1
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Diensthuber RP, Hartmann FK, Kathmann D, Franz P, Tsiavaliaris G. Switch-2 determines Mg 2+ADP-release kinetics and fine-tunes the duty ratio of Dictyostelium class-1 myosins. Front Physiol 2024; 15:1393952. [PMID: 38887318 PMCID: PMC11181000 DOI: 10.3389/fphys.2024.1393952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 05/02/2024] [Indexed: 06/20/2024] Open
Abstract
Though myosins share a structurally conserved motor domain, single amino acid variations of active site elements, including the P-loop, switch-1 and switch-2, which act as nucleotide sensors, can substantially determine the kinetic signature of a myosin, i.e., to either perform fast movement or enable long-range transport and tension generation. Switch-2 essentially contributes to the ATP hydrolysis reaction and determines product release. With few exceptions, class-1 myosin harbor a tyrosine in the switch-2 consensus sequence DIYGFE, at a position where class-2 myosins and a selection of myosins from other classes have a substitution. Here, we addressed the role of the tyrosine in switch-2 of class-1 myosins as potential determinant of the duty ratio. We generated constitutively active motor domain constructs of two class-1 myosins from the social amoeba Dictyostelium discoideum, namely, Myo1E, a high duty ratio myosin and Myo1B, a low duty ratio myosin. In Myo1E we introduced mutation Y388F and in Myo1B mutation F387Y. The detailed functional characterization by steady-state and transient kinetic experiments, combined with in vitro motility and landing assays revealed an almost reciprocal relationship of a number of critical kinetic parameters and equilibrium constants between wild-type and mutants that dictate the lifetime of the strongly actin-attached states of myosin. The Y-to-F mutation increased the duty ratio of Moy1B by almost one order of magnitude, while the introduction of the phenylalanine in switch-2 of Myo1E transformed the myosin into a low duty ratio motor. These data together with structural considerations propose a role of switch-2 in fine-tuning ADP release through a mechanism, where the class-specific tyrosine together with surrounding residues contributes to the coordination of Mg2+ and ADP. Our results highlight the importance of conserved switch-2 residues in class-1 myosins for efficient chemo-mechanical coupling, revealing that switch-2 is important to adjust the duty ratio of the amoeboid class-1 myosins for performing movement, transport or gating functions.
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Affiliation(s)
| | | | | | | | - Georgios Tsiavaliaris
- Institute for Biophysical Chemistry, OE 4350, Hannover Medical School, Hannover, Germany
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2
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Tsai FC, Guérin G, Pernier J, Bassereau P. Actin-membrane linkers: Insights from synthetic reconstituted systems. Eur J Cell Biol 2024; 103:151402. [PMID: 38461706 DOI: 10.1016/j.ejcb.2024.151402] [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: 12/03/2023] [Revised: 02/10/2024] [Accepted: 02/28/2024] [Indexed: 03/12/2024] Open
Abstract
At the cell surface, the actin cytoskeleton and the plasma membrane interact reciprocally in a variety of processes related to the remodeling of the cell surface. The actin cytoskeleton has been known to modulate membrane organization and reshape the membrane. To this end, actin-membrane linking molecules play a major role in regulating actin assembly and spatially direct the interaction between the actin cytoskeleton and the membrane. While studies in cells have provided a wealth of knowledge on the molecular composition and interactions of the actin-membrane interface, the complex molecular interactions make it challenging to elucidate the precise actions of the actin-membrane linkers at the interface. Synthetic reconstituted systems, consisting of model membranes and purified proteins, have been a powerful approach to elucidate how actin-membrane linkers direct actin assembly to drive membrane shape changes. In this review, we will focus only on several actin-membrane linkers that have been studied by using reconstitution systems. We will discuss the design principles of these reconstitution systems and how they have contributed to the understanding of the cellular functions of actin-membrane linkers. Finally, we will provide a perspective on future research directions in understanding the intricate actin-membrane interaction.
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Affiliation(s)
- Feng-Ching Tsai
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Physics of Cells and Cancer, Paris 75005, France.
| | - Gwendal Guérin
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Physics of Cells and Cancer, Paris 75005, France
| | - Julien Pernier
- Tumor Cell Dynamics Unit, Inserm U1279, Gustave Roussy Institute, Université Paris-Saclay, Villejuif 94800, France
| | - Patricia Bassereau
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Physics of Cells and Cancer, Paris 75005, France.
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3
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Li M, Xing X, Yuan J, Zeng Z. Research progress on the regulatory role of cell membrane surface tension in cell behavior. Heliyon 2024; 10:e29923. [PMID: 38720730 PMCID: PMC11076917 DOI: 10.1016/j.heliyon.2024.e29923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024] Open
Abstract
Cell membrane surface tension has emerged as a pivotal biophysical factor governing cell behavior and fate. This review systematically delineates recent advances in techniques for cell membrane surface tension quantification, mechanosensing mechanisms, and regulatory roles of cell membrane surface tension in modulating major cellular processes. Micropipette aspiration, tether pulling, and newly developed fluorescent probes enable the measurement of cell membrane surface tension with spatiotemporal precision. Cells perceive cell membrane surface tension via conduits including mechanosensitive ion channels, curvature-sensing proteins (e.g. BAR domain proteins), and cortex-membrane attachment proteins (e.g. ERM proteins). Through membrane receptors like integrins, cells convert mechanical cues into biochemical signals. This conversion triggers cytoskeletal remodeling and extracellular matrix interactions in response to environmental changes. Elevated cell membrane surface tension suppresses cell spreading, migration, and endocytosis while facilitating exocytosis. Moreover, reduced cell membrane surface tension promotes embryonic stem cell differentiation and cancer cell invasion, underscoring cell membrane surface tension as a regulator of cell plasticity. Outstanding questions remain regarding cell membrane surface tension regulatory mechanisms and roles in tissue development/disease in vivo. Emerging tools to manipulate cell membrane surface tension with high spatiotemporal control in combination with omics approaches will facilitate the elucidation of cell membrane surface tension-mediated effects on signaling networks across various cell types/states. This will accelerate the development of cell membrane surface tension-based biomarkers and therapeutics for regenerative medicine and cancer. Overall, this review provides critical insights into cell membrane surface tension as a potent orchestrator of cell function, with broader impacts across mechanobiology.
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Affiliation(s)
- Manqing Li
- School of Public Health, Sun Yat-sen University, Guangzhou, 5180080, China
| | - Xiumei Xing
- School of Public Health, Sun Yat-sen University, Guangzhou, 5180080, China
| | - Jianhui Yuan
- Nanshan District Center for Disease Control and Prevention, Shenzhen, 518054, China
| | - Zhuoying Zeng
- The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen University, Shenzhen, 518035, China
- Chemical Analysis & Physical Testing Institute, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
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4
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Brauns F, Claussen NH, Lefebvre MF, Wieschaus EF, Shraiman BI. The Geometric Basis of Epithelial Convergent Extension. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.30.542935. [PMID: 37398061 PMCID: PMC10312603 DOI: 10.1101/2023.05.30.542935] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Shape changes of epithelia during animal development, such as convergent extension, are achieved through concerted mechanical activity of individual cells. While much is known about the corresponding large scale tissue flow and its genetic drivers, fundamental questions regarding local control of contractile activity on cellular scale and its embryo-scale coordination remain open. To address these questions, we develop a quantitative, model-based analysis framework to relate cell geometry to local tension in recently obtained timelapse imaging data of gastrulating Drosophila embryos. This analysis provides a systematic decomposition of cell shape changes and T1-rearrangements into internally driven, active, and externally driven, passive, contributions. Our analysis provides evidence that germ band extension is driven by active T1 processes that self-organize through positive feedback acting on tensions. More generally, our findings suggest that epithelial convergent extension results from controlled transformation of internal force balance geometry which combines the effects of bottom-up local self-organization with the top-down, embryo-scale regulation by gene expression.
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Affiliation(s)
- Fridtjof Brauns
- Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Nikolas H. Claussen
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Matthew F. Lefebvre
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Eric F. Wieschaus
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA; The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Boris I. Shraiman
- Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
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5
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Xu M, Rutkowski DM, Rebowski G, Boczkowska M, Pollard LW, Dominguez R, Vavylonis D, Ostap EM. Myosin-I Synergizes with Arp2/3 Complex to Enhance Pushing Forces of Branched Actin Networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579714. [PMID: 38405741 PMCID: PMC10888859 DOI: 10.1101/2024.02.09.579714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Myosin-Is colocalize with Arp2/3 complex-nucleated actin networks at sites of membrane protrusion and invagination, but the mechanisms by which myosin-I motor activity coordinates with branched actin assembly to generate force are unknown. We mimicked the interplay of these proteins using the "comet tail" bead motility assay, where branched actin networks are nucleated by Arp2/3 complex on the surface of beads coated with myosin-I and the WCA domain of N-WASP. We observed that myosin-I increased bead movement efficiency by thinning actin networks without affecting growth rates. Remarkably, myosin-I triggered symmetry breaking and comet-tail formation in dense networks resistant to spontaneous fracturing. Even with arrested actin assembly, myosin-I alone could break the network. Computational modeling recapitulated these observations suggesting myosin-I acts as a repulsive force shaping the network's architecture and boosting its force-generating capacity. We propose that myosin-I leverages its power stroke to amplify the forces generated by Arp2/3 complex-nucleated actin networks.
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Affiliation(s)
- Mengqi Xu
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | | | - Grzegorz Rebowski
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Malgorzata Boczkowska
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Luther W Pollard
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Roberto Dominguez
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | | | - E Michael Ostap
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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6
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Mukadum F, Ccoa WJP, Hocky GM. Molecular simulation approaches to probing the effects of mechanical forces in the actin cytoskeleton. Cytoskeleton (Hoboken) 2024:10.1002/cm.21837. [PMID: 38334204 PMCID: PMC11310368 DOI: 10.1002/cm.21837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024]
Abstract
In this article we give our perspective on the successes and promise of various molecular and coarse-grained simulation approaches to probing the effect of mechanical forces in the actin cytoskeleton.
