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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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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3
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Rahmani S, Ahmed H, Ibazebo O, Fussner-Dupas E, Wakarchuk WW, Antonescu CN. O-GlcNAc transferase modulates the cellular endocytosis machinery by controlling the formation of clathrin-coated pits. J Biol Chem 2023; 299:102963. [PMID: 36731797 PMCID: PMC9999237 DOI: 10.1016/j.jbc.2023.102963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 02/01/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) controls the internalization and function of a wide range of cell surface proteins. CME occurs by the assembly of clathrin and many other proteins on the inner leaflet of the plasma membrane into clathrin-coated pits (CCPs). These structures recruit specific cargo destined for internalization, generate membrane curvature, and in many cases undergo scission from the plasma membrane to yield intracellular vesicles. The diversity of functions of cell surface proteins controlled via internalization by CME may suggest that regulation of CCP formation could be effective to allow cellular adaptation under different contexts. Of interest is how cues derived from cellular metabolism may regulate CME, given the reciprocal role of CME in controlling cellular metabolism. The modification of proteins with O-linked β-GlcNAc (O-GlcNAc) is sensitive to nutrient availability and may allow cellular adaptation to different metabolic conditions. Here, we examined how the modification of proteins with O-GlcNAc may control CCP formation and thus CME. We used perturbation of key enzymes responsible for protein O-GlcNAc modification, as well as specific mutants of the endocytic regulator AAK1 predicted to be impaired for O-GlcNAc modification. We identify that CCP initiation and the assembly of clathrin and other proteins within CCPs are controlled by O-GlcNAc protein modification. This reveals a new dimension of regulation of CME and highlights the important reciprocal regulation of cellular metabolism and endocytosis.
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Affiliation(s)
- Sadia Rahmani
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Ontario, Canada; Graduate Program in Molecular Science, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Hafsa Ahmed
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Osemudiamen Ibazebo
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Eden Fussner-Dupas
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Ontario, Canada; Graduate Program in Molecular Science, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Warren W Wakarchuk
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
| | - Costin N Antonescu
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, Ontario, Canada; Graduate Program in Molecular Science, Toronto Metropolitan University, Toronto, Ontario, Canada.
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4
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Cabral-Dias R, Lucarelli S, Zak K, Rahmani S, Judge G, Abousawan J, DiGiovanni LF, Vural D, Anderson KE, Sugiyama MG, Genc G, Hong W, Botelho RJ, Fairn GD, Kim PK, Antonescu CN. Fyn and TOM1L1 are recruited to clathrin-coated pits and regulate Akt signaling. J Cell Biol 2022; 221:213045. [PMID: 35238864 PMCID: PMC8899389 DOI: 10.1083/jcb.201808181] [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: 08/31/2018] [Revised: 12/15/2021] [Accepted: 01/24/2022] [Indexed: 12/24/2022] Open
Abstract
The epidermal growth factor (EGF) receptor (EGFR) controls many aspects of cell physiology. EGF binding to EGFR elicits the membrane recruitment and activation of phosphatidylinositol-3-kinase, leading to Akt phosphorylation and activation. Concomitantly, EGFR is recruited to clathrin-coated pits (CCPs), eventually leading to receptor endocytosis. Previous work uncovered that clathrin, but not receptor endocytosis, is required for EGF-stimulated Akt activation, and that some EGFR signals are enriched in CCPs. Here, we examine how CCPs control EGFR signaling. The signaling adaptor TOM1L1 and the Src-family kinase Fyn are enriched within a subset of CCPs with unique lifetimes and protein composition. Perturbation of TOM1L1 or Fyn impairs EGF-stimulated phosphorylation of Akt2 but not Akt1. EGF stimulation also triggered the TOM1L1- and Fyn-dependent recruitment of the phosphoinositide 5-phosphatase SHIP2 to CCPs. Thus, the recruitment of TOM1L1 and Fyn to a subset of CCPs underlies a role for these structures in the support of EGFR signaling leading to Akt activation.
