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Alimohamadi H, Luo EWC, Yang R, Gupta S, Nolden KA, Mandal T, Blake Hill R, Wong GCL. Dynamins combine mechano-constriction and membrane remodeling to enable two-step mitochondrial fission via a 'snap-through' instability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.19.608723. [PMID: 39229060 PMCID: PMC11370335 DOI: 10.1101/2024.08.19.608723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Mitochondrial fission is controlled by dynamin proteins, the dysregulation of which is correlated with diverse diseases. Fission dynamins are GTP hydrolysis-driven mechanoenzymes that self-oligomerize into helical structures that constrict membrane to achieve fission, but details are not well understood. However, dynamins can also remodel membranes by inducing negative Gaussian curvature, the type of curvature required for completion of fission. Here, we examine how these drastically different mechanisms synergistically exert their influences on a membrane, via a mechanical model calibrated with small-angle X-ray scattering structural data. We find that free dynamin can trigger a "snap-through instability" that enforces a shape transition from an oligomer-confined cylindrical membrane to a drastically narrower catenoid-shaped neck within the spontaneous hemi-fission regime, in a manner that depends critically on the length of the confined tube. These results indicate how the combination of dynamin assembly, and paradoxically disassembly, can lead to diverse pathways to scission.
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Affiliation(s)
- Haleh Alimohamadi
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90025, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Elizabeth Wei-Chia Luo
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90025, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Rena Yang
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90025, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Shivam Gupta
- Department of Physics, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Kelsey A Nolden
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Taraknath Mandal
- Department of Physics, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - R. Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
- Department of Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, CO, 80045, USA
| | - Gerard C. L. Wong
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90025, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
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2
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Swaminathan U, Pucadyil TJ. Reconstituting membrane fission using a high content and throughput assay. Biochem Soc Trans 2024; 52:1449-1457. [PMID: 38747723 DOI: 10.1042/bst20231325] [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: 03/13/2024] [Revised: 04/21/2024] [Accepted: 05/01/2024] [Indexed: 06/27/2024]
Abstract
Protein-mediated membrane fission has been analyzed both in bulk and at the single event resolution. Studies on membrane fission in vitro using tethers have provided fundamental insights into the process but are low in throughput. In recent years, supported membrane template (SMrT) have emerged as a facile and convenient assay system for membrane fission. SMrTs provide useful information on intermediates in the pathway to fission and are therefore high in content. They are also high in throughput because numerous fission events can be monitored in a single experiment. This review discusses the utility of SMrTs in providing insights into fission pathways and its adaptation to annotate membrane fission functions in proteins.
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Affiliation(s)
- Uma Swaminathan
- Indian Institute of Science Education and Research, Pune, India
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3
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Szewczyk-Roszczenko OK, Roszczenko P, Shmakova A, Finiuk N, Holota S, Lesyk R, Bielawska A, Vassetzky Y, Bielawski K. The Chemical Inhibitors of Endocytosis: From Mechanisms to Potential Clinical Applications. Cells 2023; 12:2312. [PMID: 37759535 PMCID: PMC10527932 DOI: 10.3390/cells12182312] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
Endocytosis is one of the major ways cells communicate with their environment. This process is frequently hijacked by pathogens. Endocytosis also participates in the oncogenic transformation. Here, we review the approaches to inhibit endocytosis, discuss chemical inhibitors of this process, and discuss potential clinical applications of the endocytosis inhibitors.
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Affiliation(s)
| | - Piotr Roszczenko
- Department of Biotechnology, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland; (P.R.); (A.B.)
| | - Anna Shmakova
- CNRS, UMR 9018, Institut Gustave Roussy, Université Paris-Saclay, 94800 Villejuif, France;
| | - Nataliya Finiuk
- Department of Regulation of Cell Proliferation and Apoptosis, Institute of Cell Biology of National Academy of Sciences of Ukraine, Drahomanov 14/16, 79005 Lviv, Ukraine;
| | - Serhii Holota
- Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine; (S.H.); (R.L.)
| | - Roman Lesyk
- Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University, Pekarska 69, 79010 Lviv, Ukraine; (S.H.); (R.L.)
| | - Anna Bielawska
- Department of Biotechnology, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland; (P.R.); (A.B.)
| | - Yegor Vassetzky
- CNRS, UMR 9018, Institut Gustave Roussy, Université Paris-Saclay, 94800 Villejuif, France;
| | - Krzysztof Bielawski
- Department of Synthesis and Technology of Drugs, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland;
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4
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De Angelis G, Badiali C, Chronopoulou L, Palocci C, Pasqua G. Confocal Microscopy Investigations of Biopolymeric PLGA Nanoparticle Uptake in Arabidopsis thaliana L. Cultured Cells and Plantlet Roots. PLANTS (BASEL, SWITZERLAND) 2023; 12:2397. [PMID: 37446957 DOI: 10.3390/plants12132397] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/26/2023] [Accepted: 06/09/2023] [Indexed: 07/15/2023]
Abstract
To date, most endocytosis studies in plant cells have focused on clathrin-dependent endocytosis, while limited evidence is available on clathrin-independent pathways. Since dynamin a is a key protein both in clathrin-mediated endocytosis and in clathrin-independent endocytic processes, this study investigated its role in the uptake of poly-(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs). The experiments were performed on cultured cells and roots of Arabidopsis thaliana. Dynasore was used to inhibit the activity of dynamin-like proteins to investigate whether PLGA NPs enter plant cells through a dynamin-like-dependent or dynamin-like-independent endocytic pathway. Observations were performed by confocal microscopy using a fluorescent probe, coumarin 6, loaded in PLGA NPs. The results showed that both cells and roots of A. thaliana rapidly take up PLGA NPs. Dynasore was administered at different concentrations and exposure times in order to identify the effective ones for inhibitory activity. Treatments with dynasore did not prevent the NPs uptake, as revealed by the presence of fluorescence emission detected in the cytoplasm. At the highest concentration and the longest exposure time to dynasore, the fluorescence of NPs was not visible due to cell death. Thus, the results suggest that, because the NPs' uptake is unaffected by dynasore exposure, NPs can enter cells and roots by following a dynamin-like-independent endocytic pathway.
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Affiliation(s)
- Giulia De Angelis
- Department of Environmental Biology, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Camilla Badiali
- Department of Environmental Biology, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Laura Chronopoulou
- Department of Chemistry, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
- Research Center for Applied Sciences to the Safeguard of Environment and Cultural Heritage (CIABC), Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Cleofe Palocci
- Department of Chemistry, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
- Research Center for Applied Sciences to the Safeguard of Environment and Cultural Heritage (CIABC), Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
| | - Gabriella Pasqua
- Department of Environmental Biology, Sapienza University of Rome, P. le Aldo Moro 5, 00185 Rome, Italy
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5
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Prichard KL, O'Brien NS, Murcia SR, Baker JR, McCluskey A. Role of Clathrin and Dynamin in Clathrin Mediated Endocytosis/Synaptic Vesicle Recycling and Implications in Neurological Diseases. Front Cell Neurosci 2022; 15:754110. [PMID: 35115907 PMCID: PMC8805674 DOI: 10.3389/fncel.2021.754110] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 12/10/2021] [Indexed: 12/17/2022] Open
Abstract
Endocytosis is a process essential to the health and well-being of cell. It is required for the internalisation and sorting of “cargo”—the macromolecules, proteins, receptors and lipids of cell signalling. Clathrin mediated endocytosis (CME) is one of the key processes required for cellular well-being and signalling pathway activation. CME is key role to the recycling of synaptic vesicles [synaptic vesicle recycling (SVR)] in the brain, it is pivotal to signalling across synapses enabling intracellular communication in the sensory and nervous systems. In this review we provide an overview of the general process of CME with a particular focus on two key proteins: clathrin and dynamin that have a central role to play in ensuing successful completion of CME. We examine these two proteins as they are the two endocytotic proteins for which small molecule inhibitors, often of known mechanism of action, have been identified. Inhibition of CME offers the potential to develop therapeutic interventions into conditions involving defects in CME. This review will discuss the roles and the current scope of inhibitors of clathrin and dynamin, providing an insight into how further developments could affect neurological disease treatments.
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Anderson RH, Sochacki KA, Vuppula H, Scott BL, Bailey EM, Schultz MM, Kerkvliet JG, Taraska JW, Hoppe AD, Francis KR. Sterols lower energetic barriers of membrane bending and fission necessary for efficient clathrin-mediated endocytosis. Cell Rep 2021; 37:110008. [PMID: 34788623 PMCID: PMC8620193 DOI: 10.1016/j.celrep.2021.110008] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 08/03/2021] [Accepted: 10/26/2021] [Indexed: 01/16/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is critical for cellular signal transduction, receptor recycling, and membrane homeostasis in mammalian cells. Acute depletion of cholesterol disrupts CME, motivating analysis of CME dynamics in the context of human disorders of cholesterol metabolism. We report that inhibition of post-squalene cholesterol biosynthesis impairs CME. Imaging of membrane bending dynamics and the CME pit ultrastructure reveals prolonged clathrin pit lifetimes and shallow clathrin-coated structures, suggesting progressive impairment of curvature generation correlates with diminishing sterol abundance. Sterol structural requirements for efficient CME include 3′ polar head group and B-ring conformation, resembling the sterol structural prerequisites for tight lipid packing and polarity. Furthermore, Smith-Lemli-Opitz fibroblasts with low cholesterol abundance exhibit deficits in CME-mediated transferrin internalization. We conclude that sterols lower the energetic costs of membrane bending during pit formation and vesicular scission during CME and suggest that reduced CME activity may contribute to cellular phenotypes observed within disorders of cholesterol metabolism. Anderson et al. demonstrate that sterol abundance and identity play a dominant role in facilitating clathrin-mediated endocytosis. Detailed analyses of clathrin-coated pits under sterol depletion support a requirement for sterol-mediated membrane bending during multiple stages of endocytosis, implicating endocytic dysfunction within the pathogenesis of disorders of cholesterol metabolism.
