151
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Baxter NJ, Zacharchenko T, Barsukov IL, Williamson MP. Pressure-Dependent Chemical Shifts in the R3 Domain of Talin Show that It Is Thermodynamically Poised for Binding to Either Vinculin or RIAM. Structure 2017; 25:1856-1866.e2. [PMID: 29153504 DOI: 10.1016/j.str.2017.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/13/2017] [Accepted: 10/26/2017] [Indexed: 12/25/2022]
Abstract
Talin mediates attachment of the cell to the extracellular matrix. It is targeted by the Rap1 effector RIAM to focal adhesion sites and subsequently undergoes force-induced conformational opening to recruit the actin-interacting protein vinculin. The conformational switch involves the talin R3 domain, which binds RIAM when closed and vinculin when open. Here, we apply pressure to R3 and measure 1H, 15N, and 13C chemical shift changes, which are fitted using a simple model, and indicate that R3 is only 50% closed: the closed form is a four-helix bundle, while in the open state helix 1 is twisted out. Strikingly, a mutant of R3 that binds RIAM with an affinity similar to wild-type but more weakly to vinculin is shown to be 0.84 kJ mol-1 more stable when closed. These results demonstrate that R3 is thermodynamically poised to bind either RIAM or vinculin, and thus constitutes a good mechanosensitive switch.
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Affiliation(s)
- Nicola J Baxter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Thomas Zacharchenko
- School of Biological Sciences, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Igor L Barsukov
- School of Biological Sciences, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Mike P Williamson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
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152
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153
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Jansen K, Atherton P, Ballestrem C. Mechanotransduction at the cell-matrix interface. Semin Cell Dev Biol 2017; 71:75-83. [DOI: 10.1016/j.semcdb.2017.07.027] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/19/2017] [Accepted: 07/19/2017] [Indexed: 01/09/2023]
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154
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Zhao X, Zeng X, Lu C, Yan J. Studying the mechanical responses of proteins using magnetic tweezers. NANOTECHNOLOGY 2017; 28:414002. [PMID: 28766506 DOI: 10.1088/1361-6528/aa837e] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The mechanical stability of proteins has been extensively studied using AFM as a single-molecule force spectroscopy method. While this has led to many important results, these studies have been mainly limited to fast unfolding at a high-force regime due to the rapid mechanical drift in most AFM stretching experiments. Therefore, there is a gap between the knowledge obtained at a high-force regime and the mechanical properties of proteins at a lower force regime which is often more physiologically relevant. Recent studies have demonstrated that this gap can be addressed by stretching single protein molecules using magnetic tweezers, due to the excellent mechanical stability this technology offers. Here we review magnetic tweezers technology and its current application in studies of the force-dependent stability and interactions of proteins.
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Affiliation(s)
- Xiaodan Zhao
- Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411, Singapore
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155
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Chen Y, Ju L, Rushdi M, Ge C, Zhu C. Receptor-mediated cell mechanosensing. Mol Biol Cell 2017; 28:3134-3155. [PMID: 28954860 PMCID: PMC5687017 DOI: 10.1091/mbc.e17-04-0228] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 09/06/2017] [Accepted: 09/19/2017] [Indexed: 12/22/2022] Open
Abstract
Mechanosensing depicts the ability of a cell to sense mechanical cues, which under some circumstances is mediated by the surface receptors. In this review, a four-step model is described for receptor-mediated mechanosensing. Platelet GPIb, T-cell receptor, and integrins are used as examples to illustrate the key concepts and players in this process. Mechanosensing describes the ability of a cell to sense mechanical cues of its microenvironment, including not only all components of force, stress, and strain but also substrate rigidity, topology, and adhesiveness. This ability is crucial for the cell to respond to the surrounding mechanical cues and adapt to the changing environment. Examples of responses and adaptation include (de)activation, proliferation/apoptosis, and (de)differentiation. Receptor-mediated cell mechanosensing is a multistep process that is initiated by binding of cell surface receptors to their ligands on the extracellular matrix or the surface of adjacent cells. Mechanical cues are presented by the ligand and received by the receptor at the binding interface; but their transmission over space and time and their conversion into biochemical signals may involve other domains and additional molecules. In this review, a four-step model is described for the receptor-mediated cell mechanosensing process. Platelet glycoprotein Ib, T-cell receptor, and integrins are used as examples to illustrate the key concepts and players in this process.
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Affiliation(s)
- Yunfeng Chen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332.,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
| | - Lining Ju
- Charles Perkins Centre and Heart Research Institute, University of Sydney, Camperdown, NSW 2006, Australia
| | - Muaz Rushdi
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Chenghao Ge
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 .,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
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156
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Abstract
Proteins fold under mechanical forces in a number of biological processes, ranging from muscle contraction to co-translational folding. As force hinders the folding transition, chaperones must play a role in this scenario, although their influence on protein folding under force has not been directly monitored yet. Here, we introduce single-molecule magnetic tweezers to study the folding dynamics of protein L in presence of the prototypical molecular chaperone trigger factor over the range of physiological forces (4–10 pN). Our results show that trigger factor increases prominently the probability of folding against force and accelerates the refolding kinetics. Moreover, we find that trigger factor catalyzes the folding reaction in a force-dependent manner; as the force increases, higher concentrations of trigger factor are needed to rescue folding. We propose that chaperones such as trigger factor can work as foldases under force, a mechanism which could be of relevance for several physiological processes. Proteins fold under mechanical force during co-translational folding at the ribosome. Here, the authors use single molecule magnetic tweezers to study the influence of chaperones on protein folding and show that the ribosomal chaperone trigger factor acts as a mechanical foldase by promoting protein folding under force.
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157
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Galletti R, Verger S, Hamant O, Ingram GC. Developing a 'thick skin': a paradoxical role for mechanical tension in maintaining epidermal integrity? Development 2017; 143:3249-58. [PMID: 27624830 DOI: 10.1242/dev.132837] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Plant aerial epidermal tissues, like animal epithelia, act as load-bearing layers and hence play pivotal roles in development. The presence of tension in the epidermis has morphogenetic implications for organ shapes but it also constantly threatens the integrity of this tissue. Here, we explore the multi-scale relationship between tension and cell adhesion in the plant epidermis, and we examine how tensile stress perception may act as a regulatory input to preserve epidermal tissue integrity and thus normal morphogenesis. From this, we identify parallels between plant epidermal and animal epithelial tissues and highlight a list of unexplored questions for future research.
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Affiliation(s)
- Roberta Galletti
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Lyon F-69342, France
| | - Stéphane Verger
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Lyon F-69342, France
| | - Olivier Hamant
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Lyon F-69342, France
| | - Gwyneth C Ingram
- Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Lyon F-69342, France
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158
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Han MKL, van der Krogt GNM, de Rooij J. Zygotic vinculin is not essential for embryonic development in zebrafish. PLoS One 2017; 12:e0182278. [PMID: 28767718 PMCID: PMC5540497 DOI: 10.1371/journal.pone.0182278] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/14/2017] [Indexed: 12/26/2022] Open
Abstract
The formation of multicellular tissues during development is governed by mechanical forces that drive cell shape and tissue architecture. Protein complexes at sites of adhesion to the extracellular matrix (ECM) and cell neighbors, not only transmit these mechanical forces, but also allow cells to respond to changes in force by inducing biochemical feedback pathways. Such force-induced signaling processes are termed mechanotransduction. Vinculin is a central protein in mechanotransduction that in both integrin-mediated cell-ECM and cadherin-mediated cell-cell adhesions mediates force-induced cytoskeletal remodeling and adhesion strengthening. Vinculin was found to be important for the integrity and remodeling of epithelial tissues in cell culture models and could therefore be expected to be of broad importance in epithelial morphogenesis in vivo. Besides a function in mouse heart development, however, the importance of vinculin in morphogenesis of other vertebrate tissues has remained unclear. To investigate this further, we knocked out vinculin functioning in zebrafish, which contain two fully functional isoforms designated as vinculin A and vinculin B that both show high sequence conservation with higher vertebrates. Using TALEN and CRISPR-Cas gene editing technology we generated vinculin-deficient zebrafish. While single vinculin A mutants are viable and able to reproduce, additional loss of zygotic vinculin B was lethal after embryonic stages. Remarkably, vinculin-deficient embryos do not show major developmental defects, apart from mild pericardial edemas. These results lead to the conclusion that vinculin is not of broad importance for the development and morphogenesis of zebrafish tissues.
