1
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Kambar N, Go YK, Snyder C, Do MN, Leal C. Structural characterization of lateral phase separation in polymer-lipid hybrid membranes. Methods Enzymol 2024; 700:235-273. [PMID: 38971602 DOI: 10.1016/bs.mie.2024.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
Hierarchic self-assembly is the main mechanism used to create diverse structures using soft materials. This is a case for both synthetic materials and biomolecular systems, as exemplified by the non-covalent organization of lipids into membranes. In nature, lipids often assemble into single bilayers, but other nanostructures are encountered, such as bilayer stacks and tubular and vesicular aggregates. Synthetic block copolymers can be engineered to recapitulate many of the structures, forms, and functions of lipid systems. When block copolymers are amphiphilic, they can be inserted or co-assembled into hybrid membranes that exhibit synergistic structural, permeability, and mechanical properties. One example is the emergence of lateral phase separation akin to the raft formation in biomembranes. When higher-order structures, such as hybrid membranes, are formed, this lateral phase separation can be correlated across membranes in the stack. This chapter outlines a set of important methods, such as X-ray Scattering, Atomic Force Microscopy, and Cryo-Electron Microscopy, that are relevant to characterizing and evaluating lateral and correlated phase separation in hybrid membranes at the nano and mesoscales. Understanding the phase behavior of polymer-lipid hybrid materials could lead to innovative advancements in biomimetic membrane separation systems.
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Affiliation(s)
- Nurila Kambar
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Yoo Kyung Go
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Corey Snyder
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Minh N Do
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Cecília Leal
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States.
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2
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Ye Y, Morita S, Chang JJ, Buckley PM, Wilhelm KB, DiMaio D, Groves JT, Barrera FN. Allosteric inhibition of the T cell receptor by a designed membrane ligand. eLife 2023; 12:e82861. [PMID: 37796108 PMCID: PMC10554751 DOI: 10.7554/elife.82861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 09/20/2023] [Indexed: 10/06/2023] Open
Abstract
The T cell receptor (TCR) is a complex molecular machine that directs the activation of T cells, allowing the immune system to fight pathogens and cancer cells. Despite decades of investigation, the molecular mechanism of TCR activation is still controversial. One of the leading activation hypotheses is the allosteric model. This model posits that binding of pMHC at the extracellular domain triggers a dynamic change in the transmembrane (TM) domain of the TCR subunits, which leads to signaling at the cytoplasmic side. We sought to test this hypothesis by creating a TM ligand for TCR. Previously we described a method to create a soluble peptide capable of inserting into membranes and binding to the TM domain of the receptor tyrosine kinase EphA2 (Alves et al., eLife, 2018). Here, we show that the approach is generalizable to complex membrane receptors, by designing a TM ligand for TCR. We observed that the designed peptide caused a reduction of Lck phosphorylation of TCR at the CD3ζ subunit in T cells. As a result, in the presence of this peptide inhibitor of TCR (PITCR), the proximal signaling cascade downstream of TCR activation was significantly dampened. Co-localization and co-immunoprecipitation in diisobutylene maleic acid (DIBMA) native nanodiscs confirmed that PITCR was able to bind to the TCR. AlphaFold-Multimer predicted that PITCR binds to the TM region of TCR, where it interacts with the two CD3ζ subunits. Our results additionally indicate that PITCR disrupts the allosteric changes in the compactness of the TM bundle that occur upon TCR activation, lending support to the allosteric TCR activation model. The TCR inhibition achieved by PITCR might be useful to treat inflammatory and autoimmune diseases and to prevent organ transplant rejection, as in these conditions aberrant activation of TCR contributes to disease.
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Affiliation(s)
- Yujie Ye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee at KnoxvilleKnoxvilleUnited States
| | - Shumpei Morita
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Justin J Chang
- Department of Genetics, Yale UniversityNew HavenUnited States
| | - Patrick M Buckley
- Department of Microbial Pathogenesis, Yale UniversityNew HavenUnited States
| | - Kiera B Wilhelm
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Daniel DiMaio
- Department of Genetics, Yale UniversityNew HavenUnited States
| | - Jay T Groves
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Institute for Digital Molecular Analytics and Science, Nanyang Technological UniversitySingaporeSingapore
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee at KnoxvilleKnoxvilleUnited States
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3
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Wijesinghe WCB, Min D. Single-Molecule Force Spectroscopy of Membrane Protein Folding. J Mol Biol 2023; 435:167975. [PMID: 37330286 DOI: 10.1016/j.jmb.2023.167975] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 06/19/2023]
Abstract
Single-molecule force spectroscopy is a unique method that can probe the structural changes of single proteins at a high spatiotemporal resolution while mechanically manipulating them over a wide force range. Here, we review the current understanding of membrane protein folding learned by using the force spectroscopy approach. Membrane protein folding in lipid bilayers is one of the most complex biological processes in which diverse lipid molecules and chaperone proteins are intricately involved. The approach of single protein forced unfolding in lipid bilayers has produced important findings and insights into membrane protein folding. This review provides an overview of the forced unfolding approach, including recent achievements and technical advances. Progress in the methods can reveal more interesting cases of membrane protein folding and clarify general mechanisms and principles.
