1
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Yang Z, Yang C, Xu P, Han L, Li Y, Peng L, Wei X, Schmid SL, Svitkina T, Chen Z. CCDC32 stabilizes clathrin-coated pits and drives their invagination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.26.600785. [PMID: 38979322 PMCID: PMC11230434 DOI: 10.1101/2024.06.26.600785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Clathrin-mediated endocytosis (CME) is essential for maintaining cellular homeostasis. Previous studies have reported more than 50 CME accessory proteins; however, the mechanism driving the invagination of clathrin-coated pits (CCPs) remains elusive. Quantitative live cell imaging reveals that CCDC32, a poorly characterized endocytic accessory protein, regulates CCP stabilization and is required for efficient CCP invagination. CCDC32 interacts with the α-appendage domain (AD) of AP2 via its coiled-coil domain to exert this function. Furthermore, we showed that the clinically observed nonsense mutations in CCDC32, which result in the development of cardio-facio-neuro-developmental syndrome (CFNDS), inhibit CME by abolishing CCDC32-AP2 interactions. Overall, our data demonstrates the function and molecular mechanism of a novel endocytic accessory protein, CCDC32, in CME regulation. Significance Statement Clathrin-mediated endocytosis (CME) happens via the initiation, stabilization, and invagination of clathrin-coated pits (CCPs). In this study, we used a combination of quantitative live cell imaging, ultrastructure electron microscopy and biochemical experiments to show that CCDC32, a poorly studied and functional ambiguous protein, acts as an important endocytic accessory protein that regulates CCP stabilization and invagination. Specifically, CCDC32 exerts this function via its interactions with AP2, and the coiled-coil domain of CCDC32 and the α-appendage domain (AD) of AP2 are essential in mediating CCDC32-AP2 interactions. Importantly, we demonstrate that clinically observed loss-of-function mutations in CCDC32 lose AP2 interaction capacity and inhibit CME, resulting in the development of cardio-facio-neuro-developmental syndrome (CFNDS).
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2
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Wei L, Guo X, Haimov E, Obashi K, Lee SH, Shin W, Sun M, Chan CY, Sheng J, Zhang Z, Mohseni A, Ghosh Dastidar S, Wu XS, Wang X, Han S, Arpino G, Shi B, Molakarimi M, Matthias J, Wurm CA, Gan L, Taraska JW, Kozlov MM, Wu LG. Clathrin mediates membrane fission and budding by constricting membrane pores. Cell Discov 2024; 10:62. [PMID: 38862506 PMCID: PMC11166961 DOI: 10.1038/s41421-024-00677-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 04/04/2024] [Indexed: 06/13/2024] Open
Abstract
Membrane budding, which underlies fundamental processes like endocytosis, intracellular trafficking, and viral infection, is thought to involve membrane coat-forming proteins, including the most observed clathrin, to form Ω-shape profiles and helix-forming proteins like dynamin to constrict Ω-profiles' pores and thus mediate fission. Challenging this fundamental concept, we report that polymerized clathrin is required for Ω-profiles' pore closure and that clathrin around Ω-profiles' base/pore region mediates pore constriction/closure in neuroendocrine chromaffin cells. Mathematical modeling suggests that clathrin polymerization at Ω-profiles' base/pore region generates forces from its intrinsically curved shape to constrict/close the pore. This new fission function may exert broader impacts than clathrin's well-known coat-forming function during clathrin (coat)-dependent endocytosis, because it underlies not only clathrin (coat)-dependent endocytosis, but also diverse endocytic modes, including ultrafast, fast, slow, bulk, and overshoot endocytosis previously considered clathrin (coat)-independent in chromaffin cells. It mediates kiss-and-run fusion (fusion pore closure) previously considered bona fide clathrin-independent, and limits the vesicular content release rate. Furthermore, analogous to results in chromaffin cells, we found that clathrin is essential for fast and slow endocytosis at hippocampal synapses where clathrin was previously considered dispensable, suggesting clathrin in mediating synaptic vesicle endocytosis and fission. These results suggest that clathrin and likely other intrinsically curved coat proteins are a new class of fission proteins underlying vesicle budding and fusion. The half-a-century concept and studies that attribute vesicle-coat contents' function to Ω-profile formation and classify budding as coat-protein (e.g., clathrin)-dependent or -independent may need to be re-defined and re-examined by considering clathrin's pivotal role in pore constriction/closure.
