1
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Oh D, Liu X, Sheetz MP, Kenney LJ. Small, Dynamic Clusters of Tir-Intimin Seed Actin Polymerization. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302580. [PMID: 37649226 DOI: 10.1002/smll.202302580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/26/2023] [Indexed: 09/01/2023]
Abstract
The understanding of actin pedestal formation by enteropathogenic Escherichia coli (EPEC) relies mainly on static ensemble information obtained from cell lysates. Here, the dynamic nature of signaling components on the subsecond timescale, which resemble phase condensates, is demonstrated. Unlike in vitro phase condensates, transfected intimin receptor (Tir) and downstream component form clusters 200 nm in diameter that are spaced ≈500 nm on average, indicating cellular regulation. On supported lipid bilayers with diffusive intimin, Tir-expressing fibroblasts formed Tir-intimin clusters even without Tir tyrosines, although Tir tyrosine phosphorylation is necessary for actin polymerization from clusters. Single-molecule tracking showed that Tir is diffusive in the clusters and exchanges with Tir in the plasma membrane. Further, Nck and N-WASP bind to the clusters and exchange with cytoplasmic molecules. Tir has a similar cluster lifetime to Nck, but longer than that of N-WASP. Actin polymerization from the clusters requires N-WASP binding, involved Arp2/3 activation, and stabilized N-WASP clusters. These dynamic properties are distinct from larger in vitro systems and do not depend significantly upon crosslinking. Thus, Tir-intimin clusters in the plasma membrane are limited in size by exchange and enhance signaling needed for actin polymerization that enables strong and stable bacterial attachment to host cells.
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Affiliation(s)
- Dongmyung Oh
- Mechanobiology Institute, National University of Singapore, bukit timah, 117411, Singapore
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Xuyao Liu
- Mechanobiology Institute, National University of Singapore, bukit timah, 117411, Singapore
| | - Michael P Sheetz
- Mechanobiology Institute, National University of Singapore, bukit timah, 117411, Singapore
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Linda J Kenney
- Mechanobiology Institute, National University of Singapore, bukit timah, 117411, Singapore
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
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2
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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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3
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Waller V, Tschanz F, Winkler R, Pruschy M. The role of EphA2 in ADAM17- and ionizing radiation-enhanced lung cancer cell migration. Front Oncol 2023; 13:1117326. [PMID: 36998455 PMCID: PMC10043294 DOI: 10.3389/fonc.2023.1117326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/01/2023] [Indexed: 03/17/2023] Open
Abstract
PurposeIonizing radiation (IR) enhances the migratory capacity of cancer cells. Here we investigate in non-small-cell-lung-cancer (NSCLC) cells a novel link between IR-enhanced ADAM17 activity and the non-canonical pathway of EphA2 in the cellular stress response to irradiation.MethodsCancer cell migration in dependence of IR, EphA2, and paracrine signaling mediated by ADAM17 was determined using transwell migration assays. Changes of EphA2 pS897 and mRNA expression levels upon different ADAM17-directed treatment strategies, including the small molecular inhibitor TMI-005, the monoclonal antibody MEDI3622, and shRNAs, were mechanistically investigated. ADAM17-mediated release and cleavage of the EphA2 ligand ephrin-A1 was measured using ELISA and an acellular cleavage assay.ResultsIrradiation with 5 Gy enhanced tumor cell migration of NSCLC NCI-H358 cells in dependence of EphA2. At the same time, IR increased growth factor-induced EphA2 S897 phosphorylation via auto- and paracrine signaling. Genetic and pharmaceutical downregulation of ADAM17 activity abrogated growth factor (e.g. amphiregulin) release, which reduced MAPK pathway-mediated EphA2 S897 phosphorylation in an auto- and paracrine way (non-canonical EphA2-pathway) in NCI-H358 and A549 cells. These signaling processes were associated with reduced cell migration towards conditioned media derived from ADAM17-deficient cells. Interestingly, ADAM17 inhibition with the small molecular inhibitor TMI-005 led to the internalization and proteasomal degradation of EphA2, which was rescued by amphiregulin or MG-132 treatment. In addition, ADAM17 inhibition also abrogated ephrin-A1 cleavage and thereby interfered with the canonical EphA2-pathway.ConclusionWe identified ADAM17 and the receptor tyrosine kinase EphA2 as two important drivers for (IR-) induced NSCLC cell migration and described a unique interrelation between ADAM17 and EphA2. We demonstrated that ADAM17 influences both, EphA2 (pS897) and its GPI-anchored ligand ephrin-A1. Using different cellular and molecular readouts, we generated a comprehensive picture of how ADAM17 and IR influence the EphA2 canonical and non-canonical pathway in NSCLC cells.
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4
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Wirth D, Paul MD, Pasquale EB, Hristova K. Direct quantification of ligand-induced lipid and protein microdomains with distinctive signaling properties. CHEMSYSTEMSCHEM 2022; 4:e202200011. [PMID: 36337751 PMCID: PMC9634703 DOI: 10.1002/syst.202200011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Indexed: 11/08/2022]
Abstract
Lipid rafts are ordered lipid domains that are enriched in saturated lipids, such as the ganglioside GM1. While lipid rafts are believed to exist in cells and to serve as signaling platforms through their enrichment in signaling components, they have not been directly observed in the plasma membrane without treatments that artificially cluster GM1 into large lattices. Here, we report that microscopic GM1-enriched domains can form, in the plasma membrane of live mammalian cells expressing the EphA2 receptor tyrosine kinase in response to its ligand ephrinA1-Fc. The GM1-enriched microdomains form concomitantly with EphA2-enriched microdomains. To gain insight into how plasma membrane heterogeneity controls signaling, we quantify the degree of EphA2 segregation and study initial EphA2 signaling steps in both EphA2-enriched and EphA2-depleted domains. By measuring dissociation constants, we demonstrate that the propensity of EphA2 to oligomerize is similar in EphA2-enriched and -depleted domains. However, surprisingly, EphA2 interacts preferentially with its downstream effector SRC in EphA2-depleted domains. The ability to induce microscopic GM1-enriched domains in live cells using a ligand for a transmembrane receptor will give us unprecedented opportunities to study the biophysical chemistry of lipid rafts.