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Affiliation(s)
- Fatemah Mukadum
- Department of Chemistry, New York University, New York, NY 10003, USA
| | | | - Glen M. Hocky
- Department of Chemistry, New York University, New York, NY 10003, USA
- Simons Center for Computational Physical Chemistry, New York, NY 10003, USA
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7
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Bastianello G, Porcella G, Beznoussenko GV, Kidiyoor G, Ascione F, Li Q, Cattaneo A, Matafora V, Disanza A, Quarto M, Mironov AA, Oldani A, Barozzi S, Bachi A, Costanzo V, Scita G, Foiani M. Cell stretching activates an ATM mechano-transduction pathway that remodels cytoskeleton and chromatin. Cell Rep 2023; 42:113555. [PMID: 38088930 DOI: 10.1016/j.celrep.2023.113555] [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: 06/30/2022] [Revised: 11/01/2023] [Accepted: 11/20/2023] [Indexed: 12/30/2023] Open
Abstract
Ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) DNA damage response (DDR) kinases contain elastic domains. ATM also responds to reactive oxygen species (ROS) and ATR to nuclear mechanical stress. Mre11 mediates ATM activation following DNA damage; ATM mutations cause ataxia telangiectasia (A-T). Here, using in vivo imaging, electron microscopy, proteomic, and mechano-biology approaches, we study how ATM responds to mechanical stress. We report that cytoskeleton and ROS, but not Mre11, mediate ATM activation following cell deformation. ATM deficiency causes hyper-stiffness, stress fiber accumulation, Yes-associated protein (YAP) nuclear enrichment, plasma and nuclear membrane alterations during interstitial migration, and H3 hyper-methylation. ATM locates to the actin cytoskeleton and, following cytoskeleton stress, promotes phosphorylation of key cytoskeleton and chromatin regulators. Our data contribute to explain some clinical features of patients with A-T and pinpoint the existence of an integrated mechano-response in which ATM and ATR have distinct roles unrelated to their canonical DDR functions.
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Affiliation(s)
- Giulia Bastianello
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy; Oncology and Haemato-Oncology Department, University of Milan, 20122 Milan, Italy.
| | | | | | - Gururaj Kidiyoor
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Flora Ascione
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Qingsen Li
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | | | | | - Andrea Disanza
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Micaela Quarto
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | | | - Amanda Oldani
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Sara Barozzi
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Angela Bachi
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy
| | - Vincenzo Costanzo
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy; Oncology and Haemato-Oncology Department, University of Milan, 20122 Milan, Italy
| | - Giorgio Scita
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy; Oncology and Haemato-Oncology Department, University of Milan, 20122 Milan, Italy
| | - Marco Foiani
- IFOM, the FIRC Institute of Molecular Oncology, 20139 Milan, Italy; Oncology and Haemato-Oncology Department, University of Milan, 20122 Milan, Italy.
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8
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Serra M, Serrano Nájera G, Chuai M, Plum AM, Santhosh S, Spandan V, Weijer CJ, Mahadevan L. A mechanochemical model recapitulates distinct vertebrate gastrulation modes. SCIENCE ADVANCES 2023; 9:eadh8152. [PMID: 38055823 PMCID: PMC10699781 DOI: 10.1126/sciadv.adh8152] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 11/06/2023] [Indexed: 12/08/2023]
Abstract
During vertebrate gastrulation, an embryo transforms from a layer of epithelial cells into a multilayered gastrula. This process requires the coordinated movements of hundreds to tens of thousands of cells, depending on the organism. In the chick embryo, patterns of actomyosin cables spanning several cells drive coordinated tissue flows. Here, we derive a minimal theoretical framework that couples actomyosin activity to global tissue flows. Our model predicts the onset and development of gastrulation flows in normal and experimentally perturbed chick embryos, mimicking different gastrulation modes as an active stress instability. Varying initial conditions and a parameter associated with active cell ingression, our model recapitulates distinct vertebrate gastrulation morphologies, consistent with recently published experiments in the chick embryo. Altogether, our results show how changes in the patterning of critical cell behaviors associated with different force-generating mechanisms contribute to distinct vertebrate gastrulation modes via a self-organizing mechanochemical process.
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Affiliation(s)
- Mattia Serra
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Guillermo Serrano Nájera
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Manli Chuai
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Alex M. Plum
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Sreejith Santhosh
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Vamsi Spandan
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Cornelis J. Weijer
- Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - L. Mahadevan
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Departments of Physics, and Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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9
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Pedersen RT, Snoberger A, Pyrpassopoulos S, Safer D, Drubin DG, Ostap EM. Endocytic myosin-1 is a force-insensitive, power-generating motor. J Cell Biol 2023; 222:e202303095. [PMID: 37549220 PMCID: PMC10406613 DOI: 10.1083/jcb.202303095] [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: 03/23/2023] [Revised: 05/17/2023] [Accepted: 07/24/2023] [Indexed: 08/09/2023] Open
Abstract
Myosins are required for clathrin-mediated endocytosis, but their precise molecular roles in this process are not known. This is, in part, because the biophysical properties of the relevant motors have not been investigated. Myosins have diverse mechanochemical activities, ranging from powerful contractility against mechanical loads to force-sensitive anchoring. To better understand the essential molecular contribution of myosin to endocytosis, we studied the in vitro force-dependent kinetics of the Saccharomyces cerevisiae endocytic type I myosin called Myo5, a motor whose role in clathrin-mediated endocytosis has been meticulously studied in vivo. We report that Myo5 is a low-duty-ratio motor that is activated ∼10-fold by phosphorylation and that its working stroke and actin-detachment kinetics are relatively force-insensitive. Strikingly, the in vitro mechanochemistry of Myo5 is more like that of cardiac myosin than that of slow anchoring myosin-1s found on endosomal membranes. We, therefore, propose that Myo5 generates power to augment actin assembly-based forces during endocytosis in cells.
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Affiliation(s)
- Ross T.A. Pedersen
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Aaron Snoberger
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Serapion Pyrpassopoulos
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel Safer
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David G. Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - E. Michael Ostap
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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10
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Báez-Cruz FA, Ostap EM. Drosophila class-I myosins that can impact left-right asymmetry have distinct ATPase kinetics. J Biol Chem 2023; 299:104961. [PMID: 37380077 PMCID: PMC10374968 DOI: 10.1016/j.jbc.2023.104961] [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: 05/08/2023] [Revised: 06/13/2023] [Accepted: 06/20/2023] [Indexed: 06/30/2023] Open
Abstract
Myosin-1D (myo1D) is important for Drosophila left-right asymmetry, and its effects are modulated by myosin-1C (myo1C). De novo expression of these myosins in nonchiral Drosophila tissues promotes cell and tissue chirality, with handedness depending on the paralog expressed. Remarkably, the identity of the motor domain determines the direction of organ chirality, rather than the regulatory or tail domains. Myo1D, but not myo1C, propels actin filaments in leftward circles in in vitro experiments, but it is not known if this property contributes to establishing cell and organ chirality. To further explore if there are differences in the mechanochemistry of these motors, we determined the ATPase mechanisms of myo1C and myo1D. We found that myo1D has a 12.5-fold higher actin-activated steady-state ATPase rate, and transient kinetic experiments revealed myo1D has an 8-fold higher MgADP release rate compared to myo1C. Actin-activated phosphate release is rate limiting for myo1C, whereas MgADP release is the rate-limiting step for myo1D. Notably, both myosins have among the tightest MgADP affinities measured for any myosin. Consistent with ATPase kinetics, myo1D propels actin filaments at higher speeds compared to myo1C in in vitro gliding assays. Finally, we tested the ability of both paralogs to transport 50 nm unilamellar vesicles along immobilized actin filaments and found robust transport by myo1D and actin binding but no transport by myo1C. Our findings support a model where myo1C is a slow transporter with long-lived actin attachments, whereas myo1D has kinetic properties associated with a transport motor.
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Affiliation(s)
- Faviolla A Báez-Cruz
- Department of Physiology, and Center for Engineering Mechanobiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - E Michael Ostap
- Department of Physiology, and Center for Engineering Mechanobiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
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11
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Pedersen RTA, Snoberger A, Pyrpassopoulos S, Safer D, Drubin DG, Ostap EM. Endocytic myosin-1 is a force-insensitive, power-generating motor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.533689. [PMID: 36993306 PMCID: PMC10055380 DOI: 10.1101/2023.03.21.533689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Myosins are required for clathrin-mediated endocytosis, but their precise molecular roles in this process are not known. This is, in part, because the biophysical properties of the relevant motors have not been investigated. Myosins have diverse mechanochemical activities, ranging from powerful contractility against mechanical loads to force-sensitive anchoring. To better understand the essential molecular contribution of myosin to endocytosis, we studied the in vitro force-dependent kinetics of the Saccharomyces cerevisiae endocytic type I myosin called Myo5, a motor whose role in clathrin-mediated endocytosis has been meticulously studied in vivo. We report that Myo5 is a low-duty-ratio motor that is activated ∼10-fold by phosphorylation, and that its working stroke and actin-detachment kinetics are relatively force-insensitive. Strikingly, the in vitro mechanochemistry of Myo5 is more like that of cardiac myosin than like that of slow anchoring myosin-1s found on endosomal membranes. We therefore propose that Myo5 generates power to augment actin assembly-based forces during endocytosis in cells. Summary Pedersen, Snoberger et al. measure the force-sensitivity of the yeast endocytic the myosin-1 called Myo5 and find that it is more likely to generate power than to serve as a force-sensitive anchor in cells. Implications for Myo5's role in clathrin-mediated endocytosis are discussed.