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Affiliation(s)
- Lisi Wei
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Xiaoli Guo
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Ehud Haimov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - Kazuki Obashi
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD, USA
| | - Sung Hoon Lee
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Chung-Ang University, Seoul, Republic of Korea
| | - Wonchul Shin
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Min Sun
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Chung Yu Chan
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Jiansong Sheng
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- 900 Clopper Rd, Suite, 130, Gaithersburg, MD, USA
| | - Zhen Zhang
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Center of Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - Ammar Mohseni
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | | | - Xin-Sheng Wu
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Xin Wang
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Sue Han
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Gianvito Arpino
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
- Emme 3 Srl - Via Luigi Meraviglia, 31 - 20020, Lainate, MI, Italy
| | - Bo Shi
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Maryam Molakarimi
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | | | | | - Lin Gan
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart, Lung and Blood Institute, Bethesda, MD, USA
| | - Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
| | - Ling-Gang Wu
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.
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3
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Kvalvaag A, Dustin ML. Clathrin controls bidirectional communication between T cells and antigen presenting cells. Bioessays 2024; 46:e2300230. [PMID: 38412391 DOI: 10.1002/bies.202300230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/29/2024]
Abstract
In circulation, T cells are spherical with selectin enriched dynamic microvilli protruding from the surface. Following extravasation, these microvilli serve another role, continuously surveying their environment for antigen in the form of peptide-MHC (pMHC) expressed on the surface of antigen presenting cells (APCs). Upon recognition of their cognate pMHC, the microvilli are initially stabilized and then flatten into F-actin dependent microclusters as the T cell spreads over the APC. Within 1-5 min, clathrin is recruited by the ESCRT-0 component Hrs to mediate release of T cell receptor (TCR) loaded vesicles directly from the plasma membrane by clathrin and ESCRT-mediated ectocytosis (CEME). After 5-10 min, Hrs is displaced by the endocytic clathrin adaptor epsin-1 to induce clathrin-mediated trans-endocytosis (CMTE) of TCR-pMHC conjugates. Here we discuss some of the functional properties of the clathrin machinery which enables it to control these topologically opposite modes of membrane transfer at the immunological synapse, and how this might be regulated during T cell activation.
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Affiliation(s)
- Audun Kvalvaag
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Michael L Dustin
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
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4
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Aftahy K, Arrasate P, Bashkirov PV, Kuzmin PI, Maurizot V, Huc I, Frolov VA. Molecular Sensing and Manipulation of Protein Oligomerization in Membrane Nanotubes with Bolaamphiphilic Foldamers. J Am Chem Soc 2023; 145:25150-25159. [PMID: 37948300 PMCID: PMC10682987 DOI: 10.1021/jacs.3c05753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 11/12/2023]
Abstract
Adaptive and reversible self-assembly of supramolecular protein structures is a fundamental characteristic of dynamic living matter. However, the quantitative detection and assessment of the emergence of mesoscale protein complexes from small and dynamic oligomeric precursors remains highly challenging. Here, we present a novel approach utilizing a short membrane nanotube (sNT) pulled from a planar membrane reservoir as nanotemplates for molecular reconstruction, manipulation, and sensing of protein oligomerization and self-assembly at the mesoscale. The sNT reports changes in membrane shape and rigidity caused by membrane-bound proteins as variations of the ionic conductivity of the sNT lumen. To confine oligomerization to the sNT, we have designed and synthesized rigid oligoamide foldamer tapes (ROFTs). Charged ROFTs incorporate into the planar and sNT membranes, mediate protein binding to the membranes, and, driven by the luminal electric field, shuttle the bound proteins between the sNT and planar membranes. Using Annexin-V (AnV) as a prototype, we show that the sNT detects AnV oligomers shuttled into the nanotube by ROFTs. Accumulation of AnV on the sNT induces its self-assembly into a curved lattice, restricting the sNT geometry and inhibiting the material uptake from the reservoir during the sNT extension, leading to the sNT fission. By comparing the spontaneous and ROFT-mediated entry of AnV into the sNT, we reveal how intricate membrane curvature sensing by small AnV oligomers controls the lattice self-assembly. These results establish sNT-ROFT as a powerful tool for molecular reconstruction and functional analyses of protein oligomerization and self-assembly, with broad application to various membrane processes.