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Affiliation(s)
- Mitchell K. L. Han
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gerard N. M. van der Krogt
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Johan de Rooij
- Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
- * E-mail:
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159
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Manso AM, Okada H, Sakamoto FM, Moreno E, Monkley SJ, Li R, Critchley DR, Ross RS. Loss of mouse cardiomyocyte talin-1 and talin-2 leads to β-1 integrin reduction, costameric instability, and dilated cardiomyopathy. Proc Natl Acad Sci U S A 2017; 114:E6250-E6259. [PMID: 28698364 PMCID: PMC5544289 DOI: 10.1073/pnas.1701416114] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Continuous contraction-relaxation cycles of the heart require strong and stable connections of cardiac myocytes (CMs) with the extracellular matrix (ECM) to preserve sarcolemmal integrity. CM attachment to the ECM is mediated by integrin complexes localized at the muscle adhesion sites termed costameres. The ubiquitously expressed cytoskeletal protein talin (Tln) is a component of muscle costameres that links integrins ultimately to the sarcomere. There are two talin genes, Tln1 and Tln2. Here, we tested the function of these two Tln forms in myocardium where Tln2 is the dominant isoform in postnatal CMs. Surprisingly, global deletion of Tln2 in mice caused no structural or functional changes in heart, presumably because CM Tln1 became up-regulated. Tln2 loss increased integrin activation, although levels of the muscle-specific β1D-integrin isoform were reduced by 50%. With this result, we produced mice that had simultaneous loss of both CM Tln1 and Tln2 and found that cardiac dysfunction occurred by 4 wk with 100% mortality by 6 mo. β1D integrin and other costameric proteins were lost from the CMs, and membrane integrity was compromised. Given that integrin protein reduction occurred with Tln loss, rescue of the phenotype was attempted through transgenic integrin overexpression, but this could not restore WT CM integrin levels nor improve heart function. Our results show that CM Tln2 is essential for proper β1D-integrin expression and that Tln1 can substitute for Tln2 in preserving heart function, but that loss of all Tln forms from the heart-muscle cell leads to myocyte instability and a dilated cardiomyopathy.
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Affiliation(s)
- Ana Maria Manso
- Division of Cardiology, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093;
- Cardiology Section, Department of Medicine, Veterans Administration Healthcare, San Diego, CA 92161
| | - Hideshi Okada
- Division of Cardiology, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093
- Cardiology Section, Department of Medicine, Veterans Administration Healthcare, San Diego, CA 92161
| | - Francesca M Sakamoto
- Division of Cardiology, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093
| | - Emily Moreno
- Division of Cardiology, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093
| | - Susan J Monkley
- Department of Molecular Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | - Ruixia Li
- Division of Cardiology, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093
| | - David R Critchley
- Department of Molecular Cell Biology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | - Robert S Ross
- Division of Cardiology, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093;
- Cardiology Section, Department of Medicine, Veterans Administration Healthcare, San Diego, CA 92161
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160
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Abstract
Myeloid cells make extensive use of the complement system in the context of recruitment, phagocytosis, and other effector functions. There are several types of complement receptors on myeloid cells, including G protein-coupled receptors for localizing the source of complement activation, and three sets of type I transmembrane proteins that link complement to phagocytosis: complement receptor 1, having an extracellular domain with tandem complement regulatory repeats; complement receptors 3 and 4, which are integrin family receptors comprising heterodimers of type I transmembrane subunits; and VSIG4, a member of the Ig superfamily. This review will focus on the role of the different classes of complement receptors and how their activities are integrated in the setting of immune tolerance and inflammatory responses.
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161
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Abstract
Talin has emerged as the key cytoplasmic protein that mediates integrin adhesion to the extracellular matrix. In this Review, we draw on experiments performed in mammalian cells in culture and Drosophila to present evidence that talin is the most important component of integrin adhesion complexes. We describe how the properties of this adaptor protein enable it to orchestrate integrin adhesions. Talin forms the core of integrin adhesion complexes by linking integrins directly to actin, increasing the affinity of integrin for ligands (integrin activation) and recruiting numerous proteins. It regulates the strength of integrin adhesion, senses matrix rigidity, increases focal adhesion size in response to force and serves as a platform for the building of the adhesion structure. Finally, the mechano-sensitive structure of talin provides a paradigm for how proteins transduce mechanical signals to chemical signals.
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Affiliation(s)
- Benjamin Klapholz
- Dept of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Nicholas H Brown
- Dept of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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162
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Dwivedi M, Winter R. Binding of Vinculin to Lipid Membranes in Its Inhibited and Activated States. Biophys J 2017; 111:1444-1453. [PMID: 27705767 DOI: 10.1016/j.bpj.2016.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 08/15/2016] [Accepted: 08/18/2016] [Indexed: 10/20/2022] Open
Abstract
Phosphoinositols are an important class of phospholipids that are involved in a myriad of cellular processes, from cell signaling to motility and adhesion. Vinculin (Vn) is a major adaptor protein that regulates focal adhesions in conjunction with PIP2 in lipid membranes and other cytoskeletal components. The binding and unbinding transitions of Vn at the membrane interface are an important link to understanding the coordination of cell signaling and motility. Using different biophysical tools, including atomic force microscopy combined with confocal fluorescence microscopy and Fourier transform infrared spectroscopy, we studied the nanoscopic interactions of activated and autoinhibited states of Vn with lipid membranes. We hypothesize that a weak interaction occurs between Vn and lipid membranes, which leads to binding of autoinhibited Vn to supported lipid bilayers, and to unbinding in freestanding lipid vesicles. Likely driving forces may include tethering of the C-terminus to the lipid membrane, as well as hydrophobic helix-membrane interactions. Conversely, activated Vn binds strongly to membranes through specific interactions with clusters of PIP2 embedded in lipid membranes. Activated Vn harbored on PIP2 clusters may form small oligomeric interaction platforms for further interaction partners, which is necessary for the proper function of focal adhesion points.
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Affiliation(s)
- Mridula Dwivedi
- Physical Chemistry I, Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany.
| | - Roland Winter
- Physical Chemistry I, Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany.
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163
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164
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Rahikainen R, von Essen M, Schaefer M, Qi L, Azizi L, Kelly C, Ihalainen TO, Wehrle-Haller B, Bastmeyer M, Huang C, Hytönen VP. Mechanical stability of talin rod controls cell migration and substrate sensing. Sci Rep 2017; 7:3571. [PMID: 28620171 PMCID: PMC5472591 DOI: 10.1038/s41598-017-03335-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/26/2017] [Indexed: 11/17/2022] Open
Abstract
Cells adhere to the surrounding tissue and probe its mechanical properties by forming cell-matrix adhesions. Talin is a critical adhesion protein and participates in the transmission of mechanical signals between extracellular matrix and cell cytoskeleton. Force induced unfolding of talin rod subdomains has been proposed to act as a cellular mechanosensor, but so far evidence linking their mechanical stability and cellular response has been lacking. Here, by utilizing computationally designed mutations, we demonstrate that stepwise destabilization of the talin rod R3 subdomain decreases cellular traction force generation, which affects talin and vinculin dynamics in cell-matrix adhesions and results in the formation of talin-rich but unstable adhesions. We observed a connection between talin stability and the rate of cell migration and also found that talin destabilization affects the usage of different integrin subtypes and sensing of extracellular matrix proteins. Experiments with truncated forms of talin confirm the mechanosensory role of the talin R3 subdomain and exclude the possibility that the observed effects are caused by the release of talin head-rod autoinhibition. In conclusion, this study provides evidence into how the controlled talin rod domain unfolding acts as a key regulator of adhesion structure and function and consequently controls central cellular processes such as cell migration and substrate sensing.
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Affiliation(s)
- Rolle Rahikainen
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | - Magdaléna von Essen
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | - Markus Schaefer
- Zoological Institute, Cell- and Neurobiology, Karlsruhe Institute of Technology (KIT), Institute of Functional Interfaces (IFG), Karlsruhe, Germany
| | - Lei Qi
- Markey Cancer Center and Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY, USA
| | - Latifeh Azizi
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | - Conor Kelly
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | - Teemu O Ihalainen
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | | | - Martin Bastmeyer
- Zoological Institute, Cell- and Neurobiology, Karlsruhe Institute of Technology (KIT), Institute of Functional Interfaces (IFG), Karlsruhe, Germany
| | - Cai Huang
- Markey Cancer Center and Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY, USA
| | - Vesa P Hytönen
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland.
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165
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Hu X, Margadant FM, Yao M, Sheetz MP. Molecular stretching modulates mechanosensing pathways. Protein Sci 2017; 26:1337-1351. [PMID: 28474792 DOI: 10.1002/pro.3188] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 01/21/2023]
Abstract
For individual cells in tissues to create the diverse forms of biological organisms, it is necessary that they must reliably sense and generate the correct forces over the correct distances and directions. There is considerable evidence that the mechanical aspects of the cellular microenvironment provide critical physical parameters to be sensed. How proteins sense forces and cellular geometry to create the correct morphology is not understood in detail but protein unfolding appears to be a major component in force and displacement sensing. Thus, the crystallographic structure of a protein domain provides only a starting point to then analyze what will be the effects of physiological forces through domain unfolding or catch-bond formation. In this review, we will discuss the recent studies of cytoskeletal and adhesion proteins that describe protein domain dynamics. Forces applied to proteins can activate or inhibit enzymes, increase or decrease protein-protein interactions, activate or inhibit protein substrates, induce catch bonds and regulate interactions with membranes or nucleic acids. Further, the dynamics of stretch-relaxation can average forces or movements to reliably regulate morphogenic movements. In the few cases where single molecule mechanics are studied under physiological conditions such as titin and talin, there are rapid cycles of stretch-relaxation that produce mechanosensing signals. Fortunately, the development of new single molecule and super-resolution imaging methods enable the analysis of single molecule mechanics in physiologically relevant conditions. Thus, we feel that stereotypical changes in cell and tissue shape involve mechanosensing that can be analyzed at the nanometer level to determine the molecular mechanisms involved.
