (FRET). Using this approach, we observed hetero-oligomerisation of BRI1 and SERK3 in the nanoclusters, which did not change upon depletion of endogenous ligand or signal activation. Upon ligand application, however, the number of BRI1-SERK3 /BAK1 hetero-oligomers was reduced, possibly due to endocytosis of active signalling units of BRI1-SERK3/BAK1 residing in the PM. We propose that formation of nanoclusters in the plant PM is subjected to biophysical restraints, while the stoichiometry of receptors inside these nanoclusters is variable and important for signal transduction.
Collapse
|
123
|
Kraft ML. Sphingolipid Organization in the Plasma Membrane and the Mechanisms That Influence It. Front Cell Dev Biol 2017; 4:154. [PMID: 28119913 PMCID: PMC5222807 DOI: 10.3389/fcell.2016.00154] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 12/27/2016] [Indexed: 11/13/2022] Open
Abstract
Sphingolipids are structural components in the plasma membranes of eukaryotic cells. Their metabolism produces bioactive signaling molecules that modulate fundamental cellular processes. The segregation of sphingolipids into distinct membrane domains is likely essential for cellular function. This review presents the early studies of sphingolipid distribution in the plasma membranes of mammalian cells that shaped the most popular current model of plasma membrane organization. The results of traditional imaging studies of sphingolipid distribution in stimulated and resting cells are described. These data are compared with recent results obtained with advanced imaging techniques, including super-resolution fluorescence detection and high-resolution secondary ion mass spectrometry (SIMS). Emphasis is placed on the new insight into the sphingolipid organization within the plasma membrane that has resulted from the direct imaging of stable isotope-labeled lipids in actual cell membranes with high-resolution SIMS. Super-resolution fluorescence techniques have recently revealed the biophysical behaviors of sphingolipids and the unhindered diffusion of cholesterol analogs in the membranes of living cells are ultimately in contrast to the prevailing hypothetical model of plasma membrane organization. High-resolution SIMS studies also conflicted with the prevailing hypothesis, showing sphingolipids are concentrated in micrometer-scale membrane domains, but cholesterol is evenly distributed within the plasma membrane. Reductions in cellular cholesterol decreased the number of sphingolipid domains in the plasma membrane, whereas disruption of the cytoskeleton eliminated them. In addition, hemagglutinin, a transmembrane protein that is thought to be a putative raft marker, did not cluster within sphingolipid-enriched regions in the plasma membrane. Thus, sphingolipid distribution in the plasma membrane is dependent on the cytoskeleton, but not on favorable interactions with cholesterol or hemagglutinin. The alternate views of plasma membrane organization suggested by these findings are discussed.
Collapse
Affiliation(s)
- Mary L Kraft
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana, IL, USA
| |
Collapse
|
124
|
Fujimoto T, Parmryd I. Interleaflet Coupling, Pinning, and Leaflet Asymmetry-Major Players in Plasma Membrane Nanodomain Formation. Front Cell Dev Biol 2017; 4:155. [PMID: 28119914 PMCID: PMC5222840 DOI: 10.3389/fcell.2016.00155] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 12/27/2016] [Indexed: 01/26/2023] Open
Abstract
The plasma membrane has a highly asymmetric distribution of lipids and contains dynamic nanodomains many of which are liquid entities surrounded by a second, slightly different, liquid environment. Contributing to the dynamics is a continuous repartitioning of components between the two types of liquids and transient links between lipids and proteins, both to extracellular matrix and cytoplasmic components, that temporarily pin membrane constituents. This make plasma membrane nanodomains exceptionally challenging to study and much of what is known about membrane domains has been deduced from studies on model membranes at equilibrium. However, living cells are by definition not at equilibrium and lipids are distributed asymmetrically with inositol phospholipids, phosphatidylethanolamines and phosphatidylserines confined mostly to the inner leaflet and glyco- and sphingolipids to the outer leaflet. Moreover, each phospholipid group encompasses a wealth of species with different acyl chain combinations whose lateral distribution is heterogeneous. It is becoming increasingly clear that asymmetry and pinning play important roles in plasma membrane nanodomain formation and coupling between the two lipid monolayers. How asymmetry, pinning, and interdigitation contribute to the plasma membrane organization is only beginning to be unraveled and here we discuss their roles and interdependence.
Collapse
Affiliation(s)
- Toyoshi Fujimoto
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine Nagoya, Japan
| | - Ingela Parmryd
- Science for Life Laboratory, Medical Cell Biology, Uppsala University Uppsala, Sweden
| |
Collapse
|
125
|
Subedi KP, Ong HL, Ambudkar IS. Assembly of ER-PM Junctions: A Critical Determinant in the Regulation of SOCE and TRPC1. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:253-276. [PMID: 29594865 DOI: 10.1007/978-3-319-55858-5_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Store-operated calcium entry (SOCE), a unique plasma membrane Ca2+ entry mechanism, is activated when ER-[Ca2+] is decreased. SOCE is mediated via the primary channel, Orai1, as well as others such as TRPC1. STIM1 and STIM2 are ER-Ca2+ sensor proteins that regulate Orai1 and TRPC1. SOCE requires assembly of STIM proteins with the plasma membrane channels which occurs within distinct regions in the cell that have been termed as endoplasmic reticulum (ER)-plasma membrane (PM) junctions. The PM and ER are in close proximity to each other within this region, which allows STIM1 in the ER to interact with and activate either Orai1 or TRPC1 in the plasma membrane. Activation and regulation of SOCE involves dynamic assembly of various components that are involved in mediating Ca2+ entry as well as those that determine the formation and stabilization of the junctions. These components include proteins in the cytosol, ER and PM, as well as lipids in the PM. Recent studies have also suggested that SOCE and its components are compartmentalized within ER-PM junctions and that this process might require remodeling of the plasma membrane lipids and reorganization of structural and scaffolding proteins. Such compartmentalization leads to the generation of spatially- and temporally-controlled Ca2+signals that are critical for regulating many downstream cellular functions.