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Affiliation(s)
- Kathrin Aftahy
- Department
of Pharmacy, Ludwig-Maximilians-Universität
München, Munich 81377, Germany
| | - Pedro Arrasate
- Biofisika
Institute (CSIC, UPV/EHU), University of
the Basque Country, Leioa 48940, Spain
- Department
of Biochemistry and Molecular Biology, University
of the Basque Country, Leioa 48940, Spain
| | - Pavel V. Bashkirov
- Research
Institute for Systems Biology and Medicine, Moscow 117246, Russia
| | - Petr I. Kuzmin
- A.N.
Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow 119071, Russia
| | - Victor Maurizot
- Univ. Bordeaux,
CNRS, Bordeaux Institut National Polytechnique, CBMN (UMR 5248), Pessac 33600, France
| | - Ivan Huc
- Department
of Pharmacy, Ludwig-Maximilians-Universität
München, Munich 81377, Germany
| | - Vadim A. Frolov
- Biofisika
Institute (CSIC, UPV/EHU), University of
the Basque Country, Leioa 48940, Spain
- Department
of Biochemistry and Molecular Biology, University
of the Basque Country, Leioa 48940, Spain
- Ikerbasque,
Basque Foundation for Science, Bilbao 48009, Spain
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5
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Hakanpää L, Abouelezz A, Lenaerts AS, Culfa S, Algie M, Bärlund J, Katajisto P, McMahon H, Almeida-Souza L. Reticular adhesions are assembled at flat clathrin lattices and opposed by active integrin α5β1. J Cell Biol 2023; 222:e202303107. [PMID: 37233325 PMCID: PMC10225744 DOI: 10.1083/jcb.202303107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/03/2023] [Accepted: 05/15/2023] [Indexed: 05/27/2023] Open
Abstract
Reticular adhesions (RAs) consist of integrin αvβ5 and harbor flat clathrin lattices (FCLs), long-lasting structures with similar molecular composition as clathrin-mediated endocytosis (CME) carriers. Why FCLs and RAs colocalize is not known. Here, we show that RAs are assembled at FCLs in a process controlled by fibronectin (FN) and its receptor, integrin α5β1. We observed that cells on FN-rich matrices displayed fewer FCLs and RAs. CME machinery inhibition abolished RAs and live-cell imaging showed that RA establishment requires FCL coassembly. The inhibitory activity of FN was mediated by the activation of integrin α5β1 at Tensin1-positive fibrillar adhesions. Conventionally, endocytosis disassembles cellular adhesions by internalizing their components. Our results present a novel paradigm in the relationship between these two processes by showing that endocytic proteins can actively function in the assembly of cell adhesions. Furthermore, we show this novel adhesion assembly mechanism is coupled to cell migration via unique crosstalk between cell-matrix adhesions.