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Affiliation(s)
- Ross TA Pedersen
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
- Present address: Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218
- Equal Contribution
| | - Aaron Snoberger
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
- Equal Contribution
| | - Serapion Pyrpassopoulos
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Daniel Safer
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - E Michael Ostap
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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12
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Clippinger Schulte SR, Scott B, Barrick SK, Stump WT, Blackwell T, Greenberg MJ. Single-molecule mechanics and kinetics of cardiac myosin interacting with regulated thin filaments. Biophys J 2023; 122:2544-2555. [PMID: 37165621 PMCID: PMC10323011 DOI: 10.1016/j.bpj.2023.05.008] [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: 01/10/2023] [Revised: 04/18/2023] [Accepted: 05/05/2023] [Indexed: 05/12/2023] Open
Abstract
The cardiac cycle is a tightly regulated process wherein the heart generates force to pump blood to the body during systole and then relaxes during diastole. Disruption of this finely tuned cycle can lead to a range of diseases including cardiomyopathies and heart failure. Cardiac contraction is driven by the molecular motor myosin, which pulls regulated thin filaments in a calcium-dependent manner. In some muscle and nonmuscle myosins, regulatory proteins on actin tune the kinetics, mechanics, and load dependence of the myosin working stroke; however, it is not well understood whether or how thin-filament regulatory proteins tune the mechanics of the cardiac myosin motor. To address this critical gap in knowledge, we used single-molecule techniques to measure the kinetics and mechanics of the substeps of the cardiac myosin working stroke in the presence and absence of thin filament regulatory proteins. We found that regulatory proteins gate the calcium-dependent interactions between myosin and the thin filament. At physiologically relevant ATP concentrations, cardiac myosin's mechanics and unloaded kinetics are not affected by thin-filament regulatory proteins. We also measured the load-dependent kinetics of cardiac myosin at physiologically relevant ATP concentrations using an isometric optical clamp, and we found that thin-filament regulatory proteins do not affect either the identity or magnitude of myosin's primary load-dependent transition. Interestingly, at low ATP concentrations at both saturating and physiologically relevant subsaturating calcium concentrations, thin-filament regulatory proteins have a small effect on actomyosin dissociation kinetics, suggesting a mechanism beyond simple steric blocking. These results have important implications for the modeling of cardiac physiology and diseases.
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Affiliation(s)
- Sarah R Clippinger Schulte
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri
| | - Brent Scott
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri
| | - Samantha K Barrick
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri
| | - W Tom Stump
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri
| | - Thomas Blackwell
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri
| | - Michael J Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri.
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13
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Lee LA, Barrick SK, Buvoli AE, Walklate J, Stump WT, Geeves M, Greenberg MJ, Leinwand LA. Distinct effects of two hearing loss-associated mutations in the sarcomeric myosin MYH7b. J Biol Chem 2023; 299:104631. [PMID: 36963494 PMCID: PMC10141508 DOI: 10.1016/j.jbc.2023.104631] [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: 11/07/2022] [Revised: 03/08/2023] [Accepted: 03/17/2023] [Indexed: 03/26/2023] Open
Abstract
For decades, sarcomeric myosin heavy chain proteins were assumed to be restricted to striated muscle where they function as molecular motors that contract muscle. However, MYH7b, an evolutionarily ancient member of this myosin family, has been detected in mammalian nonmuscle tissues, and mutations in MYH7b are linked to hereditary hearing loss in compound heterozygous patients. These mutations are the first associated with hearing loss rather than a muscle pathology, and because there are no homologous mutations in other myosin isoforms, their functional effects were unknown. We generated recombinant human MYH7b harboring the D515N or R1651Q hearing loss-associated mutation and studied their effects on motor activity and structural and assembly properties, respectively. The D515N mutation had no effect on steady-state actin-activated ATPase rate or load-dependent detachment kinetics but increased actin sliding velocity because of an increased displacement during the myosin working stroke. Furthermore, we found that the D515N mutation caused an increase in the proportion of myosin heads that occupy the disordered-relaxed state, meaning more myosin heads are available to interact with actin. Although we found no impact of the R1651Q mutation on myosin rod secondary structure or solubility, we observed a striking aggregation phenotype when this mutation was introduced into nonmuscle cells. Our results suggest that each mutation independently affects MYH7b function and structure. Together, these results provide the foundation for further study of a role for MYH7b outside the sarcomere.
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Affiliation(s)
- Lindsey A Lee
- Molecular, Cellular, and Developmental Biology Department, Boulder, Colorado, USA; BioFrontiers Institute, Boulder, Colorado, USA
| | - Samantha K Barrick
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Ada E Buvoli
- Molecular, Cellular, and Developmental Biology Department, Boulder, Colorado, USA; BioFrontiers Institute, Boulder, Colorado, USA
| | - Jonathan Walklate
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - W Tom Stump
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Michael Geeves
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Michael J Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Leslie A Leinwand
- Molecular, Cellular, and Developmental Biology Department, Boulder, Colorado, USA; BioFrontiers Institute, Boulder, Colorado, USA.
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14
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Ruiz-Franco J, Tauber J, van der Gucht J. Cross-linker Mobility Governs Fracture Behavior of Catch-Bonded Networks. PHYSICAL REVIEW LETTERS 2023; 130:118203. [PMID: 37001087 DOI: 10.1103/physrevlett.130.118203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/24/2023] [Indexed: 06/19/2023]
Abstract
While most chemical bonds weaken under the action of mechanical force (called slip bond behavior), nature has developed bonds that do the opposite: their lifetime increases as force is applied. While such catch bonds have been studied quite extensively at the single molecule level and in adhesive contacts, recent work has shown that they are also abundantly present as crosslinkers in the actin cytoskeleton. However, their role and the mechanism by which they operate in these networks have remained unclear. Here, we present computer simulations that show how polymer networks crosslinked with either slip or catch bonds respond to mechanical stress. Our results reveal that catch bonding may be required to protect dynamic networks against fracture, in particular for mobile linkers that can diffuse freely after unbinding. While mobile slip bonds lead to networks that are very weak at high stresses, mobile catch bonds accumulate in high stress regions and thereby stabilize cracks, leading to a more ductile fracture behavior. This allows cells to combine structural adaptivity at low stresses with mechanical stability at high stresses.
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Affiliation(s)
- José Ruiz-Franco
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708WE Wageningen, Netherlands
| | - Justin Tauber
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708WE Wageningen, Netherlands
| | - Jasper van der Gucht
- Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708WE Wageningen, Netherlands
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15
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Clippinger Schulte SR, Scott B, Barrick SK, Stump WT, Blackwell T, Greenberg MJ. Single Molecule Mechanics and Kinetics of Cardiac Myosin Interacting with Regulated Thin Filaments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.09.522880. [PMID: 36711892 PMCID: PMC9881944 DOI: 10.1101/2023.01.09.522880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The cardiac cycle is a tightly regulated process wherein the heart generates force to pump blood to the body during systole and then relaxes during diastole. Disruption of this finely tuned cycle can lead to a range of diseases including cardiomyopathies and heart failure. Cardiac contraction is driven by the molecular motor myosin, which pulls regulated thin filaments in a calcium-dependent manner. In some muscle and non-muscle myosins, regulatory proteins on actin tune the kinetics, mechanics, and load dependence of the myosin working stroke; however, it is not well understood whether or how thin filament regulatory proteins tune the mechanics of the cardiac myosin motor. To address this critical gap in knowledge, we used single-molecule techniques to measure the kinetics and mechanics of the substeps of the cardiac myosin working stroke in the presence and absence of thin filament regulatory proteins. We found that regulatory proteins gate the calcium-dependent interactions between myosin and the thin filament. At physiologically relevant ATP concentrations, cardiac myosin's mechanics and unloaded kinetics are not affected by thin filament regulatory proteins. We also measured the load-dependent kinetics of cardiac myosin at physiologically relevant ATP concentrations using an isometric optical clamp, and we found that thin filament regulatory proteins do not affect either the identity or magnitude of myosin's primary load-dependent transition. Interestingly, at low ATP concentrations, thin filament regulatory proteins have a small effect on actomyosin dissociation kinetics, suggesting a mechanism beyond simple steric blocking. These results have important implications for both disease modeling and computational models of muscle contraction. Significance Statement Human heart contraction is powered by the molecular motor β-cardiac myosin, which pulls on thin filaments consisting of actin and the regulatory proteins troponin and tropomyosin. In some muscle and non-muscle systems, these regulatory proteins tune the kinetics, mechanics, and load dependence of the myosin working stroke. Despite having a central role in health and disease, it is not well understood whether the mechanics or kinetics of β-cardiac myosin are affected by regulatory proteins. We show that regulatory proteins do not affect the mechanics or load-dependent kinetics of the working stroke at physiologically relevant ATP concentrations; however, they can affect the kinetics at low ATP concentrations, suggesting a mechanism beyond simple steric blocking. This has important implications for modeling of cardiac physiology and diseases.
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16
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Lee LA, Barrick SK, Meller A, Walklate J, Lotthammer JM, Tay JW, Stump WT, Bowman G, Geeves MA, Greenberg MJ, Leinwand LA. Functional divergence of the sarcomeric myosin, MYH7b, supports species-specific biological roles. J Biol Chem 2022; 299:102657. [PMID: 36334627 PMCID: PMC9800208 DOI: 10.1016/j.jbc.2022.102657] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/14/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
Myosin heavy chain 7b (MYH7b) is an evolutionarily ancient member of the sarcomeric myosin family, which typically supports striated muscle function. However, in mammals, alternative splicing prevents MYH7b protein production in cardiac and most skeletal muscles and limits expression to a subset of specialized muscles and certain nonmuscle environments. In contrast, MYH7b protein is abundant in python cardiac and skeletal muscles. Although the MYH7b expression pattern diverges in mammals versus reptiles, MYH7b shares high sequence identity across species. So, it remains unclear how mammalian MYH7b function may differ from that of other sarcomeric myosins and whether human and python MYH7b motor functions diverge as their expression patterns suggest. Thus, we generated recombinant human and python MYH7b protein and measured their motor properties to investigate any species-specific differences in activity. Our results reveal that despite having similar working strokes, the MYH7b isoforms have slower actin-activated ATPase cycles and actin sliding velocities than human cardiac β-MyHC. Furthermore, python MYH7b is tuned to have slower motor activity than human MYH7b because of slower kinetics of the chemomechanical cycle. We found that the MYH7b isoforms adopt a higher proportion of myosin heads in the ultraslow, super-relaxed state compared with human cardiac β-MyHC. These findings are supported by molecular dynamics simulations that predict MYH7b preferentially occupies myosin active site conformations similar to those observed in the structurally inactive state. Together, these results suggest that MYH7b is specialized for slow and energy-conserving motor activity and that differential tuning of MYH7b orthologs contributes to species-specific biological roles.