Collapse
Affiliation(s)
- Krishna P Subedi
- Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Hwei Ling Ong
- Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Indu S Ambudkar
- Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA.
| |
Collapse
|
126
|
Yandrapalli N, Lubart Q, Tanwar HS, Picart C, Mak J, Muriaux D, Favard C. Self assembly of HIV-1 Gag protein on lipid membranes generates PI(4,5)P 2/Cholesterol nanoclusters. Sci Rep 2016; 6:39332. [PMID: 28008947 PMCID: PMC5180241 DOI: 10.1038/srep39332] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/22/2016] [Indexed: 01/26/2023] Open
Abstract
The self-assembly of HIV-1 Gag polyprotein at the inner leaflet of the cell host plasma membrane is the key orchestrator of virus assembly. The binding between Gag and the plasma membrane is mediated by specific interaction of the Gag matrix domain and the PI(4,5)P2 lipid (PIP2). It is unknown whether this interaction could lead to local reorganization of the plasma membrane lipids. In this study, using model membranes, we examined the ability of Gag to segregate specific lipids upon self-assembly. We show for the first time that Gag self-assembly is responsible for the formation of PIP2 lipid nanoclusters, enriched in cholesterol but not in sphingomyelin. We also show that Gag mainly partition into liquid-disordered domains of these lipid membranes. Our work strongly suggests that, instead of targeting pre-existing plasma membrane lipid domains, Gag is more prone to generate PIP2/Cholesterol lipid nanodomains at the inner leaflet of the plasma membrane during early events of virus assembly.
Collapse
Affiliation(s)
- Naresh Yandrapalli
- CNRS-Université Montpellier, Centre d'études d'agents Pathogenes et de Biotechnologies pour la Santé, Montpellier, France
| | - Quentin Lubart
- CNRS-Université Grenoble, Institut National de Physique, Grenoble, France
| | | | - Catherine Picart
- CNRS-Université Grenoble, Institut National de Physique, Grenoble, France
| | - Johnson Mak
- Deakin University, School of Medicine, Melbourne, Australia
| | - Delphine Muriaux
- CNRS-Université Montpellier, Centre d'études d'agents Pathogenes et de Biotechnologies pour la Santé, Montpellier, France
| | - Cyril Favard
- CNRS-Université Montpellier, Centre d'études d'agents Pathogenes et de Biotechnologies pour la Santé, Montpellier, France
| |
Collapse
|
127
|
Oswald F, Varadarajan A, Lill H, Peterman EJG, Bollen YJM. MreB-Dependent Organization of the E. coli Cytoplasmic Membrane Controls Membrane Protein Diffusion. Biophys J 2016; 110:1139-49. [PMID: 26958890 PMCID: PMC4788719 DOI: 10.1016/j.bpj.2016.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/05/2016] [Accepted: 01/11/2016] [Indexed: 01/13/2023] Open
Abstract
The functional organization of prokaryotic cell membranes, which is essential for many cellular processes, has been challenging to analyze due to the small size and nonflat geometry of bacterial cells. Here, we use single-molecule fluorescence microscopy and three-dimensional quantitative analyses in live Escherichia coli to demonstrate that its cytoplasmic membrane contains microdomains with distinct physical properties. We show that the stability of these microdomains depends on the integrity of the MreB cytoskeletal network underneath the membrane. We explore how the interplay between cytoskeleton and membrane affects trans-membrane protein (TMP) diffusion and reveal that the mobility of the TMPs tested is subdiffusive, most likely caused by confinement of TMP mobility by the submembranous MreB network. Our findings demonstrate that the dynamic architecture of prokaryotic cell membranes is controlled by the MreB cytoskeleton and regulates the mobility of TMPs.
Collapse
Affiliation(s)
- Felix Oswald
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, the Netherlands; Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, the Netherlands; LaserLaB Amsterdam, the Netherlands
| | - Aravindan Varadarajan
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, the Netherlands; LaserLaB Amsterdam, the Netherlands
| | - Holger Lill
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, the Netherlands; LaserLaB Amsterdam, the Netherlands
| | - Erwin J G Peterman
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, the Netherlands; LaserLaB Amsterdam, the Netherlands
| | - Yves J M Bollen
- Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, the Netherlands; LaserLaB Amsterdam, the Netherlands.
| |
Collapse
|
128
|
Changede R, Sheetz M. Integrin and cadherin clusters: A robust way to organize adhesions for cell mechanics. Bioessays 2016; 39:1-12. [PMID: 27930828 DOI: 10.1002/bies.201600123] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent studies at the nanometer scale have revealed that relatively uniform clusters of adhesion proteins (50-100 nm) constitute the modular units of cell adhesion sites in both cell-matrix and cell-cell adhesions. Super resolution microscopy and membrane protein diffusion studies both suggest that even large focal adhesions are formed of 100 nm clusters that are loosely aggregated. Clusters of 20-50 adhesion molecules (integrins or cadherins) can support large forces through avidity binding interactions but can also be disassembled or endocytosed rapidly. Assembly of the clusters of integrins is force-independent and involves gathering integrins at ligand binding sites where they are stabilized by cytoplasmic adhesion proteins that crosslink the integrin cytoplasmic tails plus connect the clusters to the cell cytoskeleton. Cooperative-signaling events can occur in a single cluster without cascading to other clusters. Thus, the clusters appear to be very important elements in many cellular processes and can be considered as a critical functional module.