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Affiliation(s)
- Rebecca Cabral-Dias
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Stefanie Lucarelli
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Karolina Zak
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Sadia Rahmani
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Gurjeet Judge
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - John Abousawan
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Laura F DiGiovanni
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Dafne Vural
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Karen E Anderson
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge, UK
| | - Michael G Sugiyama
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Gizem Genc
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
| | - Wanjin Hong
- Institute of Molecular and Cell Biology, A*STAR, Singapore
| | - Roberto J Botelho
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Gregory D Fairn
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Peter K Kim
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Costin N Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada.,Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada.,Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, Ontario, Canada
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5
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Choudhry H, Aggarwal M, Pan PY. Mini-review: Synaptojanin 1 and its implications in membrane trafficking. Neurosci Lett 2021; 765:136288. [PMID: 34637856 PMCID: PMC8572151 DOI: 10.1016/j.neulet.2021.136288] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 12/04/2022]
Abstract
This mini-review aims to summarize a growing body of literature on synaptojanin 1 (Synj1), a phosphoinositide phosphatase that was initially known to have a prominent role in synaptic vesicle recycling. Synj1 is coded by the SYNJ1 gene, whose mutations and variants are associated with an increasing number of neurological disorders. To better understand the mechanistic role of Synj1 in disease pathogenesis, we review details of phosphoinositide signaling pathways and the reported involvement of Synj1 in membrane trafficking with a specific focus on Parkinson’s disease (PD). Recent studies have tremendously advanced our understanding of Synj1 protein structure and function while broadening our view of how Synj1 regulates synaptic membrane trafficking and endosomal trafficking in various organisms and cell types. A growing body of evidence points to inefficient membrane trafficking as key pathogenic mechanisms in neurodegenerative diseases associated with abnormal Synj1 expression. Despite significant progress made in the field, the mechanism by which Synj1 connects to trafficking, signaling, and pathogenesis is lacking and remains to be addressed.
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Affiliation(s)
- Hassaam Choudhry
- Dept. of Neuroscience and Cell Biology, Rutgers, Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Meha Aggarwal
- Dept. of Neuroscience and Cell Biology, Rutgers, Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Ping-Yue Pan
- Dept. of Neuroscience and Cell Biology, Rutgers, Robert Wood Johnson Medical School, 675 Hoes Lane West, Piscataway, NJ 08854, USA.
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6
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Djakbarova U, Madraki Y, Chan ET, Kural C. Dynamic interplay between cell membrane tension and clathrin-mediated endocytosis. Biol Cell 2021; 113:344-373. [PMID: 33788963 DOI: 10.1111/boc.202000110] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/08/2021] [Accepted: 03/19/2021] [Indexed: 12/26/2022]
Abstract
Deformability of the plasma membrane, the outermost surface of metazoan cells, allows cells to be dynamic, mobile and flexible. Factors that affect this deformability, such as tension on the membrane, can regulate a myriad of cellular functions, including membrane resealing, cell motility, polarisation, shape maintenance, membrane area control and endocytic vesicle trafficking. This review focuses on mechanoregulation of clathrin-mediated endocytosis (CME). We first delineate the origins of cell membrane tension and the factors that yield to its spatial and temporal fluctuations within cells. We then review the recent literature demonstrating that tension on the membrane is a fast-acting and reversible regulator of CME. Finally, we discuss tension-based regulation of endocytic clathrin coat formation during physiological processes.
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Affiliation(s)
| | - Yasaman Madraki
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA
| | - Emily T Chan
- Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, 43210, USA.,Molecular Biophysics Training Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Cömert Kural
- Department of Physics, The Ohio State University, Columbus, OH, 43210, USA.,Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, 43210, USA
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7
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Sochacki KA, Heine BL, Haber GJ, Jimah JR, Prasai B, Alfonzo-Méndez MA, Roberts AD, Somasundaram A, Hinshaw JE, Taraska JW. The structure and spontaneous curvature of clathrin lattices at the plasma membrane. Dev Cell 2021; 56:1131-1146.e3. [PMID: 33823128 PMCID: PMC8081270 DOI: 10.1016/j.devcel.2021.03.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 01/19/2021] [Accepted: 03/11/2021] [Indexed: 01/10/2023]
Abstract
Clathrin-mediated endocytosis is the primary pathway for receptor and cargo internalization in eukaryotic cells. It is characterized by a polyhedral clathrin lattice that coats budding membranes. The mechanism and control of lattice assembly, curvature, and vesicle formation at the plasma membrane has been a matter of long-standing debate. Here, we use platinum replica and cryoelectron microscopy and tomography to present a structural framework of the pathway. We determine the shape and size parameters common to clathrin-mediated endocytosis. We show that clathrin sites maintain a constant surface area during curvature across multiple cell lines. Flat clathrin is present in all cells and spontaneously curves into coated pits without additional energy sources or recruited factors. Finally, we attribute curvature generation to loosely connected and pentagon-containing flat lattices that can rapidly curve when a flattening force is released. Together, these data present a universal mechanistic model of clathrin-mediated endocytosis.
