1
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Mahanta B, Courtemanche N. The mode of subunit addition regulates the processive elongation of actin filaments by formin. J Biol Chem 2024:108071. [PMID: 39667500 DOI: 10.1016/j.jbc.2024.108071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Revised: 11/25/2024] [Accepted: 12/05/2024] [Indexed: 12/14/2024] Open
Abstract
Formins play crucial roles in actin polymerization by nucleating filaments and regulating their elongation. Formins bind the barbed ends of filaments via their dimeric FH2 domains, which step processively onto incoming actin subunits during elongation. Actin monomers can bind formin-bound barbed ends directly or undergo diffusion-mediated delivery through interactions with formin FH1 domains and profilin. Despite its fundamental importance, a clear mechanism governing processive FH2 stepping has remained elusive. In this study, we systematically characterized the polymerization behavior of the S. cerevisiae formin Bni1p using in vitro reconstitution assays and stochastic simulations. We found that Bni1p assembles populations of filaments with lengths that depend nonlinearly on the rate of elongation. This processive behavior is dictated by a variable probability of dissociation that depends on the reaction conditions. Bni1p dissociates from barbed ends with a basal off-rate, which enables prolonged filament assembly over the course of a long lifetime at the barbed end. A bias towards FH1-mediated delivery as the dominant mechanism for polymerization curtails elongation by shortening the lifetime of the formin at the filament end. This facilitates the assembly of populations of filaments with similar average lengths, even when polymerization proceeds at different rates. Our results suggest a central role for formin FH1 domains in regulating processivity. The specific effects of FH1 domains on processivity are variable and likely tailored to the physiological function of each formin.
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Affiliation(s)
- Biswaprakash Mahanta
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Naomi Courtemanche
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
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2
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Matsuzaka T, Matsugaki A, Ishihara K, Nakano T. Osteogenic tailoring of oriented bone matrix organization using on/off micropatterning for osteoblast adhesion on titanium surfaces. Acta Biomater 2024:S1742-7061(24)00728-1. [PMID: 39644943 DOI: 10.1016/j.actbio.2024.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Revised: 11/21/2024] [Accepted: 12/05/2024] [Indexed: 12/09/2024]
Abstract
Titanium (Ti) implants are well known for their mechanical reliability and chemical stability, crucial for successful bone regeneration. Various shape control and surface modification techniques to enhance biological activity have been developed. Despite the crucial importance of the collagen/apatite bone microstructure for mechanical function, antimicrobial properties, and biocompatibility, precise and versatile pattern control for regenerating the microstructure remains challenging. Here, we developed a novel osteogenic tailoring stripe-micropatterned MPC-Ti substrate that induces genetic-level control of oriented bone matrix organization. This biomaterial was created by micropatterning 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer onto a titanium (Ti) surface through a selective photoreaction. The stripe-micropatterned MPC-Ti substrate establishes a distinct interface for cell adhesion, robustly inducing osteoblast cytoskeleton alignment through actin cytoskeletal alignment, and facilitating the formation of a bone-mimicking-oriented collagen/apatite tissue. Moreover, our study revealed that this bone alignment process is promoted through the activation of the Wnt/β-catenin signaling pathway, which is triggered by nuclear deformation induced by strong cellular alignment guidance. This innovative material is essential for personalized next-generation medical devices, offering high customizability and active restoration of the bone microstructure. STATEMENT OF SIGNIFICANCE: This study demonstrates a novel osteogenic tailoring stripe-micropatterned MPC-Ti substrate that induces osteoblast alignment and bone matrix orientation based on genetic mechanism. By employing a light-reactive MPC polymer, we successfully micropatterned the titanium surface, creating a biomaterial that stimulates unidirectional osteoblast alignment and enhances the formation of natural bone-mimetic anisotropic microstructures. The innovative approach of regulating cell adhesion and cytoskeletal alignment activates the Wnt/β-catenin signaling pathway, crucial for both bone differentiation and orientation. This study presents the first biomaterial that artificially induces the construction of mechanically superior anisotropic bone tissue, and it is expected to promote functional bone regeneration by enhancing bone differentiation and orientation-targeting both the quantity and quality of bone tissue.