Collapse
Affiliation(s)
- Rishita Changede
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Michael Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| |
Collapse
|
129
|
Compartmentalization of the Cell Membrane. J Mol Biol 2016; 428:4739-4748. [DOI: 10.1016/j.jmb.2016.09.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 11/20/2022]
|
130
|
Józefowski S, Śróttek M. Lipid raft-dependent endocytosis negatively regulates responsiveness of J774 macrophage-like cells to LPS by down regulating the cell surface expression of LPS receptors. Cell Immunol 2016; 312:42-50. [PMID: 27908440 DOI: 10.1016/j.cellimm.2016.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 11/13/2016] [Accepted: 11/22/2016] [Indexed: 01/07/2023]
Abstract
Acting through CD14 and TLR4/MD-2, lipopolysaccharide (LPS) triggers strong pro-inflammatory activation of macrophages, which, if not appropriately controlled, may lead to lethal septic shock. Therefore, numerous mechanisms of negative regulation of responses to LPS exist, but whether they include down-regulation of LPS receptors is not clear. We have found that in J774 cells, the clathrin-dependent endocytic pathway enables activation of TRIF-dependent TLR4 signaling within endosomes, but is not associated with the down-regulation of TLR4 or CD14 surface expression. In contrast, lipid raft-dependent endocytosis negatively regulates the basal cell surface expression of LPS receptors and, consequently, responsiveness to LPS. Together with observations that treatments, known to selectively disrupt lipid rafts, do not inhibit LPS-stimulated cytokine production, our results suggest that lipid rafts may serve as sites in which LPS receptors are sorted for endocytosis, rather than being platforms for the assembly of TLR4-centered signaling complexes, as suggested previously.
Collapse
Affiliation(s)
- Szczepan Józefowski
- Department of Immunology, Jagiellonian University Medical College, Czysta Street 18, 31-121 Kraków, Poland.
| | - Małgorzata Śróttek
- Department of Immunology, Jagiellonian University Medical College, Czysta Street 18, 31-121 Kraków, Poland
| |
Collapse
|
131
|
Griffié J, Shannon M, Bromley CL, Boelen L, Burn GL, Williamson DJ, Heard NA, Cope AP, Owen DM, Rubin-Delanchy P. A Bayesian cluster analysis method for single-molecule localization microscopy data. Nat Protoc 2016; 11:2499-2514. [PMID: 27854362 DOI: 10.1038/nprot.2016.149] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell function is regulated by the spatiotemporal organization of the signaling machinery, and a key facet of this is molecular clustering. Here, we present a protocol for the analysis of clustering in data generated by 2D single-molecule localization microscopy (SMLM)-for example, photoactivated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM). Three features of such data can cause standard cluster analysis approaches to be ineffective: (i) the data take the form of a list of points rather than a pixel array; (ii) there is a non-negligible unclustered background density of points that must be accounted for; and (iii) each localization has an associated uncertainty in regard to its position. These issues are overcome using a Bayesian, model-based approach. Many possible cluster configurations are proposed and scored against a generative model, which assumes Gaussian clusters overlaid on a completely spatially random (CSR) background, before every point is scrambled by its localization precision. We present the process of generating simulated and experimental data that are suitable to our algorithm, the analysis itself, and the extraction and interpretation of key cluster descriptors such as the number of clusters, cluster radii and the number of localizations per cluster. Variations in these descriptors can be interpreted as arising from changes in the organization of the cellular nanoarchitecture. The protocol requires no specific programming ability, and the processing time for one data set, typically containing 30 regions of interest, is ∼18 h; user input takes ∼1 h.