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Affiliation(s)
- Laura Hakanpää
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Amr Abouelezz
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - An-Sofie Lenaerts
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Seyda Culfa
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Michael Algie
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jenny Bärlund
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Pekka Katajisto
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Leonardo Almeida-Souza
- Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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6
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Wang X, Li Y, Liu A, Padilla R, Lee DM, Kim D, Mettlen M, Chen Z, Schmid SL, Danuser G. Endocytosis gated by emergent properties of membrane-clathrin interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.02.551737. [PMID: 37577632 PMCID: PMC10418234 DOI: 10.1101/2023.08.02.551737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Clathrin-mediated endocytosis (CME), the major cellular entry pathway, starts when clathrin assembles on the plasma membrane into clathrin-coated pits (CCPs). Two populations of CCPs are detected within the same cell: 'productive' CCPs that invaginate and pinch off, forming clathrin-coated vesicles (CCVs) [1, 2], and 'abortive' CCPs [3, 4, 5] that prematurely disassemble. The mechanisms of gating between these two populations and their relations to the functions of dozens of early-acting endocytic accessory proteins (EAPs) [5, 6, 7, 8, 9] have remained elusive. Here, we use experimentally-guided modeling to integrate the clathrin machinery and membrane mechanics in a single dynamical system. We show that the split between the two populations is an emergent property of this system, in which a switch between an Open state and a Closed state follows from the competition between the chemical energy of the clathrin basket and the mechanical energy of membrane bending. In silico experiments revealed an abrupt transition between the two states that acutely depends on the strength of the clathrin basket. This critical strength is lowered by membrane-bending EAPs [10, 11, 12]. Thus, CME is poised to be shifted between abortive and productive events by small changes in membrane curvature and/or coat stability. This model clarifies the workings of a putative endocytic checkpoint whose existence was previously proposed based on statistical analyses of the lifetime distributions of CCPs [4, 13]. Overall, a mechanistic framework is established to elucidate the diverse and redundant functions of EAPs in regulating CME progression.
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7
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Jukic N, Perrino AP, Redondo-Morata L, Scheuring S. Structure and dynamics of ESCRT-III membrane remodeling proteins by high-speed atomic force microscopy. J Biol Chem 2023; 299:104575. [PMID: 36870686 PMCID: PMC10074808 DOI: 10.1016/j.jbc.2023.104575] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 02/20/2023] [Accepted: 02/23/2023] [Indexed: 03/06/2023] Open
Abstract
Endosomal Sorting Complex Required for Transport (ESCRT) proteins assemble on the cytoplasmic leaflet of membranes and remodel them. ESCRT is involved in biological processes where membranes are bent away from the cytosol, constricted, and finally severed, such as in multi-vesicular body formation (in the endosomal pathway for protein sorting) or abscission during cell division. The ESCRT system is hijacked by enveloped viruses to allow buds of nascent virions to be constricted, severed and released. ESCRT-III proteins, the most downstream components of the ESCRT system, are monomeric and cytosolic in their autoinhibited conformation. They share a common architecture, a four-helix bundle with a fifth helix that interacts with this bundle to prevent polymerizing. Upon binding to negatively charged membranes, the ESCRT-III components adopt an activated state that allows them to polymerize into filaments and spirals, and to interact with the AAA-ATPase Vps4 for polymer remodeling. ESCRT-III has been studied with electron microscopy (EM) and fluorescence microscopy (FM); these methods provided invaluable information about ESCRT assembly structures or their dynamics, respectively, but neither approach provides detailed insights into both aspects simultaneously. High-speed atomic force microscopy (HS-AFM) has overcome this shortcoming, providing movies at high spatio-temporal resolution of biomolecular processes, significantly increasing our understanding of ESCRT-III structure and dynamics. Here, we review the contributions of HS-AFM in the analysis of ESCRT-III, focusing on recent developments of non-planar and deformable HS-AFM supports. We divide the HS-AFM observations into four sequential steps in the ESCRT-III lifecycle: 1) polymerization, 2) morphology, 3) dynamics, and 4) depolymerization.