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Affiliation(s)
- Ruthellen H Anderson
- Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA; Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Kem A Sochacki
- Laboratory of Molecular Biophysics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20814, USA
| | - Harika Vuppula
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007, USA; BioSystems Networks and Translational Research Center, Brookings, SD 57007, USA
| | - Brandon L Scott
- Nanoscience and Nanoengineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, USA
| | - Elizabeth M Bailey
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007, USA; BioSystems Networks and Translational Research Center, Brookings, SD 57007, USA
| | - Maycie M Schultz
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Jason G Kerkvliet
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007, USA; BioSystems Networks and Translational Research Center, Brookings, SD 57007, USA
| | - Justin W Taraska
- Laboratory of Molecular Biophysics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20814, USA
| | - Adam D Hoppe
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD 57007, USA; BioSystems Networks and Translational Research Center, Brookings, SD 57007, USA.
| | - Kevin R Francis
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA; Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA.
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7
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Auddya D, Zhang X, Gulati R, Vasan R, Garikipati K, Rangamani P, Rudraraju S. Biomembranes undergo complex, non-axisymmetric deformations governed by Kirchhoff-Love kinematicsand revealed by a three-dimensional computational framework. Proc Math Phys Eng Sci 2021; 477:20210246. [PMID: 35153593 PMCID: PMC8580429 DOI: 10.1098/rspa.2021.0246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 10/11/2021] [Indexed: 01/10/2023] Open
Abstract
Biomembranes play a central role in various phenomena like locomotion of cells, cell-cell interactions, packaging and transport of nutrients, transmission of nerve impulses, and in maintaining organelle morphology and functionality. During these processes, the membranes undergo significant morphological changes through deformation, scission, and fusion. Modelling the underlying mechanics of such morphological changes has traditionally relied on reduced order axisymmetric representations of membrane geometry and deformation. Axisymmetric representations, while robust and extensively deployed, suffer from their inability to model-symmetry breaking deformations and structural bifurcations. To address this limitation, a three-dimensional computational mechanics framework for high fidelity modelling of biomembrane deformation is presented. The proposed framework brings together Kirchhoff–Love thin-shell kinematics, Helfrich-energy-based mechanics, and state-of-the-art numerical techniques for modelling deformation of surface geometries. Lipid bilayers are represented as spline-based surface discretizations immersed in a three-dimensional space; this enables modelling of a wide spectrum of membrane geometries, boundary conditions, and deformations that are physically admissible in a three-dimensional space. The mathematical basis of the framework and its numerical machinery are presented, and their utility is demonstrated by modelling three classical, yet non-trivial, membrane deformation problems: formation of tubular shapes and their lateral constriction, Piezo1-induced membrane footprint generation and gating response, and the budding of membranes by protein coats during endocytosis. For each problem, the full three-dimensional membrane deformation is captured, potential symmetry-breaking deformation paths identified, and various case studies of boundary and load conditions are presented. Using the endocytic vesicle budding as a case study, we also present a ‘phase diagram’ for its symmetric and broken-symmetry states.
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Affiliation(s)
- Debabrata Auddya
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Xiaoxuan Zhang
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Rahul Gulati
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ritvik Vasan
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Krishna Garikipati
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Mathematics, University of Michigan, Ann Arbor, MI 48109, USA.,Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Shiva Rudraraju
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
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8
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Cheng X, Chen K, Dong B, Yang M, Filbrun SL, Myoung Y, Huang TX, Gu Y, Wang G, Fang N. Dynamin-dependent vesicle twist at the final stage of clathrin-mediated endocytosis. Nat Cell Biol 2021; 23:859-869. [PMID: 34253896 PMCID: PMC8355216 DOI: 10.1038/s41556-021-00713-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/09/2021] [Indexed: 12/11/2022]
Abstract
Dynamin plays an important role in clathrin-mediated endocytosis (CME) by cutting the neck of nascent vesicles from the cell membrane. Here through using gold nanorods as cargos to image dynamin action during live CME, we show that near the peak of dynamin accumulation, the cargo-containing vesicles always exhibit abrupt, right-handed rotations that finish in a short time (~0.28 s). The large and quick twist, herein named the super twist, is the result of the coordinated dynamin helix action upon GTP hydrolysis. After the super twist, the rotational freedom of the vesicle drastically increases, accompanied with simultaneous or delayed translational movement, indicating that it detaches from the cell membrane. These observations suggest that dynamin-mediated scission involves a large torque generated by coordinated actions of multiple dynamins in the helix, which is the main driving force for vesicle scission.
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Affiliation(s)
- Xiaodong Cheng
- Department of Chemistry, Georgia State University, Atlanta, GA, USA.,State Key Laboratory of Physical Chemistry of Solid Surfaces, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Kuangcai Chen
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Bin Dong
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Meek Yang
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Seth L Filbrun
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Yong Myoung
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Teng-Xiang Huang
- Department of Chemistry, Georgia State University, Atlanta, GA, USA
| | - Yan Gu
- The Bristol-Myers Squibb Company, Devens, MA, USA
| | - Gufeng Wang
- Department of Chemistry, Georgia State University, Atlanta, GA, USA.
| | - Ning Fang
- Department of Chemistry, Georgia State University, Atlanta, GA, USA. .,State Key Laboratory of Physical Chemistry of Solid Surfaces, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
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9
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Kubota R, Tanaka W, Hamachi I. Microscopic Imaging Techniques for Molecular Assemblies: Electron, Atomic Force, and Confocal Microscopies. Chem Rev 2021; 121:14281-14347. [DOI: 10.1021/acs.chemrev.0c01334] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ryou Kubota
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Wataru Tanaka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- JST-ERATO, Hamachi Innovative Molecular Technology for Neuroscience, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8530, Japan
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10
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Pfitzner AK, Mercier V, Jiang X, Moser von Filseck J, Baum B, Šarić A, Roux A. An ESCRT-III Polymerization Sequence Drives Membrane Deformation and Fission. Cell 2020; 182:1140-1155.e18. [PMID: 32814015 PMCID: PMC7479521 DOI: 10.1016/j.cell.2020.07.021] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 05/04/2020] [Accepted: 07/15/2020] [Indexed: 01/02/2023]
Abstract
The endosomal sorting complex required for transport-III (ESCRT-III) catalyzes membrane fission from within membrane necks, a process that is essential for many cellular functions, from cell division to lysosome degradation and autophagy. How it breaks membranes, though, remains unknown. Here, we characterize a sequential polymerization of ESCRT-III subunits that, driven by a recruitment cascade and by continuous subunit-turnover powered by the ATPase Vps4, induces membrane deformation and fission. During this process, the exchange of Vps24 for Did2 induces a tilt in the polymer-membrane interface, which triggers transition from flat spiral polymers to helical filament to drive the formation of membrane protrusions, and ends with the formation of a highly constricted Did2-Ist1 co-polymer that we show is competent to promote fission when bound on the inside of membrane necks. Overall, our results suggest a mechanism of stepwise changes in ESCRT-III filament structure and mechanical properties via exchange of the filament subunits to catalyze ESCRT-III activity.
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Affiliation(s)
| | - Vincent Mercier
- Department of Biochemistry, University of Geneva, 1211 Geneva, Switzerland; National Center of Competence in Research in Chemical Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Xiuyun Jiang
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK; MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | | | - Buzz Baum
- Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK; MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Anđela Šarić
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK; Institute for the Physics of Living Systems, University College London, Gower Street, London WC1E 6BT, UK; MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, 1211 Geneva, Switzerland; National Center of Competence in Research in Chemical Biology, University of Geneva, 1211 Geneva, Switzerland.
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11
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Spinks GM. Advanced Actuator Materials Powered by Biomimetic Helical Fiber Topologies. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904093. [PMID: 31793710 DOI: 10.1002/adma.201904093] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/18/2019] [Indexed: 06/10/2023]
Abstract
Helical constructs are ubiquitous in nature at all size domains, from molecular to macroscopic. The helical topology confers unique mechanical functions that activate certain phenomena, such as twining vines and vital cellular functions like the folding and packing of DNA into chromosomes. The understanding of active mechanical processes in plants, certain musculature in animals, and some biochemical processes in cells provides insight into the versatility of the helix. Most of these natural systems consist of helically oriented filaments embedded in a compliant matrix. In some cases, the matrix can change volume and in others the filaments can contract and the matrix is passive. In both cases, the helically arranged fibers determine the overall shape change with a great variety of responses involving length contraction/elongation, twisting, bending, and coiling. Synthetic actuator materials and systems that employ helical topologies have been described recently and demonstrate many fascinating and complex shape changes. However, significant new opportunities exist to mimic some of the most remarkable actions in nature, including the Vorticella's coiling stalk and DNA's supercoils, in the quest for superior artificial muscles.
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Affiliation(s)
- Geoffrey M Spinks
- Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW, 2522, Australia
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12
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Gallyas Jr. F, Sumegi B. Mitochondrial Protection by PARP Inhibition. Int J Mol Sci 2020; 21:ijms21082767. [PMID: 32316192 PMCID: PMC7215481 DOI: 10.3390/ijms21082767] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/11/2020] [Accepted: 04/14/2020] [Indexed: 02/07/2023] Open
Abstract
Inhibitors of the nuclear DNA damage sensor and signalling enzyme poly(ADP-ribose) polymerase (PARP) have recently been introduced in the therapy of cancers deficient in double-strand DNA break repair systems, and ongoing clinical trials aim to extend their use from other forms of cancer non-responsive to conventional treatments. Additionally, PARP inhibitors were suggested to be repurposed for oxidative stress-associated non-oncological diseases resulting in a devastating outcome, or requiring acute treatment. Their well-documented mitochondria- and cytoprotective effects form the basis of PARP inhibitors’ therapeutic use for non-oncological diseases, yet can limit their efficacy in the treatment of cancers. A better understanding of the processes involved in their protective effects may improve the PARP inhibitors’ therapeutic potential in the non-oncological indications. To this end, we endeavoured to summarise the basic features regarding mitochondrial structure and function, review the major PARP activation-induced cellular processes leading to mitochondrial damage, and discuss the role of PARP inhibition-mediated mitochondrial protection in several oxidative stress-associated diseases.
