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van Belle GJ, Zieseniss A, Heidenreich D, Olmos M, Zhuikova A, Möbius W, Paul MW, Katschinski DM. Cargo-specific effects of hypoxia on clathrin-mediated trafficking. Pflugers Arch 2024; 476:1399-1410. [PMID: 38294517 PMCID: PMC11310247 DOI: 10.1007/s00424-024-02911-6] [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: 07/04/2023] [Revised: 12/18/2023] [Accepted: 01/11/2024] [Indexed: 02/01/2024]
Abstract
Clathrin-associated trafficking is a major mechanism for intracellular communication, as well as for cells to communicate with the extracellular environment. A decreased oxygen availability termed hypoxia has been described to influence this mechanism in the past. Mostly biochemical studies were applied in these analyses, which miss spatiotemporal information. We have applied live cell microscopy and a newly developed analysis script in combination with a GFP-tagged clathrin-expressing cell line to obtain insight into the dynamics of the effect of hypoxia. Number, mobility and directionality of clathrin-coated vesicles were analysed in non-stimulated cells as well as after stimulation with epidermal growth factor (EGF) or transferrin in normoxic and hypoxic conditions. These data reveal cargo-specific effects, which would not be observable with biochemical methods or with fixed cells and add to the understanding of cell physiology in hypoxia. The stimulus-dependent consequences were also reflected in the final cellular output, i.e. decreased EGF signaling and in contrast increased iron uptake in hypoxia.
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Affiliation(s)
- Gijsbert J van Belle
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg-August University, 37073, Göttingen, Germany
| | - Anke Zieseniss
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg-August University, 37073, Göttingen, Germany
| | - Doris Heidenreich
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg-August University, 37073, Göttingen, Germany
| | - Maxime Olmos
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg-August University, 37073, Göttingen, Germany
| | - Asia Zhuikova
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg-August University, 37073, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Electron Microscopy, City Campus, Max-Planck-Institute for Multidisciplinary Sciences, 37075, Göttingen, Germany
| | - Maarten W Paul
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Dörthe M Katschinski
- Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg-August University, 37073, Göttingen, Germany.
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2
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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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3
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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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4
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Piras A, Floris E, Dall'Asta L, Gamba A. Sorting of multiple molecular species on cell membranes. Phys Rev E 2023; 108:024401. [PMID: 37723769 DOI: 10.1103/physreve.108.024401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/05/2023] [Indexed: 09/20/2023]
Abstract
Eukaryotic cells maintain their inner order by a hectic process of sorting and distillation of molecular factors taking place on their lipid membranes. A similar sorting process is implied in the assembly and budding of enveloped viruses. To understand the properties of this molecular sorting process, we have recently proposed a physical model [Zamparo et al., Phys. Rev. Lett. 126, 088101 (2021)]10.1103/PhysRevLett.126.088101, based on (1) the phase separation of a single, initially dispersed molecular species into spatially localized sorting domains on the lipid membrane and (2) domain-induced membrane bending leading to the nucleation of submicrometric lipid vesicles, naturally enriched in the molecules of the engulfed sorting domain. The analysis of the model showed the existence of an optimal region of parameter space where sorting is most efficient. Here the model is extended to account for the simultaneous distillation of a pool of distinct molecular species. We find that the mean time spent by sorted molecules on the membrane increases with the heterogeneity of the pool (i.e., the number of distinct molecular species sorted) according to a simple scaling law, and that a large number of distinct molecular species can in principle be sorted in parallel on cell membranes without significantly interfering with each other. Moreover, sorting is found to be most efficient when the distinct molecular species have comparable homotypic affinities. We also consider how valence (i.e., the average number of interacting neighbors of a molecule in a sorting domain) affects the sorting process, finding that higher-valence molecules can be sorted with greater efficiency than lower-valence molecules.