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Affiliation(s)
- Daniel Wirth
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218
| | - Michael D. Paul
- Program in Molecular Biophysics, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218
| | - Elena B. Pasquale
- Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Road, La Jolla, CA 92037
| | - Kalina Hristova
- Department of Materials Science and Engineering, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218
- Program in Molecular Biophysics, Johns Hopkins University, 3400 Charles Street, Baltimore, MD 21218
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5
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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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6
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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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7
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Tosetti F, Alessio M, Poggi A, Zocchi MR. ADAM10 Site-Dependent Biology: Keeping Control of a Pervasive Protease. Int J Mol Sci 2021; 22:ijms22094969. [PMID: 34067041 PMCID: PMC8124674 DOI: 10.3390/ijms22094969] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/14/2022] Open
Abstract
Enzymes, once considered static molecular machines acting in defined spatial patterns and sites of action, move to different intra- and extracellular locations, changing their function. This topological regulation revealed a close cross-talk between proteases and signaling events involving post-translational modifications, membrane tyrosine kinase receptors and G-protein coupled receptors, motor proteins shuttling cargos in intracellular vesicles, and small-molecule messengers. Here, we highlight recent advances in our knowledge of regulation and function of A Disintegrin And Metalloproteinase (ADAM) endopeptidases at specific subcellular sites, or in multimolecular complexes, with a special focus on ADAM10, and tumor necrosis factor-α convertase (TACE/ADAM17), since these two enzymes belong to the same family, share selected substrates and bioactivity. We will discuss some examples of ADAM10 activity modulated by changing partners and subcellular compartmentalization, with the underlying hypothesis that restraining protease activity by spatial segregation is a complex and powerful regulatory tool.
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Affiliation(s)
- Francesca Tosetti
- Molecular Oncology and Angiogenesis Unit, IRCCS Ospedale Policlinico S. Martino Largo R. Benzi 10, 16132 Genoa, Italy;
- Correspondence:
| | - Massimo Alessio
- Proteome Biochemistry, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy;
| | - Alessandro Poggi
- Molecular Oncology and Angiogenesis Unit, IRCCS Ospedale Policlinico S. Martino Largo R. Benzi 10, 16132 Genoa, Italy;
| | - Maria Raffaella Zocchi
- Division of Immunology, Transplants and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy;
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8
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Verheyen T, Fang T, Lindenhofer D, Wang Y, Akopyan K, Lindqvist A, Högberg B, Teixeira AI. Spatial organization-dependent EphA2 transcriptional responses revealed by ligand nanocalipers. Nucleic Acids Res 2020; 48:5777-5787. [PMID: 32352518 PMCID: PMC7261182 DOI: 10.1093/nar/gkaa274] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 04/01/2020] [Accepted: 04/08/2020] [Indexed: 11/13/2022] Open
Abstract
Ligand binding induces extensive spatial reorganization and clustering of the EphA2 receptor at the cell membrane. It has previously been shown that the nanoscale spatial distribution of ligands modulates EphA2 receptor reorganization, activation and the invasive properties of cancer cells. However, intracellular signaling downstream of EphA2 receptor activation by nanoscale spatially distributed ligands has not been elucidated. Here, we used DNA origami nanostructures to control the positions of ephrin-A5 ligands at the nanoscale and investigated EphA2 activation and transcriptional responses following ligand binding. Using RNA-seq, we determined the transcriptional profiles of human glioblastoma cells treated with DNA nanocalipers presenting a single ephrin-A5 dimer or two dimers spaced 14, 40 or 100 nm apart. These cells displayed divergent transcriptional responses to the differing ephrin-A5 nano-organization. Specifically, ephrin-A5 dimers spaced 40 or 100 nm apart showed the highest levels of differential expressed genes compared to treatment with nanocalipers that do not present ephrin-A5. These findings show that the nanoscale organization of ephrin-A5 modulates transcriptional responses to EphA2 activation.
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Affiliation(s)
- Toon Verheyen
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm 17165, Sweden
| | - Trixy Fang
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm 17165, Sweden
| | - Dominik Lindenhofer
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm 17165, Sweden
| | - Yang Wang
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm 17165, Sweden
| | - Karen Akopyan
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm 17165, Sweden
| | - Arne Lindqvist
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm 17165, Sweden
| | - Björn Högberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm 17165, Sweden
| | - Ana I Teixeira
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm 17165, Sweden
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9
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Ravasio A, Myaing MZ, Chia S, Arora A, Sathe A, Cao EY, Bertocchi C, Sharma A, Arasi B, Chung VY, Greene AC, Tan TZ, Chen Z, Ong HT, Iyer NG, Huang RY, DasGupta R, Groves JT, Viasnoff V. Single-cell analysis of EphA clustering phenotypes to probe cancer cell heterogeneity. Commun Biol 2020; 3:429. [PMID: 32764731 PMCID: PMC7411022 DOI: 10.1038/s42003-020-01136-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 06/29/2020] [Indexed: 11/28/2022] Open
Abstract
The Eph family of receptor tyrosine kinases is crucial for assembly and maintenance of healthy tissues. Dysfunction in Eph signaling is causally associated with cancer progression. In breast cancer cells, dysregulated Eph signaling has been linked to alterations in receptor clustering abilities. Here, we implemented a single-cell assay and a scoring scheme to systematically probe the spatial organization of activated EphA receptors in multiple carcinoma cells. We show that cancer cells retain EphA clustering phenotype over several generations, and the degree of clustering reported for migration potential both at population and single-cell levels. Finally, using patient-derived cancer lines, we probed the evolution of EphA signalling in cell populations that underwent metastatic transformation and acquisition of drug resistance. Taken together, our scalable approach provides a reliable scoring scheme for EphA clustering that is consistent over multiple carcinomas and can assay heterogeneity of cancer cell populations in a cost- and time-effective manner. Ravasio et al. develop an assay to quantify the clustering of Eph receptor EphA2 upon ligand binding, based on the scoring of single cells. They discover that clustering phenotype predicts cell and population migration potential in cancer cells and reflects Eph associated gene expression profiles in cancer cell lines.
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Affiliation(s)
- Andrea Ravasio
- National University of Singapore, Singapore, Singapore.,Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Shumei Chia
- Genome Institute of Singapore, A-STAR, Singapore, Singapore
| | - Aditya Arora
- National University of Singapore, Singapore, Singapore
| | - Aneesh Sathe
- National University of Singapore, Singapore, Singapore
| | | | - Cristina Bertocchi
- National University of Singapore, Singapore, Singapore.,Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ankur Sharma
- Genome Institute of Singapore, A-STAR, Singapore, Singapore
| | - Bakya Arasi
- National University of Singapore, Singapore, Singapore
| | - Vin Yee Chung
- National University of Singapore, Singapore, Singapore
| | | | - Tuan Zea Tan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Zhongwen Chen
- National University of Singapore, Singapore, Singapore
| | - Hui Ting Ong
- National University of Singapore, Singapore, Singapore
| | | | - Ruby YunJu Huang
- School of Medicine & Graduate Institute of Oncology, College of Medicine, National Taiwan, Taiwan.,University Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Jay T Groves
- National University of Singapore, Singapore, Singapore.,University of California, Berkeley, CA, USA
| | - Virgile Viasnoff
- National University of Singapore, Singapore, Singapore. .,Centre National de la Recherche Scientifique, Singapore, Singapore.