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Affiliation(s)
- Ferenc Gallyas Jr.
- Department of Biochemistry and Medical Chemistry, University of Pecs Medical School, 7624 Pecs, Hungary;
- Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary
- HAS-UP Nuclear-Mitochondrial Interactions Research Group, 1245 Budapest, Hungary
- Correspondence: ; Tel.: +36-72-536-278
| | - Balazs Sumegi
- Department of Biochemistry and Medical Chemistry, University of Pecs Medical School, 7624 Pecs, Hungary;
- Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary
- HAS-UP Nuclear-Mitochondrial Interactions Research Group, 1245 Budapest, Hungary
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13
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Vasan R, Rudraraju S, Akamatsu M, Garikipati K, Rangamani P. A mechanical model reveals that non-axisymmetric buckling lowers the energy barrier associated with membrane neck constriction. SOFT MATTER 2020; 16:784-797. [PMID: 31830191 DOI: 10.1039/c9sm01494b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Membrane neck formation is essential for scission, which, as recent experiments on tubules have demonstrated, can be location dependent. The diversity of biological machinery that can constrict a neck such as dynamin, actin, ESCRTs and BAR proteins, and the range of forces and deflection over which they operate, suggest that the constriction process is functionally mechanical and robust to changes in biological environment. In this study, we used a mechanical model of the lipid bilayer to systematically investigate the influence of location, symmetry constraints, and helical forces on membrane neck constriction. Simulations from our model demonstrated that the energy barriers associated with constriction of a membrane neck are location-dependent. Importantly, if symmetry restrictions are relaxed, then the energy barrier for constriction is dramatically lowered and the membrane buckles at lower values of forcing parameters. Our simulations also show that constriction due to helical proteins further reduces the energy barrier for neck formation when compared to cylindrical proteins. These studies establish that despite different molecular mechanisms of neck formation in cells, the mechanics of constriction naturally leads to a loss of symmetry that can lower the energy barrier to constriction.
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Affiliation(s)
- R Vasan
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093, USA.
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14
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Bahrami A, Bahrami AH. Vesicle constriction by rings of Janus nanoparticles and aggregates of curved proteins. NANOTECHNOLOGY 2019; 30:345101. [PMID: 31048566 DOI: 10.1088/1361-6528/ab1ed5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Membrane constriction and associated scission by proteins and nano structures are crucial to many processes in cellular and synthetic biology. We report mechanical constriction of vesicles by rings of adsorbed Janus nanoparticles that represent synthetic nano structures and mimic contractile proteins, and by aggregates of curved crescents that mimic scaffold proteins. Membrane energetics from Monte Carlo simulations and simulated annealing of the elastic membrane model confirms spontaneous vesicle constriction by aggregates of sufficiently-curved crescents of various lengths and by rings of Janus nanoparticles with a variety of ring lengths, particle sizes, and particle area fractions. We show that shorter rings of smaller particles with higher area fractions reinforce the constriction by increasing the energetic drive towards the constricted vesicle with smaller constriction radius. We demonstrate that vesicle constriction by crescent aggregates strongly depends on the crescent curvature. In contrast to aggregates of sufficiently-curved crescents that are capable of inducing full vesicle constriction, those of near flat crescents with negligible curvature leave the vesicle unconstricted. Our results offer promising perspectives for designing membrane-constricting nano structures such as nanoparticle aggregates and clusters of synthetic curved proteins such as DNA origami scaffolds with applications in synthetic biology. Our findings reveal the significant contribution of highly-curved F-BAR domains to cell division and explain how contractile protein rings such as dynamin GTPase, actomyosin rings, and endosomal sorting complexes required for transport constrict the membrane.
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Affiliation(s)
- Arash Bahrami
- School of Mechanical Engineering, College of Engineering, University of Tehran, North Kargar St., 14399-57131 Tehran, Iran
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15
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Abstract
Dynamin proteins assemble into characteristic helical structures around necks of clathrin-coated membrane buds. Hydrolysis of dynamin-bound GTP results in both fission of the membrane neck and partial disruption of the dynamin oligomer. Imaging by atomic force microscopy reveals that, on GTP hydrolysis, dynamin oligomers undergo a dynamic remodeling and lose their distinctive helical shape. While breakup of the dynamin helix is a critical stage in clathrin-mediated endocytosis, the mechanism for this remodeling of the oligomer has not been resolved. In this paper, we formulate an analytical, elasticity-based model for the reshaping and disassembly of the dynamin scaffold. We predict that the shape of the oligomer is modulated by the orientation of dynamin's pleckstrin homology (PH) domain relative to the underlying membrane. Our results indicate that tilt of the PH domain drives deformation and fragmentation of the oligomer, in agreement with experimental observations. This model motivated the introduction of the tilted helix: a curve that maintains a fixed angle between its normal and the normal of the embedding surface. Our findings highlight the importance of tilt as a key regulator of size and morphology of membrane-bound oligomers.
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16
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Bohuszewicz O, Low HH. Structure of a mitochondrial fission dynamin in the closed conformation. Nat Struct Mol Biol 2018; 25:722-731. [PMID: 30061604 PMCID: PMC6104806 DOI: 10.1038/s41594-018-0097-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/26/2018] [Indexed: 01/05/2023]
Abstract
Dynamin 1-like proteins (DNM1-L) are mechanochemical GTPases that induce membrane fission in mitochondria and peroxisomes. Their mechanism depends on conformational changes driven by nucleotide and lipid cycling. Here we show the crystal structure of a mitochondrial fission dynamin (CmDnm1) from the algae Cyanidioschyzon merolae. Unlike other eukaryotic dynamin structures, CmDnm1 is in a hinge 1 closed conformation, with the GTPase domain compacted against the stalk. Within the crystal, CmDnm1 packs as a diamond-shaped tetramer that is consistent with an inactive off-membrane state. Crosslinking, photoinduced electron transfer assays, and electron microscopy verify these structures. In vitro, CmDnm1 forms concentration-dependent rings and protein-lipid tubes reminiscent of DNM1-L and classical dynamin with hinge 1 open. Our data provides a mechanism for filament collapse and membrane release that may extend to other dynamin family members. Additionally, hinge 1 closing may represent a key conformational change that contributes to membrane fission.
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Affiliation(s)
| | - Harry H Low
- Department of Life Sciences, Imperial College, London, UK.
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17
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McDargh ZA, Deserno M. Dynamin's helical geometry does not destabilize membranes during fission. Traffic 2018; 19:328-335. [PMID: 29437294 DOI: 10.1111/tra.12555] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 02/02/2018] [Accepted: 02/04/2018] [Indexed: 11/29/2022]
Abstract
It is now widely accepted that dynamin-mediated fission is a fundamentally mechanical process: dynamin undergoes a GTP-dependent conformational change, constricting the neck between two compartments, somehow inducing their fission. However, the exact connection between dynamin's conformational change and the scission of the neck is still unclear. In this paper, we re-evaluate the suggestion that a change in the pitch or radius of dynamin's helical geometry drives the lipid bilayer through a mechanical instability, similar to a well-known phenomenon occurring in soap films. We find that, contrary to previous claims, there is no such instability. This lends credence to an alternative model, in which dynamin drives the membrane up an energy barrier, allowing thermal fluctuations to take it into the hemifission state.
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Affiliation(s)
- Zachary A McDargh
- Chemical Engineering Department, Columbia University, New York, New York
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania
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18
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Manni MM, Tiberti ML, Pagnotta S, Barelli H, Gautier R, Antonny B. Acyl chain asymmetry and polyunsaturation of brain phospholipids facilitate membrane vesiculation without leakage. eLife 2018. [PMID: 29543154 PMCID: PMC5903860 DOI: 10.7554/elife.34394] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Phospholipid membranes form cellular barriers but need to be flexible enough to divide by fission. Phospholipids generally contain a saturated fatty acid (FA) at position sn1 whereas the sn2-FA is saturated, monounsaturated or polyunsaturated. Our understanding of the impact of phospholipid unsaturation on membrane flexibility and fission is fragmentary. Here, we provide a comprehensive view of the effects of the FA profile of phospholipids on membrane vesiculation by dynamin and endophilin. Coupled to simulations, this analysis indicates that: (i) phospholipids with two polyunsaturated FAs make membranes prone to vesiculation but highly permeable; (ii) asymmetric sn1-saturated-sn2-polyunsaturated phospholipids provide a tradeoff between efficient membrane vesiculation and low membrane permeability; (iii) When incorporated into phospholipids, docosahexaenoic acid (DHA; omega-3) makes membranes more deformable than arachidonic acid (omega-6). These results suggest an explanation for the abundance of sn1-saturated-sn2-DHA phospholipids in synaptic membranes and for the importance of the omega-6/omega-3 ratio on neuronal functions. Surrounding each living cell is a membrane that is mainly made of fat molecules called phospholipids. Similar membranes also surround many of the structures inside cells. It is important for life that these membranes are impermeable to many molecules; for example, they do not allow ions to cross them freely. The membranes also need to be flexible and allow cells to form different shapes. Flexible membranes also allow cells to move molecules around and to divide to produce new cells. Each phospholipid includes two long chains of atoms called fatty acids. There are many fatty acids but they are typically grouped into saturated and unsaturated based on their chemical structures. The omega-3 and omega-6 fats are both groups of unsaturated fatty acids that are found in brain cells. Many phospholipids in cell membranes contain one saturated and one unsaturated fatty acid but it is not clear why. By studying fat molecules in the laboratory and combining this with simulations, Manni et al. have now examined the effects of fatty acids on membranes. The investigation showed that phospholipids with both saturated and unsaturated fatty acids strike a balance between impermeable and flexible membranes. More unsaturated fatty acids make more flexible membranes but they are too permeable to be used in cells. The experiments also revealed that omega-3 unsaturated fats aid flexibility more than omega-6. This finding may help to explain why the relative amounts of omega-3 and -6 are so important in the membranes of brain cells. The connection between the fats we eat and the fatty acids in our cells is complex. Yet, findings like these serve to remind us that we need a balanced diet of different fats to keep all our cells healthy.