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Affiliation(s)
- Nebojsa Jukic
- Weill Cornell Medicine, Physiology, Biophysics and Systems Biology Graduate Program, New York, NY 10065, USA
| | - Alma P Perrino
- Weill Cornell Medicine, Department of Anesthesiology, 1300 York Avenue, New York, NY 10065, USA
| | - Lorena Redondo-Morata
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d'Infection et d'Immunité de Lille, F-59000 Lille, France
| | - Simon Scheuring
- Weill Cornell Medicine, Department of Anesthesiology, 1300 York Avenue, New York, NY 10065, USA; Weill Cornell Medicine, Department of Physiology and Biophysics, 1300 York Avenue, New York, NY 10065, USA; Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York, NY 14853, USA.
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8
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Nawara TJ, Mattheyses AL. Imaging nanoscale axial dynamics at the basal plasma membrane. Int J Biochem Cell Biol 2023; 156:106349. [PMID: 36566777 PMCID: PMC10634635 DOI: 10.1016/j.biocel.2022.106349] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/16/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
Understanding of how energetically unfavorable plasma membrane shapes form, especially in the context of dynamic processes in living cells or tissues like clathrin-mediated endocytosis is in its infancy. Even though cutting-edge microscopy techniques that bridge this gap exist, they remain underused in biomedical sciences. Here, we demystify the perceived complexity of these advanced microscopy approaches and demonstrate their power in resolving nanometer axial dynamics in living cells. Total internal reflection fluorescence microscopy based approaches are the main focus of this review. We present clathrin-mediated endocytosis as a model system when describing the principles, data acquisition requirements, data interpretation strategies, and limitations of the described techniques. We hope this standardized description will bring the approaches for measuring nanoscale axial dynamics closer to the potential users and help in choosing the right approach to the right question.
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Affiliation(s)
- Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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9
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Mund M, Tschanz A, Wu YL, Frey F, Mehl JL, Kaksonen M, Avinoam O, Schwarz US, Ries J. Clathrin coats partially preassemble and subsequently bend during endocytosis. J Cell Biol 2023; 222:213855. [PMID: 36734980 PMCID: PMC9929656 DOI: 10.1083/jcb.202206038] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/29/2022] [Accepted: 12/27/2022] [Indexed: 02/04/2023] Open
Abstract
Eukaryotic cells use clathrin-mediated endocytosis to take up a large range of extracellular cargo. During endocytosis, a clathrin coat forms on the plasma membrane, but it remains controversial when and how it is remodeled into a spherical vesicle. Here, we use 3D superresolution microscopy to determine the precise geometry of the clathrin coat at large numbers of endocytic sites. Through pseudo-temporal sorting, we determine the average trajectory of clathrin remodeling during endocytosis. We find that clathrin coats assemble first on flat membranes to 50% of the coat area before they become rapidly and continuously bent, and this mechanism is confirmed in three cell lines. We introduce the cooperative curvature model, which is based on positive feedback for curvature generation. It accurately describes the measured shapes and dynamics of the clathrin coat and could represent a general mechanism for clathrin coat remodeling on the plasma membrane.