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Affiliation(s)
- W C Bhashini Wijesinghe
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Duyoung Min
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea; Center for Wave Energy Materials, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
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4
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Montalbo RCK, Tu HL. Micropatterning of functional lipid bilayer assays for quantitative bioanalysis. BIOMICROFLUIDICS 2023; 17:031302. [PMID: 37179590 PMCID: PMC10171888 DOI: 10.1063/5.0145997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023]
Abstract
Interactions of the cell with its environment are mediated by the cell membrane and membrane-localized molecules. Supported lipid bilayers have enabled the recapitulation of the basic properties of cell membranes and have been broadly used to further our understanding of cellular behavior. Coupled with micropatterning techniques, lipid bilayer platforms have allowed for high throughput assays capable of performing quantitative analysis at a high spatiotemporal resolution. Here, an overview of the current methods of the lipid membrane patterning is presented. The fabrication and pattern characteristics are briefly described to present an idea of the quality and notable features of the methods, their utilizations for quantitative bioanalysis, as well as to highlight possible directions for the advanced micropatterning lipid membrane assays.
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5
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Cao F, Taylor MJ. Visualization of Myddosome Assembly in Live Cells. Methods Mol Biol 2023; 2654:231-250. [PMID: 37106186 DOI: 10.1007/978-1-0716-3135-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The Myddosome is an oligomeric protein complex composed of MyD88 and members of IL-1 receptor-associated kinase (IRAK) family that transduce signals from Toll-like and IL-1 family receptors. The molecular dynamics of Myddosome formation and how the Myddosome organizes downstream signaling reactions provide insight into how TLR/IL-1Rs activate a decisive cellular response critical for the induction of inflammation. Supported lipid membranes formed on a continuous glass coverslip have been extensively used to study the molecular dynamics of receptor signaling. Here, we describe a protocol for the formation of IL-1-functionalized support lipid membrane that can be used to visualize the molecular dynamics of Myddosome formation and signaling in live cells.
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Affiliation(s)
- Fakun Cao
- Max Planck Institute for Infection Biology, Berlin, Germany
| | - Marcus J Taylor
- Max Planck Institute for Infection Biology, Berlin, Germany.
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6
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McAffee DB, O'Dair MK, Lin JJ, Low-Nam ST, Wilhelm KB, Kim S, Morita S, Groves JT. Discrete LAT condensates encode antigen information from single pMHC:TCR binding events. Nat Commun 2022; 13:7446. [PMID: 36460640 PMCID: PMC9718779 DOI: 10.1038/s41467-022-35093-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
LAT assembly into a two-dimensional protein condensate is a prominent feature of antigen discrimination by T cells. Here, we use single-molecule imaging techniques to resolve the spatial position and temporal duration of each pMHC:TCR molecular binding event while simultaneously monitoring LAT condensation at the membrane. An individual binding event is sufficient to trigger a LAT condensate, which is self-limiting, and neither its size nor lifetime is correlated with the duration of the originating pMHC:TCR binding event. Only the probability of the LAT condensate forming is related to the pMHC:TCR binding dwell time. LAT condenses abruptly, but after an extended delay from the originating binding event. A LAT mutation that facilitates phosphorylation at the PLC-γ1 recruitment site shortens the delay time to LAT condensation and alters T cell antigen specificity. These results identify a function for the LAT protein condensation phase transition in setting antigen discrimination thresholds in T cells.
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Affiliation(s)
- Darren B McAffee
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Mark K O'Dair
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Jenny J Lin
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Shalini T Low-Nam
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Kiera B Wilhelm
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sungi Kim
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Shumpei Morita
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
- Institute for Digital Molecular Analytics and Science, Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore.
