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Bonilla-Quintana M, Ghisleni A, Gauthier N, Rangamani P. Dynamic mechanisms for membrane skeleton transitions. bioRxiv 2024:2024.04.29.591779. [PMID: 38746295 PMCID: PMC11092671 DOI: 10.1101/2024.04.29.591779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The plasma membrane and the underlying skeleton form a protective barrier for eukaryotic cells. The molecules forming this complex composite material constantly rearrange under mechanical stress to confer this protective capacity. One of those molecules, spectrin, is ubiquitous in the membrane skeleton and primarily located proximal to the inner leaflet of the plasma membrane and engages in protein-lipid interactions via a set of membrane-anchoring domains. Spectrin is linked by short actin filaments and its conformation varies in different types of cells. In this work, we developed a generalized network model for the membrane skeleton integrated with myosin contractility and membrane mechanics to investigate the response of the spectrin meshwork to mechanical loading. We observed that the force generated by membrane bending is important to maintain a smooth skeletal structure. This suggests that the membrane is not just supported by the skeleton, but has an active contribution to the stability of the cell structure. We found that spectrin and myosin turnover are necessary for the transition between stress and rest states in the skeleton. Our model reveals that the actin-spectrin meshwork dynamics are balanced by the membrane forces with area constraint and volume restriction promoting the stability of the membrane skeleton. Furthermore, we showed that cell attachment to the substrate promotes shape stabilization. Thus, our proposed model gives insight into the shared mechanisms of the membrane skeleton associated with myosin and membrane that can be tested in different types of cells. Significance Statement Spectrin was first observed in red blood cells, as a result of which, many theoretical models focused on understanding its function in this cell type. However, recently, experiments have shown that spectrin is an important skeletal component for many different cell types and that it can form different configurations with actin. In this work, we proposed a model to study the shared mechanisms behind the function of the actin-spectrin meshwork in different types of cells. We found that membrane dynamics in addition to spectrin and myosin turnover are necessary to achieve conformational changes when stresses are applied and to guarantee shape stability when the stresses are removed. We observed that membrane bending is important to support skeletal structure. Furthermore, our model gives insight into how cell shape is maintained despite constant spectrin turnover and myosin contraction.
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Ghisleni A, Gauthier NC. Mechanotransduction through membrane tension: It's all about propagation? Curr Opin Cell Biol 2024; 86:102294. [PMID: 38101114 DOI: 10.1016/j.ceb.2023.102294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023]
Abstract
Over the past 25 years, membrane tension has emerged as a primary mechanical factor influencing cell behavior. Although supporting evidences are accumulating, the integration of this parameter in the lifecycle of cells, organs, and tissues is complex. The plasma membrane is envisioned as a bilayer continuum acting as a 2D fluid. However, it possesses almost infinite combinations of proteins, lipids, and glycans that establish interactions with the extracellular or intracellular environments. This results in a tridimensional composite material with non-trivial dynamics and physics, and the task of integrating membrane mechanics and cellular outcome is a daunting chore for biologists. In light of the most recent discoveries, we aim in this review to provide non-specialist readers some tips on how to solve this conundrum.
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Affiliation(s)
- Andrea Ghisleni
- IFOM ETS, The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Nils C Gauthier
- IFOM ETS, The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139, Milan, Italy.