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Affiliation(s)
- Marco M Manni
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France.,Instituto Biofisika (UPV/EHU, CSIC), Leioa, Spain
| | - Marion L Tiberti
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquée, Université Côte d'Azur, Nice, France
| | - Hélène Barelli
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
| | - Romain Gautier
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
| | - Bruno Antonny
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Côte d'Azur et CNRS, Valbonne, France
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19
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Dey A, Kamat A, Nayak S, Danino D, Kesselman E, Dandekar P, Jain R. Role of proton balance in formation of self-assembled chitosan nanoparticles. Colloids Surf B Biointerfaces 2018; 166:127-134. [PMID: 29558703 DOI: 10.1016/j.colsurfb.2018.03.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 02/08/2018] [Accepted: 03/13/2018] [Indexed: 11/17/2022]
Abstract
Researchers have explored the ability of chitosan to form nanoparticles, to suit varying applications, ranging from wound-healing to gene delivery. Ionic gelation is a widely used method for formulating chitosan nanoparticles, where self-assembly plays a crucial role. This self-assembly is initially promoted by hydrophilic-hydrophobic parity amongst individual chitosan residues, along with electrostatic and Van der Waals interactions with the cross-linker. However, until now the intrinsic ability of chitosan to self-assemble is not widely studied; hence, we investigate the self-assembly of chitosan, based on proton balance between its protonated and deprotonated residues, to promote facile nanoparticle synthesis. This is one of the first reports that highlights subtle but critical influence of proton balance in the chitosan polymer on the formation of chitosan nanoparticles.
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Affiliation(s)
- Anomitra Dey
- Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Aditya Kamat
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Sonal Nayak
- Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Dganit Danino
- Department of Biotechnology & Food Engineering, Technion - Israel Institute of Technology, Hafia 3200003, Israel
| | - Ellina Kesselman
- Department of Biotechnology & Food Engineering, Technion - Israel Institute of Technology, Hafia 3200003, Israel
| | - Prajakta Dandekar
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
| | - Ratnesh Jain
- Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
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20
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Direct imaging and computational cryo-electron microscopy of ribbons and nanotubes. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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21
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Su J, Thomas AS, Grabietz T, Landgraf C, Volkmer R, Marrink SJ, Williams C, Melo MN. The N-terminal amphipathic helix of Pex11p self-interacts to induce membrane remodelling during peroxisome fission. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1292-1300. [PMID: 29501607 DOI: 10.1016/j.bbamem.2018.02.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/07/2018] [Accepted: 02/27/2018] [Indexed: 10/17/2022]
Abstract
Pex11p plays a crucial role in peroxisome fission. Previously, it was shown that a conserved N-terminal amphipathic helix in Pex11p, termed Pex11-Amph, was necessary for peroxisomal fission in vivo while in vitro studies revealed that this region alone was sufficient to bring about tubulation of liposomes with a lipid consistency resembling the peroxisomal membrane. However, molecular details of how Pex11-Amph remodels the peroxisomal membrane remain unknown. Here we have combined in silico, in vitro and in vivo approaches to gain insights into the molecular mechanisms underlying Pex11-Amph activity. Using molecular dynamics simulations, we observe that Pex11-Amph peptides form linear aggregates on a model membrane. Furthermore, we identify mutations that disrupted this aggregation in silico, which also abolished the peptide's ability to remodel liposomes in vitro, establishing that Pex11p oligomerisation plays a direct role in membrane remodelling. In vivo studies revealed that these mutations resulted in a strong reduction in Pex11 protein levels, indicating that these residues are important for Pex11p function. Taken together, our data demonstrate the power of combining in silico techniques with experimental approaches to investigate the molecular mechanisms underlying Pex11p-dependent membrane remodelling.
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Affiliation(s)
- Juanjuan Su
- Molecular Dynamics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Ann S Thomas
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Tanja Grabietz
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Christiane Landgraf
- Institut für Medizinische Immunologie, Charité-Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Rudolf Volkmer
- Institut für Medizinische Immunologie, Charité-Universitätsmedizin Berlin, 10115 Berlin, Germany; Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany
| | - Siewert J Marrink
- Molecular Dynamics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Chris Williams
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Manuel N Melo
- Molecular Dynamics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands; Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
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22
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Johannes L, Pezeshkian W, Ipsen JH, Shillcock JC. Clustering on Membranes: Fluctuations and More. Trends Cell Biol 2018; 28:405-415. [PMID: 29502867 DOI: 10.1016/j.tcb.2018.01.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 12/18/2022]
Abstract
Clustering of extracellular ligands and proteins on the plasma membrane is required to perform specific cellular functions, such as signaling and endocytosis. Attractive forces that originate in perturbations of the membrane's physical properties contribute to this clustering, in addition to direct protein-protein interactions. However, these membrane-mediated forces have not all been equally considered, despite their importance. In this review, we describe how line tension, lipid depletion, and membrane curvature contribute to membrane-mediated clustering. Additional attractive forces that arise from protein-induced perturbation of a membrane's fluctuations are also described. This review aims to provide a survey of the current understanding of membrane-mediated clustering and how this supports precise biological functions.
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Affiliation(s)
- Ludger Johannes
- Institut Curie, PSL Research University, Cellular and Chemical Biology unit, INSERM U 1143, CNRS UMR 3666, 26 rue d'Ulm, 75248 Paris Cedex 05, France.
| | - Weria Pezeshkian
- Center for Biomembrane Physics (MEMPHYS), Department of Physics, Chemistry and Pharmacy (FKF), University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - John H Ipsen
- Center for Biomembrane Physics (MEMPHYS), Department of Physics, Chemistry and Pharmacy (FKF), University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
| | - Julian C Shillcock
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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23
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Manni MM, Derganc J, Čopič A. Crowd-Sourcing of Membrane Fission. Bioessays 2017; 39. [DOI: 10.1002/bies.201700117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/06/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Marco M. Manni
- Université Côte d'Azur; CNRS, IPMC; 06560 Valbonne France
| | - Jure Derganc
- Institute of Biophysics; Faculty of Medicine; University of Ljubljana; 1000 Ljubljana Slovenia
| | - Alenka Čopič
- Institut Jacques Monod, CNRS UMR 7592; Université Paris Diderot; Sorbonne Paris Cité 75013 Paris France
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24
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McDargh ZA, Vázquez-Montejo P, Guven J, Deserno M. Constriction by Dynamin: Elasticity versus Adhesion. Biophys J 2017; 111:2470-2480. [PMID: 27926848 DOI: 10.1016/j.bpj.2016.10.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 09/29/2016] [Accepted: 10/17/2016] [Indexed: 02/01/2023] Open
Abstract
Any cellular fission process is completed when the neck connecting almost-separate membrane compartments is severed. This crucial step is somehow accomplished by proteins from the dynamin family, which polymerize into helical spirals around such necks. Much research has been devoted to elucidating the specifics of that somehow, but despite no shortage of ideas, the question is not settled. Pictorially obvious notions of strangling or pushing are difficult to render in mechanically precise terms. Moreover, because dynamin is a GTPase, it is tempting to speculate that it has a motor activity that assists the necessary severing action, but again the underlying mechanics is not obvious. We believe the difficulty to be the mechanically nontrivial nature of confining elastic filaments onto curved surfaces, for which efficient methods to conceptualize the associated forces and torques have only recently appeared. Here we investigate the implications of a conceptually simple yet mechanically challenging model: consider an elastic helical filament confined to a surface mimicking the neck between two membrane compartments, which we assume to take the shape of a catenoid. What can we say about the expected length of such adsorbed filaments, their shapes, and the forces they exert, as a function of the key parameters in the model? While real dynamin is surely more complex, we consider such a minimal model to be the indispensable baseline. Without knowing what such a model can and cannot explain, it is difficult to justify more complex mechanisms, or understand the constraints under which this machinery evolved in the first place.
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Affiliation(s)
- Zachary A McDargh
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania.
| | - Pablo Vázquez-Montejo
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois
| | - Jemal Guven
- Department of Gravitation and Field Theory, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Markus Deserno
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania
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25
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Salova AV, Belyaeva TN, Leontieva EA, Kornilova ES. EGF receptor lysosomal degradation is delayed in the cells stimulated with EGF-Quantum dot bioconjugate but earlier key events of endocytic degradative pathway are similar to that of native EGF. Oncotarget 2017; 8:44335-44350. [PMID: 28574831 PMCID: PMC5546484 DOI: 10.18632/oncotarget.17873] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 04/30/2017] [Indexed: 02/06/2023] Open
Abstract
Quantum dots (QDs) complexed to ligands recognizing surface receptors undergoing internalization are an attractive tool for live cell imaging of ligand-receptor complexes behavior and for specific tracking of the cells of interest. However, conjugation of quasi-multivalent large QD-particle to monovalent small growth factors like EGF that bound their tyrosine-kinase receptors may affect key endocytic events tightly bound to signaling. Here, by means of confocal microscopy we have addressed the key endocytic events of lysosomal degradative pathway stimulated by native EGF or EGF-QD bioconjugate. We have demonstrated that the decrease in endosome number, increase in mean endosome integrated density and the pattern of EEA1 co-localization with EGF-EGFR complexes at early stages of endocytosis were similar for the both native and QD-conjugated ligands. In both cases enlarged hollow endosomes appeared after wortmannin treatment. This indicates that early endosomal fusions and their maturation proceed similar for both ligands. EGF-QD and native EGF similarly accumulated in juxtanuclear region, and live cell imaging of endosome motion revealed the behavior described elsewhere for microtubule-facilitated motility. Finally, EGF-QD and the receptor were found in lysosomes. However, degradation of receptor part of QD-EGF-EGFR-complex was delayed compared to native EGF, but not inhibited, while QDs fluorescence was detected in lysosomes even after 24 hours. Importantly, in HeLa and A549 cells the both ligands behaved similarly. We conclude that during endocytosis EGF-QD behaves as a neutral marker for degradative pathway up to lysosomal stage and can also be used as a long-term cell marker.