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Affiliation(s)
- Tadaaki Matsuzaka
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Aira Matsugaki
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Kazuhiko Ishihara
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takayoshi Nakano
- Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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3
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Scholz J, Stephan T, Pérez AG, Csiszár A, Hersch N, Fischer LS, Brühmann S, Körber S, Litschko C, Mijanovic L, Kaufmann T, Lange F, Springer R, Pich A, Jakobs S, Peckham M, Tarantola M, Grashoff C, Merkel R, Faix J. Decisive role of mDia-family formins in cell cortex function of highly adherent cells. SCIENCE ADVANCES 2024; 10:eadp5929. [PMID: 39475610 PMCID: PMC11524191 DOI: 10.1126/sciadv.adp5929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 09/20/2024] [Indexed: 11/02/2024]
Abstract
Cortical formins, pivotal for the assembly of linear actin filaments beneath the membrane, exert only minor effects on unconfined cell migration of weakly and moderately adherent cells. However, their impact on migration and mechanostability of highly adherent cells remains poorly understood. Here, we demonstrate that loss of cortical actin filaments generated by the formins mDia1 and mDia3 drastically compromises cell migration and mechanics in highly adherent fibroblasts. Biophysical analysis of the mechanical properties of the mutant cells revealed a markedly softened cell cortex in the poorly adherent state. Unexpectedly, in the highly adherent state, associated with a hyperstretched morphology with exaggerated focal adhesions and prominent high-strain stress fibers, they exhibited even higher cortical tension compared to control. Notably, misguidance of intracellular forces, frequently accompanied by stress-fiber rupture, culminated in the formation of tension- and contractility-induced macroapertures, which was instantly followed by excessive lamellipodial protrusion at the periphery, providing critical insights into mechanotransduction of mechanically stressed and highly adherent cells.
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Affiliation(s)
- Jonas Scholz
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Till Stephan
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt/Main, Germany
| | - Aina Gallemí Pérez
- Institute for Dynamics of Complex Systems, Göttingen, Germany
- Max Planck Institute for Dynamics and Self-Organization, Department LFPB, Göttingen, Germany
| | - Agnes Csiszár
- Institute of Biological Information Processing 2: Mechanobiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Nils Hersch
- Institute of Biological Information Processing 2: Mechanobiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Lisa S. Fischer
- Institute of Integrative Cell Biology and Physiology, University of Münster, Münster, Germany
| | - Stefan Brühmann
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Sarah Körber
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
- HiLIFE Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Christof Litschko
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Lucija Mijanovic
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Thomas Kaufmann
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Felix Lange
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Ronald Springer
- Institute of Biological Information Processing 2: Mechanobiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Andreas Pich
- Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Michelle Peckham
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Marco Tarantola
- Institute for Dynamics of Complex Systems, Göttingen, Germany
- Max Planck Institute for Dynamics and Self-Organization, Department LFPB, Göttingen, Germany
| | - Carsten Grashoff
- Institute of Integrative Cell Biology and Physiology, University of Münster, Münster, Germany
| | - Rudolf Merkel
- Institute of Biological Information Processing 2: Mechanobiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Jan Faix
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
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4
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Chen T, Fernández-Espartero CH, Illand A, Tsai CT, Yang Y, Klapholz B, Jouchet P, Fabre M, Rossier O, Cui B, Lévêque-Fort S, Brown NH, Giannone G. Actin-driven nanotopography promotes stable integrin adhesion formation in developing tissue. Nat Commun 2024; 15:8691. [PMID: 39375335 PMCID: PMC11458790 DOI: 10.1038/s41467-024-52899-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 09/24/2024] [Indexed: 10/09/2024] Open
Abstract
Morphogenesis requires building stable macromolecular structures from highly dynamic proteins. Muscles are anchored by long-lasting integrin adhesions to resist contractile force. However, the mechanisms governing integrin diffusion, immobilization, and activation within developing tissues remain elusive. Here, we show that actin polymerization-driven membrane protrusions form nanotopographies that enable strong adhesion at Drosophila muscle attachment sites (MASs). Super-resolution microscopy reveals that integrins assemble adhesive belts around Arp2/3-dependent actin protrusions, forming invadosome-like structures with membrane nanotopographies. Single protein tracking shows that, during MAS development, integrins become immobile and confined within diffusion traps formed by the membrane nanotopographies. Actin filaments also display restricted motion and confinement, indicating strong mechanical connection with integrins. Using isolated muscle cells, we show that substrate nanotopography, rather than rigidity, drives adhesion maturation by regulating actin protrusion, integrin diffusion and immobilization. These results thus demonstrate that actin-polymerization-driven membrane protrusions are essential for the formation of strong integrin adhesions sites in the developing embryo, and highlight the important contribution of geometry to morphogenesis.
