1
|
Sadhanasatish T, Augustin K, Windgasse L, Chrostek-Grashoff A, Rief M, Grashoff C. A molecular optomechanics approach reveals functional relevance of force transduction across talin and desmoplakin. Sci Adv 2023; 9:eadg3347. [PMID: 37343090 DOI: 10.1126/sciadv.adg3347] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 05/17/2023] [Indexed: 06/23/2023]
Abstract
Many mechanobiological processes that govern development and tissue homeostasis are regulated on the level of individual molecular linkages, and a number of proteins experiencing piconewton-scale forces in cells have been identified. However, under which conditions these force-bearing linkages become critical for a given mechanobiological process is often still unclear. Here, we established an approach to revealing the mechanical function of intracellular molecules using molecular optomechanics. When applied to the integrin activator talin, the technique provides direct evidence that its role as a mechanical linker is indispensable for the maintenance of cell-matrix adhesions and overall cell integrity. Applying the technique to desmoplakin shows that mechanical engagement of desmosomes to intermediate filaments is expendable under homeostatic conditions yet strictly required for preserving cell-cell adhesion under stress. These results reveal a central role of talin and desmoplakin as mechanical linkers in cell adhesion structures and demonstrate that molecular optomechanics is a powerful tool to investigate the molecular details of mechanobiological processes.
Collapse
Affiliation(s)
- Tanmay Sadhanasatish
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| | - Katharina Augustin
- Center for Protein Assemblies and Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Lukas Windgasse
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| | - Anna Chrostek-Grashoff
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| | - Matthias Rief
- Center for Protein Assemblies and Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany
| | - Carsten Grashoff
- University of Münster, Institute of Integrative Cell Biology and Physiology, Münster D-48149, Germany
| |
Collapse
|
2
|
Windgasse L, Grashoff C. Multiplexed Molecular Tension Sensor Measurements Using PIE-FLIM. Methods Mol Biol 2023; 2600:221-237. [PMID: 36587101 DOI: 10.1007/978-1-0716-2851-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Genetically encoded Förster Resonance Energy Transfer (FRET)-based tension sensors were developed to enable the quantification of piconewton (pN)-scale forces that act across distinct proteins in living cells and organisms. An important extension of this technology is the multiplexing of tension sensors to monitor several independent FRET probes in parallel. Here we describe how pulsed interleaved excitation (PIE)-fluorescence lifetime imaging microscopy (FLIM) can be implemented to enable the analysis of two co-expressed tension sensor constructs. Our protocol covers all essential steps from biosensor expression and live cell PIE image acquisition to lifetime calculations.
Collapse
Affiliation(s)
- Lukas Windgasse
- Department of Quantitative Cell Biology, Institute of Integrative Cell Biology and Physiology, University of Münster, Münster, Germany
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Integrative Cell Biology and Physiology, University of Münster, Münster, Germany.
| |
Collapse
|
3
|
Bauer N, Maisuls I, Pereira da Graça A, Reinhardt D, Erapaneedi R, Kirschnick N, Schäfers M, Grashoff C, Landfester K, Vestweber D, Strassert CA, Kiefer F. Genetically encoded dual fluorophore reporters for graded oxygen-sensing in light microscopy. Biosens Bioelectron 2022; 221:114917. [DOI: 10.1016/j.bios.2022.114917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 10/31/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
|
4
|
Glogowska E, Arhatte M, Chatelain FC, Lesage F, Xu A, Grashoff C, Discher DE, Patel A, Honoré E. Piezo1 and Piezo2 foster mechanical gating of K 2P channels. Cell Rep 2021; 37:110070. [PMID: 34852225 DOI: 10.1016/j.celrep.2021.110070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 10/15/2021] [Accepted: 11/08/2021] [Indexed: 11/27/2022] Open
Abstract
Mechanoelectrical transduction is mediated by the opening of different types of force-sensitive ion channels, including Piezo1/2 and the TREK/TRAAK K2P channels. Piezo1 curves the membrane locally into an inverted dome that reversibly flattens in response to force application. Moreover, Piezo1 forms numerous preferential interactions with various membrane lipids, including cholesterol. Whether this structural architecture influences the functionality of neighboring membrane proteins is unknown. Here, we show that Piezo1/2 increase TREK/TRAAK current amplitude, slow down activation/deactivation, and remove inactivation upon mechanical stimulation. These findings are consistent with a mechanism whereby Piezo1/2 cause a local depletion of membrane cholesterol associated with a prestress of TREK/TRAAK channels. This regulation occurs in mouse fibroblasts between endogenous Piezo1 and TREK-1/2, both channel types acting in concert to delay wound healing. In conclusion, we demonstrate a community effect between different structural and functional classes of mechanosensitive ion channels.
Collapse
Affiliation(s)
- Edyta Glogowska
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut national de la santé et de la recherche médicale, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, 06560 Valbonne, France
| | - Malika Arhatte
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut national de la santé et de la recherche médicale, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, 06560 Valbonne, France
| | - Franck C Chatelain
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut national de la santé et de la recherche médicale, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, 06560 Valbonne, France
| | - Florian Lesage
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut national de la santé et de la recherche médicale, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, 06560 Valbonne, France
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Medicine and Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, 48149 Münster, Germany
| | - Dennis E Discher
- Biophysical Engineering Laboratories, Bioengineering Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amanda Patel
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut national de la santé et de la recherche médicale, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, 06560 Valbonne, France
| | - Eric Honoré
- Université Côte d'Azur, Centre National de la Recherche Scientifique, Institut national de la santé et de la recherche médicale, Institut de Pharmacologie Moléculaire et Cellulaire, Labex ICST, 06560 Valbonne, France.
| |
Collapse
|
5
|
Fischer LS, Schlichthaerle T, Chrostek‐Grashoff A, Grashoff C. Peptide-PAINT Enables Investigation of Endogenous Talin with Molecular Scale Resolution in Cells and Tissues. Chembiochem 2021; 22:2872-2879. [PMID: 34286903 PMCID: PMC8518977 DOI: 10.1002/cbic.202100301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/16/2021] [Indexed: 11/12/2022]
Abstract
Talin is a cell adhesion molecule that is indispensable for the development and function of multicellular organisms. Despite its central role for many cell biological processes, suitable methods to investigate the nanoscale organization of talin in its native environment are missing. Here, we overcome this limitation by combining single-molecule resolved PAINT (points accumulation in nanoscale topography) imaging with the IRIS (image reconstruction by integrating exchangeable single-molecule localization) approach, enabling the quantitative analysis of genetically unmodified talin molecules in cells. We demonstrate that a previously reported peptide can be utilized to specifically label the two major talin isoforms expressed in mammalian tissues with a localization precision of <10 nm. Our experiments show that the methodology performs equally well as state-of-the-art single-molecule localization techniques, and the first applications reveal a thus far undescribed cell adhesion structure in differentiating stem cells. Furthermore, we demonstrate the applicability of this peptide-PAINT technique to mouse tissues paving the way to single-protein imaging of endogenous talin proteins under physiologically relevant conditions.