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Affiliation(s)
- Anna V. Salova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Tatiana N. Belyaeva
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
| | | | - Elena S. Kornilova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia
- Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- St. Petersburg State University, St. Petersburg, Russia
- ITMO University, St. Petersburg, Russia
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26
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Abstract
Mitochondria are dynamic organelles that continually adapt their morphology by fusion and fission events. An imbalance between fusion and fission has been linked to major neurodegenerative diseases, including Huntington's, Alzheimer's, and Parkinson's diseases. A member of the Dynamin superfamily, dynamin-related protein 1 (DRP1), a dynamin-related GTPase, is required for mitochondrial membrane fission. Self-assembly of DRP1 into oligomers in a GTP-dependent manner likely drives the division process. We show here that DRP1 self-assembles in two ways: i) in the presence of the non-hydrolysable GTP analog GMP-PNP into spiral-like structures of ~36 nm diameter; and ii) in the presence of GTP into rings composed of 13-18 monomers. The most abundant rings were composed of 16 monomers and had an outer and inner ring diameter of ~30 nm and ~20 nm, respectively. Three-dimensional analysis was performed with rings containing 16 monomers. The single-particle cryo-electron microscopy map of the 16 monomer DRP1 rings suggests a side-by-side assembly of the monomer with the membrane in a parallel fashion. The inner ring diameter of 20 nm is insufficient to allow four membranes to exist as separate entities. Furthermore, we observed that mitochondria were tubulated upon incubation with DRP1 protein in vitro. The tubes had a diameter of ~ 30nm and were decorated with protein densities. These findings suggest DRP1 tubulates mitochondria, and that additional steps may be required for final mitochondrial fission.
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27
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Abstract
Exocytosis is an important cellular process controlled by metabolic signaling. It involves vesicle fusion to the plasma membrane, followed by the opening of a fusion pore, and the subsequent release of the vesicular lumen content into the extracellular space. While most modeling efforts focus on the events leading to membrane fusion, how the vesicular membrane remodels after fusing to plasma membrane remains unclear. This latter event dictates the nature and the efficiency of exocytotic vesicular secretions, and is thus critical for exocytotic function. We provide a generic membrane mechanical model to systematically study the fate of post-fusion vesicles. We show that while membrane stiffness favors full-collapse vesicle fusion into the plasma membrane, the intravesicular pressure swells the vesicle and causes the fusion pore to shrink. Dimensions of the vesicle and its associated fusion pore further modulate this mechanical antagonism. We systematically define the mechanical conditions that account for the full spectrum of the observed vesicular secretion modes. Our model therefore can serve as a unified theoretical framework that sheds light on the elaborate control mechanism of exocytosis.
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Affiliation(s)
- Thomas Stephens
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States of America. Equal contribution
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28
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Dynamic remodeling of the dynamin helix during membrane constriction. Proc Natl Acad Sci U S A 2017; 114:5449-5454. [PMID: 28484031 DOI: 10.1073/pnas.1619578114] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dynamin is a dimeric GTPase that assembles into a helix around the neck of endocytic buds. Upon GTP hydrolysis, dynamin breaks these necks, a reaction called membrane fission. Fission requires dynamin to first constrict the membrane. It is unclear, however, how dynamin helix constriction works. Here we undertake a direct high-speed atomic force microscopy imaging analysis to visualize the constriction of single dynamin-coated membrane tubules. We show GTP-induced dynamic rearrangements of the dynamin helix turns: the average distances between turns reduce with GTP hydrolysis. These distances vary, however, over time because helical turns were observed to transiently pair and dissociate. At fission sites, these cycles of association and dissociation were correlated with relative lateral displacement of the turns and constriction. Our findings show relative longitudinal and lateral displacements of helical turns related to constriction. Our work highlights the potential of high-speed atomic force microscopy for the observation of mechanochemical proteins onto membranes during action at almost molecular resolution.
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29
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Singh M, Jadhav HR, Bhatt T. Dynamin Functions and Ligands: Classical Mechanisms Behind. Mol Pharmacol 2017; 91:123-134. [PMID: 27879341 DOI: 10.1124/mol.116.105064] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 11/17/2016] [Indexed: 12/21/2022] Open
Abstract
Dynamin is a GTPase that plays a vital role in clathrin-dependent endocytosis and other vesicular trafficking processes by acting as a pair of molecular scissors for newly formed vesicles originating from the plasma membrane. Dynamins and related proteins are important components for the cleavage of clathrin-coated vesicles, phagosomes, and mitochondria. These proteins help in organelle division, viral resistance, and mitochondrial fusion/fission. Dysfunction and mutations in dynamin have been implicated in the pathophysiology of various disorders, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Charcot-Marie-Tooth disease, heart failure, schizophrenia, epilepsy, cancer, dominant optic atrophy, osteoporosis, and Down's syndrome. This review is an attempt to illustrate the dynamin-related mechanisms involved in the above-mentioned disorders and to help medicinal chemists to design novel dynamin ligands, which could be useful in the treatment of dynamin-related disorders.
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Affiliation(s)
- Mahaveer Singh
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Pilani Campus, Rajasthan, India
| | - Hemant R Jadhav
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Pilani Campus, Rajasthan, India
| | - Tanya Bhatt
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Pilani Campus, Rajasthan, India
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30
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Antonny B, Burd C, De Camilli P, Chen E, Daumke O, Faelber K, Ford M, Frolov VA, Frost A, Hinshaw JE, Kirchhausen T, Kozlov MM, Lenz M, Low HH, McMahon H, Merrifield C, Pollard TD, Robinson PJ, Roux A, Schmid S. Membrane fission by dynamin: what we know and what we need to know. EMBO J 2016; 35:2270-2284. [PMID: 27670760 PMCID: PMC5090216 DOI: 10.15252/embj.201694613] [Citation(s) in RCA: 349] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/25/2016] [Indexed: 12/04/2022] Open
Abstract
The large GTPase dynamin is the first protein shown to catalyze membrane fission. Dynamin and its related proteins are essential to many cell functions, from endocytosis to organelle division and fusion, and it plays a critical role in many physiological functions such as synaptic transmission and muscle contraction. Research of the past three decades has focused on understanding how dynamin works. In this review, we present the basis for an emerging consensus on how dynamin functions. Three properties of dynamin are strongly supported by experimental data: first, dynamin oligomerizes into a helical polymer; second, dynamin oligomer constricts in the presence of GTP; and third, dynamin catalyzes membrane fission upon GTP hydrolysis. We present the two current models for fission, essentially diverging in how GTP energy is spent. We further discuss how future research might solve the remaining open questions presently under discussion.
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Affiliation(s)
- Bruno Antonny
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis, Valbonne, France
| | - Christopher Burd
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Pietro De Camilli
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Elizabeth Chen
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Oliver Daumke
- Department of Crystallography, Max-Delbrück Centrum für Molekulare Medizin, Berlin, Germany
| | - Katja Faelber
- Department of Crystallography, Max-Delbrück Centrum für Molekulare Medizin, Berlin, Germany
| | - Marijn Ford
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Vadim A Frolov
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, Leioa, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Jenny E Hinshaw
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Tom Kirchhausen
- Departments of Cell Biology and Pediatrics, Harvard Medical School, Boston, MA, USA.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Martin Lenz
- LPTMS, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Harry H Low
- Department of Life Sciences, Imperial College, London, UK
| | | | | | - Thomas D Pollard
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | - Aurélien Roux
- Department of Biochemistry and Swiss NCCR Chemical Biology, University of Geneva, Geneva 4, Switzerland
| | - Sandra Schmid
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
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31
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Liu S, Gao Y, Zhang C, Li H, Pan S, Wang X, Du S, Deng Z, Wang L, Song Z, Chen S. SAMM50 Affects Mitochondrial Morphology through the Association of Drp1 in Mammalian Cells. FEBS Lett 2016; 590:1313-23. [PMID: 27059175 DOI: 10.1002/1873-3468.12170] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/13/2016] [Accepted: 03/31/2016] [Indexed: 01/31/2023]
Abstract
Mitochondrial fission and fusion activities are important for cell survival and function. Drp1 is a GTPase protein responsible for mitochondrial division, and SAMM50 is responsible for protein sorting and assembly. We demonstrated that SAMM50 overexpression results in Drp1-dependent mitochondrial fragmentation in HeLa cells. However, the mitochondrial fragmentation induced by SAMM50 overexpression could be reversed through co-expression with MFN2. Furthermore, SAMM50 interacts with Drp1 both in vivo and in vitro. The mitochondria in SAMM50 knockdown HeLa cells displayed a swollen phenotype, and the levels of the SAM complex and OPA1, along with the mitochondrial Drp1 levels, significantly decreased. In addition, mitochondrial inheritance was impaired in SAMM50 silenced cells. These results suggest that SAMM50 affects the Drp1-dependent mitochondrial morphology.