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Affiliation(s)
- Xian Hu
- Mechanobiology Institute, National University of Singapore, Singapore, 117411.,Department of Biosciences, University of Oslo, Oslo, 0316, Norway
| | | | - Mingxi Yao
- Mechanobiology Institute, National University of Singapore, Singapore, 117411
| | - Michael Patrick Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore, 117411.,Department of Biological Sciences, University of Columbia, New York, 10027
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166
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Mège RM, Ishiyama N. Integration of Cadherin Adhesion and Cytoskeleton at Adherens Junctions. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028738. [PMID: 28096263 DOI: 10.1101/cshperspect.a028738] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The cadherin-catenin adhesion complex is the key component of the intercellular adherens junction (AJ) that contributes both to tissue stability and dynamic cell movements in epithelial and nonepithelial tissues. The cadherin adhesion complex bridges neighboring cells and the actin-myosin cytoskeleton, and thereby contributes to mechanical coupling between cells which drives many morphogenetic events and tissue repair. Mechanotransduction at cadherin adhesions enables cells to sense, signal, and respond to physical changes in their environment. Central to this process is the dynamic link of the complex to actin filaments (F-actin), themselves structurally dynamic and subject to tension generated by myosin II motors. We discuss in this review recent breakthroughs in understanding molecular and cellular aspects of the organization of the core cadherin-catenin complex in adherens junctions, its association to F-actin, its mechanosensitive regulation, and dynamics.
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Affiliation(s)
- René Marc Mège
- Institut Jacques Monod (IJM), CNRS UMR 7592 and Université Paris Diderot, Paris, France
| | - Noboru Ishiyama
- Princess Margaret Cancer Centre, University Health Network, TMDT 4-902, Toronto, Ontario, Canada
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167
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Bouissou A, Proag A, Bourg N, Pingris K, Cabriel C, Balor S, Mangeat T, Thibault C, Vieu C, Dupuis G, Fort E, Lévêque-Fort S, Maridonneau-Parini I, Poincloux R. Podosome Force Generation Machinery: A Local Balance between Protrusion at the Core and Traction at the Ring. ACS NANO 2017; 11:4028-4040. [PMID: 28355484 DOI: 10.1021/acsnano.7b00622] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Determining how cells generate and transduce mechanical forces at the nanoscale is a major technical challenge for the understanding of numerous physiological and pathological processes. Podosomes are submicrometer cell structures with a columnar F-actin core surrounded by a ring of adhesion proteins, which possess the singular ability to protrude into and probe the extracellular matrix. Using protrusion force microscopy, we have previously shown that single podosomes produce local nanoscale protrusions on the extracellular environment. However, how cellular forces are distributed to allow this protruding mechanism is still unknown. To investigate the molecular machinery of protrusion force generation, we performed mechanical simulations and developed quantitative image analyses of nanoscale architectural and mechanical measurements. First, in silico modeling showed that the deformations of the substrate made by podosomes require protrusion forces to be balanced by local traction forces at the immediate core periphery where the adhesion ring is located. Second, we showed that three-ring proteins are required for actin polymerization and protrusion force generation. Third, using DONALD, a 3D nanoscopy technique that provides 20 nm isotropic localization precision, we related force generation to the molecular extension of talin within the podosome ring, which requires vinculin and paxillin, indicating that the ring sustains mechanical tension. Our work demonstrates that the ring is a site of tension, balancing protrusion at the core. This local coupling of opposing forces forms the basis of protrusion and reveals the podosome as a nanoscale autonomous force generator.
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Affiliation(s)
- Anaïs Bouissou
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse , CNRS, UPS, Toulouse 31400, France
| | - Amsha Proag
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse , CNRS, UPS, Toulouse 31400, France
| | - Nicolas Bourg
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Sud , CNRS UMR8214, Orsay 91405, France
- Université Paris-Sud , Centre de Photonique BioMédicale, Fédération LUMAT, CNRS, FR 2764, Orsay 91405, France
| | - Karine Pingris
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse , CNRS, UPS, Toulouse 31400, France
| | - Clément Cabriel
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Sud , CNRS UMR8214, Orsay 91405, France
- Université Paris-Sud , Centre de Photonique BioMédicale, Fédération LUMAT, CNRS, FR 2764, Orsay 91405, France
| | | | - Thomas Mangeat
- LBCMCP, Centre de Biologie Intégrative, Université de Toulouse , CNRS, UPS, Toulouse 31062, France
| | - Christophe Thibault
- CNRS, LAAS , Toulouse 31031, France
- Université de Toulouse , INSA, Toulouse 31077, France
| | - Christophe Vieu
- CNRS, LAAS , Toulouse 31031, France
- Université de Toulouse , INSA, Toulouse 31077, France
| | - Guillaume Dupuis
- Université Paris-Sud , Centre de Photonique BioMédicale, Fédération LUMAT, CNRS, FR 2764, Orsay 91405, France
| | - Emmanuel Fort
- Institut Langevin, ESPCI, CNRS, PSL Research University , Paris 75005, France
| | - Sandrine Lévêque-Fort
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Sud , CNRS UMR8214, Orsay 91405, France
- Université Paris-Sud , Centre de Photonique BioMédicale, Fédération LUMAT, CNRS, FR 2764, Orsay 91405, France
| | - Isabelle Maridonneau-Parini
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse , CNRS, UPS, Toulouse 31400, France
| | - Renaud Poincloux
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse , CNRS, UPS, Toulouse 31400, France
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168
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Mekhdjian AH, Kai F, Rubashkin MG, Prahl LS, Przybyla LM, McGregor AL, Bell ES, Barnes JM, DuFort CC, Ou G, Chang AC, Cassereau L, Tan SJ, Pickup MW, Lakins JN, Ye X, Davidson MW, Lammerding J, Odde DJ, Dunn AR, Weaver VM. Integrin-mediated traction force enhances paxillin molecular associations and adhesion dynamics that increase the invasiveness of tumor cells into a three-dimensional extracellular matrix. Mol Biol Cell 2017; 28:1467-1488. [PMID: 28381423 PMCID: PMC5449147 DOI: 10.1091/mbc.e16-09-0654] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 03/24/2017] [Accepted: 03/29/2017] [Indexed: 12/21/2022] Open
Abstract
Mammary tumor cells adopt a basal-like phenotype when invading through a dense, stiffened, 3D matrix. These cells exert higher integrin-mediated traction forces, consistent with a physical motor-clutch model, display an altered molecular organization at the nanoscale, and recruit a suite of paxillin-associated proteins implicated in metastasis. Metastasis requires tumor cells to navigate through a stiff stroma and squeeze through confined microenvironments. Whether tumors exploit unique biophysical properties to metastasize remains unclear. Data show that invading mammary tumor cells, when cultured in a stiffened three-dimensional extracellular matrix that recapitulates the primary tumor stroma, adopt a basal-like phenotype. Metastatic tumor cells and basal-like tumor cells exert higher integrin-mediated traction forces at the bulk and molecular levels, consistent with a motor-clutch model in which motors and clutches are both increased. Basal-like nonmalignant mammary epithelial cells also display an altered integrin adhesion molecular organization at the nanoscale and recruit a suite of paxillin-associated proteins implicated in invasion and metastasis. Phosphorylation of paxillin by Src family kinases, which regulates adhesion turnover, is similarly enhanced in the metastatic and basal-like tumor cells, fostered by a stiff matrix, and critical for tumor cell invasion in our assays. Bioinformatics reveals an unappreciated relationship between Src kinases, paxillin, and survival of breast cancer patients. Thus adoption of the basal-like adhesion phenotype may favor the recruitment of molecules that facilitate tumor metastasis to integrin-based adhesions. Analysis of the physical properties of tumor cells and integrin adhesion composition in biopsies may be predictive of patient outcome.