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10
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Westerfield JM, Barrera FN. Membrane receptor activation mechanisms and transmembrane peptide tools to elucidate them. J Biol Chem 2019; 295:1792-1814. [PMID: 31879273 DOI: 10.1074/jbc.rev119.009457] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Single-pass membrane receptors contain extracellular domains that respond to external stimuli and transmit information to intracellular domains through a single transmembrane (TM) α-helix. Because membrane receptors have various roles in homeostasis, signaling malfunctions of these receptors can cause disease. Despite their importance, there is still much to be understood mechanistically about how single-pass receptors are activated. In general, single-pass receptors respond to extracellular stimuli via alterations in their oligomeric state. The details of this process are still the focus of intense study, and several lines of evidence indicate that the TM domain (TMD) of the receptor plays a central role. We discuss three major mechanistic hypotheses for receptor activation: ligand-induced dimerization, ligand-induced rotation, and receptor clustering. Recent observations suggest that receptors can use a combination of these activation mechanisms and that technical limitations can bias interpretation. Short peptides derived from receptor TMDs, which can be identified by screening or rationally developed on the basis of the structure or sequence of their targets, have provided critical insights into receptor function. Here, we explore recent evidence that, depending on the target receptor, TMD peptides cannot only inhibit but also activate target receptors and can accommodate novel, bifunctional designs. Furthermore, we call for more sharing of negative results to inform the TMD peptide field, which is rapidly transforming into a suite of unique tools with the potential for future therapeutics.
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Affiliation(s)
- Justin M Westerfield
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996.
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11
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Valenzuela JI, Perez F. Localized Intercellular Transfer of Ephrin-As by Trans-endocytosis Enables Long-Term Signaling. Dev Cell 2019; 52:104-117.e5. [PMID: 31866204 DOI: 10.1016/j.devcel.2019.11.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/02/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022]
Abstract
Ephrins can elicit either contact-mediated cell-cell adhesion or repulsion, depending on the efficiency of the removal of their ligand-receptor complexes from the cell surface, thus controlling tissue morphogenesis and oncogenic development. However, the dynamic of the turnover of newly assembled ephrin-Eph complexes during cell-cell interactions remains mostly unexplored. Here, we show that ephrin-A1-EphA2 complexes are locally formed at the tip of the filopodia, at cell-to-cell contacts. Clusters of ephrin-A1 from donor cells surf on filopodia associated to EphA2-bearing subdomains of acceptor cells. Full-length ephrin-A1 is transferred to acceptor cells by trans-endocytosis through a proteolysis-independent mechanism. Trans-endocytosed ephrin-A1 bound to its receptor enables signaling to be emitted from endo-lysosomes of acceptor cells. Localized trans-endocytosis of ephrin-A1 sustains contact-mediated repulsion on cancer cells. Our results uncover the essential role played by local concentration at the tip of filopodia and the trans-endocytosis of full-length ephrin to maintain long-lasting ephrin signaling.
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Affiliation(s)
| | - Franck Perez
- Institut Curie, PSL Research University, CNRS, UMR144, 26 rue d'Ulm, 75005 Paris, France.
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12
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Abstract
A wide range of cell–microenvironmental interactions are mediated by membrane-localized receptors that bind ligands present on another cell or the extracellular matrix. This situation introduces a number of physical effects including spatial organization of receptor–ligand complexes and development of mechanical forces in cells. Unlike traditional experimental approaches, hybrid live cell–supported lipid bilayer (SLB) systems, wherein a live cell interacts with a synthetic substrate supported membrane, allow interrogation of these aspects of receptor signaling. The SLB system directly offers facile control over the identity, density, and mobility of ligands used for engaging cellular receptors. Further, application of various nano- and micropatterning techniques allows for spatial patterning of ligands. In this review, we describe the hybrid live cell–SLB system and its application in uncovering a range of spatial and mechanical aspects of receptor signaling. We highlight the T cell immunological synapse, junctions formed between EphA2- and ephrinA1-expressing cells, and adhesions formed by cadherin and integrin receptors.
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Affiliation(s)
- Kabir H. Biswas
- NTU Institute for Health Technologies, Nanyang Technological University, Singapore 637553
| | - Jay T. Groves
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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13
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Chand S, Beales P, Claeyssens F, Ciani B. Topography design in model membranes: Where biology meets physics. Exp Biol Med (Maywood) 2018; 244:294-303. [PMID: 30379575 DOI: 10.1177/1535370218809369] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
IMPACT STATEMENT Artificial membranes with complex topography aid the understanding of biological processes where membrane geometry plays a key regulatory role. In this review, we highlight how emerging material and engineering technologies have been employed to create minimal models of cell signaling pathways, in vitro. These artificial systems allow life scientists to answer ever more challenging questions with regards to mechanisms in cellular biology. In vitro reconstitution of biology is an area that draws on the expertise and collaboration between biophysicists, material scientists and biologists and has recently generated a number of high impact results, some of which are also discussed in this review.
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Affiliation(s)
- Sarina Chand
- 1 Centre for Membrane Structure and Dynamics, Krebs Institute and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK.,2 The Kroto Research Institute, University of Sheffield, Sheffield S3 7HQ, UK
| | - Paul Beales
- 3 School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Frederik Claeyssens
- 2 The Kroto Research Institute, University of Sheffield, Sheffield S3 7HQ, UK
| | - Barbara Ciani
- 1 Centre for Membrane Structure and Dynamics, Krebs Institute and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, UK
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14
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Finney AC, Orr AW. Guidance Molecules in Vascular Smooth Muscle. Front Physiol 2018; 9:1311. [PMID: 30283356 PMCID: PMC6157320 DOI: 10.3389/fphys.2018.01311] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
Several highly conserved families of guidance molecules, including ephrins, Semaphorins, Netrins, and Slits, play conserved and distinct roles in tissue remodeling during tissue patterning and disease pathogenesis. Primarily, these guidance molecules function as either secreted or surface-bound ligands that interact with their receptors to activate a variety of downstream effects, including cell contractility, migration, adhesion, proliferation, and inflammation. Vascular smooth muscle cells, contractile cells comprising the medial layer of the vessel wall and deriving from the mural population, regulate vascular tone and blood pressure. While capillaries lack a medial layer of vascular smooth muscle, mural-derived pericytes contribute similarly to capillary tone to regulate blood flow in various tissues. Furthermore, pericyte coverage is critical in vascular development, as perturbations disrupt vascular permeability and viability. During cardiovascular disease, smooth muscle cells play a more dynamic role in which suppression of contractile markers, enhanced proliferation, and migration lead to the progression of aberrant vascular remodeling. Since many types of guidance molecules are expressed in vascular smooth muscle and pericytes, these may contribute to blood vessel formation and aberrant remodeling during vascular disease. While vascular development is a large focus of the existing literature, studies emerged to address post-developmental roles for guidance molecules in pathology and are of interest as novel therapeutic targets. In this review, we will discuss the roles of guidance molecules in vascular smooth muscle and pericyte function in development and disease.
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Affiliation(s)
- Alexandra Christine Finney
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
| | - Anthony Wayne Orr
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
- Department of Pathology and Translational Medicine, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
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15
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Glazier R, Salaita K. Location, Location, Location: EphB4:Ephrin-B2 Signaling Depends on Its Spatial Arrangement. Biophys J 2018; 115:754-756. [PMID: 30082034 DOI: 10.1016/j.bpj.2018.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 07/09/2018] [Indexed: 11/26/2022] Open
Affiliation(s)
- Roxanne Glazier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
| | - Khalid Salaita
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia; Department of Chemistry, Emory University, Atlanta, Georgia.