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Affiliation(s)
- Andrea Piras
- Candiolo Cancer Institute, FPO-IRCCS, Strada Provinciale 142, km 3.95, 10060 Candiolo, Italy
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
- Italian Institute for Genomic Medicine (IIGM), Strada Provinciale 142, km 3.95, 10060 Candiolo, Italy
- Department of Oncology, University of Turin, 10060 Candiolo, Italy
| | - Elisa Floris
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
| | - Luca Dall'Asta
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
- Italian Institute for Genomic Medicine (IIGM), Strada Provinciale 142, km 3.95, 10060 Candiolo, Italy
- Collegio Carlo Alberto, Piazza Arbarello 8, 10122, Torino, Italy
| | - Andrea Gamba
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
- Italian Institute for Genomic Medicine (IIGM), Strada Provinciale 142, km 3.95, 10060 Candiolo, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
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5
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Iwamoto Y, Ye A, Shirazinejad C, Hurley JH, Drubin DG. Kinetic investigation reveals an HIV-1 Nef-dependent increase in AP-2 recruitment and productivity at endocytic sites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.18.537262. [PMID: 37131815 PMCID: PMC10153213 DOI: 10.1101/2023.04.18.537262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Lentiviruses express non-enzymatic accessory proteins whose function is to subvert cellular machinery in the infected host. The HIV-1 accessory protein Nef hijacks clathrin adaptors to degrade or mislocalize host proteins involved in antiviral defenses. Here, we investigate the interaction between Nef and clathrin-mediated endocytosis (CME), a major pathway for membrane protein internalization in mammalian cells, using quantitative live-cell microscopy in genome-edited Jurkat cells. Nef is recruited to CME sites on the plasma membrane, and this recruitment correlates with an increase in the recruitment and lifetime of CME coat protein AP-2 and late-arriving CME protein dynamin2. Furthermore, we find that CME sites that recruit Nef are more likely to recruit dynamin2, suggesting that Nef recruitment to CME sites promotes CME site maturation to ensure high efficiency in host protein downregulation.
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Affiliation(s)
- Yuichiro Iwamoto
- Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA
| | - Anna Ye
- Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA
| | - Cyna Shirazinejad
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA
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6
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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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7
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Floris E, Piras A, Pezzicoli FS, Zamparo M, Dall'Asta L, Gamba A. Phase separation and critical size in molecular sorting. Phys Rev E 2022; 106:044412. [PMID: 36397477 DOI: 10.1103/physreve.106.044412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/15/2022] [Indexed: 06/16/2023]
Abstract
Molecular sorting is a fundamental process that allows eukaryotic cells to distill and concentrate specific chemical factors in appropriate cell membrane subregions, thus endowing them with different chemical identities and functional properties. A phenomenological theory of this molecular distillation process has recently been proposed [M. Zamparo, D. Valdembri, G. Serini, I. V. Kolokolov, V. V. Lebedev, L. Dall'Asta, and A. Gamba, Phys. Rev. Lett. 126, 088101 (2021)0031-900710.1103/PhysRevLett.126.088101], based on the idea that molecular sorting emerges from the combination of (a) phase separation driven formation of sorting domains and (b) domain-induced membrane bending, leading to the production of submicrometric lipid vesicles enriched in the sorted molecules. In this framework, a natural parameter controlling the efficiency of molecular distillation is the critical size of phase separated domains. In the experiments, sorting domains appear to fall into two classes: unproductive domains, characterized by short lifetimes and low probability of extraction, and productive domains, that evolve into vesicles that ultimately detach from the membrane system. It is tempting to link these two classes to the different fates predicted by classical phase separation theory for subcritical and supercritical phase separated domains. Here, we discuss the implication of this picture in the framework of the previously introduced phenomenological theory of molecular sorting. Several predictions of the theory are verified by numerical simulations of a lattice-gas model. Sorting is observed to be most efficient when the number of sorting domains is close to a minimum. To help in the analysis of experimental data, an operational definition of the critical size of sorting domains is proposed. Comparison with experimental results shows that the statistical properties of productive and unproductive domains inferred from experimental data are in agreement with those predicted from numerical simulations of the model, compatibly with the hypothesis that molecular sorting is driven by a phase separation process.
