1
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Dow LP, Gaietta G, Kaufman Y, Swift MF, Lemos M, Lane K, Hopcroft M, Bezault A, Sauvanet C, Volkmann N, Pruitt BL, Hanein D. Morphological control enables nanometer-scale dissection of cell-cell signaling complexes. Nat Commun 2022; 13:7831. [PMID: 36539423 PMCID: PMC9768166 DOI: 10.1038/s41467-022-35409-9] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Protein micropatterning enables robust control of cell positioning on electron-microscopy substrates for cryogenic electron tomography (cryo-ET). However, the combination of regulated cell boundaries and the underlying electron-microscopy substrate (EM-grids) provides a poorly understood microenvironment for cell biology. Because substrate stiffness and morphology affect cellular behavior, we devised protocols to characterize the nanometer-scale details of the protein micropatterns on EM-grids by combining cryo-ET, atomic force microscopy, and scanning electron microscopy. Measuring force displacement characteristics of holey carbon EM-grids, we found that their effective spring constant is similar to physiological values expected from skin tissues. Despite their apparent smoothness at light-microscopy resolution, spatial boundaries of the protein micropatterns are irregular at nanometer scale. Our protein micropatterning workflow provides the means to steer both positioning and morphology of cell doublets to determine nanometer details of punctate adherens junctions. Our workflow serves as the foundation for studying the fundamental structural changes governing cell-cell signaling.
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Affiliation(s)
- Liam P. Dow
- grid.133342.40000 0004 1936 9676Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA USA
| | - Guido Gaietta
- grid.465257.70000 0004 5913 8442Scintillon Institute, San Diego, CA USA
| | - Yair Kaufman
- grid.133342.40000 0004 1936 9676Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA USA
| | - Mark F. Swift
- grid.465257.70000 0004 5913 8442Scintillon Institute, San Diego, CA USA
| | - Moara Lemos
- grid.428999.70000 0001 2353 6535Institut Pasteur, CNRS UMR3528, Structural Studies of Macromolecular Machines in Cellulo Unit, F-75015 Paris, France
| | - Kerry Lane
- grid.133342.40000 0004 1936 9676Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA USA
| | - Matthew Hopcroft
- grid.133342.40000 0004 1936 9676Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA USA
| | - Armel Bezault
- grid.428999.70000 0001 2353 6535Institut Pasteur, CNRS UMR3528, Structural Studies of Macromolecular Machines in Cellulo Unit, F-75015 Paris, France
| | - Cécile Sauvanet
- grid.428999.70000 0001 2353 6535Institut Pasteur, CNRS UMR3528, Structural Studies of Macromolecular Machines in Cellulo Unit, F-75015 Paris, France
| | - Niels Volkmann
- grid.465257.70000 0004 5913 8442Scintillon Institute, San Diego, CA USA ,Institut Pasteur, Université de Paris, CNRS UMR3528, Structural Image Analysis Unit, Paris, France
| | - Beth L. Pruitt
- grid.133342.40000 0004 1936 9676Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA USA
| | - Dorit Hanein
- grid.465257.70000 0004 5913 8442Scintillon Institute, San Diego, CA USA ,grid.428999.70000 0001 2353 6535Institut Pasteur, CNRS UMR3528, Structural Studies of Macromolecular Machines in Cellulo Unit, F-75015 Paris, France ,grid.133342.40000 0004 1936 9676Present Address: Department of Chemistry and Biochemistry, and of Biomedical Engineering, University of California, Santa Barbara, CA USA
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2
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Gaietta G, Kai F, Swift MF, Weaver VM, Volkmann N, Hanein D. Novel cryo-tomography workflow reveals nanometer-scale responses of epithelial cells to matrix stiffness and dimensionality. Mol Biol Cell 2022; 33:br28. [PMID: 36287913 PMCID: PMC9727794 DOI: 10.1091/mbc.e22-03-0092] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 02/04/2023] Open
Abstract
Matrix stiffness and dimensionality have been shown to be major determinants of cell behavior. However, a workflow for examining nanometer-scale responses of the associated molecular machinery is not available. Here, we describe a comprehensive, quantitative workflow that permits the analysis of cells responding to mechanical and dimensionality cues in their native state at nanometer scale by cryogenic electron tomography. Using this approach, we quantified distinct cytoskeletal nanoarchitectures and vesicle phenotypes induced in human mammary epithelial cells in response to stiffness and dimensionality of reconstituted basement membrane. Our workflow closely recapitulates the microenvironment associated with acinar morphogenesis and identified distinct differences in situ at nanometer scale. Using drug treatment, we showed that molecular events and nanometer-scale rearrangements triggered by engagement of apical cell receptors with reconstituted basement membrane correspond to changes induced by reduction of cortical tension. Our approach is fully adaptable to any kind of stiffness regime, extracellular matrix composition, and drug treatment.