Collapse
Affiliation(s)
- Juliette Griffié
- Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, London, UK
| | - Michael Shannon
- Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, London, UK
| | - Claire L Bromley
- MRC Centre for Developmental Biology, King's College London, London, UK
| | - Lies Boelen
- Faculty of Medicine, Imperial College London, London, UK
| | - Garth L Burn
- Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, London, UK
| | - David J Williamson
- Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, London, UK
| | - Nicholas A Heard
- Department of Mathematics, Imperial College London and Heilbronn Institute for Mathematical Research, University of Bristol, Bristol, UK
| | - Andrew P Cope
- Division of Immunology, Infection and Inflammatory Disease, Academic Department of Rheumatology, King's College London, London, UK
| | - Dylan M Owen
- Department of Physics and Randall Division of Cell and Molecular Biophysics, King's College London, London, UK
| | - Patrick Rubin-Delanchy
- Department of Statistics, University of Oxford and Heilbronn Institute for Mathematical Research, University of Bristol, Bristol, UK
| |
Collapse
|
132
|
Kumar A, Shivashankar GV. Dynamic interaction between actin and nesprin2 maintain the cell nucleus in a prestressed state. Methods Appl Fluoresc 2016; 4:044008. [DOI: 10.1088/2050-6120/4/4/044008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
133
|
Richardson DD, Fernandez-Borja M. Leukocyte adhesion and polarization: Role of glycosylphosphatidylinositol-anchored proteins. BIOARCHITECTURE 2016; 5:61-9. [PMID: 26744925 PMCID: PMC4832445 DOI: 10.1080/19490992.2015.1127466] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Leukocyte traffic out of the blood stream is crucial for an adequate immune response. Leukocyte extravasation is critically dependent on the binding of leukocyte integrins to their endothelial counterreceptors. This interaction enables the firm adhesion of leukocytes to the luminal side of the vascular wall and allows for leukocyte polarization, crawling and diapedesis. Leukocyte adhesion, polarization and migration requires the orchestrated regulation of integrin adhesion/de-adhesion dynamics and actin cytoskeleton rearrangements. Adhesion strength depends on conformational changes of integrin molecules (affinity) as well as the number of integrin molecules engaged at adhesion sites (valency). These two processes can be independently regulated and several molecules modulate either one or both processes. Cholesterol-rich membrane domains (lipid rafts) participate in integrin regulation and play an important role in leukocyte adhesion, polarization and motility. In particular, lipid raft-resident glycosyl-phosphatidyl-inositol-anchored proteins (GPI-APs) have been reported to regulate leukocyte adhesion, polarization and motility in both integrin-dependent and independent manners. Here, we present our recent discovery concerning the novel role of the GPI-AP prion protein (PrP) in the regulation of β1 integrin-mediated monocyte adhesion, migration and shape polarization in the context of existing literature on GPI-AP-dependent regulation of integrins.
Collapse
Affiliation(s)
- Dion D Richardson
- a Deptartment of Molecular Cell Biology ; Sanquin Research and Landsteiner Laboratory; University of Amsterdam ; Amsterdam , Netherlands
| | - Mar Fernandez-Borja
- a Deptartment of Molecular Cell Biology ; Sanquin Research and Landsteiner Laboratory; University of Amsterdam ; Amsterdam , Netherlands
| |
Collapse
|
134
|
Goiko M, de Bruyn JR, Heit B. Short-Lived Cages Restrict Protein Diffusion in the Plasma Membrane. Sci Rep 2016; 6:34987. [PMID: 27725698 PMCID: PMC5057110 DOI: 10.1038/srep34987] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/22/2016] [Indexed: 01/08/2023] Open
Abstract
The plasma membrane is a heterogeneous environment characterized by anomalous diffusion and the presence of microdomains that are molecularly distinct from the bulk membrane. Using single particle tracking of the C-type lectin CD93, we have identified for the first time the transient trapping of transmembrane proteins in cage-like microdomains which restrict protein diffusion. These cages are stabilized by actin-dependent confinement regions, but are separate structures with sizes and lifespans uncorrelated to those of the underlying actin corral. These membrane cages require cholesterol for their strength and stability, with cholesterol depletion decreasing both. Despite this, cages are much larger in size and are longer lived than lipid rafts, suggesting instead that cholesterol-dependent effects on membrane fluidity or molecular packing play a role in cage formation. This diffusional compartment in the plasma membrane has characteristics of both a diffusional barrier and a membrane microdomain, with a size and lifespan intermediate between short-lived microdomains such as lipid rafts and long-lasting diffusional barriers created by the actin cytoskeleton.
Collapse
Affiliation(s)
- Maria Goiko
- Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, N6A 5C1 Canada.,Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, N6A 3K7 Canada
| | - John R de Bruyn
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, N6A 3K7 Canada
| | - Bryan Heit
- Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, N6A 5C1 Canada.,Centre for Human Immunology, The University of Western Ontario, London, Ontario, N6A 5C1 Canada
| |
Collapse
|
135
|
Brameshuber M, Sevcsik E, Rossboth BK, Manner C, Deigner HP, Peksel B, Péter M, Török Z, Hermetter A, Schütz GJ. Oxidized Phospholipids Inhibit the Formation of Cholesterol-Dependent Plasma Membrane Nanoplatforms. Biophys J 2016; 110:205-13. [PMID: 26745423 DOI: 10.1016/j.bpj.2015.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/14/2015] [Accepted: 11/13/2015] [Indexed: 01/08/2023] Open
Abstract
We previously developed a single-molecule microscopy method termed TOCCSL (thinning out clusters while conserving stoichiometry of labeling), which allows for direct imaging of stable nanoscopic platforms with raft-like properties diffusing in the plasma membrane. As a consensus raft marker, we chose monomeric GFP linked via a glycosylphosphatidylinositol (GPI) anchor to the cell membrane (mGFP-GPI). With this probe, we previously observed cholesterol-dependent homo-association to nanoplatforms diffusing in the plasma membrane of live CHO cells. Here, we report the release of this homo-association upon addition of 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) or 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine, two oxidized phospholipids (oxPLs) that are typically present in oxidatively modified low-density lipoprotein. We found a dose-response relationship for mGFP-GPI nanoplatform disintegration upon addition of POVPC, correlating with the signal of the apoptosis marker Annexin V-Cy3. Similar concentrations of lysolipid showed no effect, indicating that the observed phenomena were not linked to properties of the lipid bilayer itself. Inhibition of acid sphingomyelinase by NB-19 before addition of POVPC completely abolished nanoplatform disintegration by oxPLs. In conclusion, we were able to determine how oxidized lipid species disrupt mGFP-GPI nanoplatforms in the plasma membrane. Our results favor an indirect mechanism involving acid sphingomyelinase activity rather than a direct interaction of oxPLs with nanoplatform constituents.