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Affiliation(s)
- Elisa Floris
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Andrea Piras
- Italian Institute for Genomic Medicine and Candiolo Cancer Institute IRCCS, Strada Provinciale 142, km 3.95, Candiolo (TO) 10060, Italy
| | - Francesco Saverio Pezzicoli
- Laboratoire Interdisciplinaire des Sciences du Numérique, Université Paris-Saclay, Gif-sur-Yvette, 91190 Île-de-France, France
| | - Marco Zamparo
- Dipartimento di Fisica, Università degli Studi di Bari, via Amendola 173, 70126 Bari, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
| | - Luca Dall'Asta
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
- Italian Institute for Genomic Medicine and Candiolo Cancer Institute IRCCS, Strada Provinciale 142, km 3.95, Candiolo (TO) 10060, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
- Collegio Carlo Alberto, Piazza Arbarello 8, 10122 Torino, Italy
| | - Andrea Gamba
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
- Italian Institute for Genomic Medicine and Candiolo Cancer Institute IRCCS, Strada Provinciale 142, km 3.95, Candiolo (TO) 10060, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
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8
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Zaccai NR, Kadlecova Z, Dickson VK, Korobchevskaya K, Kamenicky J, Kovtun O, Umasankar PK, Wrobel AG, Kaufman JGG, Gray SR, Qu K, Evans PR, Fritzsche M, Sroubek F, Höning S, Briggs JAG, Kelly BT, Owen DJ, Traub LM. FCHO controls AP2's initiating role in endocytosis through a PtdIns(4,5)P 2-dependent switch. SCIENCE ADVANCES 2022; 8:eabn2018. [PMID: 35486718 PMCID: PMC9054013 DOI: 10.1126/sciadv.abn2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the main mechanism by which mammalian cells control their cell surface proteome. Proper operation of the pivotal CME cargo adaptor AP2 requires membrane-localized Fer/Cip4 homology domain-only proteins (FCHO). Here, live-cell enhanced total internal reflection fluorescence-structured illumination microscopy shows that FCHO marks sites of clathrin-coated pit (CCP) initiation, which mature into uniform-sized CCPs comprising a central patch of AP2 and clathrin corralled by an FCHO/Epidermal growth factor potential receptor substrate number 15 (Eps15) ring. We dissect the network of interactions between the FCHO interdomain linker and AP2, which concentrates, orients, tethers, and partially destabilizes closed AP2 at the plasma membrane. AP2's subsequent membrane deposition drives its opening, which triggers FCHO displacement through steric competition with phosphatidylinositol 4,5-bisphosphate, clathrin, cargo, and CME accessory factors. FCHO can now relocate toward a CCP's outer edge to engage and activate further AP2s to drive CCP growth/maturation.
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Affiliation(s)
- Nathan R. Zaccai
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Zuzana Kadlecova
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | | | - Kseniya Korobchevskaya
- Kennedy Institute of Rheumatology, University of Oxford, Roosevelt Drive, Oxford OX3 7FY, UK
| | - Jan Kamenicky
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - Oleksiy Kovtun
- MRC LMB Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Perunthottathu K. Umasankar
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Antoni G. Wrobel
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | | | - Sally R. Gray
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Kun Qu
- MRC LMB Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | | | - Marco Fritzsche
- Kennedy Institute of Rheumatology, University of Oxford, Roosevelt Drive, Oxford OX3 7FY, UK
- Rosalind Franklin Institute, Harwell Campus, Didcot, UK
| | - Filip Sroubek
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - Stefan Höning
- Institute for Biochemistry I, Medical Faculty, University of Cologne, Joseph-Stelzmann-Straße 52, 50931 Cologne, Germany
| | - John A. G. Briggs
- MRC LMB Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Bernard T. Kelly
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - David J. Owen
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Linton M. Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, Pittsburgh, PA, USA
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9
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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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10
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Duan D, Hanson M, Holland DO, Johnson ME. Integrating protein copy numbers with interaction networks to quantify stoichiometry in clathrin-mediated endocytosis. Sci Rep 2022; 12:5413. [PMID: 35354856 PMCID: PMC8967901 DOI: 10.1038/s41598-022-09259-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 03/21/2022] [Indexed: 11/25/2022] Open
Abstract
Proteins that drive processes like clathrin-mediated endocytosis (CME) are expressed at copy numbers within a cell and across cell types varying from hundreds (e.g. auxilin) to millions (e.g. clathrin). These variations contain important information about function, but without integration with the interaction network, they cannot capture how supply and demand for each protein depends on binding to shared and distinct partners. Here we construct the interface-resolved network of 82 proteins involved in CME and establish a metric, a stoichiometric balance ratio (SBR), that quantifies whether each protein in the network has an abundance that is sub- or super-stoichiometric dependent on the global competition for binding. We find that highly abundant proteins (like clathrin) are super-stoichiometric, but that not all super-stoichiometric proteins are highly abundant, across three cell populations (HeLa, fibroblast, and neuronal synaptosomes). Most strikingly, within all cells there is significant competition to bind shared sites on clathrin and the central AP-2 adaptor by other adaptor proteins, resulting in most being in excess supply. Our network and systematic analysis, including response to perturbations of network components, show how competition for shared binding sites results in functionally similar proteins having widely varying stoichiometries, due to variations in both abundance and their unique network of binding partners.