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Affiliation(s)
- Guido Gaietta
- Scintillon Institute, San Diego, CA 92121,*Address correspondence to: Dorit Hanein (); Guido Gaietta (); Niels Volkmann ()
| | - Fuiboon Kai
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California San Francisco, San Francisco, CA 94143
| | | | - Valerie M. Weaver
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California San Francisco, San Francisco, CA 94143
| | - Niels Volkmann
- Scintillon Institute, San Diego, CA 92121,Structural Image Analysis Unit, Université de Paris Cité, F-75015 Paris, France,*Address correspondence to: Dorit Hanein (); Guido Gaietta (); Niels Volkmann ()
| | - Dorit Hanein
- Scintillon Institute, San Diego, CA 92121,Structural Studies of Macromolecular Machines in Cellulo Unit, Institut Pasteur, CNRS UMR3528, Université de Paris Cité, F-75015 Paris, France,*Address correspondence to: Dorit Hanein (); Guido Gaietta (); Niels Volkmann ()
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3
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Kai F, Ou G, Tourdot RW, Stashko C, Gaietta G, Swift MF, Volkmann N, Long AF, Han Y, Huang HH, Northey JJ, Leidal AM, Viasnoff V, Bryant DM, Guo W, Wiita AP, Guo M, Dumont S, Hanein D, Radhakrishnan R, Weaver VM. ECM dimensionality tunes actin tension to modulate endoplasmic reticulum function and spheroid phenotypes of mammary epithelial cells. EMBO J 2022; 41:e109205. [PMID: 35880301 PMCID: PMC9434103 DOI: 10.15252/embj.2021109205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 07/14/2021] [Revised: 06/17/2022] [Accepted: 06/22/2022] [Indexed: 12/11/2022] Open
Abstract
Patient-derived organoids and cellular spheroids recapitulate tissue physiology with remarkable fidelity. We investigated how engagement with a reconstituted basement membrane in three dimensions (3D) supports the polarized, stress resilient tissue phenotype of mammary epithelial spheroids. Cells interacting with reconstituted basement membrane in 3D had reduced levels of total and actin-associated filamin and decreased cortical actin tension that increased plasma membrane protrusions to promote negative plasma membrane curvature and plasma membrane protein associations linked to protein secretion. By contrast, cells engaging a reconstituted basement membrane in 2D had high cortical actin tension that forced filamin unfolding and endoplasmic reticulum (ER) associations. Enhanced filamin-ER interactions increased levels of PKR-like ER kinase effectors and ER-plasma membrane contact sites that compromised calcium homeostasis and diminished cell viability. Consequently, cells with decreased cortical actin tension had reduced ER stress and survived better. Consistently, cortical actin tension in cellular spheroids regulated polarized basement membrane membrane deposition and sensitivity to exogenous stress. The findings implicate cortical actin tension-mediated filamin unfolding in ER function and underscore the importance of tissue mechanics in organoid homeostasis.