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Affiliation(s)
- Lindsey A. Lee
- Molecular, Cellular, and Developmental Biology Department, Boulder, Colorado, USA,BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - Samantha K. Barrick
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Artur Meller
- The Center for Science and Engineering of Living Systems, Washington University in St Louis, St Louis, Missouri, USA
| | - Jonathan Walklate
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Jeffrey M. Lotthammer
- The Center for Science and Engineering of Living Systems, Washington University in St Louis, St Louis, Missouri, USA
| | - Jian Wei Tay
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA
| | - W. Tom Stump
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Gregory Bowman
- The Center for Science and Engineering of Living Systems, Washington University in St Louis, St Louis, Missouri, USA,Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michael A. Geeves
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Michael J. Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, Missouri, USA
| | - Leslie A. Leinwand
- Molecular, Cellular, and Developmental Biology Department, Boulder, Colorado, USA,BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, USA,For correspondence: Leslie A. Leinwand
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17
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Gong R, Jiang F, Moreland ZG, Reynolds MJ, de los Reyes SE, Gurel P, Shams A, Heidings JB, Bowl MR, Bird JE, Alushin GM. Structural basis for tunable control of actin dynamics by myosin-15 in mechanosensory stereocilia. SCIENCE ADVANCES 2022; 8:eabl4733. [PMID: 35857845 PMCID: PMC9299544 DOI: 10.1126/sciadv.abl4733] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 06/03/2022] [Indexed: 05/12/2023]
Abstract
The motor protein myosin-15 is necessary for the development and maintenance of mechanosensory stereocilia, and mutations in myosin-15 cause hereditary deafness. In addition to transporting actin regulatory machinery to stereocilia tips, myosin-15 directly nucleates actin filament ("F-actin") assembly, which is disrupted by a progressive hearing loss mutation (p.D1647G, "jordan"). Here, we present cryo-electron microscopy structures of myosin-15 bound to F-actin, providing a framework for interpreting the impacts of deafness mutations on motor activity and actin nucleation. Rigor myosin-15 evokes conformational changes in F-actin yet maintains flexibility in actin's D-loop, which mediates inter-subunit contacts, while the jordan mutant locks the D-loop in a single conformation. Adenosine diphosphate-bound myosin-15 also locks the D-loop, which correspondingly blunts actin-polymerization stimulation. We propose myosin-15 enhances polymerization by bridging actin protomers, regulating nucleation efficiency by modulating actin's structural plasticity in a myosin nucleotide state-dependent manner. This tunable regulation of actin polymerization could be harnessed to precisely control stereocilium height.
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Affiliation(s)
- Rui Gong
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Fangfang Jiang
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Zane G. Moreland
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Matthew J. Reynolds
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | | | - Pinar Gurel
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Arik Shams
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - James B. Heidings
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Michael R. Bowl
- Mammalian Genetics Unit, MRC Harwell Institute, Harwell Campus, Oxfordshire, UK
- UCL Ear Institute, University College London, London, UK
| | - Jonathan E. Bird
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Gregory M. Alushin
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
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18
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Goligorsky MS. OSCILLATORS IN THE MICROVASCULATURE - GLYCOCALYX AND BEYOND. Am J Physiol Cell Physiol 2022; 323:C432-C438. [PMID: 35759436 PMCID: PMC9359649 DOI: 10.1152/ajpcell.00170.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The growing recognition of abundance of oscillating functions in biological systems has motivated this brief overview which narrows down on the microvasculature. Specifically, it encompasses self-sustained oscillations of blood flow, hematocrit and viscosity at bifurcations; their effects on the oscillations of endothelial glycocalyx, mechanotransduction and its termination to prime endothelial cells for the subsequent mechanical signaling event; oscillating affinity of hyaluronan-CD44 binding domain; spontaneous contractility of actomyosin complexes in the cortical actin web, its effects on the tension of the plasma membrane; reversible effects of sirtuin-1 on endothelial glycocalyx; and effects of plasma membrane tension on endo-and exocytosis. Some potential interactions between those oscillators - their coupling - are discussed together with their transition into chaotic movements. Future in-depth understanding of the oscillatory activities in the microvasculature could serve as a guide to its chronotherapy under pathological conditions.
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Affiliation(s)
- Michael S Goligorsky
- Renal Research Institute and Departments of Medicine, Pharmacology and Physiology, New York Medical College at the Touro University, Valhalla, NY
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19
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Li TD, Bieling P, Weichsel J, Mullins RD, Fletcher DA. The molecular mechanism of load adaptation by branched actin networks. eLife 2022; 11:e73145. [PMID: 35748355 PMCID: PMC9328761 DOI: 10.7554/elife.73145] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Branched actin networks are self-assembling molecular motors that move biological membranes and drive many important cellular processes, including phagocytosis, endocytosis, and pseudopod protrusion. When confronted with opposing forces, the growth rate of these networks slows and their density increases, but the stoichiometry of key components does not change. The molecular mechanisms governing this force response are not well understood, so we used single-molecule imaging and AFM cantilever deflection to measure how applied forces affect each step in branched actin network assembly. Although load forces are observed to increase the density of growing filaments, we find that they actually decrease the rate of filament nucleation due to inhibitory interactions between actin filament ends and nucleation promoting factors. The force-induced increase in network density turns out to result from an exponential drop in the rate constant that governs filament capping. The force dependence of filament capping matches that of filament elongation and can be explained by expanding Brownian Ratchet theory to cover both processes. We tested a key prediction of this expanded theory by measuring the force-dependent activity of engineered capping protein variants and found that increasing the size of the capping protein increases its sensitivity to applied forces. In summary, we find that Brownian Ratchets underlie not only the ability of growing actin filaments to generate force but also the ability of branched actin networks to adapt their architecture to changing loads.
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Affiliation(s)
- Tai-De Li
- Department of Bioengineering & Biophysics Program, University of California, BerkeleyBerkeleyUnited States
- Division of Biological Systems & Engineering, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Advanced Science Research Center, City University of New YorkNew YorkUnited States
| | - Peter Bieling
- Division of Biological Systems & Engineering, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San FranciscoSan FranciscoUnited States
- Department of Systemic Cell Biology, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - Julian Weichsel
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San FranciscoSan FranciscoUnited States
| | - Daniel A Fletcher
- Department of Bioengineering & Biophysics Program, University of California, BerkeleyBerkeleyUnited States
- Division of Biological Systems & Engineering, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
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20
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Tripathy SK, Demidov VM, Gonchar IV, Wu S, Ataullakhanov FI, Grishchuk EL. Ultrafast Force-Clamp Spectroscopy of Microtubule-Binding Proteins. Methods Mol Biol 2022; 2478:609-650. [PMID: 36063336 PMCID: PMC9662813 DOI: 10.1007/978-1-0716-2229-2_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Optical trapping has been instrumental for deciphering translocation mechanisms of the force-generating cytoskeletal proteins. However, studies of the dynamic interactions between microtubules (MTs) and MT-associated proteins (MAPs) with no motor activity are lagging. Investigating the motility of MAPs that can diffuse along MT walls is a particular challenge for optical-trapping assays because thermally driven motions rely on weak and highly transient interactions. Three-bead, ultrafast force-clamp (UFFC) spectroscopy has the potential to resolve static and diffusive translocations of different MAPs with sub-millisecond temporal resolution and sub-nanometer spatial precision. In this report, we present detailed procedures for implementing UFFC, including setup of the optical instrument and feedback control, immobilization and functionalization of pedestal beads, and preparation of MT dumbbells. Example results for strong static interactions were generated using the Kinesin-7 motor CENP-E in the presence of AMP-PNP. Time resolution for MAP-MT interactions in the UFFC assay is limited by the MT dumbbell relaxation time, which is significantly longer than reported for analogous experiments using actin filaments. UFFC, however, provides a unique opportunity for quantitative studies on MAPs that glide along MTs under a dragging force, as illustrated using the kinetochore-associated Ska complex.
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Affiliation(s)
- Suvranta K Tripathy
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
| | - Vladimir M Demidov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ivan V Gonchar
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Shaowen Wu
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Fazly I Ataullakhanov
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Ekaterina L Grishchuk
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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21
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Actomyosin Complex. Subcell Biochem 2022; 99:421-470. [PMID: 36151385 PMCID: PMC9710302 DOI: 10.1007/978-3-031-00793-4_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Formation of cross-bridges between actin and myosin occurs ubiquitously in eukaryotic cells and mediates muscle contraction, intracellular cargo transport, and cytoskeletal remodeling. Myosin motors repeatedly bind to and dissociate from actin filaments in a cycle that transduces the chemical energy from ATP hydrolysis into mechanical force generation. While the general layout of surface elements within the actin-binding interface is conserved among myosin classes, sequence divergence within these motifs alters the specific contacts involved in the actomyosin interaction as well as the kinetics of mechanochemical cycle phases. Additionally, diverse lever arm structures influence the motility and force production of myosin molecules during their actin interactions. The structural differences generated by myosin's molecular evolution have fine-tuned the kinetics of its isoforms and adapted them for their individual cellular roles. In this chapter, we will characterize the structural and biochemical basis of the actin-myosin interaction and explain its relationship with myosin's cellular roles, with emphasis on the structural variation among myosin isoforms that enables their functional specialization. We will also discuss the impact of accessory proteins, such as the troponin-tropomyosin complex and myosin-binding protein C, on the formation and regulation of actomyosin cross-bridges.
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22
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Pospich S, Sweeney HL, Houdusse A, Raunser S. High-resolution structures of the actomyosin-V complex in three nucleotide states provide insights into the force generation mechanism. eLife 2021; 10:e73724. [PMID: 34812732 PMCID: PMC8735999 DOI: 10.7554/elife.73724] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/22/2021] [Indexed: 11/13/2022] Open
Abstract
The molecular motor myosin undergoes a series of major structural transitions during its force-producing motor cycle. The underlying mechanism and its coupling to ATP hydrolysis and actin binding are only partially understood, mostly due to sparse structural data on actin-bound states of myosin. Here, we report 26 high-resolution cryo-EM structures of the actomyosin-V complex in the strong-ADP, rigor, and a previously unseen post-rigor transition state that binds the ATP analog AppNHp. The structures reveal a high flexibility of myosin in each state and provide valuable insights into the structural transitions of myosin-V upon ADP release and binding of AppNHp, as well as the actomyosin interface. In addition, they show how myosin is able to specifically alter the structure of F-actin.