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Affiliation(s)
- Tianchi Chen
- Interdisciplinary Institute for Neuroscience, Université Bordeaux, CNRS, UMR 5297, Bordeaux, France.
| | - Cecilia H Fernández-Espartero
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
- Instituto de Biomedicina de Sevilla, IBiS/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Biología Celular, Universidad de Sevilla, Sevilla, Spain
| | - Abigail Illand
- Institut des sciences Moléculaires d'Orsay, Université Paris Saclay, CNRS, UMR8214, Orsay, France
| | - Ching-Ting Tsai
- Department of Chemistry and Stanford Wu-Tsai Neuroscience Institute, Stanford University, Stanford, CA, USA
| | - Yang Yang
- Department of Chemistry and Stanford Wu-Tsai Neuroscience Institute, Stanford University, Stanford, CA, USA
| | - Benjamin Klapholz
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Pierre Jouchet
- Institut des sciences Moléculaires d'Orsay, Université Paris Saclay, CNRS, UMR8214, Orsay, France
| | - Mélanie Fabre
- Interdisciplinary Institute for Neuroscience, Université Bordeaux, CNRS, UMR 5297, Bordeaux, France
| | - Olivier Rossier
- Interdisciplinary Institute for Neuroscience, Université Bordeaux, CNRS, UMR 5297, Bordeaux, France
| | - Bianxiao Cui
- Department of Chemistry and Stanford Wu-Tsai Neuroscience Institute, Stanford University, Stanford, CA, USA
| | - Sandrine Lévêque-Fort
- Institut des sciences Moléculaires d'Orsay, Université Paris Saclay, CNRS, UMR8214, Orsay, France
| | - Nicholas H Brown
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
| | - Grégory Giannone
- Interdisciplinary Institute for Neuroscience, Université Bordeaux, CNRS, UMR 5297, Bordeaux, France.
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5
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Liu X, Zhang W, Gu J, Wang J, Wang Y, Xu Z. Single-cell SERS imaging of dual cell membrane receptors expression influenced by extracellular matrix stiffness. J Colloid Interface Sci 2024; 668:335-342. [PMID: 38678888 DOI: 10.1016/j.jcis.2024.04.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
Membrane receptors perform a diverse range of cellular functions, accounting for more than half of all drug targets. The mechanical microenvironment regulates cell behaviors and phenotype. However, conventional analysis methods of membrane receptors often ignore the effects of the extracellular matrix stiffness, failing to reveal the heterogeneity of cell membrane receptors expression. Herein, we developed an in-situ surface-enhanced Raman scattering (SERS) imaging method to visualize single-cell membrane receptors on substrates with different stiffness. Two SERS substrates, Au@4-mercaptobenzonitrile@Ag@Sgc8c and Au@4-pethynylaniline@Ag@SYL3c, were employed to specifically target protein tyrosine kinase-7 (PTK7) and epithelial cell adhesion molecule (EpCAM), respectively. The polyacrylamide (PA) gels with tunable stiffness (2.5-25 kPa) were constructed to mimic extracellular matrix. The simultaneous SERS imaging of dual membrane receptors on single cancer cells on substrates with different stiffness was achieved. Our findings reveal decreased expression of PTK7 and EpCAM on cells cultured on stiffer substrates and higher migration ability of the cells. The results elucidate the heterogeneity of membrane receptors expression of cells cultured on the substrates with different stiffness. This single-cell analysis method offers an in-situ platform for investigating the impacts of extracellular matrix stiffness on the expression of membrane receptors, providing insights into the role of cell membrane receptors in cancer metastasis.
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Affiliation(s)
- Xiaopeng Liu
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, PR China
| | - Wenshu Zhang
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, PR China
| | - Jiahui Gu
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, PR China
| | - Jie Wang
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, PR China
| | - Yue Wang
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, PR China
| | - Zhangrun Xu
- Research Center for Analytical Sciences, Northeastern University, Shenyang 110819, PR China.
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6
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Jawahar A, Vermeil J, Heuvingh J, du Roure O, Piel M. The third dimension of the actin cortex. Curr Opin Cell Biol 2024; 89:102381. [PMID: 38905917 DOI: 10.1016/j.ceb.2024.102381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/15/2024] [Accepted: 05/24/2024] [Indexed: 06/23/2024]
Abstract
The actin cortex, commonly described as a thin 2-dimensional layer of actin filaments beneath the plasma membrane, is beginning to be recognized as part of a more dynamic and three-dimensional composite material. In this review, we focus on the elements that contribute to the three-dimensional architecture of the actin cortex. We also argue that actin-rich structures such as filopodia and stress fibers can be viewed as specialized integral parts of the 3D actin cortex. This broadens our definition of the cortex, shifting from its simplified characterization as a thin, two-dimensional layer of actin filaments.