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Affiliation(s)
- Shuo Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
| | - Yali Gao
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China.,Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Cheng Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
| | - Han Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
| | - Shiyi Pan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China.,Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Xiaoli Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
| | - Shiming Du
- Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
| | - Lianrong Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
| | - Zhiyin Song
- College of Life Sciences, Wuhan University, Hubei, China
| | - Shi Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Medical Research Institute, Wuhan University, Hubei, China
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32
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Two Small Molecules Block Oral Epithelial Cell Invasion by Porphyromons gingivalis. PLoS One 2016; 11:e0149618. [PMID: 26894834 PMCID: PMC4760928 DOI: 10.1371/journal.pone.0149618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/03/2016] [Indexed: 11/25/2022] Open
Abstract
Porphyromonas gingivalis is a keystone pathogen of periodontitis. One of its bacterial characteristics is the ability to invade various host cells, including nonphagocytic epithelial cells and fibroblasts, which is known to facilitate P. gingivalis adaptation and survival in the gingival environment. In this study, we investigated two small compounds, Alop1 and dynasore, for their role in inhibition of P. gingivalis invasion. Using confocal microscopy, we showed that these two compounds significantly reduced invasion of P. gingivalis and its outer membrane vesicles into human oral keratinocytes in a dose-dependent manner. The inhibitory effects of dynasore, a dynamin inhibitor, on the bacterial entry is consistent with the notion that P. gingivalis invasion is mediated by a clathrin-mediated endocytic machinery. We also observed that microtubule arrangement, but not actin, was altered in the host cells treated with Alop1 or dynasore, suggesting an involvement of microtubule in this inhibitory activity. This work provides an opportunity to develop compounds against P. gingivalis infection.
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33
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A high-throughput platform for real-time analysis of membrane fission reactions reveals dynamin function. Nat Cell Biol 2015; 17:1588-96. [PMID: 26479317 DOI: 10.1038/ncb3254] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 09/15/2015] [Indexed: 12/11/2022]
Abstract
Dynamin, the paradigmatic membrane fission catalyst, assembles as helical scaffolds that hydrolyse GTP to sever the tubular necks of clathrin-coated pits. Using a facile assay system of supported membrane tubes (SMrT) engineered to mimic the dimensions of necks of clathrin-coated pits, we monitor the dynamics of a dynamin-catalysed tube-severing reaction in real time using fluorescence microscopy. We find that GTP hydrolysis by an intact helical scaffold causes progressive constriction of the underlying membrane tube. On reaching a critical dimension of 7.3 nm in radius, the tube undergoes scission and concomitant splitting of the scaffold. In a constant GTP turnover scenario, scaffold assembly and GTP hydrolysis-induced tube constriction are kinetically inseparable events leading to tube-severing reactions occurring at timescales similar to the characteristic fission times seen in vivo. We anticipate SMrT templates to allow dynamic fluorescence-based detection of conformational changes occurring in self-assembling proteins that remodel membranes.
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34
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Richter V, Singh AP, Kvansakul M, Ryan MT, Osellame LD. Splitting up the powerhouse: structural insights into the mechanism of mitochondrial fission. Cell Mol Life Sci 2015; 72:3695-707. [PMID: 26059473 PMCID: PMC11113115 DOI: 10.1007/s00018-015-1950-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/04/2015] [Accepted: 06/04/2015] [Indexed: 01/19/2023]
Abstract
Mitochondria are dynamic organelles whose shape is regulated by the opposing processes of fission and fusion, operating in conjunction with organelle distribution along the cytoskeleton. The importance of fission and fusion homeostasis has been highlighted by a number of disease states linked to mutations in proteins involved in regulating mitochondrial morphology, in addition to changes in mitochondrial dynamics in Alzheimer's, Huntington's and Parkinson's diseases. While a number of mitochondrial morphology proteins have been identified, how they co-ordinate to assemble the fission apparatus is not clear. In addition, while the master mediator of mitochondrial fission, dynamin-related protein 1, is conserved throughout evolution, the adaptor proteins involved in its mitochondrial recruitment are not. This review focuses on our current understanding of mitochondrial fission and the proteins that regulate this process in cell homeostasis, with a particular focus on the recent mechanistic insights based on protein structures.
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Affiliation(s)
- Viviane Richter
- La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, 3086, Australia
| | - Abeer P Singh
- La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, 3086, Australia
| | - Marc Kvansakul
- La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, 3086, Australia
| | - Michael T Ryan
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, 3800, Australia.
| | - Laura D Osellame
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, 3800, Australia.
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35
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Rujiviphat J, Wong MK, Won A, Shih YL, Yip CM, McQuibban GA. Mitochondrial Genome Maintenance 1 (Mgm1) Protein Alters Membrane Topology and Promotes Local Membrane Bending. J Mol Biol 2015; 427:2599-609. [PMID: 25784211 DOI: 10.1016/j.jmb.2015.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 11/25/2022]
Abstract
Large GTPases of the dynamin superfamily promote membrane fusion and division, processes that are crucial for intracellular trafficking and organellar dynamics. To promote membrane scission, dynamin proteins polymerize, wrap around, and constrict the membrane; however, the mechanism underlying their role in membrane fusion remains unclear. We previously reported that the mitochondrial dynamin-related protein mitochondrial genome maintenance 1 (Mgm1) mediates fusion by first tethering opposing membranes and then undergoing a nucleotide-dependent structural transition. However, it is still unclear how Mgm1 directly affects the membrane to drive fusion of tethered membranes. Here, we show that Mgm1 association with the membrane alters the topography of the membrane, promoting local membrane bending. We also demonstrate that Mgm1 creates membrane ruffles resulting in the formation of tubular structures on both supported lipid bilayers and liposomes. These data suggest that Mgm1 membrane interactions impose a mechanical force on the membrane to overcome the hydrophilic repulsion of the phospholipid head groups and initiate the fusion reaction. The work reported here provides new insights into a possible mechanism of Mgm1-driven mitochondrial membrane fusion and sheds light into how members of the dynamin superfamily function as fusion molecules.
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Affiliation(s)
- Jarungjit Rujiviphat
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Michael K Wong
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9
| | - Amy Won
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9
| | - Yu-Ling Shih
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Christopher M Yip
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3E5
| | - G Angus McQuibban
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8.
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36
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Francy CA, Alvarez FJD, Zhou L, Ramachandran R, Mears JA. The mechanoenzymatic core of dynamin-related protein 1 comprises the minimal machinery required for membrane constriction. J Biol Chem 2015; 290:11692-703. [PMID: 25770210 DOI: 10.1074/jbc.m114.610881] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Indexed: 11/06/2022] Open
Abstract
Mitochondria are dynamic organelles that continually undergo cycles of fission and fusion. Dynamin-related protein 1 (Drp1), a large GTPase of the dynamin superfamily, is the main mediator of mitochondrial fission. Like prototypical dynamin, Drp1 is composed of a mechanochemical core consisting of the GTPase, middle, and GTPase effector domain regions. In place of the pleckstrin homology domain in dynamin, however, Drp1 contains an unstructured variable domain, whose function is not yet fully resolved. Here, using time-resolved EM and rigorous statistical analyses, we establish the ability of full-length Drp1 to constrict lipid bilayers through a GTP hydrolysis-dependent mechanism. We also show the variable domain limits premature Drp1 assembly in solution and promotes membrane curvature. Furthermore, the mechanochemical core of Drp1, absent of the variable domain, is sufficient to mediate GTP hydrolysis-dependent membrane constriction.
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Affiliation(s)
- Christopher A Francy
- From the Department of Pharmacology, Center for Mitochondrial Diseases, and Cleveland Center for Membrane and Structural Biology, and
| | - Frances J D Alvarez
- From the Department of Pharmacology, Center for Mitochondrial Diseases, and Cleveland Center for Membrane and Structural Biology, and
| | - Louie Zhou
- From the Department of Pharmacology, Center for Mitochondrial Diseases, and Cleveland Center for Membrane and Structural Biology, and
| | - Rajesh Ramachandran
- Cleveland Center for Membrane and Structural Biology, and the Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Jason A Mears
- From the Department of Pharmacology, Center for Mitochondrial Diseases, and Cleveland Center for Membrane and Structural Biology, and
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37
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Fuhrmans M, Müller M. Coarse-grained simulation of dynamin-mediated fission. SOFT MATTER 2015; 11:1464-1480. [PMID: 25523542 DOI: 10.1039/c4sm02533d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fission is a process in which a region of a lipid bilayer is deformed and separated from its host membrane, so that an additional, topologically independent compartment surrounded by a continuous lipid bilayer is formed. It is a fundamental process in the organization of the compartmentalization of living organisms and carefully regulated by a number of membrane-shaping proteins. An important group within these is the dynamin family of proteins that are involved in the final severance of the hourglass-shaped neck, via which the growing compartment remains connected to the main volume until the completion of fission. We present computer simulations testing different hypotheses of how dynamin proteins facilitate fission by constriction and curvature. Our results on constraint-induced fission of cylindrical membrane tubes emphasize the importance of the local creation of positive curvature and reveal a complex picture of fission, in which the topological transformation can become arrested in an intermediate stage if the proteins constituting the fission machinery are not adaptive.
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Affiliation(s)
- Marc Fuhrmans
- Institut für Theoretische Physik, Georg-August Universität, Germany.