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Affiliation(s)
- Daisy Duan
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD, 21218, USA
| | - Meretta Hanson
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD, 21218, USA
| | | | - Margaret E Johnson
- TC Jenkins Department of Biophysics, Johns Hopkins University, 3400 N Charles St, Baltimore, MD, 21218, USA.
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11
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CALM supports clathrin-coated vesicle completion upon membrane tension increase. Proc Natl Acad Sci U S A 2021; 118:2010438118. [PMID: 34155137 DOI: 10.1073/pnas.2010438118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The most represented components of clathrin-coated vesicles (CCVs) are clathrin triskelia and the adaptors clathrin assembly lymphoid myeloid leukemia protein (CALM) and the heterotetrameric complex AP2. Investigation of the dynamics of AP180-amino-terminal-homology (ANTH) recruitment during CCV formation has been hampered by CALM toxicity upon overexpression. We used knock-in gene editing to express a C-terminal-attached fluorescent version of CALM, while preserving its endogenous expression levels, and cutting-edge live-cell microscopy approaches to study CALM recruitment at forming CCVs. Our results demonstrate that CALM promotes vesicle completion upon membrane tension increase as a function of the amount of this adaptor present. Since the expression of adaptors, including CALM, differs among cells, our data support a model in which the efficiency of clathrin-mediated endocytosis is tissue specific and explain why CALM is essential during embryogenesis and red blood cell development.
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12
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Choi HJ, Wang C, Pan X, Jang J, Cao M, Brazzo JA, Bae Y, Lee K. Emerging machine learning approaches to phenotyping cellular motility and morphodynamics. Phys Biol 2021; 18:10.1088/1478-3975/abffbe. [PMID: 33971636 PMCID: PMC9131244 DOI: 10.1088/1478-3975/abffbe] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/10/2021] [Indexed: 12/22/2022]
Abstract
Cells respond heterogeneously to molecular and environmental perturbations. Phenotypic heterogeneity, wherein multiple phenotypes coexist in the same conditions, presents challenges when interpreting the observed heterogeneity. Advances in live cell microscopy allow researchers to acquire an unprecedented amount of live cell image data at high spatiotemporal resolutions. Phenotyping cellular dynamics, however, is a nontrivial task and requires machine learning (ML) approaches to discern phenotypic heterogeneity from live cell images. In recent years, ML has proven instrumental in biomedical research, allowing scientists to implement sophisticated computation in which computers learn and effectively perform specific analyses with minimal human instruction or intervention. In this review, we discuss how ML has been recently employed in the study of cell motility and morphodynamics to identify phenotypes from computer vision analysis. We focus on new approaches to extract and learn meaningful spatiotemporal features from complex live cell images for cellular and subcellular phenotyping.
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Affiliation(s)
- Hee June Choi
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States of America
- Vascular Biology Program and Department of Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, United States of America
| | - Chuangqi Wang
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States of America
- Present address. Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xiang Pan
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States of America
- Vascular Biology Program and Department of Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, United States of America
| | - Junbong Jang
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States of America
- Vascular Biology Program and Department of Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, United States of America
| | - Mengzhi Cao
- Data Science Program, Worcester Polytechnic Institute, Worcester, MA 01609, United States of America
| | - Joseph A Brazzo
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14203, United States of America
| | - Yongho Bae
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14203, United States of America
| | - Kwonmoo Lee
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States of America
- Vascular Biology Program and Department of Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, United States of America
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13
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Abstract
Cell imaging has entered the 'Big Data' era. New technologies in light microscopy and molecular biology have led to an explosion in high-content, dynamic and multidimensional imaging data. Similar to the 'omics' fields two decades ago, our current ability to process, visualize, integrate and mine this new generation of cell imaging data is becoming a critical bottleneck in advancing cell biology. Computation, traditionally used to quantitatively test specific hypotheses, must now also enable iterative hypothesis generation and testing by deciphering hidden biologically meaningful patterns in complex, dynamic or high-dimensional cell image data. Data science is uniquely positioned to aid in this process. In this Perspective, we survey the rapidly expanding new field of data science in cell imaging. Specifically, we highlight how data science tools are used within current image analysis pipelines, propose a computation-first approach to derive new hypotheses from cell image data, identify challenges and describe the next frontiers where we believe data science will make an impact. We also outline steps to ensure broad access to these powerful tools - democratizing infrastructure availability, developing sensitive, robust and usable tools, and promoting interdisciplinary training to both familiarize biologists with data science and expose data scientists to cell imaging.