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Affiliation(s)
- Kem A Sochacki
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Bridgette L Heine
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Gideon J Haber
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - John R Jimah
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bijeta Prasai
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Marco A Alfonzo-Méndez
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Aleah D Roberts
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Agila Somasundaram
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jenny E Hinshaw
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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8
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SH3BP4 promotes neuropilin-1 and α5-integrin endocytosis and is inhibited by Akt. Dev Cell 2021; 56:1164-1181.e12. [PMID: 33761321 DOI: 10.1016/j.devcel.2021.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 12/23/2020] [Accepted: 02/27/2021] [Indexed: 02/06/2023]
Abstract
Cells probe their surrounding matrix for attachment sites via integrins that are internalized by endocytosis. We find that SH3BP4 regulates integrin surface expression in a signaling-dependent manner via clathrin-coated pits (CCPs). Dephosphorylated SH3BP4 at S246 is efficiently recruited to CCPs, while upon Akt phosphorylation, SH3BP4 is sequestered by 14-3-3 adaptors and excluded from CCPs. In the absence of Akt activity, SH3BP4 binds GIPC1 and targets neuropilin-1 and α5/β1-integrin for endocytosis, leading to inhibition of cell spreading. Similarly, chemorepellent semaphorin-3a binds neuropilin-1 to activate PTEN, which antagonizes Akt and thus recruits SH3BP4 to CCPs to internalize both receptors and induce cell contraction. In PTEN mutant non-small cell lung cancer cells with high Akt activity, expression of non-phosphorylatable active SH3BP4-S246A restores semaphorin-3a induced cell contraction. Thus, SH3BP4 links Akt signaling to endocytosis of NRP1 and α5/β1-integrins to modulate cell-matrix interactions in response to intrinsic and extrinsic cues.
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9
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Chen Z, Mino RE, Mettlen M, Michaely P, Bhave M, Reed DK, Schmid SL. Wbox2: A clathrin terminal domain-derived peptide inhibitor of clathrin-mediated endocytosis. J Cell Biol 2021; 219:151850. [PMID: 32520988 PMCID: PMC7480105 DOI: 10.1083/jcb.201908189] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 12/03/2019] [Accepted: 05/14/2020] [Indexed: 12/11/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) occurs via the formation of clathrin-coated vesicles from clathrin-coated pits (CCPs). Clathrin is recruited to CCPs through interactions between the AP2 complex and its N-terminal domain, which in turn recruits endocytic accessory proteins. Inhibitors of CME that interfere with clathrin function have been described, but their specificity and mechanisms of action are unclear. Here we show that overexpression of the N-terminal domain with (TDD) or without (TD) the distal leg inhibits CME and CCP dynamics by perturbing clathrin interactions with AP2 and SNX9. TDD overexpression does not affect clathrin-independent endocytosis or, surprisingly, AP1-dependent lysosomal trafficking from the Golgi. We designed small membrane–permeant peptides that encode key functional residues within the four known binding sites on the TD. One peptide, Wbox2, encoding residues along the W-box motif binding surface, binds to SNX9 and AP2 and potently and acutely inhibits CME.