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16
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TerBush AA, Hafkamp F, Lee HJ, Coscoy L. A Kaposi's Sarcoma-Associated Herpesvirus Infection Mechanism Is Independent of Integrins α3β1, αVβ3, and αVβ5. J Virol 2018; 92:e00803-18. [PMID: 29899108 PMCID: PMC6096800 DOI: 10.1128/jvi.00803-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/08/2018] [Indexed: 12/24/2022] Open
Abstract
Host receptor usage by Kaposi's sarcoma-associated herpesvirus (KSHV) has been best studied using primary microvascular endothelial and fibroblast cells, although the virus infects a wide variety of cell types in culture and in natural infections. In these two infection models, KSHV adheres to the cell though heparan sulfate (HS) binding and then interacts with a complex of EphA2, xCT, and integrins α3β1, αVβ3, and αVβ5 to catalyze viral entry. We dissected this receptor complex at the genetic level with CRISPR-Cas9 to precisely determine receptor usage in two epithelial cell lines. Surprisingly, we discovered an infection mechanism that requires HS and EphA2 but is independent of αV- and β1-family integrin expression. Furthermore, infection appears to be independent of the EphA2 intracellular domain. We also demonstrated that while two other endogenous Eph receptors were dispensable for KSHV infection, transduced EphA4 and EphA5 significantly enhanced infection of cells lacking EphA2.IMPORTANCE Our data reveal an integrin-independent route of KSHV infection and suggest that multiple Eph receptors besides EphA2 can promote and regulate infection. Since integrins and Eph receptors are large protein families with diverse expression patterns across cells and tissues, we propose that KSHV may engage with several proteins from both families in different combinations to negotiate successful entry into diverse cell types.
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Affiliation(s)
- Allison Alwan TerBush
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Florianne Hafkamp
- Graduate School of Life Sciences, Utrecht University, Utrecht, Netherlands
| | - Hee Jun Lee
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Laurent Coscoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
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17
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Dong M, Spelke DP, Lee YK, Chung JK, Yu CH, Schaffer DV, Groves JT. Spatiomechanical Modulation of EphB4-Ephrin-B2 Signaling in Neural Stem Cell Differentiation. Biophys J 2018; 115:865-873. [PMID: 30075851 PMCID: PMC6127455 DOI: 10.1016/j.bpj.2018.06.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 03/15/2018] [Accepted: 06/06/2018] [Indexed: 01/10/2023] Open
Abstract
Interactions between EphB4 receptor tyrosine kinases and their membrane-bound ephrin-B2 ligands on apposed cells play a regulatory role in neural stem cell differentiation. With both receptor and ligand constrained to move within the membranes of their respective cells, this signaling system inevitably experiences spatial confinement and mechanical forces in conjunction with receptor-ligand binding. In this study, we reconstitute the EphB4-ephrin-B2 juxtacrine signaling geometry using a supported-lipid-bilayer system presenting laterally mobile and monomeric ephrin-B2 ligands to live neural stem cells. This experimental platform successfully reconstitutes EphB4-ephrin-B2 binding, lateral clustering, downstream signaling activation, and neuronal differentiation, all in a configuration that preserves the spatiomechanical aspects of the natural juxtacrine signaling geometry. Additionally, the supported bilayer system allows control of lateral movement and clustering of the receptor-ligand complexes through patterns of physical barriers to lateral diffusion fabricated onto the underlying substrate. The results from this study reveal a distinct spatiomechanical effect on the ability of EphB4-ephrin-B2 signaling to induce neuronal differentiation. These observations parallel similar studies of the EphA2-ephrin-A1 system in a very different biological context, suggesting that such spatiomechanical regulation may be a common feature of Eph-ephrin signaling.
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Affiliation(s)
- Meimei Dong
- Department of Chemistry, University of California Berkeley, Berkeley, California; Biophysics Graduate Group, University of California Berkeley, Berkeley, California
| | - Dawn P Spelke
- Department of Chemical Engineering, University of California Berkeley, Berkeley, California; Department of Bioengineering, University of California Berkeley, Berkeley, California
| | - Young Kwang Lee
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - Jean K Chung
- Department of Chemistry, University of California Berkeley, Berkeley, California
| | - Cheng-Han Yu
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - David V Schaffer
- Department of Chemical Engineering, University of California Berkeley, Berkeley, California; Department of Bioengineering, University of California Berkeley, Berkeley, California.
| | - Jay T Groves
- Department of Chemistry, University of California Berkeley, Berkeley, California; Biophysics Graduate Group, University of California Berkeley, Berkeley, California.
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18
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Spatially modulated ephrinA1:EphA2 signaling increases local contractility and global focal adhesion dynamics to promote cell motility. Proc Natl Acad Sci U S A 2018; 115:E5696-E5705. [PMID: 29866846 DOI: 10.1073/pnas.1719961115] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent studies have revealed pronounced effects of the spatial distribution of EphA2 receptors on cellular response to receptor activation. However, little is known about molecular mechanisms underlying this spatial sensitivity, in part due to lack of experimental systems. Here, we introduce a hybrid live-cell patterned supported lipid bilayer experimental platform in which the sites of EphA2 activation and integrin adhesion are spatially controlled. Using a series of live-cell imaging and single-molecule tracking experiments, we map the transmission of signals from ephrinA1:EphA2 complexes. Results show that ligand-dependent EphA2 activation induces localized myosin-dependent contractions while simultaneously increasing focal adhesion dynamics throughout the cell. Mechanistically, Src kinase is activated at sites of ephrinA1:EphA2 clustering and subsequently diffuses on the membrane to focal adhesions, where it up-regulates FAK and paxillin tyrosine phosphorylation. EphrinA1:EphA2 signaling triggers multiple cellular responses with differing spatial dependencies to enable a directed migratory response to spatially resolved contact with ephrinA1 ligands.