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Poli A, Pennacchio FA, Ghisleni A, di Gennaro M, Lecacheur M, Nastały P, Crestani M, Pramotton FM, Iannelli F, Beznusenko G, Mironov AA, Panzetta V, Fusco S, Sheth B, Poulikakos D, Ferrari A, Gauthier N, Netti PA, Divecha N, Maiuri P. PIP4K2B is mechanoresponsive and controls heterochromatin-driven nuclear softening through UHRF1. Nat Commun 2023; 14:1432. [PMID: 36918565 PMCID: PMC10015053 DOI: 10.1038/s41467-023-37064-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 02/23/2023] [Indexed: 03/16/2023] Open
Abstract
Phosphatidylinositol-5-phosphate (PtdIns5P)-4-kinases (PIP4Ks) are stress-regulated phosphoinositide kinases able to phosphorylate PtdIns5P to PtdIns(4,5)P2. In cancer patients their expression is typically associated with bad prognosis. Among the three PIP4K isoforms expressed in mammalian cells, PIP4K2B is the one with more prominent nuclear localisation. Here, we unveil the role of PIP4K2B as a mechanoresponsive enzyme. PIP4K2B protein level strongly decreases in cells growing on soft substrates. Its direct silencing or pharmacological inhibition, mimicking cell response to softness, triggers a concomitant reduction of the epigenetic regulator UHRF1 and induces changes in nuclear polarity, nuclear envelope tension and chromatin compaction. This substantial rewiring of the nucleus mechanical state drives YAP cytoplasmic retention and impairment of its activity as transcriptional regulator, finally leading to defects in cell spreading and motility. Since YAP signalling is essential for initiation and growth of human malignancies, our data suggest that potential therapeutic approaches targeting PIP4K2B could be beneficial in the control of the altered mechanical properties of cancer cells.
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Affiliation(s)
- Alessandro Poli
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy.
| | | | - Andrea Ghisleni
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
| | | | | | - Paulina Nastały
- Laboratory of Translational Oncology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Gdansk, Poland
| | - Michele Crestani
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Francesca M Pramotton
- EMPA-Materials Science and Technology, Dubenforf, Switzerland
- Institute for Mechanical Systems, ETH, Zurich, Switzerland
| | - Fabio Iannelli
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
| | | | | | - Valeria Panzetta
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II, Naples, Italy
- Centro di Ricerca Interdipartimentale sui Biomateriali CRIB, University of Naples Federico II, Naples, Italy
- Istituto Italiano di Tecnologia, IIT@CRIB, Naples, Italy
| | - Sabato Fusco
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Bhavwanti Sheth
- Inositide Laboratory, School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | | | - Aldo Ferrari
- Institute for Mechanical Systems, ETH, Zurich, Switzerland
| | - Nils Gauthier
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Paolo A Netti
- Department of Chemical, Materials and Production Engineering, University of Naples Federico II, Naples, Italy
- Centro di Ricerca Interdipartimentale sui Biomateriali CRIB, University of Naples Federico II, Naples, Italy
- Istituto Italiano di Tecnologia, IIT@CRIB, Naples, Italy
| | - Nullin Divecha
- Inositide Laboratory, School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Paolo Maiuri
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy.
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy.
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Ghisleni A, Bonilla-Quintana M, Crestani M, Rangamani P, Gauthier NC. Mechanically induced conformational transition of spectrin in the mammalian cell cortex. Biophys J 2023; 122:263a. [PMID: 36783297 DOI: 10.1016/j.bpj.2022.11.1511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Andrea Ghisleni
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Mayte Bonilla-Quintana
- Department of Mechanical and Aerospace Engineering, University of California San Diego, San Diego, CA, USA
| | - Michele Crestani
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, San Diego, CA, USA
| | - Nils C Gauthier
- IFOM ETS - The AIRC Institute of Molecular Oncology, Milan, Italy
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Ghisleni A, Bonilla-Quintana M, Crestani M, Fukuzawa A, Rangamani P, Gauthier N. Mechanically induced topological transition of spectrin regulates its distribution in the mammalian cortex. bioRxiv 2023:2023.01.02.522381. [PMID: 36712133 PMCID: PMC9881866 DOI: 10.1101/2023.01.02.522381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The cell cortex is a dynamic assembly that ensures cell integrity during passive deformation or active response by adapting cytoskeleton topologies with poorly understood mechanisms. The spectrin meshwork ensures such adaptation in erythrocytes and neurons. Erythrocytes rely on triangular-like lattices of spectrin tetramers, which in neurons are organized in periodic arrays. We exploited Expansion Microscopy to discover that these two distinct topologies can co-exist in other mammalian cells such as fibroblasts. We show through biophysical measurements and computational modeling that spectrin provides coverage of the cortex and, with the intervention of actomyosin, erythroid-like lattices can dynamically transition into condensates resembling neuron-like periodic arrays fenced by actin stress fibers. Spectrin condensates experience lower mechanical stress and turnover despite displaying an extension close to the contour length of the tetramer. Our study sheds light on the adaptive properties of spectrin, which ensures protection of the cortex by undergoing mechanically induced topological transitions.