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Affiliation(s)
- Zhiming Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Rosa E Mino
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Peter Michaely
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Madhura Bhave
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Dana Kim Reed
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
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10
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Find your coat: Using correlative light and electron microscopy to study intracellular protein coats. Curr Opin Cell Biol 2021; 71:21-28. [PMID: 33684808 DOI: 10.1016/j.ceb.2021.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 12/14/2022]
Abstract
Protein coats, important for vesicular trafficking in eukaryotic cells, help shape membranes and package cargo. But their dynamic construction cannot be fully understood until the distinct steps of their assembly in their native intracellular context at molecular resolution can be visualized. For this, correlative light and electron microscopy (CLEM) is an essential tool. Here, we discuss how emerging CLEM techniques have been used to study the assembly of protein coats inside cells. We review how current and developing CLEM technologies are poised to answer fundamental questions of protein coat architecture at the nanoscale.
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11
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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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12
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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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13
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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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14
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Wang X, Chen Z, Mettlen M, Noh J, Schmid SL, Danuser G. DASC, a sensitive classifier for measuring discrete early stages in clathrin-mediated endocytosis. eLife 2020; 9:53686. [PMID: 32352376 PMCID: PMC7192580 DOI: 10.7554/elife.53686] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) in mammalian cells is driven by resilient machinery that includes >70 endocytic accessory proteins (EAP). Accordingly, perturbation of individual EAPs often results in minor effects on biochemical measurements of CME, thus providing inconclusive/misleading information regarding EAP function. Live-cell imaging can detect earlier roles of EAPs preceding cargo internalization; however, this approach has been limited because unambiguously distinguishing abortive coats (ACs) from bona fide clathrin-coated pits (CCPs) is required but unaccomplished. Here, we develop a thermodynamics-inspired method, “disassembly asymmetry score classification (DASC)”, that resolves ACs from CCPs based on single channel fluorescent movies. After extensive verification, we use DASC-resolved ACs and CCPs to quantify CME progression in 11 EAP knockdown conditions. We show that DASC is a sensitive detector of phenotypic variation in CCP dynamics that is uncorrelated to the variation in biochemical measurements of CME. Thus, DASC is an essential tool for uncovering EAP function.
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Affiliation(s)
- Xinxin Wang
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Zhiming Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jungsik Noh
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
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15
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Rosselli-Murai LK, Joseph JG, Lopes-Cendes I, Liu AP, Murai MJ. The Machado-Joseph disease-associated form of ataxin-3 impacts dynamics of clathrin-coated pits. Cell Biol Int 2020; 44:1252-1259. [PMID: 31970864 DOI: 10.1002/cbin.11312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 01/22/2020] [Indexed: 12/14/2022]
Abstract
Expansion above a certain threshold in the polyglutamine (polyQ) tract of ataxin-3 is the main cause of neurodegeneration in Machado-Joseph disease. Ataxin-3 contains an N-terminal catalytic domain, called Josephin domain, and a highly aggregation-prone C-terminal domain containing the polyQ tract. Recent work has shown that protein aggregation inhibits clathrin-mediated endocytosis (CME). However, the effects of polyQ expansion in ataxin-3 on CME have not been investigated. We hypothesize that the expansion of the polyQ tract in ataxin-3 could impact CME. Here, we report that both the wild-type and the expanded ataxin-3 reduce transferrin internalization and expanded ataxin-3 impacts dynamics of clathrin-coated pits (CCPs) by reducing CCP nucleation and increasing short-lived abortive CCPs. Since endocytosis plays a central role in regulating receptor uptake and cargo release, our work highlights a potential mechanism linking protein aggregation to cellular dysregulation.