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19
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Biswas KH, Zhongwen C, Dubey AK, Oh D, Groves JT. Multicomponent Supported Membrane Microarray for Monitoring Spatially Resolved Cellular Signaling Reactions. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201800015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Kabir H. Biswas
- Mechanobiology Institute; National University of Singapore; Singapore 117411 Singapore
| | - Chen Zhongwen
- Mechanobiology Institute; National University of Singapore; Singapore 117411 Singapore
| | - Alok Kumar Dubey
- Mechanobiology Institute; National University of Singapore; Singapore 117411 Singapore
| | - Dongmyung Oh
- Mechanobiology Institute; National University of Singapore; Singapore 117411 Singapore
| | - Jay T. Groves
- Department of Chemistry; University of California; Berkeley CA 94720 USA
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20
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Early T cell receptor signals globally modulate ligand:receptor affinities during antigen discrimination. Proc Natl Acad Sci U S A 2017; 114:12190-12195. [PMID: 29087297 PMCID: PMC5699024 DOI: 10.1073/pnas.1613140114] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Antigen discrimination by T cells is based on subtle differences in binding of the T cell receptor (TCR) for its peptide major histocompatibility complex (pMHC) ligand. While such binding characteristics are readily mapped with great precision in reconstituted biochemical systems, it is less clear how these interactions are affected in the live cell environment. Here we utilize single-molecule imaging to individually resolve all of the pMHC:TCR binding events in live T cells. The quantitative measurements reveal an active feedback mechanism that globally modulates the probability of pMHC:TCR binding throughout the cell–cell interface, without affecting the unbinding rate. The result is to increase the efficiency with which TCRs scan for antigen pMHC after the first few molecular encounters have occurred. Antigen discrimination by T cells occurs at the junction between a T cell and an antigen-presenting cell. Juxtacrine binding between numerous adhesion, signaling, and costimulatory molecules defines both the topographical and lateral geometry of this cell–cell interface, within which T cell receptor (TCR) and peptide major histocompatibility complex (pMHC) interact. These physical constraints on receptor and ligand movement have significant potential to modulate their molecular binding properties. Here, we monitor individual ligand:receptor binding and unbinding events in space and time by single-molecule imaging in live primary T cells for a range of different pMHC ligands and surface densities. Direct observations of pMHC:TCR and CD80:CD28 binding events reveal that the in situ affinity of both pMHC and CD80 ligands for their respective receptors is modulated by the steady-state number of agonist pMHC:TCR interactions experienced by the cell. By resolving every single pMHC:TCR interaction it is evident that this cooperativity is accomplished by increasing the kinetic on-rate without altering the off-rate and has a component that is not spatially localized. Furthermore, positive cooperativity is observed under conditions where the T cell activation probability is low. This TCR-mediated feedback is a global effect on the intercellular junction. It is triggered by the first few individual pMHC:TCR binding events and effectively increases the efficiency of TCR scanning for antigen before the T cell is committed to activation.
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21
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Azimi A, Tuominen R, Costa Svedman F, Caramuta S, Pernemalm M, Frostvik Stolt M, Kanter L, Kharaziha P, Lehtiö J, Hertzman Johansson C, Höiom V, Hansson J, Egyhazi Brage S. Silencing FLI or targeting CD13/ANPEP lead to dephosphorylation of EPHA2, a mediator of BRAF inhibitor resistance, and induce growth arrest or apoptosis in melanoma cells. Cell Death Dis 2017; 8:e3029. [PMID: 29048432 PMCID: PMC5596587 DOI: 10.1038/cddis.2017.406] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 06/07/2017] [Accepted: 06/19/2017] [Indexed: 12/20/2022]
Abstract
A majority of patients with BRAF-mutated metastatic melanoma respond to therapy with BRAF inhibitors (BRAFi), but relapses are common owing to acquired resistance. To unravel BRAFi resistance mechanisms we have performed gene expression and mass spectrometry based proteome profiling of the sensitive parental A375 BRAF V600E-mutated human melanoma cell line and of daughter cell lines with induced BRAFi resistance. Increased expression of two novel resistance candidates, aminopeptidase-N (CD13/ANPEP) and ETS transcription factor FLI1 was observed in the BRAFi-resistant daughter cell lines. In addition, increased levels of the previously reported resistance mediators, receptor tyrosine kinase ephrine receptor A2 (EPHA2) and the hepatocyte growth factor receptor MET were also identified. The expression of these proteins was assessed in matched tumor samples from melanoma patients obtained before BRAFi and after disease progression. MET was overexpressed in all progression samples while the expression of the other candidates varied between the individual patients. Targeting CD13/ANPEP by a blocking antibody induced apoptosis in both parental A375- and BRAFi-resistant daughter cells as well as in melanoma cells with intrinsic BRAFi resistance and led to dephosphorylation of EPHA2 on S897, previously demonstrated to cause inhibition of the migratory capacity. AKT and RSK, both reported to induce EPHA2 S897 phosphorylation, were also dephosphorylated after inhibition of CD13/ANPEP. FLI1 silencing also caused decreases in EPHA2 S897 phosphorylation and in total MET protein expression. In addition, silencing of FLI1 sensitized the resistant cells to BRAFi. Furthermore, we show that BRAFi in combination with the multi kinase inhibitor dasatinib can abrogate BRAFi resistance and decrease both EPHA2 S897 phosphorylation and total FLI1 protein expression. This is the first report presenting CD13/ANPEP and FLI1 as important mediators of resistance to BRAF inhibition with potential as drug targets in BRAFi refractory melanoma.
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Affiliation(s)
- Alireza Azimi
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Rainer Tuominen
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Fernanda Costa Svedman
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Stefano Caramuta
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Pernemalm
- Science for Life Laboratory, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Marianne Frostvik Stolt
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Lena Kanter
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Pedram Kharaziha
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Janne Lehtiö
- Science for Life Laboratory, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | | | - Veronica Höiom
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Johan Hansson
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Suzanne Egyhazi Brage
- Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
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22
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Sustained α-catenin Activation at E-cadherin Junctions in the Absence of Mechanical Force. Biophys J 2017; 111:1044-52. [PMID: 27602732 DOI: 10.1016/j.bpj.2016.06.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/08/2016] [Accepted: 06/24/2016] [Indexed: 11/22/2022] Open
Abstract
Mechanotransduction at E-cadherin junctions has been postulated to be mediated in part by a force-dependent conformational activation of α-catenin. Activation of α-catenin allows it to interact with vinculin in addition to F-actin, resulting in a strengthening of junctions. Here, using E-cadherin adhesions reconstituted on synthetic, nanopatterned membranes, we show that activation of α-catenin is dependent on E-cadherin clustering, and is sustained in the absence of mechanical force or association with F-actin or vinculin. Adhesions were formed by filopodia-mediated nucleation and micron-scale assembly of E-cadherin clusters, which could be distinguished as either peripheral or central assemblies depending on their relative location at the cell-bilayer adhesion. Whereas F-actin, vinculin, and phosphorylated myosin light chain associated only with the peripheral assemblies, activated α-catenin was present in both peripheral and central assemblies, and persisted in the central assemblies in the absence of actomyosin tension. Impeding filopodia-mediated nucleation and micron-scale assembly of E-cadherin adhesion complexes by confining the movement of bilayer-bound E-cadherin on nanopatterned substrates reduced the levels of activated α-catenin. Taken together, these results indicate that although the initial activation of α-catenin requires micron-scale clustering that may allow the development of mechanical forces, sustained force is not required for maintaining α-catenin in the active state.