Collapse
Affiliation(s)
- Lisa S. Fischer
- Department of Quantitative Cell BiologyInstitute of Molecular Cell BiologyUniversity of MünsterSchlossplatz 5Münster48149Germany
| | - Thomas Schlichthaerle
- Department of BiochemistryUniversity of WashingtonSeattleWA 98195USA
- Institute for Protein DesignUniversity of WashingtonSeattleWA 98195USA
| | - Anna Chrostek‐Grashoff
- Department of Quantitative Cell BiologyInstitute of Molecular Cell BiologyUniversity of MünsterSchlossplatz 5Münster48149Germany
| | - Carsten Grashoff
- Department of Quantitative Cell BiologyInstitute of Molecular Cell BiologyUniversity of MünsterSchlossplatz 5Münster48149Germany
| |
Collapse
|
6
|
Fischer LS, Schlichthaerle T, Chrostek‐Grashoff A, Grashoff C. Cover Feature: Peptide‐PAINT Enables Investigation of Endogenous Talin with Molecular Scale Resolution in Cells and Tissues (ChemBioChem 19/2021). Chembiochem 2021. [DOI: 10.1002/cbic.202100387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Lisa S. Fischer
- Department of Quantitative Cell Biology Institute of Molecular Cell Biology University of Münster Schlossplatz 5 Münster 48149 Germany
| | - Thomas Schlichthaerle
- Department of Biochemistry University of Washington Seattle WA 98195 USA
- Institute for Protein Design University of Washington Seattle WA 98195 USA
| | - Anna Chrostek‐Grashoff
- Department of Quantitative Cell Biology Institute of Molecular Cell Biology University of Münster Schlossplatz 5 Münster 48149 Germany
| | - Carsten Grashoff
- Department of Quantitative Cell Biology Institute of Molecular Cell Biology University of Münster Schlossplatz 5 Münster 48149 Germany
| |
Collapse
|
7
|
Arif N, Zinnhardt M, Nyamay’Antu A, Teber D, Brückner R, Schaefer K, Li Y, Trappmann B, Grashoff C, Vestweber D. PECAM-1 supports leukocyte diapedesis by tension-dependent dephosphorylation of VE-cadherin. EMBO J 2021; 40:e106113. [PMID: 33604918 PMCID: PMC8090850 DOI: 10.15252/embj.2020106113] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 01/15/2021] [Accepted: 01/27/2021] [Indexed: 01/21/2023] Open
Abstract
Leukocyte extravasation is an essential step during the immune response and requires the destabilization of endothelial junctions. We have shown previously that this process depends in vivo on the dephosphorylation of VE-cadherin-Y731. Here, we reveal the underlying mechanism. Leukocyte-induced stimulation of PECAM-1 triggers dissociation of the phosphatase SHP2 which then directly targets VE-cadherin-Y731. The binding site of PECAM-1 for SHP2 is needed for VE-cadherin dephosphorylation and subsequent endocytosis. Importantly, the contribution of PECAM-1 to leukocyte diapedesis in vitro and in vivo was strictly dependent on the presence of Y731 of VE-cadherin. In addition to SHP2, dephosphorylation of Y731 required Ca2+ -signaling, non-muscle myosin II activation, and endothelial cell tension. Since we found that β-catenin/plakoglobin mask VE-cadherin-Y731 and leukocyte docking to endothelial cells exert force on the VE-cadherin-catenin complex, we propose that leukocytes destabilize junctions by PECAM-1-SHP2-triggered dephosphorylation of VE-cadherin-Y731 which becomes accessible by actomyosin-mediated mechanical force exerted on the VE-cadherin-catenin complex.
Collapse
Affiliation(s)
- Nida Arif
- Max Planck Institute for Molecular BiomedicineMünsterGermany
| | - Maren Zinnhardt
- Max Planck Institute for Molecular BiomedicineMünsterGermany
| | | | - Denise Teber
- Max Planck Institute for Molecular BiomedicineMünsterGermany
| | - Randy Brückner
- Max Planck Institute for Molecular BiomedicineMünsterGermany
| | | | - Yu‐Tung Li
- Max Planck Institute for Molecular BiomedicineMünsterGermany
| | | | - Carsten Grashoff
- Institute for Molecular Cell BiologyUniversity of MünsterMünsterGermany
| | | |
Collapse
|
8
|
Abstract
The ability of cells to generate mechanical forces, but also to sense, adapt to, and respond to mechanical signals, is crucial for many developmental, postnatal homeostatic, and pathophysiological processes. However, the molecular mechanisms underlying cellular mechanotransduction have remained elusive for many decades, as techniques to visualize and quantify molecular forces across individual proteins in cells were missing. The development of genetically encoded molecular tension sensors now allows the quantification of piconewton-scale forces that act upon distinct molecules in living cells and even whole organisms. In this review, we discuss the physical principles, advantages, and limitations of this increasingly popular method. By highlighting current examples from the literature, we demonstrate how molecular tension sensors can be utilized to obtain access to previously unappreciated biophysical parameters that define the propagation of mechanical forces on molecular scales. We discuss how the methodology can be further developed and provide a perspective on how the technique could be applied to uncover entirely novel aspects of mechanobiology in the future.
Collapse
Affiliation(s)
- Lisa S Fischer
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Srishti Rangarajan
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Tanmay Sadhanasatish
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| |
Collapse
|
9
|
Fischer LS, Klingner C, Schlichthaerle T, Strauss MT, Böttcher R, Fässler R, Jungmann R, Grashoff C. Quantitative single-protein imaging reveals molecular complex formation of integrin, talin, and kindlin during cell adhesion. Nat Commun 2021; 12:919. [PMID: 33568673 PMCID: PMC7876120 DOI: 10.1038/s41467-021-21142-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/12/2021] [Indexed: 12/21/2022] Open
Abstract
Single-molecule localization microscopy (SMLM) enabling the investigation of individual proteins on molecular scales has revolutionized how biological processes are analysed in cells. However, a major limitation of imaging techniques reaching single-protein resolution is the incomplete and often unknown labeling and detection efficiency of the utilized molecular probes. As a result, fundamental processes such as complex formation of distinct molecular species cannot be reliably quantified. Here, we establish a super-resolution microscopy framework, called quantitative single-molecule colocalization analysis (qSMCL), which permits the identification of absolute molecular quantities and thus the investigation of molecular-scale processes inside cells. The method combines multiplexed single-protein resolution imaging, automated cluster detection, in silico data simulation procedures, and widely applicable experimental controls to determine absolute fractions and spatial coordinates of interacting species on a true molecular level, even in highly crowded subcellular structures. The first application of this framework allowed the identification of a long-sought ternary adhesion complex—consisting of talin, kindlin and active β1-integrin—that specifically forms in cell-matrix adhesion sites. Together, the experiments demonstrate that qSMCL allows an absolute quantification of multiplexed SMLM data and thus should be useful for investigating molecular mechanisms underlying numerous processes in cells. Single-molecule localisation microscopy is limited by low labeling and detection efficiencies of the molecular probes. Here the authors report a framework to obtain absolute molecular quantities on a true molecular scale; the data reveal a ternary adhesion complex underlying cell-matrix adhesion.