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Affiliation(s)
- Luciana K Rosselli-Murai
- Department of Pharmacology, University of Michigan Medical School, 2301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, Michigan, 48109, USA.,Department of Mechanical Engineering, University of Michigan, 2674 GGB, 2350 Hayward, Ann Arbor, Michigan, 48109, USA
| | - Jophin G Joseph
- Department of Mechanical Engineering, University of Michigan, 2674 GGB, 2350 Hayward, Ann Arbor, Michigan, 48109, USA
| | - Iscia Lopes-Cendes
- Department of Medical Genetics, School of Medical Sciences, University of Campinas, R. Tessália Vieira de Camargo, 126, Campinas, São Paulo, 13083-970, Brazil.,The Brazilian Institute of Neuroscience and Neurotechnology, R. Vital Brasil, 251, Campinas, São Paulo, 13083-888, Brazil
| | - Allen P Liu
- Department of Mechanical Engineering, University of Michigan, 2674 GGB, 2350 Hayward, Ann Arbor, Michigan, 48109, USA
| | - Marcelo J Murai
- Department of Pharmacology, University of Michigan Medical School, 2301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, Michigan, 48109, USA.,Department of Medical Genetics, School of Medical Sciences, University of Campinas, R. Tessália Vieira de Camargo, 126, Campinas, São Paulo, 13083-970, Brazil
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16
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Wang H, Loerke D, Bruns C, Müller R, Koch PA, Puchkov D, Schultz C, Haucke V. Phosphatidylinositol 3,4-bisphosphate synthesis and turnover are spatially segregated in the endocytic pathway. J Biol Chem 2020; 295:1091-1104. [PMID: 31831620 PMCID: PMC6983852 DOI: 10.1074/jbc.ra119.011774] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 12/09/2019] [Indexed: 12/31/2022] Open
Abstract
Phosphoinositides play crucial roles in intracellular membrane dynamics and cell signaling, with phosphatidylinositol (PI) 3-phosphates being the predominant phosphoinositide lipids at endosomes and lysosomes, whereas PI 4-phosphates, such as phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), are enriched at the cell surface including sites of endocytosis. How PI 4-phosphates and PI 3-phosphates are dynamically interconverted within the endocytic pathway and how this is controlled in space and time remains poorly understood. Here, combining live imaging, genome engineering, and acute chemical and genetic manipulations, we found that local synthesis of PI(3,4)P2 by phosphatidylinositol 3-kinase C2α at plasma membrane clathrin-coated pits is spatially segregated from its hydrolysis by the PI(3,4)P2-specific inositol polyphosphate 4-phosphatase 4A (INPP4A). We observed that INPP4A is dispensable for clathrin-mediated endocytosis and is undetectable in endocytic clathrin-coated pits. Instead, we found that INPP4A partially localizes to endosomes and that loss of INPP4A in HAP1 cancer cells perturbs signaling via AKT kinase and mTOR complex 1. These results reveal a function for INPP4-mediated PI(3,4)P2 hydrolysis in local regulation of growth factor and nutrient signals at endosomes in cancer cells. They further suggest a model whereby synthesis and turnover of PI(3,4)P2 are spatially segregated within the endocytic pathway to couple endocytic membrane traffic to growth factor and nutrient signaling.
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Affiliation(s)
- Haibin Wang
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208
| | - Caroline Bruns
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Rainer Müller
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Philipp-Alexander Koch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Carsten Schultz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany,Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, Oregon 97239–3098
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany,Faculty of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany, To whom correspondence should be addressed. Tel.:
49-30-94793101; Fax:
49-30-94793109; E-mail:
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17
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Wang H, Loerke D, Bruns C, Müller R, Koch PA, Puchkov D, Schultz C, Haucke V. Phosphatidylinositol 3,4-bisphosphate synthesis and turnover are spatially segregated in the endocytic pathway. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49918-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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18
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Lehmann M, Lukonin I, Noé F, Schmoranzer J, Clementi C, Loerke D, Haucke V. Nanoscale coupling of endocytic pit growth and stability. SCIENCE ADVANCES 2019; 5:eaax5775. [PMID: 31807703 PMCID: PMC6881173 DOI: 10.1126/sciadv.aax5775] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 09/25/2019] [Indexed: 05/21/2023]
Abstract
Clathrin-mediated endocytosis, an essential process for plasma membrane homeostasis and cell signaling, is characterized by stunning heterogeneity in the size and lifetime of clathrin-coated endocytic pits (CCPs). If and how CCP growth and lifetime are coupled and how this relates to their physiological function are unknown. We combine computational modeling, automated tracking of CCP dynamics, electron microscopy, and functional rescue experiments to demonstrate that CCP growth and lifetime are closely correlated and mechanistically linked by the early-acting endocytic F-BAR protein FCHo2. FCHo2 assembles at the rim of CCPs to control CCP growth and lifetime by coupling the invagination of early endocytic intermediates to clathrin lattice assembly. Our data suggest a mechanism for the nanoscale control of CCP growth and stability that may similarly apply to other metastable structures in cells.