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7
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Kao SH, Liang SY, Cheng PL, Tu HL. Surface Viscosity-Dependent Neurite Initiation in Cortical Neurons. Adv Biol (Weinh) 2022; 6:e2101325. [PMID: 35362269 DOI: 10.1002/adbi.202101325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/14/2022] [Indexed: 01/27/2023]
Abstract
Dynamic extracellular environments profoundly affect the behavior and function of cells both biochemically and mechanically. Neurite initiation is the first step for neurons to establish intricate neuronal networks. How such a process is modulated by mechanical factors is not fully understood. Particularly, it is unknown whether the molecular clutch model, which has been used to explain cell responses to matrix rigidity, also holds for neurite initiation. To study how mechanical properties modulate neurite initiation, substrates with various well-defined surface viscosities using supported lipid bilayers (SLBs) are synthesized. The results show that ligands with intermediate viscosity greatly maximize neurite initiation in primary neurons, while neurite initiation is drastically limited on substrates with higher or lower viscosity. Importantly, biochemical characterizations reveal altered focal adhesion and calpain activity are associated with distinct neurite initiation patterns. Collectively, these results indicate that neurite initiation is surface viscosity-dependent; there is an optimal range of surface viscosities to drive neurite initiation. Upon binding to ligands of varying viscosities, calpain activity is differentially triggered and leads to distinct levels of neurite outgrowth. These findings not only enhance the understanding of how extracellular environments regulate neurons, but also demonstrate the potential utility of SLBs for neural tissue engineering applications.
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Affiliation(s)
- Shih-Han Kao
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Shu-Yang Liang
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Pei-Lin Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
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8
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Oh D, Chen Z, Biswas KH, Bai F, Ong HT, Sheetz MP, Groves JT. Competition for shared downstream signaling molecules establishes indirect negative feedback between EGFR and EphA2. Biophys J 2022; 121:1897-1908. [DOI: 10.1016/j.bpj.2022.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/21/2022] [Accepted: 04/12/2022] [Indexed: 11/02/2022] Open
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9
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Abstract
Hierarchic self-assembly underpins much of the form and function seen in synthetic or biological soft materials. Lipids are paramount examples, building themselves in nature or synthetically in a variety of meso/nanostructures. Synthetic block copolymers capture many of lipid's structural and functional properties. Lipids are typically biocompatible and high molecular weight polymers are mechanically robust and chemically versatile. The development of new materials for applications like controlled drug/gene/protein delivery, biosensors, and artificial cells often requires the combination of lipids and polymers. The emergent composite material, a "polymer-lipid hybrid membrane", displays synergistic properties not seen in pure components. Specific examples include the observation that hybrid membranes undergo lateral phase separation that can correlate in registry across multiple layers into a three-dimensional phase-separated system with enhanced permeability of encapsulated drugs. It is timely to underpin these emergent properties in several categories of hybrid systems ranging from colloidal suspensions to supported hybrid films. In this review, we discuss the form and function of a vast number of polymer-lipid hybrid systems published to date. We rationalize the results to raise new fundamental understanding of hybrid self-assembling soft materials as well as to enable the design of new supramolecular systems and applications.
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Affiliation(s)
- Yoo Kyung Go
- Department of Materials Science and Engineering, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - Cecilia Leal
- Department of Materials Science and Engineering, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
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10
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Chen Z, Oh D, Biswas KH, Zaidel-Bar R, Groves JT. Probing the effect of clustering on EphA2 receptor signaling efficiency by subcellular control of ligand-receptor mobility. eLife 2021; 10:67379. [PMID: 34414885 PMCID: PMC8397371 DOI: 10.7554/elife.67379] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 08/19/2021] [Indexed: 11/29/2022] Open
Abstract
Clustering of ligand:receptor complexes on the cell membrane is widely presumed to have functional consequences for subsequent signal transduction. However, it is experimentally challenging to selectively manipulate receptor clustering without altering other biochemical aspects of the cellular system. Here, we develop a microfabrication strategy to produce substrates displaying mobile and immobile ligands that are separated by roughly 1 µm, and thus experience an identical cytoplasmic signaling state, enabling precision comparison of downstream signaling reactions. Applying this approach to characterize the ephrinA1:EphA2 signaling system reveals that EphA2 clustering enhances both receptor phosphorylation and downstream signaling activity. Single-molecule imaging clearly resolves increased molecular binding dwell times at EphA2 clusters for both Grb2:SOS and NCK:N-WASP signaling modules. This type of intracellular comparison enables a substantially higher degree of quantitative analysis than is possible when comparisons must be made between different cells and essentially eliminates the effects of cellular response to ligand manipulation.