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Affiliation(s)
- FuiBoon Kai
- Department of Surgery, Center for Bioengineering and Tissue RegenerationUniversity of California San FranciscoSan FranciscoCAUSA
| | - Guanqing Ou
- Department of Surgery, Center for Bioengineering and Tissue RegenerationUniversity of California San FranciscoSan FranciscoCAUSA
| | - Richard W Tourdot
- Department of BioengineeringUniversity of PennsylvaniaPhiladelphiaPAUSA
- Department of Chemical and Biomolecular EngineeringUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Connor Stashko
- Department of Surgery, Center for Bioengineering and Tissue RegenerationUniversity of California San FranciscoSan FranciscoCAUSA
| | | | | | - Niels Volkmann
- Scintillon InstituteSan DiegoCAUSA
- Structural Image Analysis Unit, Department of Structural Biology and Chemistry, Institut PasteurUniversité Paris Cité, CNRS UMR3528ParisFrance
| | - Alexandra F Long
- Tetrad Graduate ProgramUniversity of California San FranciscoSan FranciscoCAUSA
- Department of Bioengineering and Therapeutic SciencesDepartment of Cell & Tissue Biology, University of California San FranciscoSan FranciscoCAUSA
| | - Yulong Han
- Department of Mechanical EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Hector H Huang
- Department of Laboratory MedicineUniversity of California San FranciscoSan FranciscoCAUSA
| | - Jason J Northey
- Department of Surgery, Center for Bioengineering and Tissue RegenerationUniversity of California San FranciscoSan FranciscoCAUSA
| | - Andrew M Leidal
- Department of PathologyUniversity of California San FranciscoSan FranciscoCAUSA
| | - Virgile Viasnoff
- Mechanobiology InstituteNational University of SingaporeSingapore CitySingapore
| | | | - Wei Guo
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Arun P Wiita
- Department of Laboratory MedicineUniversity of California San FranciscoSan FranciscoCAUSA
| | - Ming Guo
- Department of Mechanical EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Sophie Dumont
- Department of Bioengineering and Therapeutic SciencesDepartment of Cell & Tissue Biology, University of California San FranciscoSan FranciscoCAUSA
- Chan Zuckerberg BiohubSan FranciscoCAUSA
| | - Dorit Hanein
- Scintillon InstituteSan DiegoCAUSA
- Structural Studies of Macromolecular Machines in Cellulo Unit, Department of Structural Biology and Chemistry, Institut PasteurUniversité Paris Cité, CNRS UMR3528ParisFrance
| | - Ravi Radhakrishnan
- Department of BioengineeringUniversity of PennsylvaniaPhiladelphiaPAUSA
- Department of Chemical and Biomolecular EngineeringUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Valerie M Weaver
- Department of Surgery, Center for Bioengineering and Tissue RegenerationUniversity of California San FranciscoSan FranciscoCAUSA
- Departments of Radiation Oncology and Bioengineering and Therapeutic Sciences, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell ResearchUniversity of California San FranciscoSan FranciscoCAUSA
- UCSF Helen Diller Family Comprehensive Cancer CenterUniversity of California San FranciscoSan FranciscoCAUSA
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4
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Gaietta G, Swift MF, Volkmann N, Hanein D. Rapid tool for cell nanoarchitecture integrity assessment. J Struct Biol 2021; 213:107801. [PMID: 34582983 PMCID: PMC8665072 DOI: 10.1016/j.jsb.2021.107801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/23/2021] [Revised: 09/12/2021] [Accepted: 09/21/2021] [Indexed: 12/13/2022]
Abstract
With the rapid increase and accessibility of high-resolution imaging technologies of cells, the interpretation of results relies more and more on the assumption that the three-dimensional integrity of the surrounding cellular landscape is not compromised by the experimental setup. However, the only available technology for directly probing the structural integrity of whole-cell preparations at the nanoscale is electron cryo-tomography, which is time-consuming, costly, and complex. We devised an accessible, inexpensive and reliable screening assay to quickly report on the compatibility of experimental protocols with preserving the structural integrity of whole-cell preparations at the nanoscale. Our Rapid Cell Integrity Assessment (RCIA) assay is executed at room temperature and relies solely on light microscopy imaging. Using cellular electron cryo-tomography as a benchmark, we verify that RCIA accurately unveils the adverse impact of reagents and/or protocols such as those used for virus inactivation or to arrest dynamic processes on the cellular nanoarchitecture.
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Affiliation(s)
| | | | - Niels Volkmann
- Scintillon Institute, San Diego CA 92123, USA; Institut Pasteur, Université de Paris, CNRS UMR3528, Structural Image Analysis Unit, F-75015 Paris, France
| | - Dorit Hanein
- Scintillon Institute, San Diego CA 92123, USA; Institut Pasteur, CNRS UMR3528, Structural Studies of Macromolecular Machines in Cellulo Unit, F-75015 Paris, France.
