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Le Roux AL, Quiroga X, Walani N, Arroyo M, Roca-Cusachs P. The plasma membrane as a mechanochemical transducer. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180221. [PMID: 31431176 PMCID: PMC6627014 DOI: 10.1098/rstb.2018.0221] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2019] [Indexed: 12/20/2022] Open
Abstract
Cells are constantly submitted to external mechanical stresses, which they must withstand and respond to. By forming a physical boundary between cells and their environment that is also a biochemical platform, the plasma membrane (PM) is a key interface mediating both cellular response to mechanical stimuli, and subsequent biochemical responses. Here, we review the role of the PM as a mechanosensing structure. We first analyse how the PM responds to mechanical stresses, and then discuss how this mechanical response triggers downstream biochemical responses. The molecular players involved in PM mechanochemical transduction include sensors of membrane unfolding, membrane tension, membrane curvature or membrane domain rearrangement. These sensors trigger signalling cascades fundamental both in healthy scenarios and in diseases such as cancer, which cells harness to maintain integrity, keep or restore homeostasis and adapt to their external environment. This article is part of a discussion meeting issue 'Forces in cancer: interdisciplinary approaches in tumour mechanobiology'.
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Affiliation(s)
- Anabel-Lise Le Roux
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Xarxa Quiroga
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Nikhil Walani
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Marino Arroyo
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- Department of Biomedical Sciences, Universitat de Barcelona, Barcelona 08036, Spain
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Kong L, Sochacki KA, Wang H, Fang S, Canagarajah B, Kehr AD, Rice WJ, Strub MP, Taraska JW, Hinshaw JE. Cryo-EM of the dynamin polymer assembled on lipid membrane. Nature 2018; 560:258-262. [PMID: 30069048 PMCID: PMC6121775 DOI: 10.1038/s41586-018-0378-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 06/20/2018] [Indexed: 12/17/2022]
Abstract
Membrane fission is a fundamental process in the regulation and remodeling of cell membranes. Dynamin, a large GTPase, mediates membrane fission by assembling around, constricting and cleaving the necks of budding vesicles1. Here, we report a 3.75 Å resolution cryo-EM structure of the membrane-associated helical polymer of human dynamin-1 in the GMPPCP bound state. The structure defines the helical symmetry of the dynamin polymer and the positions of the oligomeric interfaces, which were validated by cell-based endocytosis assays. Compared to the lipid-free tetramer form2, membrane-associated dynamin binds to the lipid bilayer with its pleckstrin homology domain (PHD) and self-assembles across the helical rungs via the GTPase domain3. Notably, interaction with the membrane and helical assembly is accommodated by a severely bent bundle signaling element (BSE), which connects the GTPase domain with the rest of the protein. The BSE conformation is asymmetric across the inter-rung GTPase interface, and is unique compared to all known nucleotide-bound states of dynamin. The structure suggests that the BSE bends from forces generated from the GTPase dimer interaction that are transferred across the stalk to the PHD and lipid membrane. Mutations disrupting the BSE kink impaired endocytosis. We also report a 10.1 Å resolution cryo-EM map of a super-constricted dynamin polymer showing localized conformational changes at the BSE and GTPase domains induced by GTP hydrolysis that drive membrane constriction. Altogether, the results provide a structural basis for dynamin’s mechanism of action on lipid membrane.
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Affiliation(s)
- Leopold Kong
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Kem A Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Huaibin Wang
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Shunming Fang
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Bertram Canagarajah
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Andrew D Kehr
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - William J Rice
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Marie-Paule Strub
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Justin W Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD, USA
| | - Jenny E Hinshaw
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA.
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