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Affiliation(s)
- Anumita Jawahar
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France; Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France.
| | - Joseph Vermeil
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France; Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France
| | - Julien Heuvingh
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France
| | - Olivia du Roure
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France
| | - Matthieu Piel
- Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France
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7
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Chikireddy J, Lengagne L, Le Borgne R, Durieu C, Wioland H, Romet-Lemonne G, Jégou A. Fascin-induced bundling protects actin filaments from disassembly by cofilin. J Cell Biol 2024; 223:e202312106. [PMID: 38497788 PMCID: PMC10949937 DOI: 10.1083/jcb.202312106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/26/2024] [Accepted: 02/29/2024] [Indexed: 03/19/2024] Open
Abstract
Actin filament turnover plays a central role in shaping actin networks, yet the feedback mechanism between network architecture and filament assembly dynamics remains unclear. The activity of ADF/cofilin, the main protein family responsible for filament disassembly, has been mainly studied at the single filament level. This study unveils that fascin, by crosslinking filaments into bundles, strongly slows down filament disassembly by cofilin. We show that this is due to a markedly slower initiation of the first cofilin clusters, which occurs up to 100-fold slower on large bundles compared with single filaments. In contrast, severing at cofilin cluster boundaries is unaffected by fascin bundling. After the formation of an initial cofilin cluster on a filament within a bundle, we observed the local removal of fascin. Notably, the formation of cofilin clusters on adjacent filaments is highly enhanced, locally. We propose that this interfilament cooperativity arises from the local propagation of the cofilin-induced change in helicity from one filament to the other filaments of the bundle. Overall, taking into account all the above reactions, we reveal that fascin crosslinking slows down the disassembly of actin filaments by cofilin. These findings highlight the important role played by crosslinkers in tuning actin network turnover by modulating the activity of other regulatory proteins.
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Affiliation(s)
| | - Léana Lengagne
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Rémi Le Borgne
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Catherine Durieu
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Hugo Wioland
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | | | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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8
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Phua DY, Sun X, Alushin GM. Force-activated zyxin assemblies coordinate actin nucleation and crosslinking to orchestrate stress fiber repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594765. [PMID: 38798419 PMCID: PMC11118565 DOI: 10.1101/2024.05.17.594765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
As the cytoskeleton sustains cell and tissue forces, it incurs physical damage that must be repaired to maintain mechanical homeostasis. The LIM-domain protein zyxin detects force-induced ruptures in actin-myosin stress fibers, coordinating downstream repair factors to restore stress fiber integrity through unclear mechanisms. Here, we reconstitute stress fiber repair with purified proteins, uncovering detailed links between zyxin's force-regulated binding interactions and cytoskeletal dynamics. In addition to binding individual tensed actin filaments (F-actin), zyxin's LIM domains form force-dependent assemblies that bridge broken filament fragments. Zyxin assemblies engage repair factors through multi-valent interactions, coordinating nucleation of new F-actin by VASP and its crosslinking into aligned bundles by ɑ-actinin. Through these combined activities, stress fiber repair initiates within the cores of micron-scale damage sites in cells, explaining how these F-actin depleted regions are rapidly restored. Thus, zyxin's force-dependent organization of actin repair machinery inherently operates at the network scale to maintain cytoskeletal integrity.
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Affiliation(s)
- Donovan Y.Z. Phua
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Xiaoyu Sun
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Gregory M. Alushin
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
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9
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Ivanova JR, Benk AS, Schaefer JV, Dreier B, Hermann LO, Plückthun A, Missirlis D, Spatz JP. Designed Ankyrin Repeat Proteins as Actin Labels of Distinct Cytoskeletal Structures in Living Cells. ACS NANO 2024; 18:8919-8933. [PMID: 38489155 DOI: 10.1021/acsnano.3c12265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
The orchestrated assembly of actin and actin-binding proteins into cytoskeletal structures coordinates cell morphology changes during migration, cytokinesis, and adaptation to external stimuli. The accurate and unbiased visualization of the diverse actin assemblies within cells is an ongoing challenge. We describe here the identification and use of designed ankyrin repeat proteins (DARPins) as synthetic actin binders. Actin-binding DARPins were identified through ribosome display and validated biochemically. When introduced or expressed inside living cells, fluorescently labeled DARPins accumulated at actin filaments, validated through phalloidin colocalization on fixed cells. Nevertheless, different DARPins displayed different actin labeling patterns: some DARPins labeled efficiently dynamic structures, such as filopodia, lamellipodia, and blebs, while others accumulated primarily in stress fibers. This differential intracellular distribution correlated with DARPin-actin binding kinetics, as measured by fluorescence recovery after photobleaching experiments. Moreover, the rapid arrest of actin dynamics induced by pharmacological treatment led to the fast relocalization of DARPins. Our data support the hypothesis that the localization of actin probes depends on the inherent dynamic movement of the actin cytoskeleton. Compared to the widely used LifeAct probe, one DARPin exhibited enhanced signal-to-background ratio while retaining a similar ability to label stress fibers. In summary, we propose DARPins as promising actin-binding proteins for labeling or manipulation in living cells.