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Affiliation(s)
- Markus Mund
- https://ror.org/03mstc592Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany,https://ror.org/01swzsf04Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Aline Tschanz
- https://ror.org/03mstc592Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany,Candidate for Joint PhD Programme of EMBL and University of Heidelberg, Heidelberg, Germany
| | - Yu-Le Wu
- https://ror.org/03mstc592Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany,Candidate for Joint PhD Programme of EMBL and University of Heidelberg, Heidelberg, Germany
| | - Felix Frey
- https://ror.org/02e2c7k09Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Delft, Netherlands
| | - Johanna L. Mehl
- https://ror.org/03mstc592Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Marko Kaksonen
- https://ror.org/01swzsf04Department of Biochemistry, University of Geneva, Geneva, Switzerland,NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Ori Avinoam
- https://ror.org/03mstc592Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany,https://ror.org/0316ej306Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Ulrich S. Schwarz
- https://ror.org/04rcqnp59Institute for Theoretical Physics and Bioquant, Heidelberg University, Heidelberg, Germany,Bioquant, Heidelberg University, Heidelberg, Germany
| | - Jonas Ries
- https://ror.org/03mstc592Cell Biology and Biophysics, European Molecular Biology Laboratory, Heidelberg, Germany,Correspondence to Jonas Ries:
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10
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Kozlov MM, Taraska JW. Generation of nanoscopic membrane curvature for membrane trafficking. Nat Rev Mol Cell Biol 2023; 24:63-78. [PMID: 35918535 DOI: 10.1038/s41580-022-00511-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2022] [Indexed: 11/09/2022]
Abstract
Curved membranes are key features of intracellular organelles, and their generation involves dynamic protein complexes. Here we describe the fundamental mechanisms such as the hydrophobic insertion, scaffolding and crowding mechanisms these proteins use to produce membrane curvatures and complex shapes required to form intracellular organelles and vesicular structures involved in endocytosis and secretion. For each mechanism, we discuss its cellular functions as well as the underlying physical principles and the specific membrane properties required for the mechanism to be feasible. We propose that the integration of individual mechanisms into a highly controlled, robust process of curvature generation often relies on the assembly of proteins into coats. How cells unify and organize the curvature-generating factors at the nanoscale is presented for three ubiquitous coats central for membrane trafficking in eukaryotes: clathrin-coated pits, caveolae, and COPI and COPII coats. The emerging theme is that these coats arrange and coordinate curvature-generating factors in time and space to dynamically shape membranes to accomplish membrane trafficking within cells.
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Affiliation(s)
- Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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11
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Chan FY, Kurosaki R, Ganser C, Takeda T, Uchihashi T. Tip-scan high-speed atomic force microscopy with a uniaxial substrate stretching device for studying dynamics of biomolecules under mechanical stress. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113703. [PMID: 36461522 DOI: 10.1063/5.0111017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/09/2022] [Indexed: 06/17/2023]
Abstract
High-speed atomic force microscopy (HS-AFM) is a powerful tool for studying the dynamics of biomolecules in vitro because of its high temporal and spatial resolution. However, multi-functionalization, such as combination with complementary measurement methods, environment control, and large-scale mechanical manipulation of samples, is still a complex endeavor due to the inherent design and the compact sample scanning stage. Emerging tip-scan HS-AFM overcame this design hindrance and opened a door for additional functionalities. In this study, we designed a motor-driven stretching device to manipulate elastic substrates for HS-AFM imaging of biomolecules under controllable mechanical stimulation. To demonstrate the applicability of the substrate stretching device, we observed a microtubule buckling by straining the substrate and actin filaments linked by α-actinin on a curved surface. In addition, a BAR domain protein BIN1 that senses substrate curvature was observed while dynamically controlling the surface curvature. Our results clearly prove that large-scale mechanical manipulation can be coupled with nanometer-scale imaging to observe biophysical effects otherwise obscured.
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Affiliation(s)
- Feng-Yueh Chan
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Ryo Kurosaki
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Christian Ganser
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Tetsuya Takeda
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita-Ku, Okayama 700-8558, Japan
| | - Takayuki Uchihashi
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
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12
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Yang C, Colosi P, Hugelier S, Zabezhinsky D, Lakadamyali M, Svitkina T. Actin polymerization promotes invagination of flat clathrin-coated lattices in mammalian cells by pushing at lattice edges. Nat Commun 2022; 13:6127. [PMID: 36253374 PMCID: PMC9576739 DOI: 10.1038/s41467-022-33852-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/05/2022] [Indexed: 12/24/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) requires energy input from actin polymerization in mechanically challenging conditions. The roles of actin in CME are poorly understood due to inadequate knowledge of actin organization at clathrin-coated structures (CCSs). Using platinum replica electron microscopy of mammalian cells, we show that Arp2/3 complex-dependent branched actin networks, which often emerge from microtubule tips, assemble along the CCS perimeter, lack interaction with the apical clathrin lattice, and have barbed ends oriented toward the CCS. This structure is hardly compatible with the widely held "apical pulling" model describing actin functions in CME. Arp2/3 complex inhibition or epsin knockout produce large flat non-dynamic CCSs, which split into invaginating subdomains upon recovery from Arp2/3 inhibition. Moreover, epsin localization to CCSs depends on Arp2/3 activity. We propose an "edge pushing" model for CME, wherein branched actin polymerization promotes severing and invagination of flat CCSs in an epsin-dependent manner by pushing at the CCS boundary, thus releasing forces opposing the intrinsic curvature of clathrin lattices.