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23
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Vafaei S, Tabaei SR, Biswas KH, Groves JT, Cho NJ. Dynamic Cellular Interactions with Extracellular Matrix Triggered by Biomechanical Tuning of Low-Rigidity, Supported Lipid Membranes. Adv Healthc Mater 2017; 6. [PMID: 28371558 DOI: 10.1002/adhm.201700243] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Indexed: 11/09/2022]
Abstract
The behavior of cells in a tissue is regulated by chemical as well as physical signals arising from their microenvironment. While gel-based substrates have been widely used for mimicking a range of substrate rigidities, there is a need for the development of low rigidity substrates for mimicking the physical properties of soft tissues. In this study, the authors report the development of a supported lipid bilayer (SLB)-based low rigidity substrate for cell adhesion studies. SLBs are functionalized with either collagen I or fibronectin via covalent, amine coupling to a carboxyl group-modified lipid molecule. While the lipid molecules in the bilayer show long-range lateral mobility, the covalently functionalized extracellular matrix (ECM) proteins are immobile on the bilayer surface. Specific adhesion of cells results in an enrichment of the protein on the bilayer and the appearance of a zone of depletion around the cells. Further, the lateral reorganization of the ECM proteins is controlled by altering the fluidity of lipid molecules in the substrate. Thus, the experimental platform developed in this study can be utilized for addressing basic questions related to cell adhesion on low rigidity substrates as well as biomedical applications requiring adhesion of cells to low rigidity substrates.
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Affiliation(s)
- Setareh Vafaei
- Centre for Biomimetic Sensor Science; Nanyang Technological University; 50 Nanyang Drive 637553 Singapore Singapore
- School of Materials Science and Engineering; Nanyang Technological University; 50 Nanyang Avenue 639798 Singapore Singapore
| | - Seyed R. Tabaei
- Centre for Biomimetic Sensor Science; Nanyang Technological University; 50 Nanyang Drive 637553 Singapore Singapore
- School of Materials Science and Engineering; Nanyang Technological University; 50 Nanyang Avenue 639798 Singapore Singapore
| | - Kabir H. Biswas
- Mechanobiology Institute; National University of Singapore; 117411 Singapore Singapore
| | - Jay T. Groves
- Mechanobiology Institute; National University of Singapore; 117411 Singapore Singapore
- Department of Chemistry; University of California; Berkeley CA 94720 USA
| | - Nam-Joon Cho
- Centre for Biomimetic Sensor Science; Nanyang Technological University; 50 Nanyang Drive 637553 Singapore Singapore
- School of Materials Science and Engineering; Nanyang Technological University; 50 Nanyang Avenue 639798 Singapore Singapore
- School of Chemical and Biomedical Engineering; Nanyang Technological University; 62 Nanyang Drive 637459 Singapore Singapore
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24
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Ruprecht V, Monzo P, Ravasio A, Yue Z, Makhija E, Strale PO, Gauthier N, Shivashankar GV, Studer V, Albiges-Rizo C, Viasnoff V. How cells respond to environmental cues - insights from bio-functionalized substrates. J Cell Sci 2016; 130:51-61. [PMID: 27856508 DOI: 10.1242/jcs.196162] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Biomimetic materials have long been the (he)art of bioengineering. They usually aim at mimicking in vivo conditions to allow in vitro culture, differentiation and expansion of cells. The past decade has witnessed a considerable amount of progress in soft lithography, bio-inspired micro-fabrication and biochemistry, allowing the design of sophisticated and physiologically relevant micro- and nano-environments. These systems now provide an exquisite toolbox with which we can control a large set of physicochemical environmental parameters that determine cell behavior. Bio-functionalized surfaces have evolved from simple protein-coated solid surfaces or cellular extracts into nano-textured 3D surfaces with controlled rheological and topographical properties. The mechanobiological molecular processes by which cells interact and sense their environment can now be unambiguously understood down to the single-molecule level. This Commentary highlights recent successful examples where bio-functionalized substrates have contributed in raising and answering new questions in the area of extracellular matrix sensing by cells, cell-cell adhesion and cell migration. The use, the availability, the impact and the challenges of such approaches in the field of biology are discussed.
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Affiliation(s)
- Verena Ruprecht
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | | | - Andrea Ravasio
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore
| | - Zhang Yue
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore
| | - Ekta Makhija
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore
| | - Pierre Olivier Strale
- CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux F-33000, France
| | | | - G V Shivashankar
- IFOM, Via Adamello, 16, Milano 20139, Italy.,Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore
| | - Vincent Studer
- CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux F-33000, France
| | - Corinne Albiges-Rizo
- INSERM, U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Institute Albert Bonniot, University Grenoble Alpes, La Tronche F-38700, France
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore .,CNRS UMI 3639, 5A Engineering Drive 1, 117411 Singapore
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25
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Christensen SM, Tu HL, Jun JE, Alvarez S, Triplet MG, Iwig JS, Yadav KK, Bar-Sagi D, Roose JP, Groves JT. One-way membrane trafficking of SOS in receptor-triggered Ras activation. Nat Struct Mol Biol 2016; 23:838-46. [PMID: 27501536 PMCID: PMC5016256 DOI: 10.1038/nsmb.3275] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 07/08/2016] [Indexed: 02/07/2023]
Abstract
SOS is a key activator of the small GTPase Ras. In cells, SOS-Ras signaling is thought to be initiated predominantly by membrane recruitment of SOS via the adaptor Grb2 and balanced by rapidly reversible Grb2-SOS binding kinetics. However, SOS has multiple protein and lipid interactions that provide linkage to the membrane. In reconstituted-membrane experiments, these Grb2-independent interactions were sufficient to retain human SOS on the membrane for many minutes, during which a single SOS molecule could processively activate thousands of Ras molecules. These observations raised questions concerning how receptors maintain control of SOS in cells and how membrane-recruited SOS is ultimately released. We addressed these questions in quantitative assays of reconstituted SOS-deficient chicken B-cell signaling systems combined with single-molecule measurements in supported membranes. These studies revealed an essentially one-way trafficking process in which membrane-recruited SOS remains trapped on the membrane and continuously activates Ras until being actively removed via endocytosis.
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Affiliation(s)
- Sune M. Christensen
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Hsiung-Lin Tu
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Jesse E. Jun
- Department of Anatomy, University of California, San Francisco, California, USA
| | - Steven Alvarez
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Meredith G. Triplet
- Department of Chemistry, University of California, Berkeley, California, USA
| | - Jeffrey S. Iwig
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| | - Kamlesh K. Yadav
- Department of Biochemistry, New York University School of Medicine, New York, USA
| | - Dafna Bar-Sagi
- Department of Biochemistry, New York University School of Medicine, New York, USA
| | - Jeroen P. Roose
- Department of Anatomy, University of California, San Francisco, California, USA
| | - Jay T. Groves
- Department of Chemistry, University of California, Berkeley, California, USA
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26
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Li W, Chung JK, Lee YK, Groves JT. Graphene-Templated Supported Lipid Bilayer Nanochannels. NANO LETTERS 2016; 16:5022-6. [PMID: 27362914 DOI: 10.1021/acs.nanolett.6b01798] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The use of patterned substrates to impose geometrical restriction on the lateral mobility of molecules in supported lipid membranes has found widespread utility in studies of cell membranes. Here, we template-pattern supported lipid membranes with nanopatterned graphene. We utilize focused ion beam milling to pattern graphene on its growth substrate, then transfer the patterned graphene to fresh glass substrates for subsequent supported membrane formation. We observe that graphene functions as an excellent lateral diffusion barrier for supported lipid bilayers. Additionally, the observed diffusion dynamics of lipids in nanoscale graphene channels reveal extremely low boundary effects, a common problem with other materials. We suggest this is attributable to the ultimate thinness of graphene.