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Affiliation(s)
- Armen H Mekhdjian
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - FuiBoon Kai
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Matthew G Rubashkin
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Louis S Prahl
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Laralynne M Przybyla
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Alexandra L McGregor
- Nancy E. and Peter C. Meinig School of Biomedical Engineering and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Emily S Bell
- Nancy E. and Peter C. Meinig School of Biomedical Engineering and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - J Matthew Barnes
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Christopher C DuFort
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Guanqing Ou
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Alice C Chang
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Luke Cassereau
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Steven J Tan
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Michael W Pickup
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Jonathan N Lakins
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143
| | - Xin Ye
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | - Michael W Davidson
- National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Jan Lammerding
- Nancy E. and Peter C. Meinig School of Biomedical Engineering and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - David J Odde
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Alexander R Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Valerie M Weaver
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA 94143 .,Departments of Anatomy, Bioengineering and Therapeutic Sciences, and Radiation Oncology, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, and UCSF Helen Diller Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143
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169
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Stutchbury B, Atherton P, Tsang R, Wang DY, Ballestrem C. Distinct focal adhesion protein modules control different aspects of mechanotransduction. J Cell Sci 2017; 130:1612-1624. [PMID: 28302906 DOI: 10.1242/jcs.195362] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 03/08/2017] [Indexed: 12/28/2022] Open
Abstract
Focal adhesions (FAs) are macromolecular complexes that regulate cell adhesion and mechanotransduction. By performing fluorescence recovery after photobleaching (FRAP) and fluorescence loss after photoactivation (FLAP) experiments, we found that the mobility of core FA proteins correlates with their function. Structural proteins such as tensin, talin and vinculin are significantly less mobile in FAs than signaling proteins such as FAK (also known as PTK2) and paxillin. The mobilities of the structural proteins are directly influenced by substrate stiffness, suggesting that they are involved in sensing the rigidity of the extracellular environment. The turnover rates of FAK and paxillin, as well as kindlin2 (also known as FERMT2), are not influenced by substrate stiffness. By using specific Src and FAK inhibitors, we reveal that force-sensing by vinculin occurs independently of FAK and paxillin phosphorylation. However, their phosphorylation is required for downstream Rac1-driven cellular processes, such as protrusion and cell migration. Overall, we show that the FA is composed of different functional modules that separately control mechanosensing and the cellular mechano-response.
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Affiliation(s)
- Ben Stutchbury
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, England, UK
| | - Paul Atherton
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, England, UK
| | - Ricky Tsang
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, England, UK
| | - De-Yao Wang
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, England, UK
| | - Christoph Ballestrem
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, England, UK
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170
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Maki K, Nakao N, Adachi T. Nano-mechanical characterization of tension-sensitive helix bundles in talin rod. Biochem Biophys Res Commun 2017; 484:372-377. [PMID: 28131835 DOI: 10.1016/j.bbrc.2017.01.127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 01/23/2017] [Indexed: 01/11/2023]
Abstract
Tension-induced exposure of a cryptic signaling binding site is one of the most fundamental mechanisms in molecular mechanotransduction. Helix bundles in rod domains of talin, a tension-sensing protein at focal adhesions, unfurl under tension to expose cryptic vinculin binding sites. Although the difference in their mechanical stabilities would determine which helix bundle is tension-sensitive, their respective mechanical behaviors under tension have not been characterized. In this study, we evaluated the mechanical behaviors of residues 486-654 and 754-889 of talin, which form helix bundles with low and high tension-sensitivity, by employing AFM nano-tensile testing. As a result, residues 754-889 exhibited lower unfolding energy for complete unfolding than residues 486-654. In addition, we found that residues 754-889 transition into intermediate conformations under lower tension than residues 486-654. Furthermore, residues 754-889 showed shorter persistence length in the intermediate conformation than residues 486-654, suggesting that residues 754-889 under tension exhibit separated α-helices, while residues 486-654 assume a compact conformation with inter-helix interactions. Therefore, we suggest that residues 754-889 of talin work as a tension-sensitive domain to recruit vinculin at the early stage of focal adhesion development, while residues 486-654 contribute to rather robust tension-sensitivity by recruiting vinculin under high tension.
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Affiliation(s)
- Koichiro Maki
- Laboratory of Biomechanics, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin-Kawahara-cho, Sakyo, Kyoto 606-8507, Japan; Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Yoshida Honmachi, Sakyo, Kyoto 606-8501, Japan
| | - Nobuhiko Nakao
- Laboratory of Biomechanics, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin-Kawahara-cho, Sakyo, Kyoto 606-8507, Japan; Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Yoshida Honmachi, Sakyo, Kyoto 606-8501, Japan
| | - Taiji Adachi
- Laboratory of Biomechanics, Department of Biosystems Science, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin-Kawahara-cho, Sakyo, Kyoto 606-8507, Japan; Department of Micro Engineering, Graduate School of Engineering, Kyoto University, Yoshida Honmachi, Sakyo, Kyoto 606-8501, Japan.
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171
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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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172
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Sun Z, Guo SS, Fässler R. Integrin-mediated mechanotransduction. J Cell Biol 2016; 215:445-456. [PMID: 27872252 PMCID: PMC5119943 DOI: 10.1083/jcb.201609037] [Citation(s) in RCA: 615] [Impact Index Per Article: 76.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 10/26/2016] [Accepted: 10/27/2016] [Indexed: 12/16/2022] Open
Abstract
Sun, Guo, and Fässler review the function and regulation of integrin-mediated mechanotransduction and discuss how its dysregulation impacts cancer progession. Cells can detect and react to the biophysical properties of the extracellular environment through integrin-based adhesion sites and adapt to the extracellular milieu in a process called mechanotransduction. At these adhesion sites, integrins connect the extracellular matrix (ECM) with the F-actin cytoskeleton and transduce mechanical forces generated by the actin retrograde flow and myosin II to the ECM through mechanosensitive focal adhesion proteins that are collectively termed the “molecular clutch.” The transmission of forces across integrin-based adhesions establishes a mechanical reciprocity between the viscoelasticity of the ECM and the cellular tension. During mechanotransduction, force allosterically alters the functions of mechanosensitive proteins within adhesions to elicit biochemical signals that regulate both rapid responses in cellular mechanics and long-term changes in gene expression. Integrin-mediated mechanotransduction plays important roles in development and tissue homeostasis, and its dysregulation is often associated with diseases.
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Affiliation(s)
- Zhiqi Sun
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Shengzhen S Guo
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Reinhard Fässler
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
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173
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Freikamp A, Cost AL, Grashoff C. The Piconewton Force Awakens: Quantifying Mechanics in Cells. Trends Cell Biol 2016; 26:838-847. [DOI: 10.1016/j.tcb.2016.07.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/20/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023]
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174
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Maartens AP, Wellmann J, Wictome E, Klapholz B, Green H, Brown NH. Drosophila vinculin is more harmful when hyperactive than absent, and can circumvent integrin to form adhesion complexes. J Cell Sci 2016; 129:4354-4365. [PMID: 27737911 PMCID: PMC5201009 DOI: 10.1242/jcs.189878] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 10/07/2016] [Indexed: 12/12/2022] Open
Abstract
Vinculin is a highly conserved protein involved in cell adhesion and mechanotransduction, and both gain and loss of its activity causes defective cell behaviour. Here, we examine how altering vinculin activity perturbs integrin function within the context of Drosophila development. Whereas loss of vinculin produced relatively minor phenotypes, gain of vinculin activity, through a loss of head–tail autoinhibition, caused lethality. The minimal domain capable of inducing lethality is the talin-binding D1 domain, and this appears to require talin-binding activity, as lethality was suppressed by competition with single vinculin-binding sites from talin. Activated Drosophila vinculin triggered the formation of cytoplasmic adhesion complexes through the rod of talin, but independently of integrin. These complexes contain a subset of adhesion proteins but no longer link the membrane to actin. The negative effects of hyperactive vinculin were segregated into morphogenetic defects caused by its whole head domain and lethality caused by its D1 domain. These findings demonstrate the crucial importance of the tight control of the activity of vinculin. Summary: Development is more sensitive to gain of vinculin activity than its loss, and vinculin can promote cytoplasmic adhesion complexes independently of the usual integrin cue.
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Affiliation(s)
- Aidan P Maartens
- Department of Physiology, Development and Neuroscience, and the Gurdon Institute, University of Cambridge, Downing St., Cambridge CB2 1DY, UK
| | - Jutta Wellmann
- Department of Physiology, Development and Neuroscience, and the Gurdon Institute, University of Cambridge, Downing St., Cambridge CB2 1DY, UK
| | - Emma Wictome
- Department of Physiology, Development and Neuroscience, and the Gurdon Institute, University of Cambridge, Downing St., Cambridge CB2 1DY, UK
| | - Benjamin Klapholz
- Department of Physiology, Development and Neuroscience, and the Gurdon Institute, University of Cambridge, Downing St., Cambridge CB2 1DY, UK
| | - Hannah Green
- Department of Physiology, Development and Neuroscience, and the Gurdon Institute, University of Cambridge, Downing St., Cambridge CB2 1DY, UK
| | - Nicholas H Brown
- Department of Physiology, Development and Neuroscience, and the Gurdon Institute, University of Cambridge, Downing St., Cambridge CB2 1DY, UK
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175
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Abstract
Here, I argue that some of the secrets of complex biological function rely on assemblies of many heterogeneous proteins that together enable sophisticated sensing and actuating processes. Evolution seems to delight in making these structures and in continually elaborating upon their capabilities. Developing tools that can go beyond the few protein limit, both on the experimental frontier and from a theoretical, conceptual framework, should be an extremely high priority for the next generation of molecular biophysicists.