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Affiliation(s)
- Meghan K Driscoll
- Department of Bioinformatics, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Assaf Zaritsky
- Department of Software and Information Systems Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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Bhave M, Mino RE, Wang X, Lee J, Grossman HM, Lakoduk AM, Danuser G, Schmid SL, Mettlen M. Functional characterization of 67 endocytic accessory proteins using multiparametric quantitative analysis of CCP dynamics. Proc Natl Acad Sci U S A 2020; 117:31591-31602. [PMID: 33257546 PMCID: PMC7749282 DOI: 10.1073/pnas.2020346117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) begins with the nucleation of clathrin assembly on the plasma membrane, followed by stabilization and growth/maturation of clathrin-coated pits (CCPs) that eventually pinch off and internalize as clathrin-coated vesicles. This highly regulated process involves a myriad of endocytic accessory proteins (EAPs), many of which are multidomain proteins that encode a wide range of biochemical activities. Although domain-specific activities of EAPs have been extensively studied, their precise stage-specific functions have been identified in only a few cases. Using single-guide RNA (sgRNA)/dCas9 and small interfering RNA (siRNA)-mediated protein knockdown, combined with an image-based analysis pipeline, we have determined the phenotypic signature of 67 EAPs throughout the maturation process of CCPs. Based on these data, we show that EAPs can be partitioned into phenotypic clusters, which differentially affect CCP maturation and dynamics. Importantly, these clusters do not correlate with functional modules based on biochemical activities. Furthermore, we discover a critical role for SNARE proteins and their adaptors during early stages of CCP nucleation and stabilization and highlight the importance of GAK throughout CCP maturation that is consistent with GAK's multifunctional domain architecture. Together, these findings provide systematic, mechanistic insights into the plasticity and robustness of CME.
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Affiliation(s)
- Madhura Bhave
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Rosa E Mino
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Xinxin Wang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jeon Lee
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Heather M Grossman
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ashley M Lakoduk
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390;
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390;
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15
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Kell MJ, Ang SF, Pigati L, Halpern A, Fölsch H. Novel function for AP-1B during cell migration. Mol Biol Cell 2020; 31:2475-2493. [PMID: 32816642 PMCID: PMC7851849 DOI: 10.1091/mbc.e20-04-0256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The epithelial cell-specific clathrin adaptor protein (AP)-1B has a well-established role in polarized sorting of cargos to the basolateral membrane. Here we show that β1 integrin was dependent on AP-1B and its coadaptor, autosomal recessive hypercholesterolemia protein (ARH), for sorting to the basolateral membrane. We further demonstrate an unprecedented role for AP-1B at the basal plasma membrane during collective cell migration of epithelial sheets. During wound healing, expression of AP-1B (and ARH in AP–1B-positive cells) slowed epithelial-cell migration. We show that AP-1B colocalized with β1 integrin in focal adhesions during cell migration using confocal microscopy and total internal reflection fluorescence microscopy on fixed specimens. Further, AP-1B labeling in cell protrusions was distinct from labeling for the endocytic adaptor complex AP-2. Using stochastic optical reconstruction microscopy we identified numerous AP–1B-coated structures at or close to the basal plasma membrane in cell protrusions. In addition, immunoelectron microscopy showed AP-1B in coated pits and vesicles at the plasma membrane during cell migration. Lastly, quantitative real-time reverse transcription PCR analysis of human epithelial-derived cell lines revealed a loss of AP-1B expression in highly migratory metastatic cancer cells suggesting that AP-1B’s novel role at the basal plasma membrane during cell migration might be an anticancer mechanism.
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Affiliation(s)
- Margaret Johnson Kell
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Su Fen Ang
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Lucy Pigati
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Abby Halpern
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Heike Fölsch
- Department of Cell and Developmental Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
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16
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Chen Z, Schmid SL. Evolving models for assembling and shaping clathrin-coated pits. J Cell Biol 2020; 219:e202005126. [PMID: 32770195 PMCID: PMC7480099 DOI: 10.1083/jcb.202005126] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 01/01/2023] Open
Abstract
Clathrin-mediated endocytosis occurs via the assembly of clathrin-coated pits (CCPs) that invaginate and pinch off to form clathrin-coated vesicles (CCVs). It is well known that adaptor protein 2 (AP2) complexes trigger clathrin assembly on the plasma membrane, and biochemical and structural studies have revealed the nature of these interactions. Numerous endocytic accessory proteins collaborate with clathrin and AP2 to drive CCV formation. However, many questions remain as to the molecular events involved in CCP initiation, stabilization, and curvature generation. Indeed, a plethora of recent evidence derived from cell perturbation, correlative light and EM tomography, live-cell imaging, modeling, and high-resolution structural analyses has revealed more complexity and promiscuity in the protein interactions driving CCP maturation than anticipated. After briefly reviewing the evidence supporting prevailing models, we integrate these new lines of evidence to develop a more dynamic and flexible model for how redundant, dynamic, and competing protein interactions can drive endocytic CCV formation and suggest new approaches to test emerging models.