Collapse
Affiliation(s)
- Lisa S Fischer
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster, Germany.,Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Christoph Klingner
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster, Germany.,Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Thomas Schlichthaerle
- Faculty of Physics and Center for Nanoscience, LMU Munich, Munich, Germany.,Research Group Molecular Imaging and Bionanotechnology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Maximilian T Strauss
- Faculty of Physics and Center for Nanoscience, LMU Munich, Munich, Germany.,Research Group Molecular Imaging and Bionanotechnology, Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Ralph Böttcher
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Reinhard Fässler
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, LMU Munich, Munich, Germany. .,Research Group Molecular Imaging and Bionanotechnology, Max Planck Institute of Biochemistry, Martinsried, Germany.
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster, Germany. .,Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Martinsried, Germany.
| |
Collapse
|
10
|
Kanoldt V, Kluger C, Barz C, Schweizer AL, Ramanujam D, Windgasse L, Engelhardt S, Chrostek-Grashoff A, Grashoff C. Metavinculin modulates force transduction in cell adhesion sites. Nat Commun 2020; 11:6403. [PMID: 33335089 PMCID: PMC7747745 DOI: 10.1038/s41467-020-20125-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 11/13/2020] [Indexed: 12/15/2022] Open
Abstract
Vinculin is a ubiquitously expressed protein, crucial for the regulation of force transduction in cells. Muscle cells express a vinculin splice-isoform called metavinculin, which has been associated with cardiomyopathies. However, the molecular function of metavinculin has remained unclear and its role for heart muscle disorders undefined. Here, we have employed a set of piconewton-sensitive tension sensors to probe metavinculin mechanics in cells. Our experiments reveal that metavinculin bears higher molecular forces but is less frequently engaged as compared to vinculin, leading to altered force propagation in cell adhesions. In addition, we have generated knockout mice to investigate the consequences of metavinculin loss in vivo. Unexpectedly, these animals display an unaltered tissue response in a cardiac hypertrophy model. Together, the data reveal that the transduction of cell adhesion forces is modulated by expression of metavinculin, yet its role for heart muscle function seems more subtle than previously thought.
Collapse
Affiliation(s)
- Verena Kanoldt
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, 48149, Münster, Germany
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, 82152, Martinsried, Germany
| | - Carleen Kluger
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, 82152, Martinsried, Germany
| | - Christiane Barz
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, 82152, Martinsried, Germany
| | - Anna-Lena Schweizer
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, 48149, Münster, Germany
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, 82152, Martinsried, Germany
| | - Deepak Ramanujam
- Institute of Pharmacology and Toxicology, Technical University of Munich, 80802, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80802, Munich, Germany
| | - Lukas Windgasse
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, 48149, Münster, Germany
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technical University of Munich, 80802, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, 80802, Munich, Germany
| | - Anna Chrostek-Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, 48149, Münster, Germany
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, 82152, Martinsried, Germany
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, 48149, Münster, Germany.
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, 82152, Martinsried, Germany.
| |
Collapse
|
11
|
Lemke SB, Weidemann T, Cost AL, Grashoff C, Schnorrer F. A small proportion of Talin molecules transmit forces at developing muscle attachments in vivo. PLoS Biol 2019; 17:e3000057. [PMID: 30917109 PMCID: PMC6453563 DOI: 10.1371/journal.pbio.3000057] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 04/08/2019] [Accepted: 03/08/2019] [Indexed: 11/19/2022] Open
Abstract
Cells in developing organisms are subjected to particular mechanical forces that shape tissues and instruct cell fate decisions. How these forces are sensed and transmitted at the molecular level is therefore an important question, one that has mainly been investigated in cultured cells in vitro. Here, we elucidate how mechanical forces are transmitted in an intact organism. We studied Drosophila muscle attachment sites, which experience high mechanical forces during development and require integrin-mediated adhesion for stable attachment to tendons. Therefore, we quantified molecular forces across the essential integrin-binding protein Talin, which links integrin to the actin cytoskeleton. Generating flies expressing 3 Förster resonance energy transfer (FRET)-based Talin tension sensors reporting different force levels between 1 and 11 piconewton (pN) enabled us to quantify physiologically relevant molecular forces. By measuring primary Drosophila muscle cells, we demonstrate that Drosophila Talin experiences mechanical forces in cell culture that are similar to those previously reported for Talin in mammalian cell lines. However, in vivo force measurements at developing flight muscle attachment sites revealed that average forces across Talin are comparatively low and decrease even further while attachments mature and tissue-level tension remains high. Concomitantly, the Talin concentration at attachment sites increases 5-fold as quantified by fluorescence correlation spectroscopy (FCS), suggesting that only a small proportion of Talin molecules are mechanically engaged at any given time. Reducing Talin levels at late stages of muscle development results in muscle–tendon rupture in the adult fly, likely as a result of active muscle contractions. We therefore propose that a large pool of adhesion molecules is required to share high tissue forces. As a result, less than 15% of the molecules experience detectable forces at developing muscle attachment sites at the same time. Our findings define an important new concept of how cells can adapt to changes in tissue mechanics to prevent mechanical failure in vivo. The protein Talin links the transmembrane cell adhesion molecule integrin to the actin cytoskeleton. Quantitative FRET-based force measurements across Talin in vivo reveal that only few Talin molecules are under force during the development of muscle attachment sites. Cells in our body are constantly exposed to mechanical forces, which they need to sense and react to. In previous studies, fluorescent force sensors were developed to demonstrate that individual proteins in adhesion structures of a cell experience forces in the piconewton (pN) range. However, these cells were analyzed in isolation in an artificial plastic or glass environment. Here, we explored forces on adhesion proteins in their natural environment within a developing animal and used the muscle–tendon tissue in the fruit fly Drosophila as a model system. We made genetically modified fly lines with force sensors or controls inserted into the gene that produces the essential adhesion protein Talin. Using these force sensor flies, we found that only a small proportion of all the Talin proteins (<15%) present at developing muscle–tendon attachments experience detectable forces at the same time. Nevertheless, a large amount of Talin is accumulated at these attachments during fly development. We found that this large Talin pool is important to prevent rupture of the muscle–tendon connection in adult flies that produce high muscle forces during flight. In conclusion, we demonstrated that a large pool of Talin proteins is required for stable muscle–tendon attachment, likely with the individual Talin molecules dynamically sharing the mechanical load.