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Affiliation(s)
- Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Corresponding author. (V.H.); (M.L.)
| | - Ilya Lukonin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Frank Noé
- Freie Universität Berlin, Department of Mathematics and Computer Science and Department of Physics, 14195 Berlin, Germany
- Center for Theoretical Biological Physics and Department of Chemistry, Rice University, Houston, TX 77005, USA
| | - Jan Schmoranzer
- Charité Universitätsmedizin Berlin, Virchowweg 6, 10117 Berlin, Germany
| | - Cecilia Clementi
- Freie Universität Berlin, Department of Mathematics and Computer Science and Department of Physics, 14195 Berlin, Germany
- Center for Theoretical Biological Physics and Department of Chemistry, Rice University, Houston, TX 77005, USA
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Freie Universität Berlin, Faculty of Biology, Chemistry, Pharmacy, 14195 Berlin, Germany
- Corresponding author. (V.H.); (M.L.)
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19
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Wrobel AG, Kadlecova Z, Kamenicky J, Yang JC, Herrmann T, Kelly BT, McCoy AJ, Evans PR, Martin S, Müller S, Salomon S, Sroubek F, Neuhaus D, Höning S, Owen DJ. Temporal Ordering in Endocytic Clathrin-Coated Vesicle Formation via AP2 Phosphorylation. Dev Cell 2019; 50:494-508.e11. [PMID: 31430451 PMCID: PMC6706699 DOI: 10.1016/j.devcel.2019.07.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/18/2019] [Accepted: 07/15/2019] [Indexed: 11/23/2022]
Abstract
Clathrin-mediated endocytosis (CME) is key to maintaining the transmembrane protein composition of cells' limiting membranes. During mammalian CME, a reversible phosphorylation event occurs on Thr156 of the μ2 subunit of the main endocytic clathrin adaptor, AP2. We show that this phosphorylation event starts during clathrin-coated pit (CCP) initiation and increases throughout CCP lifetime. μ2Thr156 phosphorylation favors a new, cargo-bound conformation of AP2 and simultaneously creates a binding platform for the endocytic NECAP proteins but without significantly altering AP2's cargo affinity in vitro. We describe the structural bases of both. NECAP arrival at CCPs parallels that of clathrin and increases with μ2Thr156 phosphorylation. In turn, NECAP recruits drivers of late stages of CCP formation, including SNX9, via a site distinct from where NECAP binds AP2. Disruption of the different modules of this phosphorylation-based temporal regulatory system results in CCP maturation being delayed and/or stalled, hence impairing global rates of CME.
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Affiliation(s)
| | | | - Jan Kamenicky
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - Ji-Chun Yang
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Torsten Herrmann
- University of Grenoble Alpes, CNRS, CEA, IBS, 38000 Grenoble, France
| | | | - Airlie J McCoy
- CIMR, WT/MRC Building, Hills Road, Cambridge CB2 0QQ, UK
| | - Philip R Evans
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Stephen Martin
- The Francis Crick Institute, 1 Midland Road, London NW1 1ST, UK
| | - Stefan Müller
- Center for Molecular Medicine (CMMC), University of Cologne, Robert-Koch-Straße 21, 50931 Cologne, Germany
| | - Susanne Salomon
- Institute for Biochemistry I, Medical Faulty, University of Cologne, Joseph-Stelzmann-Straße 52, 50931 Cologne, Germany
| | - Filip Sroubek
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - David Neuhaus
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Stefan Höning
- Institute for Biochemistry I, Medical Faulty, University of Cologne, Joseph-Stelzmann-Straße 52, 50931 Cologne, Germany.