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5
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Robert-Paganin J, Xu XP, Swift MF, Auguin D, Robblee JP, Lu H, Fagnant PM, Krementsova EB, Trybus KM, Houdusse A, Volkmann N, Hanein D. The actomyosin interface contains an evolutionary conserved core and an ancillary interface involved in specificity. Nat Commun 2021; 12:1892. [PMID: 33767187 PMCID: PMC7994445 DOI: 10.1038/s41467-021-22093-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 11/10/2020] [Accepted: 02/08/2021] [Indexed: 11/17/2022] Open
Abstract
Plasmodium falciparum, the causative agent of malaria, moves by an atypical process called gliding motility. Actomyosin interactions are central to gliding motility. However, the details of these interactions remained elusive until now. Here, we report an atomic structure of the divergent Plasmodium falciparum actomyosin system determined by electron cryomicroscopy at the end of the powerstroke (Rigor state). The structure provides insights into the detailed interactions that are required for the parasite to produce the force and motion required for infectivity. Remarkably, the footprint of the myosin motor on filamentous actin is conserved with respect to higher eukaryotes, despite important variability in the Plasmodium falciparum myosin and actin elements that make up the interface. Comparison with other actomyosin complexes reveals a conserved core interface common to all actomyosin complexes, with an ancillary interface involved in defining the spatial positioning of the motor on actin filaments. Plasmodium falciparum moves by an atypical process called gliding motility which comprises of atypical myosin A (PfMyoA) and filaments of the dynamic and divergent PfActin-1 (PfAct1). Here authors present the cryo-EM structure of PfMyoA bound to filamentous PfAct1 stabilized with jasplakinolide and provide insights into the interactions that are required for the parasite to produce the force and motion required for infectivity.
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Affiliation(s)
| | | | | | - Daniel Auguin
- Structural Motility, Institut Curie, CNRS, UMR 144, Paris, France.,Laboratoire de Biologie des Ligneux et des Grandes Cultures (LBLGC), Université d'Orléans, INRAE, USC1328, Orléans, France
| | - James P Robblee
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - Hailong Lu
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - Patricia M Fagnant
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - Elena B Krementsova
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - Kathleen M Trybus
- Department of Molecular Physiology & Biophysics, University of Vermont, Burlington, VT, USA
| | - Anne Houdusse
- Structural Motility, Institut Curie, CNRS, UMR 144, Paris, France.
| | - Niels Volkmann
- Scintillon Institute, San Diego, CA, USA. .,Structural Image Analysis Unit, Department of Structural Biology & Chemistry, Institut Pasteur, Paris, France.
| | - Dorit Hanein
- Scintillon Institute, San Diego, CA, USA.,Structural Studies of Macromolecular Machines in Cellulo Unit, Department of Structural Biology & Chemistry, Institut Pasteur, Paris, France
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6
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Xu XP, Pokutta S, Torres M, Swift MF, Hanein D, Volkmann N, Weis WI. Structural basis of αE-catenin-F-actin catch bond behavior. eLife 2020; 9:e60878. [PMID: 32915141 PMCID: PMC7588230 DOI: 10.7554/elife.60878] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [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: 07/09/2020] [Accepted: 09/09/2020] [Indexed: 11/13/2022] Open
Abstract
Cell-cell and cell-matrix junctions transmit mechanical forces during tissue morphogenesis and homeostasis. α-Catenin links cell-cell adhesion complexes to the actin cytoskeleton, and mechanical load strengthens its binding to F-actin in a direction-sensitive manner. Specifically, optical trap experiments revealed that force promotes a transition between weak and strong actin-bound states. Here, we describe the cryo-electron microscopy structure of the F-actin-bound αE-catenin actin-binding domain, which in solution forms a five-helix bundle. In the actin-bound structure, the first helix of the bundle dissociates and the remaining four helices and connecting loops rearrange to form the interface with actin. Deletion of the first helix produces strong actin binding in the absence of force, suggesting that the actin-bound structure corresponds to the strong state. Our analysis explains how mechanical force applied to αE-catenin or its homolog vinculin favors the strongly bound state, and the dependence of catch bond strength on the direction of applied force.