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Affiliation(s)
- Sabrina Pospich
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - H Lee Sweeney
- Department of Pharmacology and Therapeutics and the Myology Institute, University of FloridaGainesvilleUnited States
| | - Anne Houdusse
- Structural Motility, Institut Curie, Centre National de la Recherche ScientifiqueParisFrance
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular PhysiologyDortmundGermany
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23
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Fowell DJ, Kim M. The spatio-temporal control of effector T cell migration. Nat Rev Immunol 2021; 21:582-596. [PMID: 33627851 PMCID: PMC9380693 DOI: 10.1038/s41577-021-00507-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2021] [Indexed: 02/08/2023]
Abstract
Effector T cells leave the lymph nodes armed with specialized functional attributes. Their antigenic targets may be located anywhere in the body, posing the ultimate challenge: how to efficiently identify the target tissue, navigate through a complex tissue matrix and, ultimately, locate the immunological insult. Recent advances in real-time in situ imaging of effector T cell migratory behaviour have revealed a great degree of mechanistic plasticity that enables effector T cells to push and squeeze their way through inflamed tissues. This process is shaped by an array of 'stop' and 'go' guidance signals including target antigens, chemokines, integrin ligands and the mechanical cues of the inflamed microenvironment. Effector T cells must sense and interpret these competing signals to correctly position themselves to mediate their effector functions for complete and durable responses in infectious disease and malignancy. Tuning T cell migration therapeutically will require a new understanding of this complex decision-making process.
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Affiliation(s)
- Deborah J. Fowell
- David H. Smith Center for Vaccine Biology and Immunology, Aab Institute for Biomedical Sciences, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY.,Department of Microbiology and Immunology, Cornell University, Ithaca, NY
| | - Minsoo Kim
- David H. Smith Center for Vaccine Biology and Immunology, Aab Institute for Biomedical Sciences, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY
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24
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Inman A, Smutny M. Feeling the force: Multiscale force sensing and transduction at the cell-cell interface. Semin Cell Dev Biol 2021; 120:53-65. [PMID: 34238674 DOI: 10.1016/j.semcdb.2021.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/11/2021] [Accepted: 06/13/2021] [Indexed: 12/13/2022]
Abstract
A universal principle of all living cells is the ability to sense and respond to mechanical stimuli which is essential for many biological processes. Recent efforts have identified critical mechanosensitive molecules and response pathways involved in mechanotransduction during development and tissue homeostasis. Tissue-wide force transmission and local force sensing need to be spatiotemporally coordinated to precisely regulate essential processes during development such as tissue morphogenesis, patterning, cell migration and organogenesis. Understanding how cells identify and interpret extrinsic forces and integrate a specific response on cell and tissue level remains a major challenge. In this review we consider important cellular and physical factors in control of cell-cell mechanotransduction and discuss their significance for cell and developmental processes. We further highlight mechanosensitive macromolecules that are known to respond to external forces and present examples of how force responses can be integrated into cell and developmental programs.
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Affiliation(s)
- Angus Inman
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV47AL, UK
| | - Michael Smutny
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV47AL, UK.
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25
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Tokuo H, Komaba S, Coluccio LM. In pancreatic β-cells myosin 1b regulates glucose-stimulated insulin secretion by modulating an early step in insulin granule trafficking from the Golgi. Mol Biol Cell 2021; 32:1210-1220. [PMID: 33826361 PMCID: PMC8351557 DOI: 10.1091/mbc.e21-03-0094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pancreatic β-cells secrete insulin, which controls blood glucose levels, and defects in insulin secretion are responsible for diabetes mellitus. The actin cytoskeleton and some myosins support insulin granule trafficking and release, although a role for the class I myosin Myo1b, an actin- and membrane-associated load-sensitive motor, in insulin biology is unknown. We found by immunohistochemistry that Myo1b is expressed in islet cells of the rat pancreas. In cultured rat insulinoma 832/13 cells, Myo1b localized near actin patches, the trans-Golgi network (TGN) marker TGN38, and insulin granules in the perinuclear region. Myo1b depletion by small interfering RNA in 832/13 cells reduced intracellular proinsulin and insulin content and glucose-stimulated insulin secretion (GSIS) and led to the accumulation of (pro)insulin secretory granules (SGs) at the TGN. Using an in situ fluorescent pulse-chase strategy to track nascent proinsulin, Myo1b depletion in insulinoma cells reduced the number of (pro)insulin-containing SGs budding from the TGN. The studies indicate for the first time that in pancreatic β-cells Myo1b controls GSIS at least in part by mediating an early stage in insulin granule trafficking from the TGN.
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Affiliation(s)
- Hiroshi Tokuo
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118-2518
| | - Shigeru Komaba
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118-2518
| | - Lynne M Coluccio
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118-2518
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Tabatabai AP, Seara DS, Tibbs J, Yadav V, Linsmeier I, Murrell MP. Detailed Balance Broken by Catch Bond Kinetics Enables Mechanical-Adaptation in Active Materials. ADVANCED FUNCTIONAL MATERIALS 2021; 31:2006745. [PMID: 34393691 PMCID: PMC8357268 DOI: 10.1002/adfm.202006745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Indexed: 05/04/2023]
Abstract
Unlike nearly all engineered materials which contain bonds that weaken under load, biological materials contain "catch" bonds which are reinforced under load. Consequently, materials, such as the cell cytoskeleton, can adapt their mechanical properties in response to their state of internal, non-equilibrium (active) stress. However, how large-scale material properties vary with the distance from equilibrium is unknown, as are the relative roles of active stress and binding kinetics in establishing this distance. Through course-grained molecular dynamics simulations, the effect of breaking of detailed balance by catch bonds on the accumulation and dissipation of energy within a model of the actomyosin cytoskeleton is explored. It is found that the extent to which detailed balance is broken uniquely determines a large-scale fluid-solid transition with characteristic time-reversal symmetries. The transition depends critically on the strength of the catch bond, suggesting that active stress is necessary but insufficient to mount an adaptive mechanical response.
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Affiliation(s)
- Alan Pasha Tabatabai
- Department of Biomedical Engineering, Yale University, 55 Prospect Street, New Haven, CT 06511, USA; Systems Biology Institute, Yale University, 850 West Campus Drive, West Haven, CT 06516, USA
| | - Daniel S Seara
- Systems Biology Institute, Yale University, 850 West Campus Drive, West Haven, CT 06516, USA; Department of Physics, Yale University, 217 Prospect Street, New Haven, CT 06511, USA
| | - Joseph Tibbs
- Department of Physics, University of Northern Iowa, Cedar Falls, IA 50614, USA
| | - Vikrant Yadav
- Department of Biomedical Engineering, Yale University, 55 Prospect Street, New Haven, CT 06511, USA; Systems Biology Institute, Yale University, 850 West Campus Drive, West Haven, CT 06516, USA
| | - Ian Linsmeier
- Department of Biomedical Engineering, Yale University, 55 Prospect Street, New Haven, CT 06511, USA; Systems Biology Institute, Yale University, 850 West Campus Drive, West Haven, CT 06516, USA
| | - Michael P Murrell
- Department of Biomedical Engineering, Yale University, 55 Prospect Street, New Haven, CT 06511, USA; Systems Biology Institute, Yale University, 850 West Campus Drive, West Haven, CT 06516, USA; Department of Physics, Yale University, 217 Prospect Street, New Haven, CT 06511, USA
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27
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Cirilo JA, Gunther LK, Yengo CM. Functional Role of Class III Myosins in Hair Cells. Front Cell Dev Biol 2021; 9:643856. [PMID: 33718386 PMCID: PMC7947357 DOI: 10.3389/fcell.2021.643856] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 11/14/2022] Open
Abstract
Cytoskeletal motors produce force and motion using the energy from ATP hydrolysis and function in a variety of mechanical roles in cells including muscle contraction, cargo transport, and cell division. Actin-based myosin motors have been shown to play crucial roles in the development and function of the stereocilia of auditory and vestibular inner ear hair cells. Hair cells can contain hundreds of stereocilia, which rely on myosin motors to elongate, organize, and stabilize their structure. Mutations in many stereocilia-associated myosins have been shown to cause hearing loss in both humans and animal models suggesting that each myosin isoform has a specific function in these unique parallel actin bundle-based protrusions. Here we review what is known about the classes of myosins that function in the stereocilia, with a special focus on class III myosins that harbor point mutations associated with delayed onset hearing loss. Much has been learned about the role of the two class III myosin isoforms, MYO3A and MYO3B, in maintaining the precise stereocilia lengths required for normal hearing. We propose a model for how class III myosins play a key role in regulating stereocilia lengths and demonstrate how their motor and regulatory properties are particularly well suited for this function. We conclude that ongoing studies on class III myosins and other stereocilia-associated myosins are extremely important and may lead to novel therapeutic strategies for the treatment of hearing loss due to stereocilia degeneration.
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Affiliation(s)
- Joseph A Cirilo
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, United States
| | - Laura K Gunther
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, United States
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, College of Medicine, Pennsylvania State University, Hershey, PA, United States
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28
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Jiang F, Takagi Y, Shams A, Heissler SM, Friedman TB, Sellers JR, Bird JE. The ATPase mechanism of myosin 15, the molecular motor mutated in DFNB3 human deafness. J Biol Chem 2021; 296:100243. [PMID: 33372036 PMCID: PMC7948958 DOI: 10.1074/jbc.ra120.014903] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 11/18/2022] Open
Abstract
Cochlear hair cells each possess an exquisite bundle of actin-based stereocilia that detect sound. Unconventional myosin 15 (MYO15) traffics and delivers critical molecules required for stereocilia development and thus is essential for building the mechanosensory hair bundle. Mutations in the human MYO15A gene interfere with stereocilia trafficking and cause hereditary hearing loss, DFNB3, but the impact of these mutations is not known, as MYO15 itself is poorly characterized. To learn more, we performed a kinetic study of the ATPase motor domain to characterize its mechanochemical cycle. Using the baculovirus-Sf9 system, we purified a recombinant minimal motor domain (S1) by coexpressing the mouse MYO15 ATPase, essential and regulatory light chains that bind its IQ domains, and UNC45 and HSP90A chaperones required for correct folding of the ATPase. MYO15 purified with either UNC45A or UNC45B coexpression had similar ATPase activities (kcat = ∼ 6 s-1 at 20 °C). Using stopped-flow and quenched-flow transient kinetic analyses, we measured the major rate constants describing the ATPase cycle, including ATP, ADP, and actin binding; hydrolysis; and phosphate release. Actin-attached ADP release was the slowest measured transition (∼12 s-1 at 20 °C), although this did not rate-limit the ATPase cycle. The kinetic analysis shows the MYO15 motor domain has a moderate duty ratio (∼0.5) and weak thermodynamic coupling between ADP and actin binding. These findings are consistent with MYO15 being kinetically adapted for processive motility when oligomerized. Our kinetic characterization enables future studies into how deafness-causing mutations affect MYO15 and disrupt stereocilia trafficking necessary for hearing.