Collapse
Affiliation(s)
| | - Eva Sevcsik
- Institute of Applied Physics, TU Wien, Vienna, Austria
| | | | | | - Hans-Peter Deigner
- Faculty of Medical and Life Sciences, Institute of Precision Medicine, Furtwangen University, Villingen-Schwenningen, Germany; Fraunhofer Institute IZI/EXIM, Furtwangen, Germany
| | - Begüm Peksel
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Mária Péter
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Zsolt Török
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Albin Hermetter
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | | |
Collapse
|
136
|
Van Blerkom J, Zimmermann S. Ganglioside-enriched microdomains define an oolemma that is functionally polarized with respect to fertilizability in the mouse. Reprod Biomed Online 2016; 33:458-475. [DOI: 10.1016/j.rbmo.2016.06.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 06/17/2016] [Accepted: 06/29/2016] [Indexed: 10/21/2022]
|
137
|
Shelby SA, Veatch SL, Holowka DA, Baird BA. Functional nanoscale coupling of Lyn kinase with IgE-FcεRI is restricted by the actin cytoskeleton in early antigen-stimulated signaling. Mol Biol Cell 2016; 27:3645-3658. [PMID: 27682583 PMCID: PMC5221596 DOI: 10.1091/mbc.e16-06-0425] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/20/2016] [Indexed: 12/13/2022] Open
Abstract
Spatial targeting of signaling components to activated receptors on the plasma membrane is key for initiating signal transduction. The actin cytoskeleton restricts antigen-stimulated colocalization of IgE-FcεRI with membrane-anchored signaling partner Lyn kinase, and this regulation is mediated by organization of plasma membrane lipids. The allergic response is initiated on the plasma membrane of mast cells by phosphorylation of the receptor for immunoglobulin E (IgE), FcεRI, by Lyn kinase after IgE-FcεRI complexes are cross-linked by multivalent antigen. Signal transduction requires reorganization of receptors and membrane signaling proteins, but this spatial regulation is not well defined. We used fluorescence localization microscopy (FLM) and pair-correlation analysis to measure the codistribution of IgE-FcεRI and Lyn on the plasma membrane of fixed cells with 20- to 25-nm resolution. We directly visualized Lyn recruitment to IgE-FcεRI within 1 min of antigen stimulation. Parallel FLM experiments captured stimulation-induced FcεRI phosphorylation and colocalization of a saturated lipid-anchor probe derived from Lyn’s membrane anchorage. We used cytochalasin and latrunculin to investigate participation of the actin cytoskeleton in regulating functional interactions of FcεRI. Inhibition of actin polymerization by these agents enhanced colocalization of IgE-FcεRI with Lyn and its saturated lipid anchor at early stimulation times, accompanied by augmented phosphorylation within FcεRI clusters. Ising model simulations provide a simplified model consistent with our results. These findings extend previous evidence that IgE-FcεRI signaling is initiated by colocalization with Lyn in ordered lipid regions and that the actin cytoskeleton regulates this functional interaction by influencing the organization of membrane lipids.
Collapse
Affiliation(s)
- Sarah A Shelby
- Department of Chemistry and Chemical Biology and Field of Biophysics, Cornell University, Ithaca, NY 14853
| | - Sarah L Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109
| | - David A Holowka
- Department of Chemistry and Chemical Biology and Field of Biophysics, Cornell University, Ithaca, NY 14853
| | - Barbara A Baird
- Department of Chemistry and Chemical Biology and Field of Biophysics, Cornell University, Ithaca, NY 14853
| |
Collapse
|
138
|
Goyette J, Gaus K. Mechanisms of protein nanoscale clustering. Curr Opin Cell Biol 2016; 44:86-92. [PMID: 27666166 DOI: 10.1016/j.ceb.2016.09.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/08/2016] [Indexed: 12/22/2022]
Abstract
Due to recent technical developments in microscopy, huge advances have been made in our understanding of the architecture of the cell membrane. It is now well appreciated that nanoscale clustering is a common feature of membrane proteins. Many of these clusters have been implicated in signal initiation and integration platforms. However, the mechanisms that mediate the dynamic nanoscale arrangement of membrane proteins are not fully understood and could involve lipid domains, electrostatic interactions between proteins and lipid, protein scaffolding as well as purely mechanical processes. In this review we summarise these mechanisms giving rise to dynamic nanoscale protein reorganisation in the plasma membrane with reference to recent examples of immune receptor clustering to illustrate general principles.