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Affiliation(s)
- Zhongwen Chen
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China.,Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Dongmyung Oh
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, United States.,Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Kabir Hassan Biswas
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Ronen Zaidel-Bar
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
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11
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Ti YT, Cheng HC, Li Y, Tu HL. Multiplexed patterning of hybrid lipid membrane and protein arrays for cell signaling study. LAB ON A CHIP 2021; 21:2711-2720. [PMID: 34109339 DOI: 10.1039/d1lc00178g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The supported lipid bilayer (SLB) is a powerful tool for studying dynamic cell-environment interactions and has been widely used for biosensing applications. Using a reusable microfluidic chip, we present here a strategy to fabricate highly multiplexed SLB and protein arrays for cell signaling research. This approach allows for the rapid patterning of hundreds of highly reproducible and size-tunable SLB arrays with distinct lipid composition and mobility. Using fluorescence microscopy and fluorescence correlation spectroscopy, the lipid mobility is found to play a central role for patterning this membrane assay. Adding protein rings as diffusion barriers extends the accessible mobility range and maintains long-term stability of the hybrid array. Subsequent protein functionalizations on the SLB could be conducted using standard conjugation methods. The utility of the hybrid array for cell signaling experiments is demonstrated by studying the immune NF-κB signaling, whose activity is triggered by the binding of the membrane receptor, toll-like-receptor 4 (TLR 4), to its ligand, lipopolysaccharide (LPS), that is functionalized on the SLB. The patterned array allows cells to adhere and spread on areas without LPS before migrating to interact with membrane-bound LPS to initiate NF-κB activation. Overall, the strategy offers an efficient route to rapidly generate easily controllable and multiplexed molecular arrays that can serve as versatile platforms for biosensing and cell signaling research.
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Affiliation(s)
- Yu-Ting Ti
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan. and Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Hsiao-Chi Cheng
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
| | - Ying Li
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan. and Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taiwan
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12
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Ulmefors H, Nissa J, Pace H, Wahlsten O, Gunnarsson A, Simon DT, Berggren M, Höök F. Formation of Supported Lipid Bilayers Derived from Vesicles of Various Compositional Complexity on Conducting Polymer/Silica Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5494-5505. [PMID: 33929845 PMCID: PMC8280725 DOI: 10.1021/acs.langmuir.1c00175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/26/2021] [Indexed: 05/30/2023]
Abstract
Supported lipid bilayers (SLBs) serve important roles as minimalistic models of cellular membranes in multiple diagnostic and pharmaceutical applications as well as in the strive to gain fundamental insights about their complex biological function. To further expand the utility of SLBs, there is a need to go beyond simple lipid compositions to thereby better mimic the complexity of native cell membranes, while simultaneously retaining their compatibility with a versatile range of analytical platforms. To meet this demand, we have in this work explored SLB formation on PEDOT:PSS/silica nanoparticle composite films and mesoporous silica films, both capable of transporting ions to an underlying conducting PEDOT:PSS film. The SLB formation process was evaluated by using the quartz crystal microbalance with dissipation (QCM-D) monitoring, total internal reflection fluorescence (TIRF) microscopy, and fluorescence recovery after photobleaching (FRAP) for membranes made of pure synthetic lipids with or without the reconstituted membrane protein β-secretase 1 (BACE1) as well as cell-derived native lipid vesicles containing overexpressed BACE1. The mesoporous silica thin film was superior to the PEDOT:PSS/silica nanoparticle composite, providing successful formation of bilayers with high lateral mobility and low defect density even for the most complex native cell membranes.
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Affiliation(s)
- Hanna Ulmefors
- Division
of Nano and Biological Physics, Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Josefin Nissa
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Hudson Pace
- Division
of Nano and Biological Physics, Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Olov Wahlsten
- Division
of Nano and Biological Physics, Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Anders Gunnarsson
- Discovery
Sciences, BioPharmaceuticals R&D, AstraZeneca, Pepparedsleden 1, 431 83 Mölndal, Sweden
| | - Daniel T. Simon
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Magnus Berggren
- Laboratory
of Organic Electronics, Department of Science and Technology, Linköping University, 601 74 Norrköping, Sweden
| | - Fredrik Höök
- Division
of Nano and Biological Physics, Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
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13
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Deliz-Aguirre R, Cao F, Gerpott FHU, Auevechanichkul N, Chupanova M, Mun Y, Ziska E, Taylor MJ. MyD88 oligomer size functions as a physical threshold to trigger IL1R Myddosome signaling. J Cell Biol 2021; 220:212080. [PMID: 33956941 PMCID: PMC8105725 DOI: 10.1083/jcb.202012071] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/24/2021] [Accepted: 04/07/2021] [Indexed: 11/22/2022] Open
Abstract
A recurring feature of innate immune receptor signaling is the self-assembly of signaling proteins into oligomeric complexes. The Myddosome is an oligomeric complex that is required to transmit inflammatory signals from TLR/IL1Rs and consists of MyD88 and IRAK family kinases. However, the molecular basis for how Myddosome proteins self-assemble and regulate intracellular signaling remains poorly understood. Here, we developed a novel assay to analyze the spatiotemporal dynamics of IL1R and Myddosome signaling in live cells. We found that MyD88 oligomerization is inducible and initially reversible. Moreover, the formation of larger, stable oligomers consisting of more than four MyD88s triggers the sequential recruitment of IRAK4 and IRAK1. Notably, genetic knockout of IRAK4 enhanced MyD88 oligomerization, indicating that IRAK4 controls MyD88 oligomer size and growth. MyD88 oligomer size thus functions as a physical threshold to trigger downstream signaling. These results provide a mechanistic basis for how protein oligomerization might function in cell signaling pathways.