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Affiliation(s)
| | - Sabine Pokutta
- Departments of Structural Biology and Molecular & Cellular Physiology, Stanford University School of MedicineStanfordUnited States
| | - Megan Torres
- Departments of Structural Biology and Molecular & Cellular Physiology, Stanford University School of MedicineStanfordUnited States
| | | | - Dorit Hanein
- Scintillon InstituteSan DiegoUnited States
- Department of Structural Biology and Chemistry, Pasteur InstituteParisFrance
| | - Niels Volkmann
- Scintillon InstituteSan DiegoUnited States
- Department of Structural Biology and Chemistry, Pasteur InstituteParisFrance
| | - William I Weis
- Departments of Structural Biology and Molecular & Cellular Physiology, Stanford University School of MedicineStanfordUnited States
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7
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Engel L, Gaietta G, Dow LP, Swift MF, Pardon G, Volkmann N, Weis WI, Hanein D, Pruitt BL. Extracellular matrix micropatterning technology for whole cell cryogenic electron microscopy studies. J Micromech Microeng 2019; 29:115018. [PMID: 32879557 PMCID: PMC7457726 DOI: 10.1088/1361-6439/ab419a] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Cryogenic electron tomography is the highest resolution tool available for structural analysis of macromolecular organization inside cells. Micropatterning of extracellular matrix (ECM) proteins is an established in vitro cell culture technique used to control cell shape. Recent traction force microscopy studies have shown correlation between cell morphology and the regulation of force transmission. However, it remains unknown how cells sustain increased strain energy states and localized stresses at the supramolecular level. Here, we report a technology to enable direct observation of mesoscale organization in epithelial cells under morphological modulation, using a maskless protein photopatterning method (PRIMO) to confine cells to ECM micropatterns on electron microscopy substrates. These micropatterned cell culture substrates can be used in mechanobiology research to correlate changes in nanometer-scale organization at cell-cell and cell-ECM contacts to strain energy states and traction stress distribution in the cell.
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Affiliation(s)
- Leeya Engel
- Department of Bioengineering, Stanford University, Stanford, California
- Correspondence:
| | - Guido Gaietta
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Liam P. Dow
- Department of Bioengineering, Stanford University, Stanford, California
- Biomolecular Science and Engineering Program, University of California, Santa Barbara
| | - Mark F. Swift
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Gaspard Pardon
- Department of Bioengineering, Stanford University, Stanford, California
| | - Niels Volkmann
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - William I. Weis
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine
| | - Dorit Hanein
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California
| | - Beth L. Pruitt
- Department of Bioengineering, Stanford University, Stanford, California
- Biomolecular Science and Engineering Program, University of California, Santa Barbara
- Departments of Mechanical Engineering and Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara
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8
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López CA, Swift MF, Xu XP, Hanein D, Volkmann N, Gnanakaran S. Biophysical Characterization of a Nanodisc with and without BAX: An Integrative Study Using Molecular Dynamics Simulations and Cryo-EM. Structure 2019; 27:988-999.e4. [DOI: 10.1016/j.str.2019.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 12/21/2018] [Accepted: 03/15/2019] [Indexed: 10/27/2022]
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9
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Metlagel Z, Krey JF, Song J, Swift MF, Tivol WJ, Dumont RA, Thai J, Chang A, Seifikar H, Volkmann N, Hanein D, Barr-Gillespie PG, Auer M. Electron cryo-tomography of vestibular hair-cell stereocilia. J Struct Biol 2019; 206:149-155. [PMID: 30822456 DOI: 10.1016/j.jsb.2019.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 11/24/2022]
Abstract
High-resolution imaging of hair-cell stereocilia of the inner ear has contributed substantially to our understanding of auditory and vestibular function. To provide three-dimensional views of the structure of stereocilia cytoskeleton and membranes, we developed a method for rapidly freezing unfixed stereocilia on electron microscopy grids, which allowed subsequent 3D imaging by electron cryo-tomography. Structures of stereocilia tips, shafts, and tapers were revealed, demonstrating that the actin paracrystal was not perfectly ordered. This sample-preparation and imaging procedure will allow for examination of structural features of stereocilia in a near-native state.