Collapse
Affiliation(s)
- Jesse Goyette
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney 2052, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney 2052, Australia
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney 2052, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney 2052, Australia.
| |
Collapse
|
139
|
Levental I, Veatch S. The Continuing Mystery of Lipid Rafts. J Mol Biol 2016; 428:4749-4764. [PMID: 27575334 DOI: 10.1016/j.jmb.2016.08.022] [Citation(s) in RCA: 192] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/16/2016] [Accepted: 08/19/2016] [Indexed: 12/12/2022]
Abstract
Since its initial formalization nearly 20 years ago, the concept of lipid rafts has generated a tremendous amount of attention and interest and nearly as much controversy. The controversy is perhaps surprising because the notion itself is intuitive: compartmentalization in time and space is a ubiquitous theme at all scales of biology, and therefore, the partitioning of cellular membranes into lateral subdivision should be expected. Nevertheless, the physicochemical principles responsible for compartmentalization and the molecular mechanisms by which they are functionalized remain nearly as mysterious today as they were two decades ago. Herein, we review recent literature on this topic with a specific focus on the major open questions in the field including: (1) what are the best tools to assay raft behavior in living membranes? (2) what is the function of the complex lipidome of mammalian cells with respect to membrane organization? (3) what are the mechanisms that drive raft formation and determine their properties? (4) how can rafts be modulated? (5) how is membrane compartmentalization integrated into cellular signaling? Despite decades of intensive research, this compelling field remains full of fundamental questions.
Collapse
Affiliation(s)
- Ilya Levental
- McGovern Medical School at the University of Texas Houston, Department of Integrative Biology and Pharmacology
| | | |
Collapse
|
140
|
Welf ES, Driscoll MK, Dean KM, Schäfer C, Chu J, Davidson MW, Lin MZ, Danuser G, Fiolka R. Quantitative Multiscale Cell Imaging in Controlled 3D Microenvironments. Dev Cell 2016; 36:462-75. [PMID: 26906741 DOI: 10.1016/j.devcel.2016.01.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 11/11/2015] [Accepted: 01/26/2016] [Indexed: 12/30/2022]
Abstract
The microenvironment determines cell behavior, but the underlying molecular mechanisms are poorly understood because quantitative studies of cell signaling and behavior have been challenging due to insufficient spatial and/or temporal resolution and limitations on microenvironmental control. Here we introduce microenvironmental selective plane illumination microscopy (meSPIM) for imaging and quantification of intracellular signaling and submicrometer cellular structures as well as large-scale cell morphological and environmental features. We demonstrate the utility of this approach by showing that the mechanical properties of the microenvironment regulate the transition of melanoma cells from actin-driven protrusion to blebbing, and we present tools to quantify how cells manipulate individual collagen fibers. We leverage the nearly isotropic resolution of meSPIM to quantify the local concentration of actin and phosphatidylinositol 3-kinase signaling on the surfaces of cells deep within 3D collagen matrices and track the many small membrane protrusions that appear in these more physiologically relevant environments.
Collapse
Affiliation(s)
- Erik S Welf
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Meghan K Driscoll
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kevin M Dean
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Claudia Schäfer
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jun Chu
- Departments of Bioengineering and Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Michael W Davidson
- National High Magnetic Field Laboratory, Department of Biological Science, Florida State University, Tallahassee, FL 32310, USA
| | - Michael Z Lin
- Departments of Bioengineering and Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Reto Fiolka
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
141
|
Chen J, Gao J, Cai M, Xu H, Jiang J, Tian Z, Wang H. Mechanistic insights into the distribution of carbohydrate clusters on cell membranes revealed by dSTORM imaging. NANOSCALE 2016; 8:13611-13619. [PMID: 27362510 DOI: 10.1039/c6nr02513g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cell surface carbohydrates play significant roles in many physiological processes and act as primary markers to indicate various cellular physiological states. The functions of carbohydrates are always associated with their expression and distribution on cell membranes. Based on our previous work, we found that carbohydrates tend to form clusters; however, the underlying mechanism of these clusters remains unknown. Through the direct stochastic optical reconstruction microscopy (dSTORM) strategy, we found that with the contributions of lipid raft as a stable factor and actin cytoskeleton as a restrictive factor, carbohydrate clusters can stably exist with restricted size. Additionally, we revealed that the formation of most carbohydrate clusters (Gal and GlcANc clusters) depended on the carbohydrate-binding proteins (i.e., galectins) cross-linking their specific carbohydrate ligands. Our results clarify the organizational mechanism of carbohydrates on cell surfaces from their formation, stable existence and size-restriction, which promotes a better understanding of the relationship between the function and distribution of carbohydrates, as well as the structure of cell membranes.
Collapse
Affiliation(s)
- Junling Chen
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China. and University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Jing Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
| | - Mingjun Cai
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
| | - Haijiao Xu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
| | - Junguang Jiang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
| | - Zhiyuan Tian
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongda Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
| |
Collapse
|
142
|
Sharonov GV, Balatskaya MN, Tkachuk VA. Glycosylphosphatidylinositol-anchored proteins as regulators of cortical cytoskeleton. BIOCHEMISTRY (MOSCOW) 2016; 81:636-50. [DOI: 10.1134/s0006297916060110] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
143
|
Mattila PK, Batista FD, Treanor B. Dynamics of the actin cytoskeleton mediates receptor cross talk: An emerging concept in tuning receptor signaling. J Cell Biol 2016; 212:267-80. [PMID: 26833785 PMCID: PMC4748574 DOI: 10.1083/jcb.201504137] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Recent evidence implicates the actin cytoskeleton in the control of receptor signaling. This may be of particular importance in the context of immune receptors, such as the B cell receptor, where dysregulated signaling can result in autoimmunity and malignancy. Here, we discuss the role of the actin cytoskeleton in controlling receptor compartmentalization, dynamics, and clustering as a means to regulate receptor signaling through controlling the interactions with protein partners. We propose that the actin cytoskeleton is a point of integration for receptor cross talk through modulation of protein dynamics and clustering. We discuss the implication of this cross talk via the cytoskeleton for both ligand-induced and low-level constitutive (tonic) signaling necessary for immune cell survival.