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Affiliation(s)
| | - Fakun Cao
- Max Planck Institute for Infection Biology, Berlin, Germany
| | | | | | | | - YeVin Mun
- Max Planck Institute for Infection Biology, Berlin, Germany
| | - Elke Ziska
- Max Planck Institute for Infection Biology, Berlin, Germany
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14
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Dam T, Junghans V, Humphrey J, Chouliara M, Jönsson P. Calcium Signaling in T Cells Is Induced by Binding to Nickel-Chelating Lipids in Supported Lipid Bilayers. Front Physiol 2021; 11:613367. [PMID: 33551841 PMCID: PMC7859345 DOI: 10.3389/fphys.2020.613367] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/30/2020] [Indexed: 12/26/2022] Open
Abstract
Supported lipid bilayers (SLBs) are one of the most common cell-membrane model systems to study cell-cell interactions. Nickel-chelating lipids are frequently used to functionalize the SLB with polyhistidine-tagged ligands. We show here that these lipids by themselves can induce calcium signaling in T cells, also when having protein ligands on the SLB. This is important to avoid "false" signaling events in cell studies with SLBs, but also to better understand the molecular mechanisms involved in T-cell signaling. Jurkat T cells transfected with the non-signaling molecule rat CD48 were found to bind to ligand-free SLBs containing ≥2 wt% nickel-chelating lipids upon which calcium signaling was induced. This signaling fraction steadily increased from 24 to 60% when increasing the amount of nickel-chelating lipids from 2 to 10 wt%. Both the signaling fraction and signaling time did not change significantly compared to ligand-free SLBs when adding the CD48-ligand rat CD2 to the SLB. Blocking the SLB with bovine serum albumin reduced the signaling fraction to 11%, while preserving CD2 binding and the exclusion of the phosphatase CD45 from the cell-SLB contacts. Thus, CD45 exclusion alone was not sufficient to result in calcium signaling. In addition, more cells signaled on ligand-free SLBs with copper-chelating lipids instead of nickel-chelating lipids and the signaling was found to be predominantly via T-cell receptor (TCR) triggering. Hence, it is possible that the nickel-chelating lipids act as ligands to the cell's TCRs, an interaction that needs to be blocked to avoid unwanted cell activation.
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Affiliation(s)
- Tommy Dam
- Department of Chemistry, Lund University, Lund, Sweden
| | | | - Jane Humphrey
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden
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15
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Role of Actin Cytoskeleton in E-cadherin-Based Cell–Cell Adhesion Assembly and Maintenance. J Indian Inst Sci 2021. [DOI: 10.1007/s41745-020-00214-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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16
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Lippert AH, Dimov IB, Winkel AK, Humphrey J, McColl J, Chen KY, Santos AM, Jenkins E, Franze K, Davis SJ, Klenerman D. Soft Polydimethylsiloxane-Supported Lipid Bilayers for Studying T Cell Interactions. Biophys J 2021; 120:35-45. [PMID: 33248128 PMCID: PMC7820804 DOI: 10.1016/j.bpj.2020.11.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/22/2020] [Accepted: 11/17/2020] [Indexed: 12/23/2022] Open
Abstract
Much of what we know about the early stages of T cell activation has been obtained from studies of T cells interacting with glass-supported lipid bilayers that favor imaging but are orders of magnitude stiffer than typical cells. We developed a method for attaching lipid bilayers to polydimethylsiloxane polymer supports, producing "soft bilayers" with physiological levels of mechanical resistance (Young's modulus of 4 kPa). Comparisons of T cell behavior on soft and glass-supported bilayers revealed that whereas late stages of T cell activation are thought to be substrate-stiffness dependent, early calcium signaling was unaffected by substrate rigidity, implying that early steps in T cell receptor triggering are not mechanosensitive. The exclusion of large receptor-type phosphatases was observed on the soft bilayers, however, even though it is yet to be demonstrated at authentic cell-cell contacts. This work sets the stage for an imaging-based exploration of receptor signaling under conditions closely mimicking physiological cell-cell contact.