Collapse
Affiliation(s)
- Sandra B. Lemke
- Max Planck Institute of Biochemistry, Martinsried, Germany
- * E-mail: (FS); (CG); (SBL)
| | | | - Anna-Lena Cost
- Max Planck Institute of Biochemistry, Martinsried, Germany
- University of Münster, Institute for Molecular Cell Biology, Münster, Germany
| | - Carsten Grashoff
- Max Planck Institute of Biochemistry, Martinsried, Germany
- University of Münster, Institute for Molecular Cell Biology, Münster, Germany
- * E-mail: (FS); (CG); (SBL)
| | - Frank Schnorrer
- Max Planck Institute of Biochemistry, Martinsried, Germany
- Aix Marseille University, CNRS, IBDM, Marseille, France
- * E-mail: (FS); (CG); (SBL)
| |
Collapse
|
12
|
Affiliation(s)
- Anna‐Lena Cost
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry Martinsried Germany
- Department of Quantitative Cell Biology, Institute of Molecular Cell BiologyUniversity of Münster Münster Germany
| | - Samira Khalaji
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry Martinsried Germany
- Department of Quantitative Cell Biology, Institute of Molecular Cell BiologyUniversity of Münster Münster Germany
| | - Carsten Grashoff
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry Martinsried Germany
- Department of Quantitative Cell Biology, Institute of Molecular Cell BiologyUniversity of Münster Münster Germany
| |
Collapse
|
13
|
Kanoldt V, Fischer L, Grashoff C. Unforgettable force – crosstalk and memory of mechanosensitive structures. Biol Chem 2018; 400:687-698. [DOI: 10.1515/hsz-2018-0328] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/11/2018] [Indexed: 12/11/2022]
Abstract
Abstract
The ability of cells to sense and respond to mechanical stimuli is crucial for many developmental and homeostatic processes, while mechanical dysfunction of cells has been associated with numerous pathologies including muscular dystrophies, cardiovascular defects and epithelial disorders. Yet, how cells detect and process mechanical information is still largely unclear. In this review, we outline major mechanisms underlying cellular mechanotransduction and we summarize the current understanding of how cells integrate information from distinct mechanosensitive structures to mediate complex mechanoresponses. We also discuss the concept of mechanical memory and describe how cells store information on previous mechanical events for different periods of time.
Collapse
Affiliation(s)
- Verena Kanoldt
- Group of Molecular Mechanotransduction , Max Planck Institute of Biochemistry , 82152 Martinsried , Germany
| | - Lisa Fischer
- Group of Molecular Mechanotransduction , Max Planck Institute of Biochemistry , 82152 Martinsried , Germany
| | - Carsten Grashoff
- Group of Molecular Mechanotransduction , Max Planck Institute of Biochemistry , 82152 Martinsried , Germany
- Department of Quantitative Cell Biology , Institute of Molecular Cell Biology, University of Münster , 48149 Münster , Germany
| |
Collapse
|
14
|
Ringer P, Colo G, Fässler R, Grashoff C. Sensing the mechano-chemical properties of the extracellular matrix. Matrix Biol 2017; 64:6-16. [DOI: 10.1016/j.matbio.2017.03.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 12/13/2022]
|
15
|
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] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/20/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023]
|
16
|
Freikamp A, Mehlich A, Klingner C, Grashoff C. Investigating piconewton forces in cells by FRET-based molecular force microscopy. J Struct Biol 2016; 197:37-42. [PMID: 26980477 DOI: 10.1016/j.jsb.2016.03.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 03/11/2016] [Accepted: 03/12/2016] [Indexed: 11/16/2022]
Abstract
The ability of cells to sense and respond to mechanical forces is crucial for a wide range of developmental and pathophysiological processes. The molecular mechanisms underlying cellular mechanotransduction, however, are largely unknown because suitable techniques to measure mechanical forces across individual molecules in cells have been missing. In this article, we highlight advances in the development of molecular force sensing techniques and discuss our recently expanded set of FRET-based tension sensors that allows the analysis of mechanical forces with piconewton sensitivity in cells. In addition, we provide a theoretical framework for the design of additional tension sensor modules with adjusted force sensitivity.
Collapse
Affiliation(s)
- Andrea Freikamp
- 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
| | - Christoph Klingner
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany
| | - Carsten Grashoff
- Max Planck Institute of Biochemistry, Group of Molecular Mechanotransduction, Martinsried D-82152, Germany.
| |
Collapse
|
17
|
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: 234] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
18
|
Grashoff C, Mehlich A, Austen K, Ringer P, Rief M, Grashoff C. Evaluation of Molecular Tension Sensors using Single-Molecule Force Spectroscopy and Live Cell FRET imaging. ACTA ACUST UNITED AC 2015. [DOI: 10.1038/protex.2015.095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
19
|
Cost AL, Ringer P, Chrostek-Grashoff A, Grashoff C. How to Measure Molecular Forces in Cells: A Guide to Evaluating Genetically-Encoded FRET-Based Tension Sensors. Cell Mol Bioeng 2014; 8:96-105. [PMID: 25798203 PMCID: PMC4361753 DOI: 10.1007/s12195-014-0368-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 11/21/2014] [Indexed: 12/16/2022] Open
Abstract
The ability of cells to sense and respond to mechanical forces is central to a wide range of biological processes and plays an important role in numerous pathologies. The molecular mechanisms underlying cellular mechanotransduction, however, have remained largely elusive because suitable methods to investigate subcellular force propagation were missing. Here, we review recent advances in the development of biosensors that allow molecular force measurements. We describe the underlying principle of currently available techniques and propose a strategy to systematically evaluate new Förster resonance energy transfer (FRET)-based biosensors.