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Affiliation(s)
- Julia R Ivanova
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
- Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
- Max Planck School Matter to Life, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Amelie S Benk
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - Jonas V Schaefer
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- CSL Behring AG, 3014 Bern, Switzerland
| | - Birgit Dreier
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Leon O Hermann
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Dimitris Missirlis
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
- Institute for Molecular Systems Engineering and Advanced Materials, Heidelberg University, INF 225, D-69120 Heidelberg, Germany
| | - Joachim P Spatz
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
- Institute for Molecular Systems Engineering and Advanced Materials, Heidelberg University, INF 225, D-69120 Heidelberg, Germany
- Max Planck School Matter to Life, Jahnstrasse 29, 69120 Heidelberg, Germany
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10
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Cao R, Tian H, Tian Y, Fu X. A Hierarchical Mechanotransduction System: From Macro to Micro. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2302327. [PMID: 38145330 PMCID: PMC10953595 DOI: 10.1002/advs.202302327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 10/27/2023] [Indexed: 12/26/2023]
Abstract
Mechanotransduction is a strictly regulated process whereby mechanical stimuli, including mechanical forces and properties, are sensed and translated into biochemical signals. Increasing data demonstrate that mechanotransduction is crucial for regulating macroscopic and microscopic dynamics and functionalities. However, the actions and mechanisms of mechanotransduction across multiple hierarchies, from molecules, subcellular structures, cells, tissues/organs, to the whole-body level, have not been yet comprehensively documented. Herein, the biological roles and operational mechanisms of mechanotransduction from macro to micro are revisited, with a focus on the orchestrations across diverse hierarchies. The implications, applications, and challenges of mechanotransduction in human diseases are also summarized and discussed. Together, this knowledge from a hierarchical perspective has the potential to refresh insights into mechanotransduction regulation and disease pathogenesis and therapy, and ultimately revolutionize the prevention, diagnosis, and treatment of human diseases.
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Affiliation(s)
- Rong Cao
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
| | - Huimin Tian
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
| | - Yan Tian
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
| | - Xianghui Fu
- Department of Endocrinology and MetabolismCenter for Diabetes Metabolism ResearchState Key Laboratory of Biotherapy and Cancer CenterWest China Medical SchoolWest China HospitalSichuan University and Collaborative Innovation CenterChengduSichuan610041China
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11
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Ruperti F, Becher I, Stokkermans A, Wang L, Marschlich N, Potel C, Maus E, Stein F, Drotleff B, Schippers KJ, Nickel M, Prevedel R, Musser JM, Savitski MM, Arendt D. Molecular profiling of sponge deflation reveals an ancient relaxant-inflammatory response. Curr Biol 2024; 34:361-375.e9. [PMID: 38181793 DOI: 10.1016/j.cub.2023.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/03/2023] [Accepted: 12/07/2023] [Indexed: 01/07/2024]
Abstract
A hallmark of animals is the coordination of whole-body movement. Neurons and muscles are central to this, yet coordinated movements also exist in sponges that lack these cell types. Sponges are sessile animals with a complex canal system for filter-feeding. They undergo whole-body movements resembling "contractions" that lead to canal closure and water expulsion. Here, we combine live 3D optical coherence microscopy, pharmacology, and functional proteomics to elucidate the sequence and detail of shape changes, the tissues and molecular physiology involved, and the control of these movements. Morphometric analysis and targeted perturbation suggest that the movement is driven by the relaxation of actomyosin stress fibers in epithelial canal cells, which leads to whole-body deflation via collapse of the incurrent and expansion of the excurrent canal system. Thermal proteome profiling and quantitative phosphoproteomics confirm the control of cellular relaxation by an Akt/NO/PKG/PKA pathway. Agitation-induced deflation leads to differential phosphorylation of proteins forming epithelial cell junctions, implying their mechanosensitive role. Unexpectedly, untargeted metabolomics detect a concomitant decrease in antioxidant molecules during deflation, reflecting an increase in reactive oxygen species. Together with the secretion of proteinases, cytokines, and granulin, this indicates an inflammation-like state of the deflating sponge reminiscent of vascular endothelial cells experiencing oscillatory shear stress. These results suggest the conservation of an ancient relaxant-inflammatory response of perturbed fluid-carrying systems in animals and offer a possible mechanism for whole-body coordination through diffusible paracrine signals and mechanotransduction.
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Affiliation(s)
- Fabian Ruperti
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Collaboration for joint Ph.D. degree between EMBL and Heidelberg University, Faculty of Biosciences 69117 Heidelberg, Germany
| | - Isabelle Becher
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | - Ling Wang
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Nick Marschlich
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany
| | - Clement Potel
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Emanuel Maus
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Frank Stein
- Proteomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Bernhard Drotleff
- Metabolomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Klaske J Schippers
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Michael Nickel
- Bionic consulting Dr. Michael Nickel, 71686 Remseck am Neckar, Germany
| | - Robert Prevedel
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Jacob M Musser
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA.
| | - Mikhail M Savitski
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Proteomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany.