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Affiliation(s)
- Wan Li
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Jean K Chung
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Young Kwang Lee
- Department of Chemistry, University of California , Berkeley, California 94720, United States
| | - Jay T Groves
- Department of Chemistry, University of California , Berkeley, California 94720, United States
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27
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Ma VPY, Liu Y, Blanchfield L, Su H, Evavold BD, Salaita K. Ratiometric Tension Probes for Mapping Receptor Forces and Clustering at Intermembrane Junctions. NANO LETTERS 2016; 16:4552-9. [PMID: 27192323 PMCID: PMC6061938 DOI: 10.1021/acs.nanolett.6b01817] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Short-range communication between cells is required for the survival of multicellular organisms. One mechanism of chemical signaling between adjacent cells employs surface displayed ligands and receptors that only bind when two cells make physical contact. Ligand-receptor complexes that form at the cell-cell junction and physically bridge two cells likely experience mechanical forces. A fundamental challenge in this area pertains to mapping the mechanical forces experienced by ligand-receptor complexes within such a fluid intermembrane junction. Herein, we describe the development of ratiometric tension probes for direct imaging of receptor tension, clustering, and lateral transport within a model cell-cell junction. These probes employ two fluorescent reporters that quantify both the ligand density and the ligand tension and thus generate a tension signal independent of clustering. As a proof-of-concept, we applied the ratiometric tension probes to map the forces experienced by the T-cell receptor (TCR) during activation and showed the first direct evidence that the TCR-ligand complex experiences sustained pN forces within a fluid membrane junction. We envision that the ratiometric tension probes will be broadly useful for investigating mechanotransduction in juxtacrine signaling pathways.
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Affiliation(s)
- Victor Pui-Yan Ma
- Department of Chemistry, Emory University, Atlanta, GA 30322, United States
| | - Yang Liu
- Department of Chemistry, Emory University, Atlanta, GA 30322, United States
| | - Lori Blanchfield
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, United States
| | - Hanquan Su
- Department of Chemistry, Emory University, Atlanta, GA 30322, United States
| | - Brian D. Evavold
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, United States
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA 30322, United States
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, United States
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28
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Biswas KH, Groves JT. A Microbead Supported Membrane-Based Fluorescence Imaging Assay Reveals Intermembrane Receptor-Ligand Complex Dimension with Nanometer Precision. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6775-6780. [PMID: 27264296 DOI: 10.1021/acs.langmuir.6b01377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Receptor-ligand complexes spanning a cell-cell interface inevitably establish a preferred intermembrane spacing based on the molecular dimensions and orientation of the complexes. This couples molecular binding events to membrane mechanics and large-scale spatial organization of receptors on the cell surface. Here, we describe a straightforward, epi-fluorescence-based method to precisely determine intermembrane receptor-ligand dimension at adhesions established by receptor-ligand binding between apposed membranes in vitro. Adhesions were reconstituted between planar and silica microbead supported membranes via specific interaction between cognate receptor/ligand pairs (EphA2/EphrinA1 and E-cadherin/anti-E-cadherin antibody). Epi-fluorescence imaging of the ligand enrichment zone in the supported membrane beneath the adhering microbead, combined with a simple geometrical interpretation, proves sufficient to estimate intermembrane receptor-ligand dimension with better than 1 nm precision. An advantage of this assay is that no specialized equipment or imaging methods are required.
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Affiliation(s)
- Kabir H Biswas
- Mechanobiology Institute, National University of Singapore , Singapore 117411, Singapore
| | - Jay T Groves
- Mechanobiology Institute, National University of Singapore , Singapore 117411, Singapore
- Department of Chemistry, University of California , Berkeley, California 94720, United States
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Phosphotyrosine-mediated LAT assembly on membranes drives kinetic bifurcation in recruitment dynamics of the Ras activator SOS. Proc Natl Acad Sci U S A 2016; 113:8218-23. [PMID: 27370798 DOI: 10.1073/pnas.1602602113] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The assembly of cell surface receptors with downstream signaling molecules is a commonly occurring theme in multiple signaling systems. However, little is known about how these assemblies modulate reaction kinetics and the ultimate propagation of signals. Here, we reconstitute phosphotyrosine-mediated assembly of extended linker for the activation of T cells (LAT):growth factor receptor-bound protein 2 (Grb2):Son of Sevenless (SOS) networks, derived from the T-cell receptor signaling system, on supported membranes. Single-molecule dwell time distributions reveal two, well-differentiated kinetic species for both Grb2 and SOS on the LAT assemblies. The majority fraction of membrane-recruited Grb2 and SOS both exhibit fast kinetics and single exponential dwell time distributions, with average dwell times of hundreds of milliseconds. The minor fraction exhibits much slower kinetics, extending the dwell times to tens of seconds. Considering this result in the context of the multistep process by which the Ras GEF (guanine nucleotide exchange factor) activity of SOS is activated indicates that kinetic stabilization from the LAT assembly may be important. This kinetic proofreading effect would additionally serve as a stochastic noise filter by reducing the relative probability of spontaneous SOS activation in the absence of receptor triggering. The generality of receptor-mediated assembly suggests that such effects may play a role in multiple receptor proximal signaling processes.
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Chen J, Xie ZR, Wu Y. Elucidating the general principles of cell adhesion with a coarse-grained simulation model. MOLECULAR BIOSYSTEMS 2016; 12:205-18. [DOI: 10.1039/c5mb00612k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Coarse-grained simulation of interplay between cell adhesion and cell signaling.