Collapse
Affiliation(s)
- Anna-Lena Cost
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Germany
| | - Pia Ringer
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Germany
| | - Anna Chrostek-Grashoff
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Germany
| | - Carsten Grashoff
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152 Germany
| |
Collapse
|
20
|
Leerberg JM, Gomez GA, Verma S, Moussa EJ, Wu SK, Priya R, Hoffman BD, Grashoff C, Schwartz MA, Yap AS. Tension-sensitive actin assembly supports contractility at the epithelial zonula adherens. Curr Biol 2014; 24:1689-99. [PMID: 25065757 DOI: 10.1016/j.cub.2014.06.028] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/10/2014] [Accepted: 06/12/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND Actomyosin-based contractility acts on cadherin junctions to support tissue integrity and morphogenesis. The actomyosin apparatus of the epithelial zonula adherens (ZA) is built by coordinating junctional actin assembly with Myosin II activation. However, the physical interaction between Myosin and actin filaments that is necessary for contractility can induce actin filament turnover, potentially compromising the contractile apparatus itself. RESULTS We now identify tension-sensitive actin assembly as one cellular solution to this design paradox. We show that junctional actin assembly is maintained by contractility in established junctions and increases when contractility is stimulated. The underlying mechanism entails the tension-sensitive recruitment of vinculin to the ZA. Vinculin, in turn, directly recruits Mena/VASP proteins to support junctional actin assembly. By combining strategies that uncouple Mena/VASP from vinculin or ectopically target Mena/VASP to junctions, we show that tension-sensitive actin assembly is necessary for junctional integrity and effective contractility at the ZA. CONCLUSIONS We conclude that tension-sensitive regulation of actin assembly represents a mechanism for epithelial cells to resolve potential design contradictions that are inherent in the way that the junctional actomyosin system is assembled. This emphasizes that maintenance and regulation of the actin scaffolds themselves influence how cells generate contractile tension.
Collapse
Affiliation(s)
- Joanne M Leerberg
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia
| | - Guillermo A Gomez
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia
| | - Suzie Verma
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia
| | - Elliott J Moussa
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia
| | - Selwin K Wu
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia
| | - Rashmi Priya
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia
| | - Brenton D Hoffman
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Carsten Grashoff
- Group of Molecular Mechanotransduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Martin A Schwartz
- Yale Cardiovascular Research Center and Departments of Cardiovascular Medicine, Cell Biology, and Biomedical Engineering, Yale University, New Haven, CT 06520, USA
| | - Alpha S Yap
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia 4072, Australia.
| |
Collapse
|
21
|
Kayser J, Haslbeck M, Dempfle L, Krause M, Grashoff C, Buchner J, Herrmann H, Bausch AR. The small heat shock protein Hsp27 affects assembly dynamics and structure of keratin intermediate filament networks. Biophys J 2014; 105:1778-85. [PMID: 24138853 DOI: 10.1016/j.bpj.2013.09.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/02/2013] [Accepted: 09/09/2013] [Indexed: 01/07/2023] Open
Abstract
The mechanical properties of living cells are essential for many processes. They are defined by the cytoskeleton, a composite network of protein fibers. Thus, the precise control of its architecture is of paramount importance. Our knowledge about the molecular and physical mechanisms defining the network structure remains scarce, especially for the intermediate filament cytoskeleton. Here, we investigate the effect of small heat shock proteins on the keratin 8/18 intermediate filament cytoskeleton using a well-controlled model system of reconstituted keratin networks. We demonstrate that Hsp27 severely alters the structure of such networks by changing their assembly dynamics. Furthermore, the C-terminal tail domain of keratin 8 is shown to be essential for this effect. Combining results from fluorescence and electron microscopy with data from analytical ultracentrifugation reveals the crucial role of kinetic trapping in keratin network formation.
Collapse
Affiliation(s)
- Jona Kayser
- Lehrstuhl für Zellbiophysik, Technische Universität München, Garching, Germany
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Elad N, Volberg T, Patla I, Hirschfeld-Warneken V, Grashoff C, Spatz JP, Fässler R, Geiger B, Medalia O. The role of integrin-linked kinase in the molecular architecture of focal adhesions. J Cell Sci 2013; 126:4099-107. [PMID: 23843624 DOI: 10.1242/jcs.120295] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Integrin-mediated focal adhesions (FAs) are large, multi-protein complexes that link the actin cytoskeleton to the extracellular matrix and take part in adhesion-mediated signaling. These adhesions are highly complex and diverse at the molecular level; thus, assigning particular structural or signaling functions to specific components is highly challenging. Here, we combined functional, structural and biophysical approaches to assess the role of a major FA component, namely, integrin-linked kinase (ILK), in adhesion formation. We show here that ILK plays a key role in the formation of focal complexes, early forms of integrin adhesions, and confirm its involvement in the assembly of fibronectin-bound fibrillar adhesions. Examination of ILK-null fibroblasts by cryo-electron tomography pointed to major structural changes in their FAs, manifested as disarray of the associated actin filaments and an increase in the packing density of FA-related particles. Interestingly, adhesion of the mutant cells to the substrate required a higher ligand density than in control cells. These data indicate that ILK has a key role in integrin adhesion assembly and sub-structure, and in the regulation of the FA-associated cytoskeleton.
Collapse
Affiliation(s)
- Nadav Elad
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, Beer-Sheva 84120, Israel
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Moik D, Böttcher A, Makhina T, Grashoff C, Bulus N, Zent R, Fässler R. Mutations in the paxillin-binding site of integrin-linked kinase (ILK) destabilize the pseudokinase domain and cause embryonic lethality in mice. J Biol Chem 2013; 288:18863-71. [PMID: 23658024 DOI: 10.1074/jbc.m113.470476] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrin-linked kinase (ILK) localizes to focal adhesions (FAs) where it regulates cell spreading, migration, and growth factor receptor signaling. Previous reports showed that overexpressed ILK in which Val(386) and Thr(387) were substituted with glycine residues (ILK-VT/GG) could neither interact with paxillin nor localize to FA in cells expressing endogenous wild-type ILK, implying that paxillin binding to ILK is required for its localization to FAs. Here, we show that introducing this mutation into the germ line of mice (ILK-VT/GG) caused vasculogenesis defects, resulting in a general developmental delay and death at around embryonic day 12.5. Fibroblasts isolated from ILK-VT/GG mice contained mutant ILK in FAs, showed normal adhesion to and spreading on extracellular matrix substrates but displayed impaired migration. Biochemical analysis revealed that VT/GG substitutions decreased ILK protein stability leading to decreased ILK levels and reduced binding to paxillin and α-parvin. Because paxillin depletion did not affect ILK localization to FAs, the embryonic lethality and the in vitro migration defects are likely due to the reduced levels of ILK-VT/GG and diminished binding to parvins.
