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Block MR, Destaing O, Petropoulos C, Planus E, Albigès-Rizo C, Fourcade B. Integrin-mediated adhesion as self-sustained waves of enzymatic activation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:042704. [PMID: 26565269 DOI: 10.1103/physreve.92.042704] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Indexed: 06/05/2023]
Abstract
Integrin receptors mediate interaction between the cellular actin-cytoskeleton and extracellular matrix. Based on their activation properties, we propose a reaction-diffusion model where the kinetics of the two-state receptors is modulated by their lipidic environment. This environment serves as an activator variable, while a second variable plays the role of a scaffold protein and controls the self-sustained activation of the receptors. Due to receptor diffusion which couples dynamically the activator and the inhibitor, our model connects major classes of reaction diffusion systems for excitable media. Spot and rosette solutions, characterized by receptor clustering into localized static or dynamic structures, are organized into a phase diagram. It is shown that diffusion and kinetics of receptors determines the dynamics and the stability of these structures. We discuss this model as a precursor model for cell signaling in the context of podosomes forming actoadhesive metastructures, and we study how generic signaling defects influence their organization.
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Affiliation(s)
- M R Block
- Chromatine and Epigenetics, Institut Albert Bonniot, INSERM-CNRS U823, 38042 Grenoble Cedex, France
- Dysad, Institut Albert Bonniot, INSERM-CNRS U823, Université Joseph Fourier, 38042 Grenoble Cedex, France
| | - O Destaing
- Dysad, Institut Albert Bonniot, INSERM-CNRS U823, Université Joseph Fourier, 38042 Grenoble Cedex, France
| | - C Petropoulos
- Dysad, Institut Albert Bonniot, INSERM-CNRS U823, Université Joseph Fourier, 38042 Grenoble Cedex, France
| | - E Planus
- Dysad, Institut Albert Bonniot, INSERM-CNRS U823, Université Joseph Fourier, 38042 Grenoble Cedex, France
| | - C Albigès-Rizo
- Dysad, Institut Albert Bonniot, INSERM-CNRS U823, Université Joseph Fourier, 38042 Grenoble Cedex, France
| | - B Fourcade
- Dysad, Institut Albert Bonniot, INSERM-CNRS U823, Université Joseph Fourier, 38042 Grenoble Cedex, France
- Laboratoire Joliot Curie, CNRS Ens-Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France
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Ali O, Guillou H, Destaing O, Albigès-Rizo C, Block MR, Fourcade B. Cooperativity between integrin activation and mechanical stress leads to integrin clustering. Biophys J 2011; 100:2595-604. [PMID: 21641304 DOI: 10.1016/j.bpj.2011.03.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 03/01/2011] [Accepted: 03/17/2011] [Indexed: 12/31/2022] Open
Abstract
Integrins are transmembrane receptors involved in crucial cellular biological functions such as migration, adhesion, and spreading. Upon the modulation of integrin affinity toward their extracellular ligands by cytoplasmic proteins (inside-out signaling) these receptors bind to their ligands and cluster into nascent adhesions. This clustering results in the increase in the mechanical linkage among the cell and substratum, cytoskeleton rearrangements, and further outside-in signaling. Based on experimental observations of the distribution of focal adhesions in cells attached to micropatterned surfaces, we introduce a physical model relying on experimental numerical constants determined in the literature. In this model, allosteric integrin activation works in synergy with the stress build by adhesion and the membrane rigidity to allow the clustering to nascent adhesions independently of actin but dependent on the integrin diffusion onto adhesive surfaces. The initial clustering could provide a template to the mature adhesive structures. Predictions of our model for the organization of focal adhesions are discussed in comparison with experiments using adhesive protein microarrays.
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Affiliation(s)
- O Ali
- INSERM U823-CNRS ERL 5284, Institut Albert Bonniot, Equipe Dysad, Site Santé, La Tronche, Grenoble cedex 9, France
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