| | - David J Owen
- CIMR, WT/MRC Building, Hills Road, Cambridge CB2 0QQ, UK
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20
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Ditlev JA, Vega AR, Köster DV, Su X, Tani T, Lakoduk AM, Vale RD, Mayor S, Jaqaman K, Rosen MK. A composition-dependent molecular clutch between T cell signaling condensates and actin. eLife 2019; 8:e42695. [PMID: 31268421 PMCID: PMC6624021 DOI: 10.7554/elife.42695] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 06/14/2019] [Indexed: 01/04/2023] Open
Abstract
During T cell activation, biomolecular condensates form at the immunological synapse (IS) through multivalency-driven phase separation of LAT, Grb2, Sos1, SLP-76, Nck, and WASP. These condensates move radially at the IS, traversing successive radially-oriented and concentric actin networks. To understand this movement, we biochemically reconstituted LAT condensates with actomyosin filaments. We found that basic regions of Nck and N-WASP/WASP promote association and co-movement of LAT condensates with actin, indicating conversion of weak individual affinities to high collective affinity upon phase separation. Condensates lacking these components were propelled differently, without strong actin adhesion. In cells, LAT condensates lost Nck as radial actin transitioned to the concentric network, and engineered condensates constitutively binding actin moved aberrantly. Our data show that Nck and WASP form a clutch between LAT condensates and actin in vitro and suggest that compositional changes may enable condensate movement by distinct actin networks in different regions of the IS.
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Affiliation(s)
- Jonathon A Ditlev
- Howard Hughes Medical Institute, Summer Institute, Marine Biological LaboratoryWoods HoleUnited States
- Department of BiophysicsHoward Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
| | - Anthony R Vega
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Darius Vasco Köster
- Howard Hughes Medical Institute, Summer Institute, Marine Biological LaboratoryWoods HoleUnited States
- National Centre for Biological Sciences, Tata Institute for Fundamental ResearchBangaloreIndia
| | - Xiaolei Su
- Howard Hughes Medical Institute, Summer Institute, Marine Biological LaboratoryWoods HoleUnited States
- Department of Cellular and Molecular PharmacologyHoward Hughes Medical Institute, University of California, San FranciscoSan FranciscoUnited States
| | - Tomomi Tani
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological LaboratoryWoods HoleUnited States
| | - Ashley M Lakoduk
- Department of Cell BiologyUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Ronald D Vale
- Howard Hughes Medical Institute, Summer Institute, Marine Biological LaboratoryWoods HoleUnited States
- Department of Cellular and Molecular PharmacologyHoward Hughes Medical Institute, University of California, San FranciscoSan FranciscoUnited States
| | - Satyajit Mayor
- Howard Hughes Medical Institute, Summer Institute, Marine Biological LaboratoryWoods HoleUnited States
- National Centre for Biological Sciences, Tata Institute for Fundamental ResearchBangaloreIndia
| | - Khuloud Jaqaman
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasUnited States
- Lyda Hill Department of BioinformaticsUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Michael K Rosen
- Howard Hughes Medical Institute, Summer Institute, Marine Biological LaboratoryWoods HoleUnited States
- Department of BiophysicsHoward Hughes Medical Institute, University of Texas Southwestern Medical CenterDallasUnited States
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21
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Abstract
High-resolution fluorescence microscopy is increasingly contributing to our understanding of molecular processes. By utilizing single-molecule intensity information, imaging experiments can be rendered quantitative, yielding insights into the stoichiometry and kinetics of the components of a molecular assembly. Here, we describe the experimental and analytical steps needed to study the assembly of clathrin-coated vesicles with single-molecule resolution, using total internal reflection fluorescence microscopy. Many components of the protocol are broadly applicable to the characterization of other molecular processes.