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Affiliation(s)
- Jiawen Chen
- Department of Systems and Computational Biology
- Albert Einstein College of Medicine of Yeshiva University
- Bronx
- USA
| | - Zhong-Ru Xie
- Department of Systems and Computational Biology
- Albert Einstein College of Medicine of Yeshiva University
- Bronx
- USA
| | - Yinghao Wu
- Department of Systems and Computational Biology
- Albert Einstein College of Medicine of Yeshiva University
- Bronx
- USA
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Angelin A, Weigel S, Garrecht R, Meyer R, Bauer J, Kumar RK, Hirtz M, Niemeyer CM. Multiscale Origami Structures as Interface for Cells. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201509772] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Alessandro Angelin
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Simone Weigel
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Ruben Garrecht
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Rebecca Meyer
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Jens Bauer
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Ravi Kapoor Kumar
- Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Michael Hirtz
- Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Christof M. Niemeyer
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
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Angelin A, Weigel S, Garrecht R, Meyer R, Bauer J, Kumar RK, Hirtz M, Niemeyer CM. Multiscale Origami Structures as Interface for Cells. Angew Chem Int Ed Engl 2015; 54:15813-7. [DOI: 10.1002/anie.201509772] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 11/12/2015] [Indexed: 01/07/2023]
Affiliation(s)
- Alessandro Angelin
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Simone Weigel
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Ruben Garrecht
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Rebecca Meyer
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Jens Bauer
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Ravi Kapoor Kumar
- Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Michael Hirtz
- Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
| | - Christof M. Niemeyer
- Karlsruhe Institute of Technology (KIT), Institute for Biological Interfaces (IBG 1), Hermann‐von‐Helmholtz‐Platz, 76344 Eggenstein‐Leopoldshafen (Germany)
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Saha S, Lee IH, Polley A, Groves JT, Rao M, Mayor S. Diffusion of GPI-anchored proteins is influenced by the activity of dynamic cortical actin. Mol Biol Cell 2015; 26:4033-45. [PMID: 26378258 PMCID: PMC4710234 DOI: 10.1091/mbc.e15-06-0397] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/07/2015] [Indexed: 12/22/2022] Open
Abstract
Membrane proteins that couple to cortical actin show temperature-independent diffusion. The loss of this coupling and perturbation of cortical actomyosin dynamics render the diffusion temperature dependent. The findings suggest that active fluctuations arising from dynamic actin filaments at the cortex can drive diffusion on the cell membrane. Molecular diffusion at the surface of living cells is believed to be predominantly driven by thermal kicks. However, there is growing evidence that certain cell surface molecules are driven by the fluctuating dynamics of cortical cytoskeleton. Using fluorescence correlation spectroscopy, we measure the diffusion coefficient of a variety of cell surface molecules over a temperature range of 24–37°C. Exogenously incorporated fluorescent lipids with short acyl chains exhibit the expected increase of diffusion coefficient over this temperature range. In contrast, we find that GPI-anchored proteins exhibit temperature-independent diffusion over this range and revert to temperature-dependent diffusion on cell membrane blebs, in cells depleted of cholesterol, and upon acute perturbation of actin dynamics and myosin activity. A model transmembrane protein with a cytosolic actin-binding domain also exhibits the temperature-independent behavior, directly implicating the role of cortical actin. We show that diffusion of GPI-anchored proteins also becomes temperature dependent when the filamentous dynamic actin nucleator formin is inhibited. However, changes in cortical actin mesh size or perturbation of branched actin nucleator Arp2/3 do not affect this behavior. Thus cell surface diffusion of GPI-anchored proteins and transmembrane proteins that associate with actin is driven by active fluctuations of dynamic cortical actin filaments in addition to thermal fluctuations, consistent with expectations from an “active actin-membrane composite” cell surface.
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Affiliation(s)
- Suvrajit Saha
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore 560065, India
| | - Il-Hyung Lee
- Department of Chemistry, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720
| | | | - Jay T Groves
- Department of Chemistry, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720
| | - Madan Rao
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore 560065, India Raman Research Institute, Bangalore 560080, India
| | - Satyajit Mayor
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore 560065, India Institute for Stem Cell Biology and Regenerative Medicine, Bangalore 560065, India
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Thiede-Stan NK, Schwab ME. Attractive and repulsive factors act through multi-subunit receptor complexes to regulate nerve fiber growth. J Cell Sci 2015; 128:2403-14. [PMID: 26116576 DOI: 10.1242/jcs.165555] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In the nervous system, attractive and repulsive factors guide neuronal growth, pathfinding and target innervation during development, learning and regeneration after injury. Repulsive and growth-inhibitory factors, such as some ephrins, semaphorins, netrins and myelin-associated growth inhibitors, restrict nerve fiber growth, whereas neurotrophins, and other ephrins, semaphorins and netrins attract fibers and promote neurite growth. Several of these guidance molecules also play crucial roles in vasculogenesis, and regulate cell migration and tissue formation in different organs. Precise and highly specific signal transduction in space and time is required in all these cases, which primarily depends on the presence and function of specific receptors. Interestingly, many of these ligands act through multi-subunit receptor complexes. In this Commentary, we review the current knowledge of how complexes of the receptors for attractive and repulsive neurite growth regulatory factors are reorganized in a spatial and temporal manner, and reveal the implications that such dynamics have on the signaling events that coordinate neurite fiber growth.
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Affiliation(s)
- Nina K Thiede-Stan
- Brain Research Institute, University of Zurich, Department of Health Sciences & Technology, ETH Zurich, Zurich 8057, Switzerland
| | - Martin E Schwab
- Brain Research Institute, University of Zurich, Department of Health Sciences & Technology, ETH Zurich, Zurich 8057, Switzerland
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Abstract
Eph receptor tyrosine kinases control cell-cell interactions during normal and oncogenic development, and are implicated in a range of processes including angiogenesis, stem cell maintenance and metastasis. They are thus of great interest as targets for cancer therapy. EphA3, originally isolated from leukemic and melanoma cells, is presently one of the most promising therapeutic targets, with multiple tumor-promoting roles in a variety of cancer types. This review focuses on EphA3, its functions in controlling cellular behavior, both in normal and pathological development, and most particularly in cancer.
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Affiliation(s)
- Peter W Janes
- Department of Biochemistry and Molecular Biology, Monash University , Victoria , Australia and
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Abstract
Eph receptor tyrosine kinases and the corresponding ephrin ligands play a pivotal role in the glioma development and progression. Aberrant protein expression levels of the Eph receptors and ephrins are often associated with higher tumor grade and poor prognosis. Their function in tumorigenesis is complex due to the intricate network of possible co-occurring interactions between neighboring tumor cells and tumor microenvironment. Both Ephs and ephrins localize on the surface of tumor cells, tumor vasculature, glioma stem cells, tumor cells infiltrating brain, and immune cells infiltrating tumors. They can both promote and inhibit tumorigenicity depending on the downstream forward and reverse signalling generated. All the above-mentioned features make the Ephs/ephrins system an intriguing candidate for the development of new therapeutic strategies in glioma treatment. This review will give a general overview on the structure and the function of Ephs and ephrins, with a particular emphasis on the state of the knowledge of their role in malignant gliomas.
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Affiliation(s)
- Sara Ferluga
- Department of Neurosurgery, Brain Tumor Center of Excellence, Comprehensive Cancer Center of Wake Forest University, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Waldemar Debinski
- Department of Neurosurgery, Brain Tumor Center of Excellence, Comprehensive Cancer Center of Wake Forest University, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
- To whom correspondence should be addressed: Waldemar Debinski, M.D., Ph.D., Director of Brain Tumor Center of Excellence, Thomas K. Hearn Jr. Brain Tumor Research Center, Professor of Neurosurgery, Radiation Oncology, and Cancer Biology, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC 27157, Phone: (336) 716-9712, Fax: (336) 713-7639,
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