Collapse
Affiliation(s)
- Pieta K Mattila
- Institute of Biomedicine, MediCity, University of Turku, 20520 Turku, Finland
| | - Facundo D Batista
- Lymphocyte Interaction Laboratory, The Francis Crick Institute, Cancer Research UK, London WC2A 3LY, England, UK
| | - Bebhinn Treanor
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M5T 1C6, Canada
| |
Collapse
|
144
|
Na+ Influx Induced by New Antimalarials Causes Rapid Alterations in the Cholesterol Content and Morphology of Plasmodium falciparum. PLoS Pathog 2016; 12:e1005647. [PMID: 27227970 PMCID: PMC4881962 DOI: 10.1371/journal.ppat.1005647] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/28/2016] [Indexed: 12/27/2022] Open
Abstract
Among the several new antimalarials discovered over the past decade are at least three clinical candidate drugs, each with a distinct chemical structure, that disrupt Na+ homeostasis resulting in a rapid increase in intracellular Na+ concentration ([Na+]i) within the erythrocytic stages of Plasmodium falciparum. At present, events triggered by Na+ influx that result in parasite demise are not well-understood. Here we report effects of two such drugs, a pyrazoleamide and a spiroindolone, on intraerythrocytic P. falciparum. Within minutes following the exposure to these drugs, the trophozoite stage parasite, which normally contains little cholesterol, was made permeant by cholesterol-dependent detergents, suggesting it acquired a substantial amount of the lipid. Consistently, the merozoite surface protein 1 and 2 (MSP1 and MSP2), glycosylphosphotidylinositol (GPI)-anchored proteins normally uniformly distributed in the parasite plasma membrane, coalesced into clusters. These alterations were not observed following drug treatment of P. falciparum parasites adapted to grow in a low [Na+] growth medium. Both cholesterol acquisition and MSP1 coalescence were reversible upon the removal of the drugs, implicating an active process of cholesterol exclusion from trophozoites that we hypothesize is inhibited by high [Na+]i. Electron microscopy of drug-treated trophozoites revealed substantial morphological changes normally seen at the later schizont stage including the appearance of partial inner membrane complexes, dense organelles that resemble "rhoptries" and apparent nuclear division. Together these results suggest that [Na+]i disruptor drugs by altering levels of cholesterol in the parasite, dysregulate trophozoite to schizont development and cause parasite demise.
Collapse
|
145
|
Chakraborty S, Pal S, Chatterjee S, Barma M. Large compact clusters and fast dynamics in coupled nonequilibrium systems. Phys Rev E 2016; 93:050102. [PMID: 27300811 DOI: 10.1103/physreve.93.050102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Indexed: 06/06/2023]
Abstract
We demonstrate particle clustering on macroscopic scales in a coupled nonequilibrium system where two species of particles are advected by a fluctuating landscape and modify the landscape in the process. The phase diagram generated by varying the particle-landscape coupling, valid for all particle densities and in both one and two dimensions, shows novel nonequilibrium phases. While particle species are completely phase separated, the landscape develops macroscopically ordered regions coexisting with a disordered region, resulting in coarsening and steady state dynamics on time scales which grow algebraically with size, not seen earlier in systems with pure domains.
Collapse
Affiliation(s)
- Shauri Chakraborty
- Department of Theoretical Sciences, S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098, India
| | - Sukla Pal
- Department of Theoretical Sciences, S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098, India
| | - Sakuntala Chatterjee
- Department of Theoretical Sciences, S.N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata 700098, India
| | - Mustansir Barma
- TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Osman Sagar Road, Narsingi, Hyderabad 500075, India
| |
Collapse
|
146
|
Tilsner J, Nicolas W, Rosado A, Bayer EM. Staying Tight: Plasmodesmal Membrane Contact Sites and the Control of Cell-to-Cell Connectivity in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2016; 67:337-64. [PMID: 26905652 DOI: 10.1146/annurev-arplant-043015-111840] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Multicellularity differs in plants and animals in that the cytoplasm, plasma membrane, and endomembrane of plants are connected between cells through plasmodesmal pores. Plasmodesmata (PDs) are essential for plant life and serve as conduits for the transport of proteins, small RNAs, hormones, and metabolites during developmental and defense signaling. They are also the only pathways available for viruses to spread within plant hosts. The membrane organization of PDs is unique, characterized by the close apposition of the endoplasmic reticulum and the plasma membrane and spoke-like filamentous structures linking the two membranes, which define PDs as membrane contact sites (MCSs). This specialized membrane arrangement is likely critical for PD function. Here, we review how PDs govern developmental and defensive signaling in plants, compare them with other types of MCSs, and discuss in detail the potential functional significance of the MCS nature of PDs.