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Ovejero JG, Fusi L, Park-Holohan SJ, Ghisleni A, Narayanan T, Irving M, Brunello E. Cooling intact and demembranated trabeculae from rat heart releases myosin motors from their inhibited conformation. J Gen Physiol 2022; 154:212988. [PMID: 35089319 PMCID: PMC8823665 DOI: 10.1085/jgp.202113029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 01/10/2022] [Indexed: 12/26/2022] Open
Abstract
Myosin filament–based regulation supplements actin filament–based regulation to control the strength and speed of contraction in heart muscle. In diastole, myosin motors form a folded helical array that inhibits actin interaction; during contraction, they are released from that array. A similar structural transition has been observed in mammalian skeletal muscle, in which cooling below physiological temperature has been shown to reproduce some of the structural features of the activation of myosin filaments during active contraction. Here, we used small-angle x-ray diffraction to characterize the structural changes in the myosin filaments associated with cooling of resting and relaxed trabeculae from the right ventricle of rat hearts from 39°C to 7°C. In intact quiescent trabeculae, cooling disrupted the folded helical conformation of the myosin motors and induced extension of the filament backbone, as observed in the transition from diastole to peak systolic force at 27°C. Demembranation of trabeculae in relaxing conditions induced expansion of the filament lattice, but the structure of the myosin filaments was mostly preserved at 39°C. Cooling of relaxed demembranated trabeculae induced changes in motor conformation and filament structure similar to those observed in intact quiescent trabeculae. Osmotic compression of the filament lattice to restore its spacing to that of intact trabeculae at 39°C stabilized the helical folded state against disruption by cooling. The myosin filament structure and motor conformation of intact trabeculae at 39°C were largely preserved in demembranated trabeculae at 27°C or above in the presence of Dextran, allowing the physiological mechanisms of myosin filament–based regulation to be studied in those conditions.
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Affiliation(s)
- Jesus G Ovejero
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Luca Fusi
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK.,Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | - So-Jin Park-Holohan
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Andrea Ghisleni
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | | | - Malcolm Irving
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Elisabetta Brunello
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
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7
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Filomena MC, Yamamoto DL, Carullo P, Medvedev R, Ghisleni A, Piroddi N, Scellini B, Crispino R, D'Autilia F, Zhang J, Felicetta A, Nemska S, Serio S, Tesi C, Catalucci D, Linke WA, Polishchuk R, Poggesi C, Gautel M, Bang ML. Myopalladin knockout mice develop cardiac dilation and show a maladaptive response to mechanical pressure overload. eLife 2021; 10:e58313. [PMID: 34558411 PMCID: PMC8547954 DOI: 10.7554/elife.58313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/23/2021] [Indexed: 12/13/2022] Open
Abstract
Myopalladin (MYPN) is a striated muscle-specific immunoglobulin domain-containing protein located in the sarcomeric Z-line and I-band. MYPN gene mutations are causative for dilated (DCM), hypertrophic, and restrictive cardiomyopathy. In a yeast two-hybrid screening, MYPN was found to bind to titin in the Z-line, which was confirmed by microscale thermophoresis. Cardiac analyses of MYPN knockout (MKO) mice showed the development of mild cardiac dilation and systolic dysfunction, associated with decreased myofibrillar isometric tension generation and increased resting tension at longer sarcomere lengths. MKO mice exhibited a normal hypertrophic response to transaortic constriction (TAC), but rapidly developed severe cardiac dilation and systolic dysfunction, associated with fibrosis, increased fetal gene expression, higher intercalated disc fold amplitude, decreased calsequestrin-2 protein levels, and increased desmoplakin and SORBS2 protein levels. Cardiomyocyte analyses showed delayed Ca2+ release and reuptake in unstressed MKO mice as well as reduced Ca2+ spark amplitude post-TAC, suggesting that altered Ca2+ handling may contribute to the development of DCM in MKO mice.