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Affiliation(s)
- Anna H Lippert
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
| | - Ivan B Dimov
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alexander K Winkel
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Jane Humphrey
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - James McColl
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Kevin Y Chen
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Ana M Santos
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Edward Jenkins
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Simon J Davis
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
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17
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Zhang J, Zhao R, Li B, Farrukh A, Hoth M, Qu B, Del Campo A. Micropatterned soft hydrogels to study the interplay of receptors and forces in T cell activation. Acta Biomater 2021; 119:234-246. [PMID: 33099024 DOI: 10.1016/j.actbio.2020.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 09/28/2020] [Accepted: 10/15/2020] [Indexed: 12/30/2022]
Abstract
The analysis of T cell responses to mechanical properties of antigen presenting cells (APC) is experimentally challenging at T cell-APC interfaces. Soft hydrogels with adjustable mechanical properties and biofunctionalization are useful reductionist models to address this problem. Here, we report a methodology to fabricate micropatterned soft hydrogels with defined stiffness to form spatially confined T cell/hydrogel contact interfaces at micrometer scale. Using automatized microcontact printing we prepared arrays of anti-CD3 microdots on poly(acrylamide) hydrogels with Young's Modulus in the range of 2 to 50 kPa. We optimized the printing process to obtain anti-CD3 microdots with constant area (50 µm2, corresponding to 8 µm diameter) and comparable anti-CD3 density on hydrogels of different stiffness. The anti-CD3 arrays were recognized by T cells and restricted cell attachment to the printed areas. To test functionality of the hydrogel-T cell contact, we analyzed several key events downstream of T cell receptor (TCR) activation. Anti-CD3 arrays on hydrogels activated calcium influx, induced rearrangement of the actin cytoskeleton, and led to Zeta-chain-associated protein kinase 70 (ZAP70) phosphorylation. Interestingly, upon increase in the stiffness, ZAP70 phosphorylation was enhanced, whereas the rearrangements of F-actin (F-actin clearance) and phosphorylated ZAP70 (ZAP70/pY centralization) were unaffected. Our results show that micropatterned hydrogels allow tuning of stiffness and receptor presentation to analyze TCR mediated T cell activation as function of mechanical, biochemical, and geometrical parameters.
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Affiliation(s)
- Jingnan Zhang
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany; Chemistry Department, Saarland University, 66123 Saarbrücken, Germany
| | - Renping Zhao
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421 Germany
| | - Bin Li
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Aleeza Farrukh
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Markus Hoth
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421 Germany
| | - Bin Qu
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany; Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, 66421 Germany
| | - Aránzazu Del Campo
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany; Chemistry Department, Saarland University, 66123 Saarbrücken, Germany.
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18
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Wong JJ, Chen Z, Chung JK, Groves JT, Jardetzky TS. EphrinB2 clustering by Nipah virus G is required to activate and trap F intermediates at supported lipid bilayer-cell interfaces. SCIENCE ADVANCES 2021; 7:eabe1235. [PMID: 33571127 PMCID: PMC7840137 DOI: 10.1126/sciadv.abe1235] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Paramyxovirus membrane fusion requires an attachment protein that binds to a host cell receptor and a fusion protein that merges the viral and host membranes. For Nipah virus (NiV), the G attachment protein binds ephrinB2/B3 receptors and activates F-mediated fusion. To visualize dynamic events of these proteins at the membrane interface, we reconstituted NiV fusion activation by overlaying F- and G-expressing cells onto ephrinB2-functionalized supported lipid bilayers and used TIRF microscopy to follow F, G, and ephrinB2. We found that G and ephrinB2 form clusters and that oligomerization of ephrinB2 is necessary for F activation. Single-molecule tracking of F particles revealed accumulation of an immobilized intermediate upon activation. We found no evidence for stable F-G protein complexes before or after activation. These observations lead to a revised model for NiV fusion activation and provide a foundation for investigating other multicomponent viral fusion systems.