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Affiliation(s)
- Fangfang Jiang
- Department of Pharmacology and Therapeutics, and the Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Arik Shams
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - Sarah M Heissler
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, USA
| | - James R Sellers
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jonathan E Bird
- Department of Pharmacology and Therapeutics, and the Myology Institute, University of Florida College of Medicine, Gainesville, Florida, USA.
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29
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Computational Tool for Ensemble Averaging of Single-Molecule Data. Biophys J 2020; 120:10-20. [PMID: 33248132 DOI: 10.1016/j.bpj.2020.10.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 11/22/2022] Open
Abstract
Molecular motors couple chemical transitions to conformational changes that perform mechanical work in a wide variety of biological processes. Disruption of this coupling can lead to diseases, and therefore there is a need to accurately measure mechanochemical coupling in motors in both health and disease. Optical tweezers with nanometer spatial and millisecond temporal resolution have provided valuable insights into these processes. However, fluctuations due to Brownian motion can make it difficult to precisely resolve these conformational changes. One powerful analysis technique that has improved our ability to accurately measure mechanochemical coupling in motor proteins is ensemble averaging of individual trajectories. Here, we present a user-friendly computational tool, Software for Precise Analysis of Single Molecules (SPASM), for generating ensemble averages of single-molecule data. This tool utilizes several conceptual advances, including optimized procedures for identifying single-molecule interactions and the implementation of a change-point algorithm, to more precisely resolve molecular transitions. Using both simulated and experimental data, we demonstrate that these advances allow for accurate determination of the mechanics and kinetics of the myosin working stroke with a smaller set of data. Importantly, we provide our open-source MATLAB-based program with a graphical user interface that enables others to readily apply these advances to the analysis of their own data.
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Abstract
Myosins constitute a superfamily of actin-based molecular motor proteins that mediates a variety of cellular activities including muscle contraction, cell migration, intracellular transport, the formation of membrane projections, cell adhesion, and cell signaling. The 12 myosin classes that are expressed in humans share sequence similarities especially in the N-terminal motor domain; however, their enzymatic activities, regulation, ability to dimerize, binding partners, and cellular functions differ. It is becoming increasingly apparent that defects in myosins are associated with diseases including cardiomyopathies, colitis, glomerulosclerosis, neurological defects, cancer, blindness, and deafness. Here, we review the current state of knowledge regarding myosins and disease.
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31
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Abstract
Directed movements on actin filaments within the cell are powered by molecular motors of the myosin superfamily. On actin filaments, myosin motors convert the energy from ATP into force and movement. Myosin motors power such diverse cellular functions as cytokinesis, membrane trafficking, organelle movements, and cellular migration. Myosin generates force and movement via a number of structural changes associated with hydrolysis of ATP, binding to actin, and release of the ATP hydrolysis products while bound to actin. Herein we provide an overview of those structural changes and how they relate to the actin-myosin ATPase cycle. These structural changes are the basis of chemo-mechanical transduction by myosin motors.
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32
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Single-Molecule Biophysical Techniques to Study Actomyosin Force Transduction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020. [PMID: 32451857 DOI: 10.1007/978-3-030-38062-5_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Inside the cellular environment, molecular motors can work in concert to conduct a variety of important physiological functions and processes that are vital for the survival of a cell. However, in order to decipher the mechanism of how these molecular motors work, single-molecule microscopy techniques have been popular methods to understand the molecular basis of the emerging ensemble behavior of these motor proteins.In this chapter, we discuss various single-molecule biophysical imaging techniques that have been used to expose the mechanics and kinetics of myosins. The chapter should be taken as a general overview and introductory guide to the many existing techniques; however, since other chapters will discuss some of these techniques more thoroughly, the readership should refer to those chapters for further details and discussions. In particular, we will focus on scattering-based single-molecule microscopy methods, some of which have become more popular in the recent years and around which the work in our laboratories has been centered.
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Chabaud M, Paillon N, Gaus K, Hivroz C. Mechanobiology of antigen‐induced T cell arrest. Biol Cell 2020; 112:196-212. [DOI: 10.1111/boc.201900093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/19/2020] [Accepted: 03/29/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Mélanie Chabaud
- Institut Curie‐PSL Research University INSERM U932 Paris France
- EMBL Australia Node in Single Molecule Science, School of Medical SciencesUniversity of New South Wales Sydney NSW Australia
- ARC Centre of Excellence in Advanced Molecular ImagingUniversity of New South Wales Sydney NSW Australia
| | - Noémie Paillon
- Institut Curie‐PSL Research University INSERM U932 Paris France
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical SciencesUniversity of New South Wales Sydney NSW Australia
- ARC Centre of Excellence in Advanced Molecular ImagingUniversity of New South Wales Sydney NSW Australia
| | - Claire Hivroz
- Institut Curie‐PSL Research University INSERM U932 Paris France
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34
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Linari M, Piazzesi G, Pertici I, Dantzig JA, Goldman YE, Lombardi V. Straightening Out the Elasticity of Myosin Cross-Bridges. Biophys J 2020; 118:994-1002. [PMID: 31968230 PMCID: PMC7063436 DOI: 10.1016/j.bpj.2020.01.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/21/2019] [Accepted: 01/06/2020] [Indexed: 11/30/2022] Open
Abstract
In a contracting muscle, myosin cross-bridges extending from thick filaments pull the interdigitating thin (actin-containing) filaments during cyclical ATP-driven interactions toward the center of the sarcomere, the structural unit of striated muscle. Cross-bridge attachments in the sarcomere have been reported to exhibit a similar stiffness under both positive and negative forces. However, in vitro measurements on filaments with a sparse complement of heads detected a decrease of the cross-bridge stiffness at negative forces attributed to the buckling of the subfragment 2 tail portion. Here, we review some old and new data that confirm that cross-bridge stiffness is nearly linear in the muscle filament lattice. The implications of high myosin stiffness at positive and negative strains are considered in muscle fibers and in nonmuscle intracellular cargo transport.
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Affiliation(s)
- Marco Linari
- PhysioLab, Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Gabriella Piazzesi
- PhysioLab, Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Irene Pertici
- PhysioLab, Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Jody A Dantzig
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yale E Goldman
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Vincenzo Lombardi
- PhysioLab, Department of Biology, University of Florence, Sesto Fiorentino, Italy.
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35
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Katoh K. FAK-Dependent Cell Motility and Cell Elongation. Cells 2020; 9:cells9010192. [PMID: 31940873 PMCID: PMC7017285 DOI: 10.3390/cells9010192] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/02/2020] [Accepted: 01/08/2020] [Indexed: 12/20/2022] Open
Abstract
Fibroblastic cells show specific substrate selectivity for typical cell–substrate adhesion. However, focal adhesion kinase (FAK) contributes to controlling the regulation of orientation and polarity. When fibroblasts attach to micropatterns, tyrosine-phosphorylated proteins and FAK are both detected along the inner border between the adhesive micropatterns and the nonadhesive glass surface. FAK likely plays important roles in regulation of cell adhesion to the substrate, as FAK is a tyrosine-phosphorylated protein that acts as a signal transduction molecule at sites of cell–substrate attachment, called focal adhesions. FAK has been suggested to play a role in the attachment of cells at adhesive micropatterns by affecting cell polarity. Therefore, the localization of FAK might play a key role in recognition of the border of the cell with the adhesive micropattern, thus regulating cell polarity and the cell axis. This review discusses the regulation and molecular mechanism of cell proliferation and cell elongation by FAK and its associated signal transduction proteins.
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Affiliation(s)
- Kazuo Katoh
- Laboratory of Human Anatomy and Cell Biology, Faculty of Health Sciences, Tsukuba University of Technology Tsukuba-city, Ibaraki, Japan
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36
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Zhong J, Yang Y, Liao L, Zhang C. Matrix stiffness-regulated cellular functions under different dimensionalities. Biomater Sci 2020; 8:2734-2755. [DOI: 10.1039/c9bm01809c] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The microenvironments that cells encounter with in vitro.
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Affiliation(s)
- Jiajun Zhong
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instruments (Sun Yat-sen University)
- School of Biomedical Engineering
- Sun Yat-Sen University
- Guangzhou
- P. R. China
| | - Yuexiong Yang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instruments (Sun Yat-sen University)
- School of Biomedical Engineering
- Sun Yat-Sen University
- Guangzhou
- P. R. China
| | - Liqiong Liao
- Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering
- Biomaterials Research Center
- School of Biomedical Engineering
- Southern Medical University
- Guangzhou
| | - Chao Zhang
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instruments (Sun Yat-sen University)
- School of Biomedical Engineering
- Sun Yat-Sen University
- Guangzhou
- P. R. China
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37
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Unconventional Myosins: How Regulation Meets Function. Int J Mol Sci 2019; 21:ijms21010067. [PMID: 31861842 PMCID: PMC6981383 DOI: 10.3390/ijms21010067] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 01/24/2023] Open
Abstract
Unconventional myosins are multi-potent molecular motors that are assigned important roles in fundamental cellular processes. Depending on their mechano-enzymatic properties and structural features, myosins fulfil their roles by acting as cargo transporters along the actin cytoskeleton, molecular anchors or tension sensors. In order to perform such a wide range of roles and modes of action, myosins need to be under tight regulation in time and space. This is achieved at multiple levels through diverse regulatory mechanisms: the alternative splicing of various isoforms, the interaction with their binding partners, their phosphorylation, their applied load and the composition of their local environment, such as ions and lipids. This review summarizes our current knowledge of how unconventional myosins are regulated, how these regulatory mechanisms can adapt to the specific features of a myosin and how they can converge with each other in order to ensure the required tight control of their function.