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Affiliation(s)
- Maria Carmela Filomena
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Daniel L Yamamoto
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
| | - Pierluigi Carullo
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
| | - Roman Medvedev
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Cardiac Surgery, University of VeronaVeronaItaly
| | - Andrea Ghisleni
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Nicoletta Piroddi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Beatrice Scellini
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Roberta Crispino
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | | | - Jianlin Zhang
- Department of Medicine, University of California, San DiegoLa JollaUnited States
| | - Arianna Felicetta
- IRCCS Humanitas Research HospitalMilanItaly
- Humanitas UniversityPieve EmanueleItaly
| | | | | | - Chiara Tesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | | | - Wolfgang A Linke
- Institute of Physiology II, University of MuensterMuensterGermany
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Corrado Poggesi
- Department of Experimental and Clinical Medicine, University of FlorenceFlorenceItaly
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research ExcellenceLondonUnited Kingdom
| | - Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB) - National Research Council (CNR), Milan unitMilanItaly
- IRCCS Humanitas Research HospitalMilanItaly
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Sponga A, Arolas JL, Schwarz TC, Jeffries CM, Rodriguez Chamorro A, Kostan J, Ghisleni A, Drepper F, Polyansky A, De Almeida Ribeiro E, Pedron M, Zawadzka-Kazimierczuk A, Mlynek G, Peterbauer T, Doto P, Schreiner C, Hollerl E, Mateos B, Geist L, Faulkner G, Kozminski W, Svergun DI, Warscheid B, Zagrovic B, Gautel M, Konrat R, Djinović-Carugo K. Order from disorder in the sarcomere: FATZ forms a fuzzy complex and phase-separated macromolecular condensates with α-actinin. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321093946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Sponga A, Arolas JL, Schwarz TC, Jeffries CM, Rodriguez Chamorro A, Kostan J, Ghisleni A, Drepper F, Polyansky A, De Almeida Ribeiro E, Pedron M, Zawadzka-Kazimierczuk A, Mlynek G, Peterbauer T, Doto P, Schreiner C, Hollerl E, Mateos B, Geist L, Faulkner G, Kozminski W, Svergun DI, Warscheid B, Zagrovic B, Gautel M, Konrat R, Djinović-Carugo K. Order from disorder in the sarcomere: FATZ forms a fuzzy but tight complex and phase-separated condensates with α-actinin. Sci Adv 2021; 7:eabg7653. [PMID: 34049882 PMCID: PMC8163081 DOI: 10.1126/sciadv.abg7653] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/13/2021] [Indexed: 05/03/2023]
Abstract
In sarcomeres, α-actinin cross-links actin filaments and anchors them to the Z-disk. FATZ (filamin-, α-actinin-, and telethonin-binding protein of the Z-disk) proteins interact with α-actinin and other core Z-disk proteins, contributing to myofibril assembly and maintenance. Here, we report the first structure and its cellular validation of α-actinin-2 in complex with a Z-disk partner, FATZ-1, which is best described as a conformational ensemble. We show that FATZ-1 forms a tight fuzzy complex with α-actinin-2 and propose an interaction mechanism via main molecular recognition elements and secondary binding sites. The obtained integrative model reveals a polar architecture of the complex which, in combination with FATZ-1 multivalent scaffold function, might organize interaction partners and stabilize α-actinin-2 preferential orientation in Z-disk. Last, we uncover FATZ-1 ability to phase-separate and form biomolecular condensates with α-actinin-2, raising the question whether FATZ proteins can create an interaction hub for Z-disk proteins through membraneless compartmentalization during myofibrillogenesis.