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12
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Nalbant P, Wagner J, Dehmelt L. Direct investigation of cell contraction signal networks by light-based perturbation methods. Pflugers Arch 2023; 475:1439-1452. [PMID: 37851146 DOI: 10.1007/s00424-023-02864-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/21/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023]
Abstract
Cell contraction plays an important role in many physiological and pathophysiological processes. This includes functions in skeletal, heart, and smooth muscle cells, which lead to highly coordinated contractions of multicellular assemblies, and functions in non-muscle cells, which are often highly localized in subcellular regions and transient in time. While the regulatory processes that control cell contraction in muscle cells are well understood, much less is known about cell contraction in non-muscle cells. In this review, we focus on the mechanisms that control cell contraction in space and time in non-muscle cells, and how they can be investigated by light-based methods. The review particularly focusses on signal networks and cytoskeletal components that together control subcellular contraction patterns to perform functions on the level of cells and tissues, such as directional migration and multicellular rearrangements during development. Key features of light-based methods that enable highly local and fast perturbations are highlighted, and how experimental strategies can capitalize on these features to uncover causal relationships in the complex signal networks that control cell contraction.
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Affiliation(s)
- Perihan Nalbant
- Department of Molecular Cell Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Room T03 R01 D33, Universitätsstrasse 2, 45141, Essen, Germany.
| | - Jessica Wagner
- Department of Molecular Cell Biology, Center of Medical Biotechnology, University of Duisburg-Essen, Room T03 R01 D33, Universitätsstrasse 2, 45141, Essen, Germany
| | - Leif Dehmelt
- Department of Systemic Cell Biology, Fakultät für Chemie und Chemische Biologie, Max Planck Institute of Molecular Physiology, and Dortmund University of Technology, Room CP-02-157, Otto-Hahn-Str. 4a, 44227, Dortmund, Germany.
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13
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Chen J, Yan D, Chen Y. Understanding the driving force for cell migration plasticity. Biophys J 2023; 122:3570-3576. [PMID: 37041746 PMCID: PMC10541478 DOI: 10.1016/j.bpj.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/22/2023] [Accepted: 04/07/2023] [Indexed: 04/13/2023] Open
Abstract
Cell migration is a complex phenomenon. Not only do different cells migrate in different default modes, but the same cell can also change its migration mode to adapt to different terrains. This complexity has riddled cell biologists and biophysicists for decades in that, despite the development of many powerful tools over the past 30 years, how cells move is still being actively investigated. This is because we have yet to fully understand the mystery of cell migration plasticity, particularly the reciprocal relation between force generation and migration mode transition. Herein we explore the future directions, in terms of measurement platforms and imaging-based techniques, to facilitate the undertaking of elucidating the relation between force generation machinery and migration mode transition. By briefly reviewing the evolution of the platforms and techniques developed in the past, we propose the desirable features to be added to achieve high measurement accuracy and improved temporal and spatial resolution, permitting us to unveil the mystery of cell migration plasticity.
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Affiliation(s)
- Junjie Chen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland; Center for Cell Dynamics, Johns Hopkins University, Baltimore, Maryland
| | - Daniel Yan
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland; Center for Cell Dynamics, Johns Hopkins University, Baltimore, Maryland
| | - Yun Chen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland; Center for Cell Dynamics, Johns Hopkins University, Baltimore, Maryland.
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14
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Ruperti F, Becher I, Stokkermans A, Wang L, Marschlich N, Potel C, Maus E, Stein F, Drotleff B, Schippers K, Nickel M, Prevedel R, Musser JM, Savitski MM, Arendt D. Molecular profiling of sponge deflation reveals an ancient relaxant-inflammatory response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551666. [PMID: 37577507 PMCID: PMC10418225 DOI: 10.1101/2023.08.02.551666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
A hallmark of animals is the coordination of whole-body movement. Neurons and muscles are central to this, yet coordinated movements also exist in sponges that lack these cell types. Sponges are sessile animals with a complex canal system for filter-feeding. They undergo whole-body movements resembling "contractions" that lead to canal closure and water expulsion. Here, we combine 3D optical coherence microscopy, pharmacology, and functional proteomics to elucidate anatomy, molecular physiology, and control of these movements. We find them driven by the relaxation of actomyosin stress fibers in epithelial canal cells, which leads to whole-body deflation via collapse of the incurrent and expansion of the excurrent system, controlled by an Akt/NO/PKG/A pathway. A concomitant increase in reactive oxygen species and secretion of proteinases and cytokines indicate an inflammation-like state reminiscent of vascular endothelial cells experiencing oscillatory shear stress. This suggests an ancient relaxant-inflammatory response of perturbed fluid-carrying systems in animals.