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Affiliation(s)
| | - Sandra L. Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX
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17
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Mino RE, Chen Z, Mettlen M, Schmid SL. An internally eGFP-tagged α-adaptin is a fully functional and improved fiduciary marker for clathrin-coated pit dynamics. Traffic 2020; 21:603-616. [PMID: 32657003 PMCID: PMC7495412 DOI: 10.1111/tra.12755] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/05/2020] [Accepted: 07/06/2020] [Indexed: 12/18/2022]
Abstract
Clathrin mediated endocytosis (CME) has been extensively studied in living cells by quantitative total internal reflection fluorescence microscopy (TIRFM). Fluorescent protein fusions to subunits of the major coat proteins, clathrin light chains or the heterotetrameric adaptor protein (AP2) complexes, have been used as fiduciary markers of clathrin coated pits (CCPs). However, the functionality of these fusion proteins has not been rigorously compared. Here, we generated stable cells lines overexpressing mRuby‐CLCa and/or μ2‐eGFP, σ2‐eGFP, two markers currently in use, or a novel marker generated by inserting eGFP into the unstructured hinge region of the α subunit (α‐eGFP). Using biochemical and TIRFM‐based assays, we compared the functionality of the AP2 markers. All of the eGFP‐tagged subunits were efficiently incorporated into AP2 and displayed greater accuracy in image‐based CCP analyses than mRuby‐CLCa. However, overexpression of either μ2‐eGFP or σ2‐eGFP impaired transferrin receptor uptake. In addition, μ2‐eGFP reduced the rates of CCP initiation and σ2‐eGFP perturbed AP2 incorporation into CCPs and CCP maturation. In contrast, CME and CCP dynamics were unperturbed in cells overexpressing α‐eGFP. Moreover, α‐eGFP was a more sensitive and accurate marker of CCP dynamics than mRuby‐CLCa. Thus, our work establishes α‐eGFP as a robust, fully functional marker for CME.
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Affiliation(s)
- Rosa E Mino
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Zhiming Chen
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Marcel Mettlen
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Sandra L Schmid
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
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18
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Bhave M, Mettlen M, Wang X, Schmid SL. Early and nonredundant functions of dynamin isoforms in clathrin-mediated endocytosis. Mol Biol Cell 2020; 31:2035-2047. [PMID: 32579424 PMCID: PMC7543069 DOI: 10.1091/mbc.e20-06-0363] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Dynamin GTPases (Dyn1 and Dyn2) are indispensable proteins of the core clathrin-mediated endocytosis (CME) machinery. Best known for their role in fission at the late stages of CME, many studies have suggested that dynamin also plays a regulatory role during the early stages of CME; however, detailed studies regarding isoform-specific early regulatory functions of the dynamins are lacking. With a recent understanding of the regulation of Dyn1 in nonneuronal cells and improved algorithms for highly sensitive and quantitative analysis of clathrin-coated pit (CCP) dynamics, we have evaluated the differential functions of dynamin isoforms in CME using domain swap chimeras. We report that Dyn1 and Dyn2 play nonredundant, early regulatory roles during CME in nonneuronal cells. The proline/arginine-rich domain of Dyn2 is important for its targeting to nascent and growing CCPs, whereas the membrane-binding and curvature-generating pleckstrin homology domain of Dyn1 plays an important role in stabilizing nascent CCPs. We confirm the enhanced ability of dephosphorylated Dyn1 to support CME, even at substoichiometric levels compared with Dyn2. Domain swap chimeras also revealed previously unknown functional differences in the GTPase and stalk domains. Our study significantly extends the current understanding of the regulatory roles played by dynamin isoforms during early stages of CME.
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Affiliation(s)
- Madhura Bhave
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX 75390
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX 75390
| | - Xinxin Wang
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX 75390.,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, TX 75390
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX 75390
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