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Affiliation(s)
- Antonio Sponga
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Joan L Arolas
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Thomas C Schwarz
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Cy M Jeffries
- European Molecular Biology Laboratory (EMBL), Hamburg Unit, Hamburg, Germany
| | - Ariadna Rodriguez Chamorro
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Julius Kostan
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Andrea Ghisleni
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Friedel Drepper
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Anton Polyansky
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
- National Research University Higher School of Economics, Moscow 101000, Russia
| | - Euripedes De Almeida Ribeiro
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Miriam Pedron
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Anna Zawadzka-Kazimierczuk
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Georg Mlynek
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Thomas Peterbauer
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Dr. BohrGasse 9, A-1030 Vienna, Austria
| | - Pierantonio Doto
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Claudia Schreiner
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Eneda Hollerl
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Borja Mateos
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Leonhard Geist
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | | | - Wiktor Kozminski
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Dmitri I Svergun
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Bojan Zagrovic
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Mathias Gautel
- King's College London BHF Centre for Research Excellence, Randall Centre for Cell and Molecular Biophysics, London SE1 1UL, UK
| | - Robert Konrat
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max Perutz Labs, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.
- Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
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Pocaterra A, Santinon G, Romani P, Brian I, Dimitracopoulos A, Ghisleni A, Carnicer-Lombarte A, Forcato M, Braghetta P, Montagner M, Galuppini F, Aragona M, Pennelli G, Bicciato S, Gauthier N, Franze K, Dupont S. F-actin dynamics regulates mammalian organ growth and cell fate maintenance. J Hepatol 2019; 71:130-142. [PMID: 30878582 DOI: 10.1016/j.jhep.2019.02.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/31/2019] [Accepted: 02/22/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS In vitro, cell function can be potently regulated by the mechanical properties of cells and of their microenvironment. Cells measure these features by developing forces via their actomyosin cytoskeleton, and respond accordingly by regulating intracellular pathways, including the transcriptional coactivators YAP/TAZ. Whether mechanical cues are relevant for in vivo regulation of adult organ homeostasis, and whether this occurs through YAP/TAZ, remains largely unaddressed. METHODS We developed Capzb conditional knockout mice and obtained primary fibroblasts to characterize the role of CAPZ in vitro. In vivo functional analyses were carried out by inducing Capzb inactivation in adult hepatocytes, manipulating YAP/Hippo activity by hydrodynamic tail vein injections, and treating mice with the ROCK inhibitor, fasudil. RESULTS We found that the F-actin capping protein CAPZ restrains actomyosin contractility: Capzb inactivation alters stress fiber and focal adhesion dynamics leading to enhanced myosin activity, increased traction forces, and increased liver stiffness. In vitro, this rescues YAP from inhibition by a small cellular geometry; in vivo, it induces YAP activation in parallel to the Hippo pathway, causing extensive hepatocyte proliferation and leading to striking organ overgrowth. Moreover, Capzb is required for the maintenance of the differentiated hepatocyte state, for metabolic zonation, and for gluconeogenesis. In keeping with changes in tissue mechanics, inhibition of the contractility regulator ROCK, or deletion of the Yap1 mechanotransducer, reverse the phenotypes emerging in Capzb-null livers. CONCLUSIONS These results indicate a previously unsuspected role for CAPZ in tuning the mechanical properties of cells and tissues, which is required in hepatocytes for the maintenance of the differentiated state and to regulate organ size. More generally, it indicates for the first time that mechanotransduction has a physiological role in maintaining liver homeostasis in mammals. LAY SUMMARY The mechanical properties of cells and tissues (i.e. whether they are soft or stiff) are thought to be important regulators of cell behavior. Herein, we found that inactivation of the protein CAPZ alters the mechanical properties of cells and liver tissues, leading to YAP hyperactivation. In turn, this profoundly alters liver physiology, causing organ overgrowth, defects in liver cell differentiation and metabolism. These results reveal a previously uncharacterized role for mechanical signals in the maintenance of adult liver homeostasis.