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Affiliation(s)
- Fabian Ruperti
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- Collaboration for joint Ph.D. degree between EMBL and Heidelberg University, Faculty of Biosciences 69117 Heidelberg, Germany
| | - Isabelle Becher
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | - Ling Wang
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Nick Marschlich
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany
| | - Clement Potel
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Emanuel Maus
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Frank Stein
- Proteomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Bernhard Drotleff
- Metabolomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Klaske Schippers
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Michael Nickel
- Bionic Consulting Dr. Michael Nickel, 71686 Remseck am Neckar, Germany
| | - Robert Prevedel
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Jacob M Musser
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA
| | - Mikhail M Savitski
- Genome Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- Proteomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Detlev Arendt
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- Centre for Organismal Studies (COS), University of Heidelberg, 69120 Heidelberg, Germany
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15
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Fang C, Shao X, Tian Y, Chu Z, Lin Y. Size-dependent response of cells in epithelial tissue modulated by contractile stress fibers. Biophys J 2023; 122:1315-1324. [PMID: 36809876 PMCID: PMC10111366 DOI: 10.1016/j.bpj.2023.02.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 01/07/2023] [Accepted: 02/18/2023] [Indexed: 02/24/2023] Open
Abstract
Although cells with distinct apical areas have been widely observed in epithelial tissues, how the size of cells affects their behavior during tissue deformation and morphogenesis as well as key physical factors modulating such influence remains elusive. Here, we showed that the elongation of cells within the monolayer under anisotropic biaxial stretching increases with their size because the strain released by local cell rearrangement (i.e., T1 transition) is more significant for small cells that possess higher contractility. On the other hand, by incorporating the nucleation, peeling, merging, and breakage dynamics of subcellular stress fibers into classical vertex formulation, we found that stress fibers with orientations predominantly aligned with the main stretching direction will be formed at tricellular junctions, in good agreement with recent experiments. The contractile forces generated by stress fibers help cells to resist imposed stretching, reduce the occurrence of T1 transitions, and, consequently, modulate their size-dependent elongation. Our findings demonstrate that epithelial cells could utilize their size and internal structure to regulate their physical and related biological behaviors. The theoretical framework proposed here can also be extended to investigate the roles of cell geometry and intracellular contraction in processes such as collective cell migration and embryo development.
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Affiliation(s)
- Chao Fang
- School of Science, Harbin Institute of Technology, Shenzhen, Guangdong, China; Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong; HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, Guangdong, China
| | - Xueying Shao
- Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong; HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, Guangdong, China; Advanced Biomedical Instrumentation Centre, Hong Kong Science Park, Shatin, New Territories, Hong Kong
| | - Ye Tian
- Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong; HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, Guangdong, China
| | - Zhiqin Chu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong; School of Biological Sciences, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Yuan Lin
- Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong; HKU-Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, Guangdong, China; Advanced Biomedical Instrumentation Centre, Hong Kong Science Park, Shatin, New Territories, Hong Kong.
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16
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Mavrakis M, Juanes MA. The compass to follow: Focal adhesion turnover. Curr Opin Cell Biol 2023; 80:102152. [PMID: 36796142 DOI: 10.1016/j.ceb.2023.102152] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 01/09/2023] [Accepted: 01/14/2023] [Indexed: 02/16/2023]
Abstract
How cells move is a fundamental biological question. The directionality of adherent migrating cells depends on the assembly and disassembly (turnover) of focal adhesions (FAs). FAs are micron-sized actin-based structures that link cells to the extracellular matrix. Traditionally, microtubules have been considered key to triggering FA turnover. Through the years, advancements in biochemistry, biophysics, and bioimaging tools have been invaluable for many research groups to unravel a variety of mechanisms and molecular players that contribute to FA turnover, beyond microtubules. Here, we discuss recent discoveries of key molecular players that affect the dynamics and organization of the actin cytoskeleton to enable timely FA turnover and consequently proper directed cell migration.
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Affiliation(s)
- Manos Mavrakis
- Institut Fresnel, CNRS, Aix-Marseille Univ, Centrale Marseille, 13013 Marseille, France
| | - M Angeles Juanes
- School of Health and Life Science, Teesside University, Middlesbrough, TS1 3BX, United Kingdom; National Horizons Centre, Teesside University, Darlington DL1 1HG, United Kingdom; Centro de Investigación Príncipe Felipe, Valencia, 46012, Spain.