Collapse
Affiliation(s)
- Jens Tilsner
- Biomedical Sciences Research Complex, University of St Andrews, Fife KY16 9ST, United Kingdom;
- Cell and Molecular Sciences, The James Hutton Institute, Dundee DD2 5DA, United Kingdom
| | - William Nicolas
- Laboratory of Membrane Biogenesis, UMR5200 CNRS, University of Bordeaux, 33883 Villenave d'Ornon Cedex, France; ,
| | - Abel Rosado
- Department of Botany, Faculty of Sciences, University of British Columbia, Vancouver V6T 1Z4, Canada;
| | - Emmanuelle M Bayer
- Laboratory of Membrane Biogenesis, UMR5200 CNRS, University of Bordeaux, 33883 Villenave d'Ornon Cedex, France; ,
| |
Collapse
|
147
|
Masters TA, Sheetz MP, Gauthier NC. F-actin waves, actin cortex disassembly and focal exocytosis driven by actin-phosphoinositide positive feedback. Cytoskeleton (Hoboken) 2016; 73:180-96. [PMID: 26915738 DOI: 10.1002/cm.21287] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/11/2016] [Accepted: 02/18/2016] [Indexed: 12/29/2022]
Abstract
Actin polymerization is controlled by the phosphoinositide composition of the plasma membrane. However, the molecular mechanisms underlying the spatiotemporal regulation of actin network organization over extended length scales are still unclear. To observe phosphoinositide-dependent cytoskeletal dynamics we combined the model system of frustrated phagocytosis, total internal reflection microscopy and manipulation of the buffer tonicity. We found that macrophages interacting with IgG-coated glass substrates formed circular F-actin waves on their ventral surface enclosing a region of plasma membrane devoid of cortical actin. Plasma membrane free of actin cortex was strongly depleted of PI(4,5)P2 , but enriched in PI(3,4)P2 and displayed a fivefold increase in exocytosis. Wave formation could be promoted by application of a hypotonic shock. The actin waves were characteristic of a bistable wavefront at the boundary between the regions of membrane containing and lacking cortical actin. Phosphoinositide modifiers and RhoGTPase activities dramatically redistributed with respect to the wavefronts, which often exhibited spatial oscillations. Perturbation of either lipid or actin cytoskeleton-related pathways led to rapid loss of both the polarized lipid distribution and the wavefront. As waves travelled over the plasma membrane, wavefront actin was seen to rapidly polymerize and depolymerize at pre-existing clusters of FcγRIIA, coincident with rapid changes in lipid composition. Thus the potential of receptors to support rapid F-actin polymerization appears to depend acutely on the local concentrations of multiple lipid species. We propose that interdependence through positive feedback from the cytoskeleton to lipid modifiers leads to coordinated local cortex remodeling, focal exocytosis, and organizes extended actin networks.
Collapse
Affiliation(s)
- Thomas A Masters
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Michael P Sheetz
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore.,Department of Biological Sciences, Columbia University, New York, New York, 10027
| | - Nils C Gauthier
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| |
Collapse
|
148
|
Zurzolo C, Simons K. Glycosylphosphatidylinositol-anchored proteins: Membrane organization and transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:632-9. [DOI: 10.1016/j.bbamem.2015.12.018] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 12/12/2015] [Accepted: 12/15/2015] [Indexed: 11/17/2022]
|
149
|
Roles for lipid heterogeneity in immunoreceptor signaling. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:830-836. [PMID: 26995463 DOI: 10.1016/j.bbalip.2016.03.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 03/12/2016] [Accepted: 03/14/2016] [Indexed: 11/22/2022]
Abstract
Immune receptors that specifically recognize foreign antigens to activate leukocytes in adaptive immune responses belong to a family of multichain cell surface proteins. All of these contain immunoreceptor tyrosine-based activation motifs in one or more subunits that initiate signaling cascades following stimulated tyrosine phosphorylation by Src-family kinases. As highlighted in this review, lipids participate in this initial activation step, as well as in more downstream signaling steps. We summarize evidence for cholesterol-dependent ordered lipids serving to regulate the store-operated Ca(2+) channel, Orai1, and we describe the sensitivity of Orai1 coupling to the ER Ca(2+) sensor, STIM1, to inhibition by polyunsaturated fatty acids. Phosphoinositides play key roles in regulating STIM1-Orai1 coupling, as well as in the stimulated Ca(2+) oscillations that are a consequence of IgE receptor signaling in mast cells. They also participate in the coupling between the plasma membrane and the actin cytoskeleton, which regulates immune receptor responses in T cells, B cells, and mast cells, both positively and negatively, depending on the cellular context. Recent studies show that other phospholipids with mostly saturated acylation also participate in coupling between receptors and the actin cytoskeleton. Lipid heterogeneity is a central feature of the intimate relationship between the plasma membrane and the actin cytoskeleton. The detailed nature of these interactions and how they are dynamically regulated to initiate and propagate receptor-mediated cell signaling are challenging questions for further investigation. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
Collapse
|
150
|
Cortical actin and the plasma membrane: inextricably intertwined. Curr Opin Cell Biol 2016; 38:81-9. [PMID: 26986983 DOI: 10.1016/j.ceb.2016.02.021] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/09/2016] [Accepted: 02/25/2016] [Indexed: 11/22/2022]
Abstract
The plasma membrane serves as a barrier, separating the cell from its external environment. Simultaneously it acts as a site for information transduction, entry of nutrients, receptor signaling, and adapts to the shape of the cell. This requires local control of organization at multiple scales in this heterogeneous fluid lipid bilayer with a plethora of proteins and a closely juxtaposed dynamic cortical cytoskeleton. New membrane models highlight the influence of the underlying cortical actin on the diffusion of membrane components. Myosin motors as well as proteins that remodel actin filaments have additionally been implicated in defining the organization of many membrane constituents. Here we provide a perspective of the intimate relationship of the membrane lipid matrix and the underlying cytoskeleton.
Collapse
|