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38
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Pyrpassopoulos S, Shuman H, Ostap EM. Modulation of Kinesin's Load-Bearing Capacity by Force Geometry and the Microtubule Track. Biophys J 2019; 118:243-253. [PMID: 31883614 PMCID: PMC6952184 DOI: 10.1016/j.bpj.2019.10.045] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/03/2019] [Accepted: 10/15/2019] [Indexed: 11/27/2022] Open
Abstract
Kinesin motors and their associated microtubule tracks are essential for long-distance transport of cellular cargos. Intracellular activity and proper recruitment of kinesins is regulated by biochemical signaling, cargo adaptors, microtubule-associated proteins, and mechanical forces. In this study, we found that the effect of opposing forces on the kinesin-microtubule attachment duration depends strongly on experimental assay geometry. Using optical tweezers and the conventional single-bead assay, we show that detachment of kinesin from the microtubule is likely accelerated by forces vertical to the long axis of the microtubule due to contact of the single bead with the underlying microtubule. We used the three-bead assay to minimize the vertical force component and found that when the opposing forces are mainly parallel to the microtubule, the median value of attachment durations between kinesin and microtubules can be up to 10-fold longer than observed using the single-bead assay. Using the three-bead assay, we also found that not all microtubule protofilaments are equivalent interacting substrates for kinesin and that the median value of attachment durations of kinesin varies by more than 10-fold, depending on the relative angular position of the forces along the circumference of the microtubule. Thus, depending on the geometry of forces across the microtubule, kinesin can switch from a fast detaching motor (median attachment duration <0.2 s) to a persistent motor that sustains attachment (median attachment duration >3 s) at high forces (5 pN). Our data show that the load-bearing capacity of the kinesin motor is highly variable and can be dramatically affected by off-axis forces and forces across the microtubule lattice, which has implications for a range of cellular activities, including cell division and organelle transport.
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Affiliation(s)
- Serapion Pyrpassopoulos
- Pennsylvania Muscle Institute, Department of Physiology, and the Center for Engineering Mechanobiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania.
| | - Henry Shuman
- Pennsylvania Muscle Institute, Department of Physiology, and the Center for Engineering Mechanobiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania
| | - E Michael Ostap
- Pennsylvania Muscle Institute, Department of Physiology, and the Center for Engineering Mechanobiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania.
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39
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Merino F, Pospich S, Raunser S. Towards a structural understanding of the remodeling of the actin cytoskeleton. Semin Cell Dev Biol 2019; 102:51-64. [PMID: 31836290 PMCID: PMC7221352 DOI: 10.1016/j.semcdb.2019.11.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 12/03/2022]
Abstract
Actin filaments (F-actin) are a key component of eukaryotic cells. Whether serving as a scaffold for myosin or using their polymerization to push onto cellular components, their function is always related to force generation. To control and fine-tune force production, cells have a large array of actin-binding proteins (ABPs) dedicated to control every aspect of actin polymerization, filament localization, and their overall mechanical properties. Although great advances have been made in our biochemical understanding of the remodeling of the actin cytoskeleton, the structural basis of this process is still being deciphered. In this review, we summarize our current understanding of this process. We outline how ABPs control the nucleation and disassembly, and how these processes are affected by the nucleotide state of the filaments. In addition, we highlight recent advances in the understanding of actomyosin force generation, and describe recent advances brought forward by the developments of electron cryomicroscopy.
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Affiliation(s)
- Felipe Merino
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Sabrina Pospich
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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40
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Abstract
The regulation of actin dynamics is essential for various cellular processes. Former evidence suggests a correlation between the function of non-conventional myosin motors and actin dynamics. Here we investigate the contribution of myosin 1b to actin dynamics using sliding motility assays. We observe that sliding on myosin 1b immobilized or bound to a fluid bilayer enhances actin depolymerization at the barbed end, while sliding on myosin II, although 5 times faster, has no effect. This work reveals a non-conventional myosin motor as another type of depolymerase and points to its singular interactions with the actin barbed end. Former evidence suggests a correlation between the function of non-conventional myosin motors and actin dynamics. Here authors use in vitro assays in which they observe that actin sliding on myosin 1b immobilized or bound to a fluid bilayer enhances actin depolymerization at the barbed end.
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41
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Robert-Paganin J, Pylypenko O, Kikuti C, Sweeney HL, Houdusse A. Force Generation by Myosin Motors: A Structural Perspective. Chem Rev 2019; 120:5-35. [PMID: 31689091 DOI: 10.1021/acs.chemrev.9b00264] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Generating force and movement is essential for the functions of cells and organisms. A variety of molecular motors that can move on tracks within cells have evolved to serve this role. How these motors interact with their tracks and how that, in turn, leads to the generation of force and movement is key to understanding the cellular roles that these motor-track systems serve. This review is focused on the best understood of these systems, which is the molecular motor myosin that moves on tracks of filamentous (F-) actin. The review highlights both the progress and the limits of our current understanding of how force generation can be controlled by F-actin-myosin interactions. What has emerged are insights they may serve as a framework for understanding the design principles of a number of types of molecular motors and their interactions with their tracks.
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Affiliation(s)
- Julien Robert-Paganin
- Structural Motility , UMR 144 CNRS/Curie Institute , 26 rue d'ulm , 75258 Paris cedex 05 , France
| | - Olena Pylypenko
- Structural Motility , UMR 144 CNRS/Curie Institute , 26 rue d'ulm , 75258 Paris cedex 05 , France
| | - Carlos Kikuti
- Structural Motility , UMR 144 CNRS/Curie Institute , 26 rue d'ulm , 75258 Paris cedex 05 , France
| | - H Lee Sweeney
- Department of Pharmacology & Therapeutics and the Myology Institute , University of Florida College of Medicine , PO Box 100267, Gainesville , Florida 32610-0267 , United States
| | - Anne Houdusse
- Structural Motility , UMR 144 CNRS/Curie Institute , 26 rue d'ulm , 75258 Paris cedex 05 , France
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42
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Ma R, Berro J. Crosslinking actin networks produces compressive force. Cytoskeleton (Hoboken) 2019; 76:346-354. [PMID: 31278856 PMCID: PMC7001507 DOI: 10.1002/cm.21552] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/21/2019] [Accepted: 07/02/2019] [Indexed: 11/11/2022]
Abstract
Actin has been shown to be essential for clathrin-mediated endocytosis in yeast. However, actin polymerization alone is likely insufficient to produce enough force to deform the membrane against the huge turgor pressure of yeast cells. In this paper, we used Brownian dynamics simulations to demonstrate that crosslinking of a meshwork of nonpolymerizing actin filaments is able to produce compressive forces. We show that the force can be up to several thousand pico-Newtons if the crosslinker has a high stiffness. The force decays over time as a result of crosslinker turnover, and is a result of converting chemical binding energy into elastic energy.
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Affiliation(s)
- Rui Ma
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
- Nanobiology Institute, Yale University, West Haven, Connecticut
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
- Nanobiology Institute, Yale University, West Haven, Connecticut
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut
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43
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Lee G, Han SB, Lee JH, Kim HW, Kim DH. Cancer Mechanobiology: Microenvironmental Sensing and Metastasis. ACS Biomater Sci Eng 2019; 5:3735-3752. [PMID: 33405888 DOI: 10.1021/acsbiomaterials.8b01230] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The cellular microenvironment plays an important role in regulating cancer progress. Cancer can physically and chemically remodel its surrounding extracellular matrix (ECM). Critical cellular behaviors such as recognition of matrix geometry and rigidity, cell polarization and motility, cytoskeletal reorganization, and proliferation can be changed as a consequence of these ECM alternations. Here, we present an overview of cancer mechanobiology in detail, focusing on cancer microenvironmental sensing of exogenous cues and quantification of cancer-substrate interactions. In addition, mechanics of metastasis classified with tumor progression will be discussed. The mechanism underlying cancer mechanosensation and tumor progression may provide new insights into therapeutic strategies to alleviate cancer malignancy.
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Affiliation(s)
- GeonHui Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea
| | - Seong-Beom Han
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea
| | - Jung-Hwan Lee
- Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 31116, South Korea.,Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan 31116, South Korea
| | - Hae-Won Kim
- Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 31116, South Korea.,Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan 31116, South Korea.,Department of Nanobiomedical Science and BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, South Korea
| | - Dong-Hwee Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, South Korea
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44
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Du Y, Pan J, Choi JH. A review on optical imaging of DNA nanostructures and dynamic processes. Methods Appl Fluoresc 2019; 7:012002. [PMID: 30523978 DOI: 10.1088/2050-6120/aaed11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
DNA self-assembly offers a powerful means to construct complex nanostructures and program dynamic molecular processes such as strand displacement. DNA nanosystems pack high structural complexity in a small scale (typically, <100 nm) and span dynamic features over long periods of time, which bring new challenges for characterizations. The spatial and temporal features of DNA nanosystems require novel experimental methods capable of high resolution imaging over long time periods. This article reviews recent advances in optical imaging methods for characterizing self-assembled DNA nanosystems, with particular emphasis on super-resolved fluorescence microscopy. Several advanced strategies are developed to obtain accurate and detailed images of intricate DNA nanogeometries and to perform precise tracking of molecular motions in dynamic processes. We present state-of-the-art instruments and imaging strategies including localization microscopy and spectral imaging. We discuss how they are used in biological studies and biomedical applications, and also provide current challenges and future outlook. Overall, this review serves as a practical guide in optical microscopy for the field of DNA nanotechnology.