Collapse
Affiliation(s)
- Daniel Moik
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | | | | | | | | | | | | |
Collapse
|
24
|
Azimifar SB, Böttcher RT, Zanivan S, Grashoff C, Krüger M, Legate KR, Mann M, Fässler R. Induction of membrane circular dorsal ruffles requires co-signalling of integrin-ILK-complex and EGF receptor. J Cell Sci 2013; 125:435-48. [PMID: 22357970 DOI: 10.1242/jcs.091652] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Integrin and receptor tyrosine kinase signalling networks cooperate to regulate various biological functions. The molecular details underlying the integration of both signalling networks remain largely uncharacterized. Here we identify a signalling module composed of a fibronectin-α5β1-integrin-integrin-linked-kinase (ILK) complex that, in concert with epidermal growth factor (EGF) cues, cooperatively controls the formation of transient actin-based circular dorsal ruffles (DRs) in fibroblasts. DR formation depends on the precise spatial activation of Src at focal adhesions by integrin and EGF receptor signals, in an ILK-dependent manner. In a SILAC-based phosphoproteomics screen we identified the tumour-suppressor Cyld as being required for DR formation induced by α5β1 integrin and EGF receptor co-signalling. Furthermore, EGF-induced Cyld tyrosine phosphorylation is controlled by integrin-ILK and Src as a prerequisite for DR formation. This study provides evidence for a novel function of integrin-ILK and EGF signalling crosstalk in mediating Cyld tyrosine phosphorylation and fast actin-based cytoskeletal rearrangements.
Collapse
Affiliation(s)
- S Babak Azimifar
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Hortelano S, López-Fontal R, Través PG, Villa N, Grashoff C, Boscá L, Luque A. ILK mediates LPS-induced vascular adhesion receptor expression and subsequent leucocyte trans-endothelial migration. Cardiovasc Res 2010; 86:283-92. [PMID: 20164118 DOI: 10.1093/cvr/cvq050] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIMS The inflammatory response to injurious agents is tightly regulated to avoid adverse consequences of inappropriate leucocyte accumulation or failed resolution. Lipopolysaccharide (LPS)-activated endothelium recruits leucocytes to the inflamed tissue through controlled expression of membrane-associated adhesion molecules. LPS responses in macrophages are known to be regulated by integrin-linked kinase (ILK); in this study, we investigated the role of ILK in the regulation of the LPS-elicited inflammatory response in endothelium. METHODS AND RESULTS This study was performed on immortalized mouse endothelial cells (EC) isolated from lung and coronary vasculature. Cells were thoroughly characterized and the role of ILK in the regulation of the LPS response was investigated by suppressing ILK expression using siRNA and shRNA technologies. Phenotypic and functional analyses confirmed that the immortalized cells behaved as true EC. LPS induced the expression of the inflammatory genes E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). ILK knockdown impaired LPS-mediated endothelial activation by preventing the induction of ICAM-1 and VCAM-1. Blockade of the LPS-induced response inhibited the inflammatory-related processes of firm adhesion and trans-endothelial migration of leucocytes. CONCLUSION ILK is involved in the expression of cell adhesion molecules by EC activated with the inflammatory stimulus LPS. This reduced expression modulates leucocyte adhesion to the endothelium and the extravasation process. This finding suggests ILK as a potential anti-inflammatory target for the development of vascular-specific treatments for inflammation-related diseases.
Collapse
Affiliation(s)
- Sonsoles Hortelano
- Department of Regenerative Cardiology, Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, Melchor Fernandez Almagro 3, E-28029 Madrid, Spain
| | | | | | | | | | | | | |
Collapse
|
26
|
Stanchi F, Grashoff C, Nguemeni Yonga CF, Grall D, Fässler R, Van Obberghen-Schilling E. Molecular dissection of the ILK-PINCH-parvin triad reveals a fundamental role for the ILK kinase domain in the late stages of focal-adhesion maturation. J Cell Sci 2009; 122:1800-11. [PMID: 19435803 DOI: 10.1242/jcs.044602] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Integrin-linked kinase (ILK) and cytoplasmic adaptors of the PINCH and parvin families form a ternary complex, termed IPP, that localizes to integrin adhesions. We show here that deletion of the genes encoding ILK or PINCH1 similarly blocks maturation of focal adhesions to tensin-rich and phosphotyrosine-poor fibrillar adhesions (FBs) by downregulating expression or recruitment of tensin and destabilizing alpha5beta1-integrin-cytoskeleton linkages. As IPP components are interdependent for integrin targeting and protein stability, functional dissection of the complex was achieved by fusing ILK, PINCH, parvin or their individual motifs to the cytoplasmic tail of beta3 integrin, normally excluded from FBs. Using this novel gain-of-function approach, we demonstrated that expression of the C-terminal kinase domain of ILK can restore tensin recruitment and prompt focal-adhesion maturation in IPP-null cells. Debilitating mutations in the paxillin- or ATP-binding sites of ILK, together with alpha-parvin silencing, revealed a determinant role for ILK-parvin association, but not for direct paxillin binding, in this function. We propose a model in which the C-terminal domain of ILK promotes integrin sorting by reinforcing alpha5beta1-integrin-actin linkage and controls force transmission by targeting tensin to maturing adhesions.
Collapse
Affiliation(s)
- Fabio Stanchi
- Institute of Developmental Biology and Cancer Research, University of Nice-Sophia Antiopolis, CNRS-UMR6543, Centre Antoine Lacassagne, 33 Avenue de Valombrose, 06189 Nice, France
| | | | | | | | | | | |
Collapse
|
27
|
Bergmann S, Lang A, Rohde M, Agarwal V, Rennemeier C, Grashoff C, Preissner KT, Hammerschmidt S. Integrin-linked kinase is required for vitronectin-mediated internalization of Streptococcus pneumoniae by host cells. J Cell Sci 2009; 122:256-67. [PMID: 19118218 DOI: 10.1242/jcs.035600] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
By interacting with components of the human host, including extracellular matrix (ECM) proteins, Streptococcus pneumoniae has evolved various strategies for colonization. Here, we characterized the interaction of pneumococci with the adhesive glycoprotein vitronectin and the contribution of this protein to pneumococcal uptake by host cells in an integrin-dependent manner. Specific interaction of S. pneumoniae with the heparin-binding sites of purified multimeric vitronectin was demonstrated by flow cytometry analysis. Host-cell-bound vitronectin promoted pneumococcal adherence to and invasion into human epithelial and endothelial cells. Pneumococci were trapped by microspike-like structures, which were induced upon contact of pneumococci with host-cell-bound vitronectin. Alphavbeta3 integrin was identified as the major cellular receptor for vitronectin-mediated adherence and uptake of pneumococci. Ingestion of pneumococci by host cells via vitronectin required a dynamic actin cytoskeleton and was dependent on integrin-linked kinase (ILK), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt), as demonstrated by gene silencing or in inhibition experiments. In conclusion, pneumococci exploit the vitronectin-alphavbeta3-integrin complex as a cellular receptor for invasion and this integrin-mediated internalization requires the cooperation between the host signalling molecules ILK, PI3K and Akt.