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Affiliation(s)
| | - Giulia Santinon
- Department of Molecular Medicine DMM, University of Padova, Italy
| | - Patrizia Romani
- Department of Molecular Medicine DMM, University of Padova, Italy
| | - Irene Brian
- Department of Molecular Medicine DMM, University of Padova, Italy
| | | | - Andrea Ghisleni
- Institute FIRC (Italian Foundation for Cancer Research) of Molecular Oncology (IFOM Institute FIRC for Molecular Oncology), Milan, Italy
| | | | - Mattia Forcato
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Paola Braghetta
- Department of Molecular Medicine DMM, University of Padova, Italy
| | - Marco Montagner
- Department of Molecular Medicine DMM, University of Padova, Italy
| | | | | | | | - Silvio Bicciato
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Nils Gauthier
- Institute FIRC (Italian Foundation for Cancer Research) of Molecular Oncology (IFOM Institute FIRC for Molecular Oncology), Milan, Italy
| | - Kristian Franze
- Department of Physiology Development and Neuroscience, University of Cambridge, UK
| | - Sirio Dupont
- Department of Molecular Medicine DMM, University of Padova, Italy.
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Garcia Ovejero J, Fusi L, Park-Holohan SJ, Ghisleni A, Narayanan T, Irving M, Brunello E. The Off-To-On Transition of Thick Filaments in Isolated Trabeculae from Rat Heart Induced by Cooling. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Hastings R, de Villiers CP, Hooper C, Ormondroyd L, Pagnamenta A, Lise S, Salatino S, Knight SJL, Taylor JC, Thomson KL, Arnold L, Chatziefthimiou SD, Konarev PV, Wilmanns M, Ehler E, Ghisleni A, Gautel M, Blair E, Watkins H, Gehmlich K. Combination of Whole Genome Sequencing, Linkage, and Functional Studies Implicates a Missense Mutation in Titin as a Cause of Autosomal Dominant Cardiomyopathy With Features of Left Ventricular Noncompaction. ACTA ACUST UNITED AC 2016; 9:426-435. [PMID: 27625337 PMCID: PMC5068189 DOI: 10.1161/circgenetics.116.001431] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/31/2016] [Indexed: 11/16/2022]
Abstract
Supplemental Digital Content is available in the text. Background— High throughput next-generation sequencing techniques have made whole genome sequencing accessible in clinical practice; however, the abundance of variation in the human genomes makes the identification of a disease-causing mutation on a background of benign rare variants challenging. Methods and Results— Here we combine whole genome sequencing with linkage analysis in a 3-generation family affected by cardiomyopathy with features of autosomal dominant left ventricular noncompaction cardiomyopathy. A missense mutation in the giant protein titin is the only plausible disease-causing variant that segregates with disease among the 7 surviving affected individuals, with interrogation of the entire genome excluding other potential causes. This A178D missense mutation, affecting a conserved residue in the second immunoglobulin-like domain of titin, was introduced in a bacterially expressed recombinant protein fragment and biophysically characterized in comparison to its wild-type counterpart. Multiple experiments, including size exclusion chromatography, small-angle x ray scattering, and circular dichroism spectroscopy suggest partial unfolding and domain destabilization in the presence of the mutation. Moreover, binding experiments in mammalian cells show that the mutation markedly impairs binding to the titin ligand telethonin. Conclusions— Here we present genetic and functional evidence implicating the novel A178D missense mutation in titin as the cause of a highly penetrant familial cardiomyopathy with features of left ventricular noncompaction. This expands the spectrum of titin’s roles in cardiomyopathies. It furthermore highlights that rare titin missense variants, currently often ignored or left uninterpreted, should be considered to be relevant for cardiomyopathies and can be identified by the approach presented here.