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Affiliation(s)
- Yancheng Du
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907
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45
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Kanoldt V, Fischer L, Grashoff C. Unforgettable force – crosstalk and memory of mechanosensitive structures. Biol Chem 2018; 400:687-698. [DOI: 10.1515/hsz-2018-0328] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/11/2018] [Indexed: 12/11/2022]
Abstract
Abstract
The ability of cells to sense and respond to mechanical stimuli is crucial for many developmental and homeostatic processes, while mechanical dysfunction of cells has been associated with numerous pathologies including muscular dystrophies, cardiovascular defects and epithelial disorders. Yet, how cells detect and process mechanical information is still largely unclear. In this review, we outline major mechanisms underlying cellular mechanotransduction and we summarize the current understanding of how cells integrate information from distinct mechanosensitive structures to mediate complex mechanoresponses. We also discuss the concept of mechanical memory and describe how cells store information on previous mechanical events for different periods of time.
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Affiliation(s)
- Verena Kanoldt
- Group of Molecular Mechanotransduction , Max Planck Institute of Biochemistry , 82152 Martinsried , Germany
| | - Lisa Fischer
- Group of Molecular Mechanotransduction , Max Planck Institute of Biochemistry , 82152 Martinsried , Germany
| | - Carsten Grashoff
- Group of Molecular Mechanotransduction , Max Planck Institute of Biochemistry , 82152 Martinsried , Germany
- Department of Quantitative Cell Biology , Institute of Molecular Cell Biology, University of Münster , 48149 Münster , Germany
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46
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Woody MS, Greenberg MJ, Barua B, Winkelmann DA, Goldman YE, Ostap EM. Positive cardiac inotrope omecamtiv mecarbil activates muscle despite suppressing the myosin working stroke. Nat Commun 2018; 9:3838. [PMID: 30242219 PMCID: PMC6155018 DOI: 10.1038/s41467-018-06193-2] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/21/2018] [Indexed: 02/05/2023] Open
Abstract
Omecamtiv mecarbil (OM) is a positive cardiac inotrope in phase-3 clinical trials for treatment of heart failure. Although initially described as a direct myosin activator, subsequent studies are at odds with this description and do not explain OM-mediated increases in cardiac performance. Here we show, via single-molecule, biophysical experiments on cardiac myosin, that OM suppresses myosin's working stroke and prolongs actomyosin attachment 5-fold, which explains inhibitory actions of the drug observed in vitro. OM also causes the actin-detachment rate to become independent of both applied load and ATP concentration. Surprisingly, increased myocardial force output in the presence of OM can be explained by cooperative thin-filament activation by OM-inhibited myosin molecules. Selective suppression of myosin is an unanticipated route to muscle activation that may guide future development of therapeutic drugs.
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Affiliation(s)
- Michael S Woody
- Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, 700A Clinical Research Building, Philadelphia, PA, 19104-6085, USA
| | - Michael J Greenberg
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, 700A Clinical Research Building, Philadelphia, PA, 19104-6085, USA.,Department of Biochemistry and Molecular Biophysics, Washington University in Saint Louis, St. Louis, 63110, MO, USA
| | - Bipasha Barua
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, 675 Hoes Lane, Piscataway, NJ, 08854, USA
| | - Donald A Winkelmann
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers University, 675 Hoes Lane, Piscataway, NJ, 08854, USA
| | - Yale E Goldman
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, 700A Clinical Research Building, Philadelphia, PA, 19104-6085, USA.
| | - E Michael Ostap
- Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, 700A Clinical Research Building, Philadelphia, PA, 19104-6085, USA.
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47
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Gardini L, Heissler SM, Arbore C, Yang Y, Sellers JR, Pavone FS, Capitanio M. Dissecting myosin-5B mechanosensitivity and calcium regulation at the single molecule level. Nat Commun 2018; 9:2844. [PMID: 30030431 PMCID: PMC6054644 DOI: 10.1038/s41467-018-05251-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 06/22/2018] [Indexed: 11/08/2022] Open
Abstract
Myosin-5B is one of three members of the myosin-5 family of actin-based molecular motors. Despite its fundamental role in recycling endosome trafficking and in collective actin network dynamics, the molecular mechanisms underlying its motility are inherently unknown. Here we combine single-molecule imaging and high-speed laser tweezers to dissect the mechanoenzymatic properties of myosin-5B. We show that a single myosin-5B moves processively in 36-nm steps, stalls at ~2 pN resistive forces, and reverses its directionality at forces >2 pN. Interestingly, myosin-5B mechanosensitivity differs from that of myosin-5A, while it is strikingly similar to kinesin-1. In particular, myosin-5B run length is markedly and asymmetrically sensitive to force, a property that might be central to motor ensemble coordination. Furthermore, we show that Ca2+ does not affect the enzymatic activity of the motor unit, but abolishes myosin-5B processivity through calmodulin dissociation, providing important insights into the regulation of postsynaptic cargoes trafficking in neuronal cells.
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Affiliation(s)
- Lucia Gardini
- LENS-European Laboratory for Non-linear Spectroscopy, University of Florence, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
- National Institute of Optics-National Research Council, Largo Fermi 6, 50125, Florence, Italy
| | - Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892-8015, USA
| | - Claudia Arbore
- LENS-European Laboratory for Non-linear Spectroscopy, University of Florence, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Via Sansone 1, 50019, Sesto Fiorentino, Italy
| | - Yi Yang
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892-8015, USA
- Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892-8015, USA
| | - Francesco S Pavone
- LENS-European Laboratory for Non-linear Spectroscopy, University of Florence, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy
- National Institute of Optics-National Research Council, Largo Fermi 6, 50125, Florence, Italy
- Department of Physics and Astronomy, University of Florence, Via Sansone 1, 50019, Sesto Fiorentino, Italy
| | - Marco Capitanio
- LENS-European Laboratory for Non-linear Spectroscopy, University of Florence, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.
- Department of Physics and Astronomy, University of Florence, Via Sansone 1, 50019, Sesto Fiorentino, Italy.
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48
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Liu C, Kawana M, Song D, Ruppel KM, Spudich JA. Controlling load-dependent kinetics of β-cardiac myosin at the single-molecule level. Nat Struct Mol Biol 2018; 25:505-514. [PMID: 29867217 PMCID: PMC6092189 DOI: 10.1038/s41594-018-0069-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/26/2018] [Indexed: 01/29/2023]
Abstract
Concepts in molecular tension sensing in biology are growing and have their origins in studies of muscle contraction. In the heart muscle, a key parameter of contractility is the detachment rate of myosin from actin, which determines the time that myosin is bound to actin in a force-producing state and, importantly, depends on the load (force) against which myosin works. Here we measure the detachment rate of single molecules of human β-cardiac myosin and its load dependence. We find that both can be modulated by both small-molecule compounds and cardiomyopathy-causing mutations. Furthermore, effects of mutations can be reversed by introducing appropriate compounds. Our results suggest that activating versus inhibitory perturbations of cardiac myosin are discriminated by the aggregate result on duty ratio, average force, and ultimately average power output and suggest that cardiac contractility can be controlled by tuning the load-dependent kinetics of single myosin molecules.
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Affiliation(s)
- Chao Liu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA.
| | - Masataka Kawana
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Dan Song
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Kathleen M Ruppel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA, USA
| | - James A Spudich
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA.
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49
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Ma R, Berro J. Structural organization and energy storage in crosslinked actin assemblies. PLoS Comput Biol 2018; 14:e1006150. [PMID: 29813051 PMCID: PMC5993335 DOI: 10.1371/journal.pcbi.1006150] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 06/08/2018] [Accepted: 04/18/2018] [Indexed: 11/19/2022] Open
Abstract
During clathrin-mediated endocytosis in yeast cells, short actin filaments (< 200nm) and crosslinking protein fimbrin assemble to drive the internalization of the plasma membrane. However, the organization of the actin meshwork during endocytosis remains largely unknown. In addition, only a small fraction of the force necessary to elongate and pinch off vesicles can be accounted for by actin polymerization alone. In this paper, we used mathematical modeling to study the self-organization of rigid actin filaments in the presence of elastic crosslinkers in conditions relevant to endocytosis. We found that actin filaments condense into either a disordered meshwork or an ordered bundle depending on filament length and the mechanical and kinetic properties of the crosslinkers. Our simulations also demonstrated that these nanometer-scale actin structures can store a large amount of elastic energy within the crosslinkers (up to 10kBT per crosslinker). This conversion of binding energy into elastic energy is the consequence of geometric constraints created by the helical pitch of the actin filaments, which results in frustrated configurations of crosslinkers attached to filaments. We propose that this stored elastic energy can be used at a later time in the endocytic process. As a proof of principle, we presented a simple mechanism for sustained torque production by ordered detachment of crosslinkers from a pair of parallel filaments.
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Affiliation(s)
- Rui Ma
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
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50
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Iuliano O, Yoshimura A, Prospéri MT, Martin R, Knölker HJ, Coudrier E. Myosin 1b promotes axon formation by regulating actin wave propagation and growth cone dynamics. J Cell Biol 2018; 217:2033-2046. [PMID: 29588377 PMCID: PMC5987710 DOI: 10.1083/jcb.201703205] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 12/20/2017] [Accepted: 03/02/2018] [Indexed: 02/06/2023] Open
Abstract
Single-headed myosin 1 has been identified in neurons, but its function in these cells is still unclear. We demonstrate that depletion of myosin 1b (Myo1b), inhibition of its motor activity, or its binding to phosphoinositides impairs the formation of the axon, whereas overexpression of Myo1b increases the number of axon-like structures. Myo1b is associated with growth cones and actin waves, two major contributors to neuronal symmetry breaking. We show that Myo1b controls the dynamics of the growth cones and the anterograde propagation of the actin waves. By coupling the membrane to the actin cytoskeleton, Myo1b regulates the size of the actin network as well as the stability and size of filopodia in the growth cones. Our data provide the first evidence that a myosin 1 plays a major role in neuronal symmetry breaking and argue for a mechanical control of the actin cytoskeleton both in actin waves and in the growth cones by this myosin.
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Affiliation(s)
- Olga Iuliano
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, UMR 144, Paris, France
| | - Azumi Yoshimura
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, UMR 144, Paris, France
| | - Marie-Thérèse Prospéri
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, UMR 144, Paris, France
| | - René Martin
- Department of Chemistry, Technische Univesität Dresden, Dresden, Germany
| | | | - Evelyne Coudrier
- Institut Curie, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, UMR 144, Paris, France
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