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Affiliation(s)
- Herbert Levine
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
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176
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Li Z, Lee H, Zhu C. Molecular mechanisms of mechanotransduction in integrin-mediated cell-matrix adhesion. Exp Cell Res 2016; 349:85-94. [PMID: 27720950 DOI: 10.1016/j.yexcr.2016.10.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 01/09/2023]
Abstract
Cell-matrix adhesion complexes are multi-protein structures linking the extracellular matrix (ECM) to the cytoskeleton. They are essential to both cell motility and function by bidirectionally sensing and transmitting mechanical and biochemical stimulations. Several types of cell-matrix adhesions have been identified and they share many key molecular components, such as integrins and actin-integrin linkers. Mechanochemical coupling between ECM molecules and the actin cytoskeleton has been observed from the single cell to the single molecule level and from immune cells to neuronal cells. However, the mechanisms underlying force regulation of integrin-mediated mechanotransduction still need to be elucidated. In this review article, we focus on integrin-mediated adhesions and discuss force regulation of cell-matrix adhesions and key adaptor molecules, three different force-dependent behaviors, and molecular mechanisms for mechanochemical coupling in force regulation.
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Affiliation(s)
- Zhenhai Li
- Molecular Modeling and Simulation Group, National Institutes for Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215, Japan
| | - Hyunjung Lee
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Cheng Zhu
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; George W Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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177
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Haining AM, von Essen M, Attwood S, Hytönen VP, del Río Hernández A. All Subdomains of the Talin Rod Are Mechanically Vulnerable and May Contribute To Cellular Mechanosensing. ACS NANO 2016; 10:6648-58. [PMID: 27380548 PMCID: PMC4982699 DOI: 10.1021/acsnano.6b01658] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/05/2016] [Indexed: 05/27/2023]
Abstract
Although the relevance of mechanotransduction in cell signaling is currently appreciated, the mechanisms that drive this process remain largely unknown. Mechanical unfolding of proteins may trigger distinct downstream signals in cells, providing a mechanism for cellular mechanotransduction. Force-induced unfolding of talin, a prominent focal adhesion protein, has been demonstrated previously for a small portion of its rod domain. Here, using single-molecule atomic force microscopy (smAFM), we show that the entire talin rod can be unfolded by mechanical extension, over a physiological range of forces between 10 and 40 pN. We also demonstrate, through a combination of smAFM and steered molecular dynamics, that the different bundles within the talin rod exhibit a distinct hierarchy of mechanical stability. These results provide a mechanism by which different force conditions within the cell control a graduated unfolding of the talin rod. Mechanical unfolding of the rod subdomains, and the subsequent effect on talin's binding interactions, would allow for a finely tuned cellular response to internally or externally applied forces.
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Affiliation(s)
- Alexander
William M. Haining
- Cellular
and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Magdaléna von Essen
- BioMediTech, University of Tampere, Biokatu 6, FI-33520 Tampere, Finland
- Fimlab
Laboratories, Biokatu
4, FI-33520 Tampere, Finland
| | - Simon
J. Attwood
- Cellular
and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Vesa P. Hytönen
- BioMediTech, University of Tampere, Biokatu 6, FI-33520 Tampere, Finland
- Fimlab
Laboratories, Biokatu
4, FI-33520 Tampere, Finland
| | - Armando del Río Hernández
- Cellular
and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
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178
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Hu X, Jing C, Xu X, Nakazawa N, Cornish VW, Margadant FM, Sheetz MP. Cooperative Vinculin Binding to Talin Mapped by Time-Resolved Super Resolution Microscopy. NANO LETTERS 2016; 16:4062-8. [PMID: 27210030 PMCID: PMC5367886 DOI: 10.1021/acs.nanolett.6b00650] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The dimeric focal adhesion protein talin contains up to 22 cryptic vinculin binding sites that are exposed by unfolding. Using a novel method to monitor the in situ dynamics of the talin dimer stretch, we find that in contrast to several prevalent talin dimer models the integrin-binding talin N-termini are separated by 162 ± 44 nm on average whereas as expected the C-terminal dimerization domains colocalize and are mobile. Using vinculin tagged by DHFR-TMP Atto655 label, we found that optimal vinculin and vinculin head binding occurred when talin was stretched to 180 nm, while the controls did not bind to talin. Surprisingly, multiple vinculins bound within a single second in narrowly localized regions of the talin rod during stretching. We suggest that talin stretches as an antiparallel dimer and that activates vinculin binding in a cooperative manner, consistent with the stabilization of folded talin by other binding proteins.
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Affiliation(s)
- Xian Hu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Chaoran Jing
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xiaochun Xu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Naotaka Nakazawa
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Virginia W. Cornish
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Felix M. Margadant
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Michael P. Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Department of Biological Sciences, Columbia University, New York, New York 10027, United States
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179
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Bouchet BP, Gough RE, Ammon YC, van de Willige D, Post H, Jacquemet G, Altelaar AM, Heck AJ, Goult BT, Akhmanova A. Talin-KANK1 interaction controls the recruitment of cortical microtubule stabilizing complexes to focal adhesions. eLife 2016; 5. [PMID: 27410476 PMCID: PMC4995097 DOI: 10.7554/elife.18124] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 07/12/2016] [Indexed: 12/23/2022] Open
Abstract
The cross-talk between dynamic microtubules and integrin-based adhesions to the extracellular matrix plays a crucial role in cell polarity and migration. Microtubules regulate the turnover of adhesion sites, and, in turn, focal adhesions promote the cortical microtubule capture and stabilization in their vicinity, but the underlying mechanism is unknown. Here, we show that cortical microtubule stabilization sites containing CLASPs, KIF21A, LL5β and liprins are recruited to focal adhesions by the adaptor protein KANK1, which directly interacts with the major adhesion component, talin. Structural studies showed that the conserved KN domain in KANK1 binds to the talin rod domain R7. Perturbation of this interaction, including a single point mutation in talin, which disrupts KANK1 binding but not the talin function in adhesion, abrogates the association of microtubule-stabilizing complexes with focal adhesions. We propose that the talin-KANK1 interaction links the two macromolecular assemblies that control cortical attachment of actin fibers and microtubules. DOI:http://dx.doi.org/10.7554/eLife.18124.001 Animal cells are organized into tissues and organs. A scaffold-like framework outside of the cells called the extracellular matrix provides support to the cells and helps to hold them in place. Cells attach to the extracellular matrix via structures called focal adhesions on the cell surface; these structures contain a protein called talin. For a cell to be able to move, the existing focal adhesions must be broken down and new adhesions allowed to form. This process is regulated by the delivery and removal of different materials along fibers called microtubules. Microtubules can usually grow and shrink rapidly, but near focal adhesions they are captured at the surface of the cell and become more stable. However, it is not clear how focal adhesions promote microtubule capture and stability. Bouchet et al. found that a protein called KANK1 binds to the focal adhesion protein talin in human cells grown in a culture dish. This allows KANK1 to recruit microtubules to the cell surface around the focal adhesions by binding to particular proteins that are associated with microtubules. Disrupting the interaction between KANK1 and talin by making small alterations in these two proteins blocked the ability of focal adhesions to capture surrounding microtubules. The next step following on from this work will be to find out whether this process also takes place in the cells within an animal’s body, such as a fly or a mouse. DOI:http://dx.doi.org/10.7554/eLife.18124.002
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Affiliation(s)
- Benjamin P Bouchet
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Rosemarie E Gough
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - York-Christoph Ammon
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Dieudonnée van de Willige
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Harm Post
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, Utrecht, The Netherlands.,Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.,The Netherlands Proteomics Centre, Utrecht University, Utrecht, The Netherlands
| | | | - Af Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, Utrecht, The Netherlands.,Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.,The Netherlands Proteomics Centre, Utrecht University, Utrecht, The Netherlands
| | - Albert Jr Heck
- Biomolecular Mass Spectrometry and Proteomics, Utrecht University, Utrecht, The Netherlands.,Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.,The Netherlands Proteomics Centre, Utrecht University, Utrecht, The Netherlands
| | - Benjamin T Goult
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
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180
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Yao M, Goult BT, Klapholz B, Hu X, Toseland CP, Guo Y, Cong P, Sheetz MP, Yan J. The mechanical response of talin. Nat Commun 2016; 7:11966. [PMID: 27384267 PMCID: PMC4941051 DOI: 10.1038/ncomms11966] [Citation(s) in RCA: 232] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/17/2016] [Indexed: 12/28/2022] Open
Abstract
Talin, a force-bearing cytoplasmic adapter essential for integrin-mediated cell adhesion, links the actin cytoskeleton to integrin-based cell-extracellular matrix adhesions at the plasma membrane. Its C-terminal rod domain, which contains 13 helical bundles, plays important roles in mechanosensing during cell adhesion and spreading. However, how the structural stability and transition kinetics of the 13 helical bundles of talin are utilized in the diverse talin-dependent mechanosensing processes remains poorly understood. Here we report the force-dependent unfolding and refolding kinetics of all talin rod domains. Using experimentally determined kinetics parameters, we determined the dynamics of force fluctuation during stretching of talin under physiologically relevant pulling speeds and experimentally measured extension fluctuation trajectories. Our results reveal that force-dependent stochastic unfolding and refolding of talin rod domains make talin a very effective force buffer that sets a physiological force range of only a few pNs in the talin-mediated force transmission pathway.