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Affiliation(s)
- Zoltan Metlagel
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jocelyn F Krey
- Oregon Hearing Research Center & Vollum Institute, Oregon Health & Science University, Portland, OR, USA
| | - Junha Song
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mark F Swift
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, San Diego, USA
| | - William J Tivol
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Rachel A Dumont
- Oregon Hearing Research Center & Vollum Institute, Oregon Health & Science University, Portland, OR, USA
| | - Jasmine Thai
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alex Chang
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Helia Seifikar
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Niels Volkmann
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, San Diego, USA
| | - Dorit Hanein
- Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, San Diego, USA
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center & Vollum Institute, Oregon Health & Science University, Portland, OR, USA
| | - Manfred Auer
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Kumar A, Anderson KL, Swift MF, Hanein D, Volkmann N, Schwartz MA. Local Tension on Talin in Focal Adhesions Correlates with F-Actin Alignment at the Nanometer Scale. Biophys J 2018; 115:1569-1579. [PMID: 30274833 PMCID: PMC6372196 DOI: 10.1016/j.bpj.2018.08.045] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/15/2018] [Accepted: 08/29/2018] [Indexed: 01/31/2023] Open
Abstract
Cellular force transmission and mechanotransduction are critical in embryogenesis, normal physiology, and many diseases. Talin plays a key role in these processes by linking integrins to force-generating actomyosin. Using the previously characterized FRET-based talin tension sensor, we observed variations of tension both between and within individual focal adhesions in the same cell. Assembling and sliding adhesions showed gradients with higher talin tension toward the cell center, whereas mature, stable adhesions had uniform talin tension. Total talin accumulation was maximal in high-tension regions; by contrast, vinculin intensity was flat or maximal at the adhesion center, and actin intensity was maximal toward the cell center. To investigate mechanism, we combined talin tension imaging with cellular cryotomography to visualize the correlated actin organization at nanometer resolution. Regions of high talin tension had highly aligned linear actin filaments, whereas regions of low tension had less-well-aligned F-actin. These results reveal an orchestrated spatiotemporal relationship between talin tension, actin/vinculin localization, local actin organization, and focal adhesion dynamics.
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Affiliation(s)
- Abhishek Kumar
- Department of Medicine (Cardiology) and Yale Cardiovascular Research Center, Yale University, New Haven, Connecticut
| | - Karen L Anderson
- Bioinformatics and Structural Biology Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California
| | - Mark F Swift
- Bioinformatics and Structural Biology Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California
| | - Dorit Hanein
- Bioinformatics and Structural Biology Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California.
| | - Niels Volkmann
- Bioinformatics and Structural Biology Program, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, California
| | - Martin A Schwartz
- Department of Medicine (Cardiology) and Yale Cardiovascular Research Center, Yale University, New Haven, Connecticut; Departments of Cell Biology and Biomedical Engineering, Yale University, New Haven, Connecticut.
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11
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Anderson KL, Page C, Swift MF, Suraneni P, Janssen MEW, Pollard TD, Li R, Volkmann N, Hanein D. Redefining the Role of the Arp2/3 Complex: Regulation of Morphology at the Leading Edge. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.120] [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] [Indexed: 11/15/2022] Open
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12
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Anderson KL, Page C, Swift MF, Suraneni P, Janssen MEW, Pollard TD, Li R, Volkmann N, Hanein D. Nano-scale actin-network characterization of fibroblast cells lacking functional Arp2/3 complex. J Struct Biol 2016; 197:312-321. [PMID: 28013022 DOI: 10.1016/j.jsb.2016.12.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [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: 12/11/2016] [Accepted: 12/18/2016] [Indexed: 01/06/2023]
Abstract
Arp2/3 complex is thought to be the primary protrusive force generator in cell migration by controlling the assembly and turnover of the branched filament network that pushes the leading edge of moving cells forward. However, mouse fibroblasts without functional Arp2/3 complex migrate at rates similar to wild-type cells, contradicting this paradigm. We show by correlative fluorescence and large-scale cryo-tomography studies combined with automated actin-network analysis that the absence of functional Arp2/3 complex has profound effects on the nano-scale architecture of actin networks. Our quantitative analysis at the single-filament level revealed that cells lacking functional Arp2/3 complex fail to regulate location-dependent fine-tuning of actin filament growth and organization that is distinct from its role in the formation and regulation of dendritic actin networks.
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Affiliation(s)
- Karen L Anderson
- Bioinformatics and Structural Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, United States
| | - Christopher Page
- Bioinformatics and Structural Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, United States
| | - Mark F Swift
- Bioinformatics and Structural Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, United States
| | - Praveen Suraneni
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Mandy E W Janssen
- Bioinformatics and Structural Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, United States
| | - Thomas D Pollard
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States; Department of Cell Biology and of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Rong Li
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Niels Volkmann
- Bioinformatics and Structural Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, United States.
| | - Dorit Hanein
- Bioinformatics and Structural Biology Program, Sanford-Burnham Medical Research Institute, La Jolla, CA, United States.
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