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Affiliation(s)
- Joyce J Wong
- Department of Structural Biology, Stanford University, Stanford, CA, USA
| | - Zhongwen Chen
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Jean K Chung
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
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19
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Belardi B, Son S, Felce JH, Dustin ML, Fletcher DA. Cell-cell interfaces as specialized compartments directing cell function. Nat Rev Mol Cell Biol 2020; 21:750-764. [PMID: 33093672 DOI: 10.1038/s41580-020-00298-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2020] [Indexed: 12/14/2022]
Abstract
Cell-cell interfaces are found throughout multicellular organisms, from transient interactions between motile immune cells to long-lived cell-cell contacts in epithelia. Studies of immune cell interactions, epithelial cell barriers, neuronal contacts and sites of cell-cell fusion have identified a core set of features shared by cell-cell interfaces that critically control their function. Data from diverse cell types also show that cells actively and passively regulate the localization, strength, duration and cytoskeletal coupling of receptor interactions governing cell-cell signalling and physical connections between cells, indicating that cell-cell interfaces have a unique membrane organization that emerges from local molecular and cellular mechanics. In this Review, we discuss recent findings that support the emerging view of cell-cell interfaces as specialized compartments that biophysically constrain the arrangement and activity of their protein, lipid and glycan components. We also review how these biophysical features of cell-cell interfaces allow cells to respond with high selectivity and sensitivity to multiple inputs, serving as the basis for wide-ranging cellular functions. Finally, we consider how the unique properties of cell-cell interfaces present opportunities for therapeutic intervention.
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Affiliation(s)
- Brian Belardi
- Department of Bioengineering & Biophysics Program, UC Berkeley, Berkeley, CA, USA
| | - Sungmin Son
- Department of Bioengineering & Biophysics Program, UC Berkeley, Berkeley, CA, USA
| | | | | | - Daniel A Fletcher
- Department of Bioengineering & Biophysics Program, UC Berkeley, Berkeley, CA, USA. .,Division of Biological Systems & Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, USA.
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20
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Gubieda AG, Packer JR, Squires I, Martin J, Rodriguez J. Going with the flow: insights from Caenorhabditis elegans zygote polarization. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190555. [PMID: 32829680 PMCID: PMC7482210 DOI: 10.1098/rstb.2019.0555] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2020] [Indexed: 12/12/2022] Open
Abstract
Cell polarity is the asymmetric distribution of cellular components along a defined axis. Polarity relies on complex signalling networks between conserved patterning proteins, including the PAR (partitioning defective) proteins, which become segregated in response to upstream symmetry breaking cues. Although the mechanisms that drive the asymmetric localization of these proteins are dependent upon cell type and context, in many cases the regulation of actomyosin cytoskeleton dynamics is central to the transport, recruitment and/or stabilization of these polarity effectors into defined subcellular domains. The transport or advection of PAR proteins by an actomyosin flow was first observed in the Caenorhabditis elegans zygote more than a decade ago. Since then a multifaceted approach, using molecular methods, high-throughput screens, and biophysical and computational models, has revealed further aspects of this flow and how polarity regulators respond to and modulate it. Here, we review recent findings on the interplay between actomyosin flow and the PAR patterning networks in the polarization of the C. elegans zygote. We also discuss how these discoveries and developed methods are shaping our understanding of other flow-dependent polarizing systems. This article is part of a discussion meeting issue 'Contemporary morphogenesis'.
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Affiliation(s)
| | | | | | | | - Josana Rodriguez
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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21
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Belling JN, Cheung KM, Jackman JA, Sut TN, Allen M, Park JH, Jonas SJ, Cho NJ, Weiss PS. Lipid Bicelle Micropatterning Using Chemical Lift-Off Lithography. ACS APPLIED MATERIALS & INTERFACES 2020; 12:13447-13455. [PMID: 32092250 PMCID: PMC7092747 DOI: 10.1021/acsami.9b20617] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Supported lipid membranes are versatile biomimetic coatings for the chemical functionalization of inorganic surfaces. Developing simple and effective fabrication strategies to form supported lipid membranes with micropatterned geometries is a long-standing challenge. Herein, we demonstrate how the combination of chemical lift-off lithography (CLL) and easily prepared lipid bicelle nanostructures can yield micropatterned, supported lipid membranes on gold surfaces with high pattern resolution, conformal character, and biofunctionality. Using CLL, we functionalized gold surfaces with patterned arrays of hydrophilic and hydrophobic self-assembled monolayers (SAMs). Time-lapse fluorescence microscopy imaging revealed that lipid bicelles adsorbed preferentially onto the hydrophilic SAM regions, while there was negligible lipid adsorption onto the hydrophobic SAM regions. Functional receptors could be embedded within the lipid bicelles, which facilitated selective detection of receptor-ligand binding interactions in a model streptavidin-biotin system. Quartz crystal microbalance-dissipation measurements further identified that lipid bicelles adsorb irreversibly and remain intact on top of the hydrophilic SAM regions. Taken together, our findings indicate that lipid bicelles are useful lipid nanostructures for reproducibly assembling micropatterned, supported lipid membranes with precise pattern fidelity.