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Affiliation(s)
- Mingxi Yao
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | | | - Benjamin Klapholz
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Anatomy Building, Downing street, Cambridge CB2 3DY, UK
| | - Xian Hu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | | | - Yingjian Guo
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Peiwen Cong
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Michael P. Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
- Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore
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181
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Zacharchenko T, Qian X, Goult BT, Jethwa D, Almeida TB, Ballestrem C, Critchley DR, Lowy DR, Barsukov IL. LD Motif Recognition by Talin: Structure of the Talin-DLC1 Complex. Structure 2016; 24:1130-41. [PMID: 27265849 PMCID: PMC4938799 DOI: 10.1016/j.str.2016.04.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 11/25/2022]
Abstract
Cell migration requires coordination between integrin-mediated cell adhesion to the extracellular matrix and force applied to adhesion sites. Talin plays a key role in coupling integrin receptors to the actomyosin contractile machinery, while deleted in liver cancer 1 (DLC1) is a Rho GAP that binds talin and regulates Rho, and therefore actomyosin contractility. We show that the LD motif of DLC1 forms a helix that binds to the four-helix bundle of the talin R8 domain in a canonical triple-helix arrangement. We demonstrate that the same R8 surface interacts with the paxillin LD1 and LD2 motifs. We identify key charged residues that stabilize the R8 interactions with LD motifs and demonstrate their importance in vitro and in cells. Our results suggest a network of competitive interactions in adhesion complexes that involve LD motifs, and identify mutations that can be used to analyze the biological roles of specific protein-protein interactions in cell migration.
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Affiliation(s)
- Thomas Zacharchenko
- Institute of Integrative Biology, University of Liverpool, BioSciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Xiaolan Qian
- Laboratory of Cellular Oncology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Benjamin T Goult
- School of Biosciences, University of Kent, Kent, Canterbury, CT2 7NJ, UK
| | - Devina Jethwa
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Teresa B Almeida
- Institute of Integrative Biology, University of Liverpool, BioSciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Christoph Ballestrem
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - David R Critchley
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Douglas R Lowy
- Laboratory of Cellular Oncology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Igor L Barsukov
- Institute of Integrative Biology, University of Liverpool, BioSciences Building, Crown Street, Liverpool L69 7ZB, UK.
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182
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Elosegui-Artola A, Oria R, Chen Y, Kosmalska A, Pérez-González C, Castro N, Zhu C, Trepat X, Roca-Cusachs P. Mechanical regulation of a molecular clutch defines force transmission and transduction in response to matrix rigidity. Nat Cell Biol 2016; 18:540-8. [PMID: 27065098 DOI: 10.1038/ncb3336] [Citation(s) in RCA: 481] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 03/08/2016] [Indexed: 12/12/2022]
Abstract
Cell function depends on tissue rigidity, which cells probe by applying and transmitting forces to their extracellular matrix, and then transducing them into biochemical signals. Here we show that in response to matrix rigidity and density, force transmission and transduction are explained by the mechanical properties of the actin-talin-integrin-fibronectin clutch. We demonstrate that force transmission is regulated by a dynamic clutch mechanism, which unveils its fundamental biphasic force/rigidity relationship on talin depletion. Force transduction is triggered by talin unfolding above a stiffness threshold. Below this threshold, integrins unbind and release force before talin can unfold. Above the threshold, talin unfolds and binds to vinculin, leading to adhesion growth and YAP nuclear translocation. Matrix density, myosin contractility, integrin ligation and talin mechanical stability differently and nonlinearly regulate both force transmission and the transduction threshold. In all cases, coupling of talin unfolding dynamics to a theoretical clutch model quantitatively predicts cell response.
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Affiliation(s)
| | - Roger Oria
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain.,University of Barcelona, Barcelona 08028, Spain
| | - Yunfeng Chen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Anita Kosmalska
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain.,University of Barcelona, Barcelona 08028, Spain
| | - Carlos Pérez-González
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain.,University of Barcelona, Barcelona 08028, Spain
| | - Natalia Castro
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain.,University of Barcelona, Barcelona 08028, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona 08010, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Madrid 28029, Spain
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia, Barcelona 08028, Spain.,University of Barcelona, Barcelona 08028, Spain
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183
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Byron A, Frame MC. Adhesion protein networks reveal functions proximal and distal to cell-matrix contacts. Curr Opin Cell Biol 2016; 39:93-100. [PMID: 26930633 PMCID: PMC5094910 DOI: 10.1016/j.ceb.2016.02.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 02/09/2016] [Accepted: 02/09/2016] [Indexed: 12/15/2022]
Abstract
Cell adhesion to the extracellular matrix is generally mediated by integrin receptors, which bind to intracellular adhesion proteins that form multi-molecular scaffolding and signalling complexes. The networks of proteins, and their interactions, are dynamic, mechanosensitive and extremely complex. Recent efforts to characterise adhesions using a variety of technologies, including imaging, proteomics and bioinformatics, have provided new insights into their composition, organisation and how they are regulated, and have also begun to reveal unexpected roles for so-called adhesion proteins in other cellular compartments (for example, the nucleus or centrosomes) in diseases such as cancer. We believe this is opening a new chapter on understanding the wider functions of adhesion proteins, both proximal and distal to cell-matrix contacts.
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Affiliation(s)
- Adam Byron
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom.
| | - Margaret C Frame
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
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184
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Han MKL, de Rooij J. Converging and Unique Mechanisms of Mechanotransduction at Adhesion Sites. Trends Cell Biol 2016; 26:612-623. [PMID: 27036655 DOI: 10.1016/j.tcb.2016.03.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/07/2016] [Accepted: 03/08/2016] [Indexed: 12/31/2022]
Abstract
The molecular mechanisms by which physical forces control tissue development are beginning to be elucidated. Sites of adhesion between both cells and the extracellular environment [extracellular matrix (ECM) or neighboring cells] contain protein complexes capable of sensing fluctuations in tensile forces. Tension-dependent changes in the dynamics and composition of these complexes mark the transformation of physical input into biochemical signals that defines mechanotransduction. It is becoming apparent that, although the core constituents of these different adhesions are distinct, principles and proteins involved in mechanotransduction are conserved. Here, we discuss the current knowledge of overlapping and distinct aspects of mechanotransduction between integrin and cadherin adhesion complexes.
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Affiliation(s)
- Mitchell K L Han
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Stratenum 3.231, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Johan de Rooij
- Department of Molecular Cancer Research, Center for Molecular Medicine, University Medical Center Utrecht, Stratenum 3.231, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands.
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185
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Comrie WA, Burkhardt JK. Action and Traction: Cytoskeletal Control of Receptor Triggering at the Immunological Synapse. Front Immunol 2016; 7:68. [PMID: 27014258 PMCID: PMC4779853 DOI: 10.3389/fimmu.2016.00068] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/12/2016] [Indexed: 01/03/2023] Open
Abstract
It is well known that F-actin dynamics drive the micron-scale cell shape changes required for migration and immunological synapse (IS) formation. In addition, recent evidence points to a more intimate role for the actin cytoskeleton in promoting T cell activation. Mechanotransduction, the conversion of mechanical input into intracellular biochemical changes, is thought to play a critical role in several aspects of immunoreceptor triggering and downstream signal transduction. Multiple molecules associated with signaling events at the IS have been shown to respond to physical force, including the TCR, costimulatory molecules, adhesion molecules, and several downstream adapters. In at least some cases, it is clear that the relevant forces are exerted by dynamics of the T cell actomyosin cytoskeleton. Interestingly, there is evidence that the cytoskeleton of the antigen-presenting cell also plays an active role in T cell activation, by countering the molecular forces exerted by the T cell at the IS. Since actin polymerization is itself driven by TCR and costimulatory signaling pathways, a complex relationship exists between actin dynamics and receptor activation. This review will focus on recent advances in our understanding of the mechanosensitive aspects of T cell activation, paying specific attention to how F-actin-directed forces applied from both sides of the IS fit into current models of receptor triggering and activation.
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Affiliation(s)
- William A Comrie
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
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186
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Wyatt T, Baum B, Charras G. A question of time: tissue adaptation to mechanical forces. Curr Opin Cell Biol 2016; 38:68-73. [PMID: 26945098 DOI: 10.1016/j.ceb.2016.02.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 10/22/2022]
Abstract
While much attention has been focused on the force-generating mechanisms responsible for shaping developing embryos, less is known about the ways in which cells in animal tissues respond to mechanical stimuli. Forces will arise within a tissue as the result of processes such as local cell death, growth and division, but they can also be an indirect consequence of morphogenetic movements in neighbouring tissues or be imposed from the outside, for example, by gravity. If not dealt with, the accumulation of stress and the resulting tissue deformation can pose a threat to tissue integrity and structure. Here we follow the time-course of events by which cells and tissues return to their preferred state following a mechanical perturbation. In doing so, we discuss the spectrum of biological and physical mechanisms known to underlie mechanical homeostasis in animal tissues.