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17
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Lappalainen P, Kotila T, Jégou A, Romet-Lemonne G. Biochemical and mechanical regulation of actin dynamics. Nat Rev Mol Cell Biol 2022; 23:836-852. [PMID: 35918536 DOI: 10.1038/s41580-022-00508-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2022] [Indexed: 12/30/2022]
Abstract
Polymerization of actin filaments against membranes produces force for numerous cellular processes, such as migration, morphogenesis, endocytosis, phagocytosis and organelle dynamics. Consequently, aberrant actin cytoskeleton dynamics are linked to various diseases, including cancer, as well as immunological and neurological disorders. Understanding how actin filaments generate forces in cells, how force production is regulated by the interplay between actin-binding proteins and how the actin-regulatory machinery responds to mechanical load are at the heart of many cellular, developmental and pathological processes. During the past few years, our understanding of the mechanisms controlling actin filament assembly and disassembly has evolved substantially. It has also become evident that the activities of key actin-binding proteins are not regulated solely by biochemical signalling pathways, as mechanical regulation is critical for these proteins. Indeed, the architecture and dynamics of the actin cytoskeleton are directly tuned by mechanical load. Here we discuss the general mechanisms by which key actin regulators, often in synergy with each other, control actin filament assembly, disassembly, and monomer recycling. By using an updated view of actin dynamics as a framework, we discuss how the mechanics and geometry of actin networks control actin-binding proteins, and how this translates into force production in endocytosis and mesenchymal cell migration.
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Affiliation(s)
- Pekka Lappalainen
- Institute of Biotechnology and Helsinki Institute of Life Sciences, University of Helsinki, Helsinki, Finland.
| | - Tommi Kotila
- Institute of Biotechnology and Helsinki Institute of Life Sciences, University of Helsinki, Helsinki, Finland
| | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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18
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Narasimhan S, Holmes WR, Kaverina I. Merging of ventral fibers at adhesions drives the remodeling of cellular contractile systems in fibroblasts. Cytoskeleton (Hoboken) 2022; 79:81-93. [PMID: 35996927 PMCID: PMC9770016 DOI: 10.1002/cm.21722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/10/2022] [Accepted: 08/17/2022] [Indexed: 01/30/2023]
Abstract
Ventral stress fibers (VSFs) are contractile actin fibers dynamically attached to cell-matrix focal adhesions. VSFs are critical in cellular traction force production and migration. VSFs vary from randomly oriented short, thinner fibers to long, thick fibers that span along the whole long axis of a cell. De novo VSF formation was shown to occur by cortical actin mesh condensation or by crosslinking of dorsal stress fibers and transverse arcs at the cell front. However, the formation of long VSFs that extend across the whole cell axis is not well understood. Here, we report a novel phenomenon of VSF merging in migratory fibroblast cells, which is guided by mechanical force balance and contributes to VSF alignment along the long cell axis. The mechanism of VSF merging involves two steps: connection of two ventral fibers by an emerging myosin II bridge at an intervening adhesion and intervening adhesion dissolution. Our data indicate that these two steps are interdependent: slow adhesion disassembly leads to the slowing of the myosin bridge formation. Cellular data and computational modeling show that the contact angle between merging fibers decides successful merging, with shallow angles leading to merge failure. Our data and modeling further show that merging increases the share of uniformly aligned long VSFs, likely contributing to directional traction force production. Thus, we characterize merging as a process for dynamic reorganization of VSFs with functional significance for directional cell migration.
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Affiliation(s)
| | | | - Irina Kaverina
- Department of Cell and Developmental Biology, Vanderbilt University
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19
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Fernandez-Gonzalez R, Peifer M. Powering morphogenesis: multiscale challenges at the interface of cell adhesion and the cytoskeleton. Mol Biol Cell 2022; 33. [PMID: 35696393 DOI: 10.1091/mbc.e21-09-0452] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Among the defining features of the animal kingdom is the ability of cells to change shape and move. This underlies embryonic and postembryonic development, tissue homeostasis, regeneration, and wound healing. Cell shape change and motility require linkage of the cell's force-generating machinery to the plasma membrane at cell-cell and cell-extracellular matrix junctions. Connections of the actomyosin cytoskeleton to cell-cell adherens junctions need to be both resilient and dynamic, preventing tissue disruption during the dramatic events of embryonic morphogenesis. In the past decade, new insights radically altered the earlier simple paradigm that suggested simple linear linkage via the cadherin-catenin complex as the molecular mechanism of junction-cytoskeleton interaction. In this Perspective we provide a brief overview of our current state of knowledge and then focus on selected examples highlighting what we view as the major unanswered questions in our field and the approaches that offer exciting new insights at multiple scales from atomic structure to tissue mechanics.
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Affiliation(s)
- Rodrigo Fernandez-Gonzalez
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G5, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5S 3G5, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.,Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Mark Peifer
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599-3280.,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280
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