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Affiliation(s)
- Changsong Yang
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Patricia Colosi
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Siewert Hugelier
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Daniel Zabezhinsky
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Melike Lakadamyali
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Tatyana Svitkina
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
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13
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Smith SM, Smith CJ. Capturing the mechanics of clathrin-mediated endocytosis. Curr Opin Struct Biol 2022; 75:102427. [PMID: 35872561 DOI: 10.1016/j.sbi.2022.102427] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/13/2022] [Accepted: 06/16/2022] [Indexed: 02/01/2023]
Abstract
Clathrin-mediated endocytosis enables selective uptake of molecules into cells in response to changing cellular needs. It occurs through assembly of coat components around the plasma membrane that determine vesicle contents and facilitate membrane bending to form a clathrin-coated transport vesicle. In this review we discuss recent cryo-electron microscopy structures that have captured a series of events in the life cycle of a clathrin-coated vesicle. Both single particle analysis and tomography approaches have revealed details of the clathrin lattice structure itself, how AP2 may interface with clathrin within a coated vesicle and the importance of PIP2 binding for assembly of the yeast adaptors Sla2 and Ent1 on the membrane. Within cells, cryo-electron tomography of clathrin in flat lattices and high-speed AFM studies provided new insights into how clathrin morphology can adapt during CCV formation. Thus, key mechanical processes driving clathrin-mediated endocytosis have been captured through multiple techniques working in partnership.
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Affiliation(s)
- Sarah M Smith
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Corinne J Smith
- School of Life Sciences, University of Warwick, Coventry, UK.
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14
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Nawara TJ, Williams YD, Rao TC, Hu Y, Sztul E, Salaita K, Mattheyses AL. Imaging vesicle formation dynamics supports the flexible model of clathrin-mediated endocytosis. Nat Commun 2022; 13:1732. [PMID: 35365614 PMCID: PMC8976038 DOI: 10.1038/s41467-022-29317-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 02/24/2022] [Indexed: 12/11/2022] Open
Abstract
Clathrin polymerization and changes in plasma membrane architecture are necessary steps in forming vesicles to internalize cargo during clathrin-mediated endocytosis (CME). Simultaneous analysis of clathrin dynamics and membrane structure is challenging due to the limited axial resolution of fluorescence microscopes and the heterogeneity of CME. This has fueled conflicting models of vesicle assembly and obscured the roles of flat clathrin assemblies. Here, using Simultaneous Two-wavelength Axial Ratiometry (STAR) microscopy, we bridge this critical knowledge gap by quantifying the nanoscale dynamics of clathrin-coat shape change during vesicle assembly. We find that de novo clathrin accumulations generate both flat and curved structures. High-throughput analysis reveals that the initiation of vesicle curvature does not directly correlate with clathrin accumulation. We show clathrin accumulation is preferentially simultaneous with curvature formation at shorter-lived clathrin-coated vesicles (CCVs), but favors a flat-to-curved transition at longer-lived CCVs. The broad spectrum of curvature initiation dynamics revealed by STAR microscopy supports multiple productive mechanisms of vesicle formation and advocates for the flexible model of CME. Despite decades of research, the dynamics of clathrin-coated vesicle formation is ambiguous. Here, authors use STAR microscopy to quantify the nanoscale dynamics of vesicle formation, supporting the flexible model of clathrin-mediated endocytosis.
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Affiliation(s)
- Tomasz J Nawara
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yancey D Williams
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yuesong Hu
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Elizabeth Sztul
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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