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38
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Schweitzer Y, Kozlov MM. Membrane-mediated interaction between strongly anisotropic protein scaffolds. PLoS Comput Biol 2015; 11:e1004054. [PMID: 25710602 PMCID: PMC4339200 DOI: 10.1371/journal.pcbi.1004054] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/21/2014] [Indexed: 12/29/2022] Open
Abstract
Specialized proteins serve as scaffolds sculpting strongly curved membranes of intracellular organelles. Effective membrane shaping requires segregation of these proteins into domains and is, therefore, critically dependent on the protein-protein interaction. Interactions mediated by membrane elastic deformations have been extensively analyzed within approximations of large inter-protein distances, small extents of the protein-mediated membrane bending and small deviations of the protein shapes from isotropic spherical segments. At the same time, important classes of the realistic membrane-shaping proteins have strongly elongated shapes with large and highly anisotropic curvature. Here we investigated, computationally, the membrane mediated interaction between proteins or protein oligomers representing membrane scaffolds with strongly anisotropic curvature, and addressed, quantitatively, a specific case of the scaffold geometrical parameters characterizing BAR domains, which are crucial for membrane shaping in endocytosis. In addition to the previously analyzed contributions to the interaction, we considered a repulsive force stemming from the entropy of the scaffold orientation. We computed this interaction to be of the same order of magnitude as the well-known attractive force related to the entropy of membrane undulations. We demonstrated the scaffold shape anisotropy to cause a mutual aligning of the scaffolds and to generate a strong attractive interaction bringing the scaffolds close to each other to equilibrium distances much smaller than the scaffold size. We computed the energy of interaction between scaffolds of a realistic geometry to constitute tens of kBT, which guarantees a robust segregation of the scaffolds into domains.
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Affiliation(s)
- Yonatan Schweitzer
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael M. Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail:
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39
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Li G, Zhou J, Budhraja A, Hu X, Chen Y, Cheng Q, Liu L, Zhou T, Li P, Liu E, Gao N. Mitochondrial translocation and interaction of cofilin and Drp1 are required for erucin-induced mitochondrial fission and apoptosis. Oncotarget 2015; 6:1834-49. [PMID: 25595902 PMCID: PMC4359335 DOI: 10.18632/oncotarget.2795] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 11/20/2014] [Indexed: 01/12/2023] Open
Abstract
Cofilin is a member of the actin-depolymerizing factor (ADF) family protein, which plays an essential role in regulation of the mitochondrial apoptosis. It remains unclear how cofilin regulates the mitochondrial apoptosis. Here, we report for the first time that natural compound 4-methylthiobutyl isothiocyanate (erucin) found in consumable cruciferous vegetables induces mitochondrial fission and apoptosis in human breast cancer cells through the mitochondrial translocation of cofilin. Importantly, cofilin regulates erucin-induced mitochondrial fission by interacting with dynamin-related protein (Drp1). Knockdown of cofilin or Drp1 markedly reduced erucin-mediated mitochondrial translocation and interaction of cofilin and Drp1, mitochondrial fission, and apoptosis. Only dephosphorylated cofilin (Ser 3) and Drp1 (Ser 637) are translocated to the mitochondria. Cofilin S3E and Drp1 S637D mutants, which mimick the phosphorylated forms, suppressed mitochondrial translocation, fission, and apoptosis. Moreover, both dephosphorylation and mitochondrial translocation of cofilin and Drp1 are dependent on ROCK1 activation. In vivo findings confirmed that erucin-mediated inhibition of tumor growth in a breast cancer cell xenograft mouse model is associated with the mitochondrial translocation of cofilin and Drp1, fission and apoptosis. Our study reveals a novel role of cofilin in regulation of mitochondrial fission and suggests erucin as a potential drug for treatment of breast cancer.
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Affiliation(s)
- Guobing Li
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Jing Zhou
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Amit Budhraja
- 3 Cell & Molecular Biology, St. Jude Children's Research Hospital, Memphis TN 38105, USA
| | - Xiaoye Hu
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Yibiao Chen
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Qi Cheng
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Lei Liu
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Ting Zhou
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
| | - Ping Li
- 2 State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Ehu Liu
- 2 State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Ning Gao
- 1 College of Pharmacy, 3rd Military Medical University, Chongqing 400038, China
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40
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Mishra R, Smaczynska-de Rooij II, Goldberg MW, Ayscough KR. Expression of Vps1 I649K, a self-assembly defective yeast dynamin, leads to formation of extended endocytic invaginations. Commun Integr Biol 2014. [DOI: 10.4161/cib.14206] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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41
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Abstract
Among the proteins involved in lipid membrane remodeling in intracellular traffic, dynamin has been the focus of many studies, as it was the first protein shown to be mechanistically involved in membrane fission: the reaction by which a vesicle neck can be severed to release a free vesicle. After almost 25 years of research, a wide variety of data from various techniques has been acquired on the mechanism by which dynamin breaks membranes. However, the literature may sometimes sound confusing, and the primary goal of this review will be to provide a stepping stone towards a potential consensus on how dynamin may work. I will then discuss the most recent findings in light of previous work, and the future possible lines of research in the field of dynamin.
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42
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Abstract
Dynamin is a large GTPase that mediates plasma membrane fission during clathrin-mediated endocytosis. Dynamin assembles into polymers on the necks of budding membranes in cells and has been shown to undergo GTP-dependent conformational changes that lead to membrane fission in vitro. Recent efforts have shed new light on the mechanisms of dynamin-mediated fission, yet exactly how dynamin performs this function in vivo is still not fully understood. Dynamin interacts with a number of proteins during the endocytic process. These interactions are mediated by the C-terminal proline-rich domain (PRD) of dynamin binding to SH3 domain-containing proteins. Three of these dynamin-binding partners (intersectin, amphiphysin and endophilin) have been shown to play important roles in the clathrin-mediated endocytosis process. They promote dynamin-mediated plasma membrane fission by regulating three important sequential steps in the process: recruitment of dynamin to sites of endocytosis; assembly of dynamin into a functional fission complex at the necks of clathrin-coated pits (CCPs); and regulation of dynamin-stimulated GTPase activity, a key requirement for fission.
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43
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Pinot M, Vanni S, Pagnotta S, Lacas-Gervais S, Payet LA, Ferreira T, Gautier R, Goud B, Antonny B, Barelli H. Lipid cell biology. Polyunsaturated phospholipids facilitate membrane deformation and fission by endocytic proteins. Science 2014; 345:693-7. [PMID: 25104391 DOI: 10.1126/science.1255288] [Citation(s) in RCA: 262] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Phospholipids (PLs) with polyunsaturated acyl chains are extremely abundant in a few specialized cellular organelles such as synaptic vesicles and photoreceptor discs, but their effect on membrane properties is poorly understood. Here, we found that polyunsaturated PLs increased the ability of dynamin and endophilin to deform and vesiculate synthetic membranes. When cells incorporated polyunsaturated fatty acids into PLs, the plasma membrane became more amenable to deformation by a pulling force and the rate of endocytosis was accelerated, in particular, under conditions in which cholesterol was limiting. Molecular dynamics simulations and biochemical measurements indicated that polyunsaturated PLs adapted their conformation to membrane curvature. Thus, by reducing the energetic cost of membrane bending and fission, polyunsaturated PLs may help to support rapid endocytosis.
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Affiliation(s)
- Mathieu Pinot
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Nice Sophia Antipolis and CNRS, 06560 Valbonne, France. Unité Mixte de Recherche 144, Institut Curie and CNRS, F-75248 Paris, France
| | - Stefano Vanni
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Nice Sophia Antipolis and CNRS, 06560 Valbonne, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquée, Université Nice Sophia Antipolis, Parc Valrose, 06000 Nice, France
| | - Sandra Lacas-Gervais
- Centre Commun de Microscopie Appliquée, Université Nice Sophia Antipolis, Parc Valrose, 06000 Nice, France
| | - Laurie-Anne Payet
- Signalisation et Transports Ioniques Membranaires, Université de Poitiers and CNRS, Poitiers, France
| | - Thierry Ferreira
- Signalisation et Transports Ioniques Membranaires, Université de Poitiers and CNRS, Poitiers, France
| | - Romain Gautier
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Nice Sophia Antipolis and CNRS, 06560 Valbonne, France
| | - Bruno Goud
- Unité Mixte de Recherche 144, Institut Curie and CNRS, F-75248 Paris, France
| | - Bruno Antonny
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Nice Sophia Antipolis and CNRS, 06560 Valbonne, France.
| | - Hélène Barelli
- Institut de Pharmacologie Moléculaire et Cellulaire, Université Nice Sophia Antipolis and CNRS, 06560 Valbonne, France
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44
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Sundborger AC, Fang S, Heymann JA, Ray P, Chappie JS, Hinshaw JE. A dynamin mutant defines a superconstricted prefission state. Cell Rep 2014; 8:734-42. [PMID: 25088425 DOI: 10.1016/j.celrep.2014.06.054] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/08/2014] [Accepted: 06/25/2014] [Indexed: 11/25/2022] Open
Abstract
Dynamin is a 100 kDa GTPase that organizes into helical assemblies at the base of nascent clathrin-coated vesicles. Formation of these oligomers stimulates the intrinsic GTPase activity of dynamin, which is necessary for efficient membrane fission during endocytosis. Recent evidence suggests that the transition state of dynamin's GTP hydrolysis reaction serves as a key determinant of productive fission. Here, we present the structure of a transition-state-defective dynamin mutant K44A trapped in a prefission state at 12.5 Å resolution. This structure constricts to 3.7 nm, reaching the theoretical limit required for spontaneous membrane fission. Computational docking indicates that the ground-state conformation of the dynamin polymer is sufficient to achieve this superconstricted prefission state and reveals how a two-start helical symmetry promotes the most efficient packing of dynamin tetramers around the membrane neck. These data suggest a model for the assembly and regulation of the minimal dynamin fission machine.