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Affiliation(s)
- Tom Wyatt
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK; Centre for Mathematics, Physics and Engineering in the Life Sciences and Experimental Biology, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK
| | - Buzz Baum
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK.
| | - Guillaume Charras
- London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK; Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
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187
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IPP Complex Reinforces Adhesion by Relaying Tension-Dependent Signals to Inhibit Integrin Turnover. Cell Rep 2016; 14:2668-82. [DOI: 10.1016/j.celrep.2016.02.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/05/2016] [Accepted: 02/08/2016] [Indexed: 12/19/2022] Open
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188
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Navarro AP, Collins MA, Folker ES. The nucleus is a conserved mechanosensation and mechanoresponse organelle. Cytoskeleton (Hoboken) 2016; 73:59-67. [PMID: 26849407 DOI: 10.1002/cm.21277] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 01/22/2016] [Accepted: 01/22/2016] [Indexed: 11/05/2022]
Abstract
Cells in vivo exist in a dynamic environment where they experience variable mechanical influences. The precise mechanical environment influences cell-cell interactions, cell-extracellular matrix interactions, and in-turn, cell morphology and cell function. Therefore, the ability of each cell to constantly and rapidly alter their behavior in response to variations in their mechanical environment is essential for cell viability, development, and function. Mechanotransduction, the process by which mechanical force is translated into a biochemical signal to activate downstream cellular responses, is thus crucial to cell function during development and homeostasis. Although much research has focused on how protein complexes at the cell cortex respond to mechanical stress to initiate mechanotransduction, the nucleus has emerged as crucial to the ability of the cell to perceive and respond to changes in its mechanical environment. This additional method for mechanosensing allows for direct transmission of force through the cytoskeleton to the nucleus, which can increase the speed at which a cell changes its transcriptional profile. This review discusses recent work demonstrating the importance of the nucleus in mediating the cellular response to internal and external force, establishing the nucleus as an important mechanosensing organelle.
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Affiliation(s)
- Alexandra P Navarro
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02142
| | - Mary Ann Collins
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, 02467
| | - Eric S Folker
- Department of Biology, Boston College, Chestnut Hill, Massachusetts, 02467
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189
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Haining AWM, Lieberthal TJ, Hernández ADR. Talin: a mechanosensitive molecule in health and disease. FASEB J 2016; 30:2073-85. [DOI: 10.1096/fj.201500080r] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/09/2016] [Indexed: 12/22/2022]
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190
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Work Done by Titin Protein Folding Assists Muscle Contraction. Cell Rep 2016; 14:1339-1347. [PMID: 26854230 DOI: 10.1016/j.celrep.2016.01.025] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 09/30/2015] [Accepted: 01/04/2016] [Indexed: 01/29/2023] Open
Abstract
Current theories of muscle contraction propose that the power stroke of a myosin motor is the sole source of mechanical energy driving the sliding filaments of a contracting muscle. These models exclude titin, the largest protein in the human body, which determines the passive elasticity of muscles. Here, we show that stepwise unfolding/folding of titin immunoglobulin (Ig) domains occurs in the elastic I band region of intact myofibrils at physiological sarcomere lengths and forces of 6-8 pN. We use single-molecule techniques to demonstrate that unfolded titin Ig domains undergo a spontaneous stepwise folding contraction at forces below 10 pN, delivering up to 105 zJ of additional contractile energy, which is larger than the mechanical energy delivered by the power stroke of a myosin motor. Thus, it appears inescapable that folding of titin Ig domains is an important, but as yet unrecognized, contributor to the force generated by a contracting muscle.
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191
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Atherton P, Stutchbury B, Wang DY, Jethwa D, Tsang R, Meiler-Rodriguez E, Wang P, Bate N, Zent R, Barsukov IL, Goult BT, Critchley DR, Ballestrem C. Vinculin controls talin engagement with the actomyosin machinery. Nat Commun 2015; 6:10038. [PMID: 26634421 PMCID: PMC4686655 DOI: 10.1038/ncomms10038] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 10/26/2015] [Indexed: 12/20/2022] Open
Abstract
The link between extracellular-matrix-bound integrins and intracellular F-actin is essential for cell spreading and migration. Here, we demonstrate how the actin-binding proteins talin and vinculin cooperate to provide this link. By expressing structure-based talin mutants in talin null cells, we show that while the C-terminal actin-binding site (ABS3) in talin is required for adhesion complex assembly, the central ABS2 is essential for focal adhesion (FA) maturation. Thus, although ABS2 mutants support cell spreading, the cells lack FAs, fail to polarize and exert reduced force on the surrounding matrix. ABS2 is inhibited by the preceding mechanosensitive vinculin-binding R3 domain, and deletion of R2R3 or expression of constitutively active vinculin generates stable force-independent FAs, although cell polarity is compromised. Our data suggest a model whereby force acting on integrin-talin complexes via ABS3 promotes R3 unfolding and vinculin binding, activating ABS2 and locking talin into an actin-binding configuration that stabilizes FAs. The mechanosensitive proteins talin and vinculin mediate the linkage between integrin-bound extracellular matrix and the actin cytoskeleton. Here the authors dissect distinct roles for two actin-binding sites within talin on adhesion complex assembly and maturation, which are regulated by vinculin binding to talin.
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Affiliation(s)
- Paul Atherton
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Ben Stutchbury
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - De-Yao Wang
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Devina Jethwa
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Ricky Tsang
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | | | - Pengbo Wang
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
| | - Neil Bate
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Roy Zent
- Vanderbilt Centre for Kidney Disease, Vanderbilt Division of Nephrology, S-3223 Medical Centre, North Nashville, Tennessee, USA
| | - Igor L Barsukov
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Benjamin T Goult
- School of Biosciences, University of Kent, Canterbury, KENT CT2 7NJ, UK
| | - David R Critchley
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Christoph Ballestrem
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, UK
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192
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Austen K, Ringer P, Mehlich A, Chrostek-Grashoff A, Kluger C, Klingner C, Sabass B, Zent R, Rief M, Grashoff C. Extracellular rigidity sensing by talin isoform-specific mechanical linkages. Nat Cell Biol 2015; 17:1597-606. [PMID: 26523364 PMCID: PMC4662888 DOI: 10.1038/ncb3268] [Citation(s) in RCA: 239] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 10/08/2015] [Indexed: 12/13/2022]
Abstract
The ability of cells to adhere and sense differences in tissue stiffness is crucial for organ development and function. The central mechanisms by which adherent cells detect extracellular matrix compliance, however, are still unknown. Using two single-molecule-calibrated biosensors that allow the analysis of a previously inaccessible but physiologically highly relevant force regime in cells, we demonstrate that the integrin activator talin establishes mechanical linkages following cell adhesion, which are indispensable for cells to probe tissue stiffness. Talin linkages are exposed to a range of piconewton forces and bear, on average, 7-10 pN during cell adhesion depending on their association with F-actin and vinculin. Disruption of talin's mechanical engagement does not impair integrin activation and initial cell adhesion but prevents focal adhesion reinforcement and thus extracellular rigidity sensing. Intriguingly, talin mechanics are isoform specific so that expression of either talin-1 or talin-2 modulates extracellular rigidity sensing.
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Affiliation(s)
- Katharina Austen
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
| | - Pia Ringer
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
| | - Alexander Mehlich
- Technical University of Munich, Physics Department E22, Garching D-85748, Germany
| | - Anna Chrostek-Grashoff
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
| | - Carleen Kluger
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
| | - Christoph Klingner
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
| | - Benedikt Sabass
- Princeton University, Department of Mechanical & Aerospace Engineering, Princeton, NJ 08544, USA
| | - Roy Zent
- Vanderbilt University, Division of Nephrology, Department of Medicine, Nashville, Tennessee 37232, USA
| | - Matthias Rief
- Technical University of Munich, Physics Department E22, Garching D-85748, Germany
- Munich Centre for Integrated Protein Science, Munich D-81377, Germany
| | - Carsten Grashoff
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
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193
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Krishnan R, Park JA, Seow CY, Lee PVS, Stewart AG. Cellular Biomechanics in Drug Screening and Evaluation: Mechanopharmacology. Trends Pharmacol Sci 2015; 37:87-100. [PMID: 26651416 DOI: 10.1016/j.tips.2015.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/12/2015] [Accepted: 10/23/2015] [Indexed: 12/14/2022]
Abstract
The study of mechanobiology is now widespread. The impact of cell and tissue mechanics on cellular responses is well appreciated. However, knowledge of the impact of cell and tissue mechanics on pharmacological responsiveness, and its application to drug screening and mechanistic investigations, have been very limited in scope. We emphasize the need for a heightened awareness of the important bidirectional influence of drugs and biomechanics in all living systems. We propose that the term 'mechanopharmacology' be applied to approaches that employ in vitro systems, biomechanically appropriate to the relevant (patho)physiology, to identify new drugs and drug targets. This article describes the models and techniques that are being developed to transform drug screening and evaluation, ranging from a 2D environment to the dynamic 3D environment of the target expressed in the disease of interest.