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Ribeiro EDA, Pinotsis N, Ghisleni A, Salmazo A, Konarev PV, Kostan J, Sjöblom B, Schreiner C, Polyansky AA, Gkougkoulia EA, Holt MR, Aachmann FL, Zagrović B, Bordignon E, Pirker KF, Svergun DI, Gautel M, Djinović-Carugo K. The structure and regulation of human muscle α-actinin. Cell 2014; 159:1447-60. [PMID: 25433700 PMCID: PMC4259493 DOI: 10.1016/j.cell.2014.10.056] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 10/01/2014] [Accepted: 10/24/2014] [Indexed: 11/29/2022]
Abstract
The spectrin superfamily of proteins plays key roles in assembling the actin cytoskeleton in various cell types, crosslinks actin filaments, and acts as scaffolds for the assembly of large protein complexes involved in structural integrity and mechanosensation, as well as cell signaling. α-actinins in particular are the major actin crosslinkers in muscle Z-disks, focal adhesions, and actin stress fibers. We report a complete high-resolution structure of the 200 kDa α-actinin-2 dimer from striated muscle and explore its functional implications on the biochemical and cellular level. The structure provides insight into the phosphoinositide-based mechanism controlling its interaction with sarcomeric proteins such as titin, lays a foundation for studying the impact of pathogenic mutations at molecular resolution, and is likely to be broadly relevant for the regulation of spectrin-like proteins. Structure of human α-actinin-2 in an autoinhibited closed conformation Facilitation of PIP2-induced allosteric modulation for opening and titin binding Essentiality of structural flexibility for crosslinking antiparallel F-actin Relevance for the intramolecular pseudoligand regulation mechanism of the spectrin family
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Affiliation(s)
- Euripedes de Almeida Ribeiro
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Nikos Pinotsis
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Andrea Ghisleni
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Anita Salmazo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Petr V Konarev
- European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Julius Kostan
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Björn Sjöblom
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Claudia Schreiner
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Anton A Polyansky
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria; M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Eirini A Gkougkoulia
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Mark R Holt
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Finn L Aachmann
- Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491 Trondheim, Norway
| | - Bojan Zagrović
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Enrica Bordignon
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Katharina F Pirker
- Division of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Mathias Gautel
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK.
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria; Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia.
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Ribeiro E, Pinotsis N, Ghisleni A, Salmazo A, Konarev P, Kostan J, Gkougkoulia E, Aachmann F, Pirker K, Svergun D, Gautel M, Djinovic-Carugo K. Structure of muscle α-actinin: Insights into its regulation and Z-disk assembly. Acta Crystallogr A Found Adv 2014. [DOI: 10.1107/s2053273314095680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
α-Actinin is the major component of the Z-disk, where it cross-links actin filaments from adjacent sarcomeres. It is an antiparallel dimer of 200 kDa, containing in each subunit an N-terminal actin binding domain (ABD), a central rod domain assembled from spectrin-like repeats that mediate the antiparallel assembly, and a C-terminal calmodulin-like (CaM-like) domain with 4 EF-hand motifs. Additionally to actin filaments, α-actinin binds multiple other cytoskeletal and signalling proteins. In striated muscle, the tightly defined numbers of α-actinin crosslinks between the antiparallel actin filaments at the Z-disk are organised by specific binding sites on the giant molecular blueprint of the sarcomere, titin. These titin Z-repeats contain a short, hydrophobic, α-actinin binding motif. To achieve ordered cytoskeletal assemblies, the binding properties of α-actinin must be tightly spatiotemporally regulated, in muscle α-actinin its actin and titin binding properties are regulated by phosphoinositide. Biochemical analyses led to propose previously that the α-actinin - titin interaction is regulated by an intramolecular mechanism, where the short sequence between the ABD and the rod interacts with the CaM-like domain in a pseudoligand complex, acting effectively as an intramolecular autoinhibitor. Here, we present the first complete crystallographic structure of sarcomeric human α-actinin complemented by small angle X-ray scattering data, electron-electron paramagnetic resonance, biochemical and in vivo cell biophysics studies of structure-informed mutants, which give insight into its molecular assembly and Z-disk architecture as well as into the mechanism of α-actinin function and regulation.
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