Collapse
Affiliation(s)
- Simone Bergmann
- Max von Pettenkofer-Institute for Hygiene and Medical Microbiology, Ludwig-Maximilians University, Pettenkoferstrasse 9a, 80336 München, Germany
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Maier S, Lutz R, Gelman L, Sarasa-Renedo A, Schenk S, Grashoff C, Chiquet M. Tenascin-C induction by cyclic strain requires integrin-linked kinase. Biochim Biophys Acta 2008; 1783:1150-62. [PMID: 18269918 DOI: 10.1016/j.bbamcr.2008.01.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 01/11/2008] [Accepted: 01/14/2008] [Indexed: 12/15/2022]
Abstract
Induction of tenascin-C mRNA by cyclic strain in fibroblasts depends on RhoA and Rho dependent kinase (ROCK). Here we show that integrin-linked kinase (ILK) is required upstream of this pathway. In ILK-deficient fibroblasts, RhoA was not activated and tenascin-C mRNA remained low after cyclic strain; tenascin-C expression was unaffected by ROCK inhibition. In ILK wild-type but not ILK-/- fibroblasts, cyclic strain-induced reorganization of actin stress fibers and focal adhesions, as well as nuclear translocation of MAL, a transcriptional co-activator that links actin assembly to gene expression. These findings support a role for RhoA in ILK-mediated mechanotransduction. Rescue of ILK -/- fibroblasts by expression of wild-type ILK restored these responses to cyclic strain. Mechanosensation is not entirely abolished in ILK -/- fibroblasts, since cyclic strain activated Erk-1/2 and PKB/Akt, and induced c-fos mRNA in these cells. Conversely, lysophosphatidic acid stimulated RhoA and induced both c-fos and tenascin-C mRNA in ILK -/- cells. Thus, the signaling pathways controlling tenascin-C expression are functional in the absence of ILK, but are not triggered by cyclic strain. Our results indicate that ILK is selectively required for the induction of specific genes by mechanical stimulation via RhoA-mediated pathways.
Collapse
Affiliation(s)
- Silke Maier
- Friedrich Miescher Institute for Biomedical Research, Novartis Research Foundation, CH-4058 Basel, Switzerland
| | | | | | | | | | | | | |
Collapse
|
29
|
Lorenz K, Grashoff C, Torka R, Sakai T, Langbein L, Bloch W, Aumailley M, Fässler R. Integrin-linked kinase is required for epidermal and hair follicle morphogenesis. ACTA ACUST UNITED AC 2007; 177:501-13. [PMID: 17485490 PMCID: PMC2064816 DOI: 10.1083/jcb.200608125] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Integrin-linked kinase (ILK) links integrins to the actin cytoskeleton and is believed to phosphorylate several target proteins. We report that a keratinocyte-restricted deletion of the ILK gene leads to epidermal defects and hair loss. ILK-deficient epidermal keratinocytes exhibited a pronounced integrin-mediated adhesion defect leading to epidermal detachment and blister formation, disruption of the epidermal–dermal basement membrane, and the translocation of proliferating, integrin-expressing keratinocytes to suprabasal epidermal cell layers. The mutant hair follicles were capable of producing hair shaft and inner root sheath cells and contained stem cells and generated proliferating progenitor cells, which were impaired in their downward migration and hence accumulated in the outer root sheath and failed to replenish the hair matrix. In vitro studies with primary ILK-deficient keratinocytes attributed the migration defect to a reduced migration velocity and an impaired stabilization of the leading-edge lamellipodia, which compromised directional and persistent migration. We conclude that ILK plays important roles for epidermis and hair follicle morphogenesis by modulating integrin-mediated adhesion, actin reorganization, and plasma membrane dynamics in keratinocytes.
Collapse
Affiliation(s)
- Katrin Lorenz
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Dueck T, Grashoff C, Broekhuijsen G, Marcelis L. EFFICIENCY OF LIGHT ENERGY USED BY LEAVES SITUATED IN DIFFERENT LEVELS OF A SWEET PEPPER CANOPY. ACTA ACUST UNITED AC 2006. [DOI: 10.17660/actahortic.2006.711.25] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
31
|
Affiliation(s)
- Mario Gimona
- Unit of Actin Cytoskeleton Regulation, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Via Nazionale 8a, 66030 Santa Maria Imbaro, Italy.
| | | | | |
Collapse
|
32
|
Abstract
Integrin-mediated cell adhesion regulates a vast number of biological processes including migration, survival and proliferation of cells. It is therefore not surprising that defects in integrin function are often rate-limiting for development and profoundly affect the progression of several diseases. The functions of integrins are mediated through the recruitment of cytoplasmic plaque proteins. One of these is integrin-linked kinase, which connects integrins to the actin cytoskeleton and transduces signals through integrins to the extracellular matrix and from integrins to various subcellular compartments.
Collapse
Affiliation(s)
- Carsten Grashoff
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | | | | | | | | |
Collapse
|
33
|
Grashoff C, Aszódi A, Sakai T, Hunziker EB, Fässler R. Integrin-linked kinase regulates chondrocyte shape and proliferation. EMBO Rep 2003; 4:432-8. [PMID: 12671688 PMCID: PMC1319157 DOI: 10.1038/sj.embor.embor801] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2002] [Revised: 01/21/2003] [Accepted: 01/31/2003] [Indexed: 01/29/2023] Open
Abstract
The interaction of chondrocytes with the extracellular-matrix environment is mediated mainly by integrins. Ligated integrins are recruited to focal adhesions (FAs) together with scaffolding proteins and kinases, such as integrin-linked kinase (Ilk). Ilk binds the cytoplasmic domain of beta1-, beta2- and beta3-integrins and recruits adaptors and kinases, and is thought to stimulate downstream signalling events through phosphorylation of protein kinase B/Akt (Pkb/Akt) and glycogen synthase kinase 3-beta (GSK3-beta). Here, we show that mice with a chondrocyte-specific disruption of the gene encoding Ilk develop chondrodysplasia, and die at birth due to respiratory distress. The chondrodysplasia was characterized by abnormal chondrocyte shape and decreased chondrocyte proliferation. In addition, Ilk-deficient chondrocytes showed adhesion defects, failed to spread and formed fewer FAs and actin stress fibres. Surprisingly, phosphorylation of Pkb/Akt and GSK3-beta is unaffected in Ilk-deficient chondrocytes. These findings suggest that Ilk regulates actin reorganization in chondrocytes and modulates chondrocyte growth independently of phosphorylation of Pkb/Akt and GSK3-beta.