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Affiliation(s)
- Jason N. Belling
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Kevin M. Cheung
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Joshua A. Jackman
- School of Chemical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea
- SKKU-UCLA-NTU Precision Biology Research Center, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Tun Naw Sut
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Matthew Allen
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Jae Hyeon Park
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Steven J. Jonas
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
- Children’s Discovery and Innovation Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Eli & Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Nam-Joon Cho
- SKKU-UCLA-NTU Precision Biology Research Center, Sungkyunkwan University, Suwon 16419, Republic of Korea
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Paul S. Weiss
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- SKKU-UCLA-NTU Precision Biology Research Center, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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22
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Czernohlavek C, Schuster B. Formation and characteristics of mixed lipid/polymer membranes on a crystalline surface-layer protein lattice. Biointerphases 2020; 15:011002. [PMID: 31948239 PMCID: PMC7116081 DOI: 10.1116/1.5132390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The implementation of self-assembled biomolecules on solid materials, in particular, sensor and electrode surfaces, gains increasing importance for the design of stable functional platforms, bioinspired materials, and biosensors. The present study reports on the formation of a planar hybrid lipid/polymer membrane on a crystalline surface layer protein (SLP) lattice. The latter acts as a connecting layer linking the biomolecules to the inorganic base plate. In this approach, chemically bound lipids provided hydrophobic anchoring moieties for the hybrid lipid/polymer membrane on the recrystallized SLP lattice. The rapid solvent exchange technique was the method of choice to generate the planar hybrid lipid/polymer membrane on the SLP lattice. The formation process and completeness of the latter were investigated by quartz crystal microbalance with dissipation monitoring and by an enzymatic assay using the protease subtilisin A, respectively. The present data provide evidence for the formation of a hybrid lipid/polymer membrane on an S-layer lattice with a diblock copolymer content of 30%. The hybrid lipid/polymer showed a higher stiffness compared to the pure lipid bilayer. Most interestingly, both the pure and hybrid membrane prevented the proteolytic degradation of the underlying S-layer protein by the action of subtilisin A. Hence, these results provide evidence for the formation of defect-free membranes anchored to the S-layer lattice.
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Affiliation(s)
- Christian Czernohlavek
- Department of NanoBiotechnology, Institute for Synthetic Bioarchitectures, University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, 1190 Vienna, Austria
| | - Bernhard Schuster
- Department of NanoBiotechnology, Institute for Synthetic Bioarchitectures, University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, 1190 Vienna, Austria
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23
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Biswas KH. Molecular Mobility-Mediated Regulation of E-Cadherin Adhesion. Trends Biochem Sci 2019; 45:163-173. [PMID: 31810601 DOI: 10.1016/j.tibs.2019.10.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/22/2019] [Accepted: 10/30/2019] [Indexed: 12/12/2022]
Abstract
Cells in epithelial tissues utilize homotypic E-cadherin interaction-mediated adhesions to both physically adhere to each other and sense the physical properties of their microenvironment, such as the presence of other cells in close vicinity or an alteration in the mechanical tension of the tissue. These position E-cadherin centrally in organogenesis and other processes, and its function is therefore tightly regulated through a variety of means including endocytosis and gene expression. How does membrane molecular mobility of E-cadherin, and thus membrane physical properties and associated actin cytoskeleton, impinges on the assembly of adhesive clusters and signaling is discussed.
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Affiliation(s)
- Kabir H Biswas
- College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar Foundation, Doha 34110, Qatar.
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24
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Illukkumbura R, Bland T, Goehring NW. Patterning and polarization of cells by intracellular flows. Curr Opin Cell Biol 2019; 62:123-134. [PMID: 31760155 PMCID: PMC6968950 DOI: 10.1016/j.ceb.2019.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/11/2019] [Accepted: 10/16/2019] [Indexed: 11/19/2022]
Abstract
Beginning with Turing’s seminal work [1], decades of research have demonstrated the fundamental ability of biochemical networks to generate and sustain the formation of patterns. However, it is increasingly appreciated that biochemical networks both shape and are shaped by physical and mechanical processes [2, 3, 4]. One such process is fluid flow. In many respects, the cytoplasm, membrane and actin cortex all function as fluids, and as they flow, they drive bulk transport of molecules throughout the cell. By coupling biochemical activity to long range molecular transport, flows can shape the distributions of molecules in space. Here we review the various types of flows that exist in cells, with the aim of highlighting recent advances in our understanding of how flows are generated and how they contribute to intracellular patterning processes, such as the establishment of cell polarity.
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Affiliation(s)
| | - Tom Bland
- The Francis Crick Institute, London, UK; Institute for the Physics of Living Systems, University College London, London, UK
| | - Nathan W Goehring
- The Francis Crick Institute, London, UK; Institute for the Physics of Living Systems, University College London, London, UK; MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
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