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Affiliation(s)
- Ramaswamy Krishnan
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Jin-Ah Park
- Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Chun Y Seow
- Center for Heart Lung Innovation, St Pauls Hospital, University of British Columbia, Vancouver, Canada
| | - Peter V-S Lee
- Department of Mechanical Engineering, University of Melbourne, Melbourne, Australia
| | - Alastair G Stewart
- Lung Health Research Centre, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia.
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194
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Schulte C, Ferraris GMS, Oldani A, Galluzzi M, Podestà A, Puricelli L, de Lorenzi V, Lenardi C, Milani P, Sidenius N. Lamellipodial tension, not integrin/ligand binding, is the crucial factor to realise integrin activation and cell migration. Eur J Cell Biol 2015; 95:1-14. [PMID: 26616200 DOI: 10.1016/j.ejcb.2015.10.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 10/05/2015] [Accepted: 10/13/2015] [Indexed: 12/13/2022] Open
Abstract
The molecular clutch (MC) model proposes that actomyosin-driven force transmission permits integrin-dependent cell migration. To investigate the MC, we introduced diverse talin (TLN) and integrin variants into Flp-In™ T-Rex™ HEK293 cells stably expressing uPAR. Vitronectin variants served as substrate providing uPAR-mediated cell adhesion and optionally integrin binding. This particular system allowed us to selectively analyse key MC proteins and interactions, effectively from the extracellular matrix substrate to intracellular f-actin, and to therewith study mechanobiological aspects of MC engagement also uncoupled from integrin/ligand binding. With this experimental approach, we found that for the initial PIP2-dependent membrane/TLN/f-actin linkage and persistent lamellipodia formation the C-terminal TLN actin binding site (ABS) is dispensable. The establishment of an adequate MC-mediated lamellipodial tension instead depends predominantly on the coupling of this C-terminal TLN ABS to the actomyosin-driven retrograde actin flow force. This lamellipodial tension is crucial for full integrin activation eventually determining integrin-dependent cell migration. In the integrin/ligand-independent condition the frictional membrane resistance participates to these processes. Integrin/ligand binding can also contribute but is not necessarily required.
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Affiliation(s)
- Carsten Schulte
- Unit of Cell Matrix Signalling, IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy; CIMaINa (Interdisciplinary Centre for Nanostructured Material and Interfaces) and Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy.
| | - Gian Maria Sarra Ferraris
- Unit of Cell Matrix Signalling, IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Amanda Oldani
- Imaging Unit, IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Massimiliano Galluzzi
- CIMaINa (Interdisciplinary Centre for Nanostructured Material and Interfaces) and Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Alessandro Podestà
- CIMaINa (Interdisciplinary Centre for Nanostructured Material and Interfaces) and Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Luca Puricelli
- CIMaINa (Interdisciplinary Centre for Nanostructured Material and Interfaces) and Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Valentina de Lorenzi
- Unit of Cell Matrix Signalling, IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Cristina Lenardi
- CIMaINa (Interdisciplinary Centre for Nanostructured Material and Interfaces) and Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Paolo Milani
- CIMaINa (Interdisciplinary Centre for Nanostructured Material and Interfaces) and Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
| | - Nicolai Sidenius
- Unit of Cell Matrix Signalling, IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
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195
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Jack of all trades: functional modularity in the adherens junction. Curr Opin Cell Biol 2015; 36:32-40. [DOI: 10.1016/j.ceb.2015.06.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/20/2015] [Accepted: 06/30/2015] [Indexed: 11/22/2022]
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196
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Abstract
Integrin-based focal adhesions integrate biochemical and biomechanical signals from the extracellular matrix and the actin cytoskeleton. The combination of three-dimensional super-resolution imaging and loss- or gain-of-function protein mutants now links the nanoscale dynamic localization of proteins to their activation and function within focal adhesions.
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197
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Abstract
Mechanical stimuli are known to be potent regulators of the form and function of cells and organisms. Although biological regulation has classically been understood in terms of principles from solution biochemistry, advancements in many fields have led to the development of a suite of techniques that are able to reveal the interplay between mechanical loading and changes in the biochemical properties of proteins in systems ranging from single molecules to living organisms. Here, we review these techniques and highlight the emergence of a new molecular-scale understanding of the mechanisms mediating the detection and response of cells to mechanical stimuli, a process termed mechanotransduction. Specifically, we focus on the role of subcellular adhesion structures in sensing the stiffness of the surrounding environment because this process is pertinent to applications in tissue engineering as well the onset of several mechanosensitive disease states, including cancer.
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Affiliation(s)
- Andrew S LaCroix
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708;
| | - Katheryn E Rothenberg
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708;
| | - Brenton D Hoffman
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708;
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198
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Le S, Liu R, Lim CT, Yan J. Uncovering mechanosensing mechanisms at the single protein level using magnetic tweezers. Methods 2015; 94:13-8. [PMID: 26318089 DOI: 10.1016/j.ymeth.2015.08.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 08/01/2015] [Accepted: 08/25/2015] [Indexed: 11/28/2022] Open
Abstract
Mechanosensing of the micro-environments has been shown to be essential for cell survival, growth, differentiation and migration. The mechanosensing pathways are mediated by a set of mechanosensitive proteins located at focal adhesion and cell-cell adherens junctions as well as in the cytoskeleton network. Here we review the applications of magnetic tweezers on elucidating the molecular mechanisms of the mechanosensing proteins. The scope of this review includes the principles of the magnetic tweezers technology, theoretical analysis of force-dependent stability and interaction of mechanosensing proteins, and recent findings obtained using magnetic tweezers.
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Affiliation(s)
- Shimin Le
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Department of Physics, National University of Singapore, Singapore 117542, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore
| | - Ruchuan Liu
- Department of Physics, National University of Singapore, Singapore 117542, Singapore; College of Physics, Chongqing University, Chongqing 401331, China
| | - Chwee Teck Lim
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Department of Biomedical Engineering, National University of Singapore, Singapore 117575, Singapore; Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore.
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Department of Physics, National University of Singapore, Singapore 117542, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore.
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199
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Abstract
Insight into how molecular machines perform their biological functions depends on knowledge of the spatial organization of the components, their connectivity, geometry, and organizational hierarchy. However, these parameters are difficult to determine in multicomponent assemblies such as integrin-based focal adhesions (FAs). We have previously applied 3D superresolution fluorescence microscopy to probe the spatial organization of major FA components, observing a nanoscale stratification of proteins between integrins and the actin cytoskeleton. Here we combine superresolution imaging techniques with a protein engineering approach to investigate how such nanoscale architecture arises. We demonstrate that talin plays a key structural role in regulating the nanoscale architecture of FAs, akin to a molecular ruler. Talin diagonally spans the FA core, with its N terminus at the membrane and C terminus demarcating the FA/stress fiber interface. In contrast, vinculin is found to be dispensable for specification of FA nanoscale architecture. Recombinant analogs of talin with modified lengths recapitulated its polarized orientation but altered the FA/stress fiber interface in a linear manner, consistent with its modular structure, and implicating the integrin-talin-actin complex as the primary mechanical linkage in FAs. Talin was found to be ∼97 nm in length and oriented at ∼15° relative to the plasma membrane. Our results identify talin as the primary determinant of FA nanoscale organization and suggest how multiple cellular forces may be integrated at adhesion sites.
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200
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Jurchenko C, Salaita KS. Lighting Up the Force: Investigating Mechanisms of Mechanotransduction Using Fluorescent Tension Probes. Mol Cell Biol 2015; 35:2570-82. [PMID: 26031334 PMCID: PMC4524122 DOI: 10.1128/mcb.00195-15] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The ability of cells to sense the physical nature of their surroundings is critical to the survival of multicellular organisms. Cellular response to physical cues from adjacent cells and the extracellular matrix leads to a dynamic cycle in which cells respond by remodeling their local microenvironment, fine-tuning cell stiffness, polarity, and shape. Mechanical regulation is important in cellular development, normal morphogenesis, and wound healing. The mechanisms by which these finely balanced mechanotransduction events occur, however, are not well understood. In large part, this is due to the limited availability of tools to study molecular mechanotransduction events in live cells. Several classes of molecular tension probes have been recently developed which are rapidly transforming the study of mechanotransduction. Molecular tension probes are primarily based on fluorescence resonance energy transfer (FRET) and report on piconewton scale tension events in live cells. In this minireview, we describe the two main classes of tension probes, genetically encoded tension sensors and immobilized tension sensors, and discuss the advantages and limitations of each type. We discuss future opportunities to address major biological questions and outline the challenges facing the next generation of molecular tension probes.
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Affiliation(s)
- Carol Jurchenko
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
| | - Khalid S Salaita
- Department of Chemistry, Emory University, Atlanta, Georgia, USA
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