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Affiliation(s)
- Anna C Sundborger
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shunming Fang
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jürgen A Heymann
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pampa Ray
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joshua S Chappie
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14850, USA.
| | - Jenny E Hinshaw
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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45
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Daumke O, Roux A, Haucke V. BAR domain scaffolds in dynamin-mediated membrane fission. Cell 2014; 156:882-92. [PMID: 24581490 DOI: 10.1016/j.cell.2014.02.017] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Indexed: 10/25/2022]
Abstract
Biological membranes undergo constant remodeling by membrane fission and fusion to change their shape and to exchange material between subcellular compartments. During clathrin-mediated endocytosis, the dynamic assembly and disassembly of protein scaffolds comprising members of the bin-amphiphysin-rvs (BAR) domain protein superfamily constrain the membrane into distinct shapes as the pathway progresses toward fission by the GTPase dynamin. In this Review, we discuss how BAR domain protein assembly and disassembly are controlled in space and time and which structural and biochemical features allow the tight regulation of their shape and function to enable dynamin-mediated membrane fission.
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Affiliation(s)
- Oliver Daumke
- Max-Delbrück Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, 13125 Berlin, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany.
| | - Aurélien Roux
- University of Geneva, Department of Biochemistry, 30 quai Ernest Ansermet, 1211 Geneva 4, Switzerland, and Swiss National Centre for Competence in Research Programme Chemical Biology, 1211 Geneva, Switzerland.
| | - Volker Haucke
- Leibniz Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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46
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Shah C, Hegde BG, Morén B, Behrmann E, Mielke T, Moenke G, Spahn CMT, Lundmark R, Daumke O, Langen R. Structural insights into membrane interaction and caveolar targeting of dynamin-like EHD2. Structure 2014; 22:409-420. [PMID: 24508342 DOI: 10.1016/j.str.2013.12.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/16/2013] [Accepted: 12/21/2013] [Indexed: 01/17/2023]
Abstract
The dynamin-related Eps15-homology domain-containing protein 2 (EHD2) is a membrane-remodeling ATPase that regulates the dynamics of caveolae. Here, we established an electron paramagnetic resonance (EPR) approach to characterize structural features of membrane-bound EHD2. We show that residues at the tip of the helical domain can insert into the membrane and may create membrane curvature by a wedging mechanism. Using EPR and X-ray crystallography, we found that the N terminus is folded into a hydrophobic pocket of the GTPase domain in solution and can be released into the membrane. Cryoelectron microscopy demonstrated that the N terminus is not essential for oligomerization of EHD2 into a membrane-anchored scaffold. Instead, we found a function of the N terminus in regulating targeting and stable association of EHD2 to caveolae. Our data uncover an unexpected, membrane-induced regulatory switch in EHD2 and demonstrate the versatility of EPR to study structure and function of dynamin superfamily proteins.
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Affiliation(s)
- Claudio Shah
- Max-Delbrück-Center for Molecular Medicine, Crystallography, Robert-Rössle-Straße 10, 13092 Berlin, Germany.,Institute of Chemistry and Biochemistry, Free University Berlin, Takustraße 6, 14195 Berlin, Germany
| | - Balachandra G Hegde
- Post Graduate Department of Physics, Rani Channamma University, Vidyasangama, Belagavi-591156, India
| | - Björn Morén
- Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Elmar Behrmann
- Institute of Medical Physics and Biophysics, Charité, Charitéplatz 1, 10117 Berlin, Germany
| | - Thorsten Mielke
- Institute of Medical Physics and Biophysics, Charité, Charitéplatz 1, 10117 Berlin, Germany.,UltraStrukturNetzwerk, Max-Planck-Institute for Molecular Genetics, Ihnestraße 73, 14195 Berlin
| | - Gregor Moenke
- Max-Delbrück-Center for Molecular Medicine, Crystallography, Robert-Rössle-Straße 10, 13092 Berlin, Germany
| | - Christian M T Spahn
- Institute of Medical Physics and Biophysics, Charité, Charitéplatz 1, 10117 Berlin, Germany
| | - Richard Lundmark
- Medical Biochemistry and Biophysics, Umeå University, 901 87 Umeå, Sweden
| | - Oliver Daumke
- Max-Delbrück-Center for Molecular Medicine, Crystallography, Robert-Rössle-Straße 10, 13092 Berlin, Germany.,Institute of Medical Physics and Biophysics, Charité, Charitéplatz 1, 10117 Berlin, Germany
| | - Ralf Langen
- Zilkha Neurogenetic Institute, University of Southern California, 1501 San Pablo Street, Los Angeles, CA 90033, USA
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Fujimoto M, Tsutsumi N. Dynamin-related proteins in plant post-Golgi traffic. FRONTIERS IN PLANT SCIENCE 2014; 5:408. [PMID: 25237312 PMCID: PMC4154393 DOI: 10.3389/fpls.2014.00408] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 07/31/2014] [Indexed: 05/21/2023]
Abstract
Membrane traffic between two organelles begins with the formation of transport vesicles from the donor organelle. Dynamin-related proteins (DRPs), which are large multidomain GTPases, play crucial roles in vesicle formation in post-Golgi traffic. Numerous in vivo and in vitro studies indicate that animal dynamins, which are members of DRP family, assemble into ring- or helix-shaped structures at the neck of a bud site on the donor membrane, where they constrict and sever the neck membrane in a GTP hydrolysis-dependent manner. While much is known about DRP-mediated trafficking in animal cells, little is known about it in plant cells. So far, two structurally distinct subfamilies of plant DRPs (DRP1 and DRP2) have been found to participate in various pathways of post-Golgi traffic. This review summarizes the structural and functional differences between these two DRP subfamilies, focusing on their molecular, cellular and developmental properties. We also discuss the molecular networks underlying the functional machinery centering on these two DRP subfamilies. Furthermore, we hope that this review will provide direction for future studies on the mechanisms of vesicle formation that are not only unique to plants but also common to eukaryotes.
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Affiliation(s)
- Masaru Fujimoto
- *Correspondence: Masaru Fujimoto, Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan e-mail:
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Johannes L, Wunder C, Bassereau P. Bending "on the rocks"--a cocktail of biophysical modules to build endocytic pathways. Cold Spring Harb Perspect Biol 2014; 6:6/1/a016741. [PMID: 24384570 DOI: 10.1101/cshperspect.a016741] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Numerous biological processes rely on endocytosis. The construction of endocytic pits is achieved by a bewildering complexity of biochemical factors that function in clathrin-dependent and -independent pathways. In this review, we argue that this complexity can be conceptualized by a deceptively small number of physical principles that fall into two broad categories: passive mechanisms, such as asymmetric transbilayer stress, scaffolding, line tension, and crowding, and active mechanisms driven by mechanochemical enzymes and/or cytoskeleton. We illustrate how the functional identity of biochemical modules depends on system parameters such as local protein density on membranes, thus explaining some of the controversy in the field. Different modules frequently operate in parallel in the same step and often are shared by apparently divergent uptake processes. The emergence of a novel endocytic classification system may thus be envisioned in which functional modules are the elementary bricks.
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Affiliation(s)
- Ludger Johannes
- Institut Curie-Centre de Recherche, Traffic, Signaling and Delivery Group, 75248 Paris Cedex 05, France
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49
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González-Jamett AM, Momboisse F, Haro-Acuña V, Bevilacqua JA, Caviedes P, Cárdenas AM. Dynamin-2 function and dysfunction along the secretory pathway. Front Endocrinol (Lausanne) 2013; 4:126. [PMID: 24065954 PMCID: PMC3776141 DOI: 10.3389/fendo.2013.00126] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/31/2013] [Indexed: 12/21/2022] Open
Abstract
Dynamin-2 is a ubiquitously expressed mechano-GTPase involved in different stages of the secretory pathway. Its most well-known function relates to the scission of nascent vesicles from the plasma membrane during endocytosis; however, it also participates in the formation of new vesicles from the Golgi network, vesicle trafficking, fusion processes and in the regulation of microtubule, and actin cytoskeleton dynamics. Over the last 8 years, more than 20 mutations in the dynamin-2 gene have been associated to two hereditary neuromuscular disorders: Charcot-Marie-Tooth neuropathy and centronuclear myopathy. Most of these mutations are grouped in the pleckstrin homology domain; however, there are no common mutations associated with both disorders, suggesting that they differently impact on dynamin-2 function in diverse tissues. In this review, we discuss the impact of these disease-related mutations on dynamin-2 function during vesicle trafficking and endocytotic processes.
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Affiliation(s)
- Arlek M. González-Jamett
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Fanny Momboisse
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Valentina Haro-Acuña
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Jorge A. Bevilacqua
- Programa de Anatomía y Biología del Desarrollo, ICBM, Facultad de Medicina, Departamento de Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Universidad de Chile, Santiago, Chile
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ana María Cárdenas
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- *Correspondence: Ana María Cárdenas, Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Gran Bretaña 1111, Playa Ancha 2360102, Valparaíso, Chile e-mail:
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50
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Ramakrishnan N, Sunil Kumar PB, Ipsen JH. Membrane-mediated aggregation of curvature-inducing nematogens and membrane tubulation. Biophys J 2013; 104:1018-28. [PMID: 23473484 DOI: 10.1016/j.bpj.2012.12.045] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 11/20/2012] [Accepted: 12/11/2012] [Indexed: 11/30/2022] Open
Abstract
The shapes of cell membranes are largely regulated by membrane-associated, curvature-active proteins. Herein, we use a numerical model of the membrane, recently developed by us, with elongated membrane inclusions possessing spontaneous directional curvatures that could be different along, and perpendicular to, the membrane's long axis. We show that, due to membrane-mediated interactions, these curvature-inducing membrane-nematogens can aggregate spontaneously, even at low concentrations, and change the local shape of the membrane. We demonstrate that for a large group of such inclusions, where the two spontaneous curvatures have equal sign, the tubular conformation and sometimes the sheet conformation of the membrane are the common equilibrium shapes. We elucidate the factors necessary for the formation of these protein lattices. Furthermore, the elastic properties of the tubes, such as their compressional stiffness and persistence length, are calculated. Finally, we discuss the possible role of nematic disclination in capping and branching of the tubular membranes.
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Affiliation(s)
- N Ramakrishnan
- Department of Physics, Indian Institute of Technology Madras, Chennai, India
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