Collapse
Affiliation(s)
- Carsten Grashoff
- Department of Molecular Medicine, Max Planck Institute for Biochemistry, 82152 Martinsried, Germany
| | - Attila Aszódi
- Department of Molecular Medicine, Max Planck Institute for Biochemistry, 82152 Martinsried, Germany
| | - Takao Sakai
- Department of Molecular Medicine, Max Planck Institute for Biochemistry, 82152 Martinsried, Germany
| | - Ernst B. Hunziker
- ITI Research Institute for Dental and Skeletal Biology, University of Bern, 3010 Bern, Switzerland
| | - Reinhard Fässler
- Department of Molecular Medicine, Max Planck Institute for Biochemistry, 82152 Martinsried, Germany
- Tel: +49 89 8578 2897; Fax: +49 89 8578 2422;
| |
Collapse
|
34
|
Sakai T, Li S, Docheva D, Grashoff C, Sakai K, Kostka G, Braun A, Pfeifer A, Yurchenco PD, Fässler R. Integrin-linked kinase (ILK) is required for polarizing the epiblast, cell adhesion, and controlling actin accumulation. Genes Dev 2003; 17:926-40. [PMID: 12670870 PMCID: PMC196029 DOI: 10.1101/gad.255603] [Citation(s) in RCA: 312] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Integrin-mediated cell-matrix interactions are essential for development, tissue homeostasis, and repair. Upon ligand binding, integrins are recruited into focal adhesions (FAs). Integrin-linked kinase (ILK) is an FA component that interacts with the cytoplasmic domains of integrins, recruits adaptor proteins that link integrins to the actin cytoskeleton, and phosphorylates the serine/threonine kinases PKB/Akt and GSK-3beta. Here we show that mice lacking ILK expression die at the peri-implantation stage because they fail to polarize their epiblast and to cavitate. The impaired epiblast polarization is associated with abnormal F-actin accumulation at sites of integrin attachments to the basement membrane (BM) zone. Likewise, ILK-deficient fibroblasts showed abnormal F-actin aggregates associated with impaired cell spreading and delayed formation of stress fibers and FAs. Finally, ILK-deficient fibroblasts have diminished proliferation rates. However, insulin or PDGF treatment did not impair phosphorylation of PKB/Akt and GSK-3beta, indicating that the proliferation defect is not due to absent or reduced ILK-mediated phosphorylation of these substrates in vivo. Furthermore, expression of a mutant ILK lacking kinase activity and/or paxillin binding in ILK-deficient fibroblasts can rescue cell spreading, F-actin organization, FA formation, and proliferation. Altogether these data show that mammalian ILK modulates actin rearrangements at integrin-adhesion sites.
Collapse
Affiliation(s)
- Takao Sakai
- Max Planck Institute of Biochemistry, Department of Molecular Medicine, 82152 Martinsried, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
Grashoff C, Verkerke D. Effect of pattern of water supply on Vicia faba L. 3. Plant water relations, expansive growth and stomatal reactions. ACTA ACUST UNITED AC 1991. [DOI: 10.18174/njas.v39i4.16535] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Faba beans cv. Minica, Wierboon, Kristall, Felix, Optica and Alfred grown in the field in the Netherlands were irrigated to near field capacity, or water stressed, between the onset of flowering and the end of the growing season. Leaf water potential ( psi ), osmotic potential ( pi ) and turgor (P) were linearly related to leaf relative water content (RWC) with no significant differences between cultivars. At full turgor, pi hardly differed between water supply treatments, and the slopes of pi vs. RWC were not significantly different between treatments, indicating the absence of osmotic adjustment. Water supply did not affect the slope of P vs. RWC, and it was concluded that the faba bean cultivars lacked mechanisms to keep P high during water stress. Internode growth during flowering was 2-3 times greater in the well watered than in the stressed treatment. In greenhouse studies with cv. Minica, vegetative growth decreased linearly with decreasing P. Maximum stomatal conductance in the field decreased with psi from an estimated maximum level of 1.0 s/cm (at full turgidity and light intensity >800 micro E/msuperscript 2 per s), following a negative exponential curve. It was concluded that vegetative (expansive) growth decreases faster with decreasing P or psi than the stomatal conductance (and most probably faster than the rate of photosynthesis). It is suggested that this result may help to explain the positive effect of mild water stress on reproductive growth in faba beans. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Collapse
|
37
|
Grashoff C. Effect of pattern of water supply on Vicia faba L. 2. Pod retention and filling, and dry matter partitioning, production and water use. ACTA ACUST UNITED AC 1990. [DOI: 10.18174/njas.v38i2.16600] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pod retention and pod filling of V. faba was studied under different patterns of water supply. Mild water shortage during flowering, followed by plenty of water after flowering (d-i), resulted in high seed yields at lower stem nodes (defined as the first podding node to node number 11) in cv. Alfred. The inverse treatment (i-d: plenty of water during flowering, followed by increasing water shortage after flowering), but also i-i (plenty of water during and after flowering), showed 20-60% lower seed yields at those nodes. This effect was mainly due to a lower number of pods per node. In i-i, but not in i-d, the low pod retention at lower nodes was compensated for at higher nodes (defined as from node 12 to the last podding node). These results helped to explain the mechanism of the interaction between water supply pattern and the development of reproductive sinks. The quantitative consequences of these effects on the relation between total water use and seed yield are discussed. Without taking into account different water supply patterns, a linear relation between total water use (represented by total DM production) and seed yield already explained 75-85% of the variation in seed yield. If different water supply patterns were included in the regression analysis, >90% of the variation in seed yield could be explained. The i-i patterns, compared with d-i, resulted in suboptimum DM partitioning to reproductive organs, but showed a smaller seed yield variability. This indicated that defining and maintaining the optimum level of (mild) water shortage under varying climatological conditions needed further attention. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Collapse
|
38
|
Abstract
V. faba cultivars including cv. Minica, Kristall, Alfred and Optica were grown with (a) full irrigation, or restricted irrigation (b) after the start of flowering, (c) after the end of flowering, (d) before flowering or (e) during flowering. Irrigation from the start of flowering stimulated vegetative growth but reduced initial reproductive growth and final seed yield compared with restricted water during flowering only. In 1982-84 using cv. Minica, treatment (e) gave high av. seed yields (7 t/ha), optimum harvest index (0.61 g/g) and a relatively small range of seed yields (2.2 t/ha), while (d) gave 7.1 t/ha, lower harvest index (0.57) and a small range of seed yields (1.4 t/ha). The other treatments and no irrigation gave much lower seed yields and a larger range of seed yields. Treatment (c) gave the lowest harvest index. Similar results were obtained with cv. Alfred. It was concluded that the amount and distribution of rainfall was a major reason for variability in seed yield of this crop. (Abstract retrieved from CAB Abstracts by CABI’s permission)
Collapse
|