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22
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From Flat to Curved Clathrin: Controlling a Plastic Ratchet. Trends Cell Biol 2019; 29:241-256. [DOI: 10.1016/j.tcb.2018.12.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/04/2018] [Accepted: 12/09/2018] [Indexed: 01/13/2023]
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23
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Maib H, Ferreira F, Vassilopoulos S, Smythe E. Cargo regulates clathrin-coated pit invagination via clathrin light chain phosphorylation. J Cell Biol 2018; 217:4253-4266. [PMID: 30228161 PMCID: PMC6279376 DOI: 10.1083/jcb.201805005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/20/2018] [Accepted: 09/07/2018] [Indexed: 12/18/2022] Open
Abstract
Phosphorylation of clathrin light chains (CLCs) regulates GPCR uptake but is dispensable for transferrin internalization. Maib et al. show that CLCb phosphorylation is required for efficient auxilin-mediated clathrin exchange to promote coated pit invagination in a cargo-specific manner. Clathrin light chains (CLCs) control selective uptake of a range of G protein–coupled receptors (GPCRs), although the mechanism by which this occurs has remained elusive thus far. In particular, site-specific phosphorylation of CLCb controls the uptake of the purinergic GPCR P2Y12, but it is dispensable for the constitutive uptake of the transferrin receptor (TfR). We demonstrate that phosphorylation of CLCb is required for the maturation of clathrin-coated pits (CCPs) through the transition of flat lattices into invaginated buds. This transition is dependent on efficient clathrin exchange regulated by CLCb phosphorylation and mediated through auxilin. Strikingly, this rearrangement is required for the uptake of P2Y12 but not TfR. These findings link auxilin-mediated clathrin exchange to early stages of CCP invagination in a cargo-specific manner. This supports a model in which CCPs invaginate with variable modes of curvature depending on the cargo they incorporate.
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Affiliation(s)
- Hannes Maib
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Filipe Ferreira
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Stéphane Vassilopoulos
- Sorbonne Université, INSERM, Institute of Myology, Centre for Research in Myology, UMRS 974, Paris, France
| | - Elizabeth Smythe
- Centre for Membrane Interactions and Dynamics, Department of Biomedical Science, University of Sheffield, Sheffield, UK
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24
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Picco A, Kaksonen M. Quantitative imaging of clathrin-mediated endocytosis. Curr Opin Cell Biol 2018; 53:105-110. [PMID: 30025292 DOI: 10.1016/j.ceb.2018.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 04/24/2018] [Accepted: 06/11/2018] [Indexed: 11/29/2022]
Abstract
Clathrin-mediated endocytosis is a process by which eukaryotic cells bend a small region of their plasma membrane to form a transport vesicle that carries specific cargo molecules into the cell. Endocytosis controls the composition of the plasma membrane, imports nutrients and regulates many signalling pathways. The roles of most of the proteins involved in endocytosis have been thoroughly characterised. However, how these proteins cooperate in the cell to drive the endocytic process is not well understood. Microscopy methods have been instrumental in describing the dynamics and the molecular mechanism of endocytosis. Here, we will review the challenges and the recent advances in visualising the endocytic machinery and we will reflect on how the integration of current imaging technologies can lead us toward a quantitative understanding of the molecular mechanisms of endocytosis.
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Affiliation(s)
- Andrea Picco
- Department of Biochemistry and NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Marko Kaksonen
- Department of Biochemistry and NCCR Chemical Biology, University of Geneva, Geneva, Switzerland.
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25
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Ma R, Berro J. Structural organization and energy storage in crosslinked actin assemblies. PLoS Comput Biol 2018; 14:e1006150. [PMID: 29813051 PMCID: PMC5993335 DOI: 10.1371/journal.pcbi.1006150] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 06/08/2018] [Accepted: 04/18/2018] [Indexed: 11/19/2022] Open
Abstract
During clathrin-mediated endocytosis in yeast cells, short actin filaments (< 200nm) and crosslinking protein fimbrin assemble to drive the internalization of the plasma membrane. However, the organization of the actin meshwork during endocytosis remains largely unknown. In addition, only a small fraction of the force necessary to elongate and pinch off vesicles can be accounted for by actin polymerization alone. In this paper, we used mathematical modeling to study the self-organization of rigid actin filaments in the presence of elastic crosslinkers in conditions relevant to endocytosis. We found that actin filaments condense into either a disordered meshwork or an ordered bundle depending on filament length and the mechanical and kinetic properties of the crosslinkers. Our simulations also demonstrated that these nanometer-scale actin structures can store a large amount of elastic energy within the crosslinkers (up to 10kBT per crosslinker). This conversion of binding energy into elastic energy is the consequence of geometric constraints created by the helical pitch of the actin filaments, which results in frustrated configurations of crosslinkers attached to filaments. We propose that this stored elastic energy can be used at a later time in the endocytic process. As a proof of principle, we presented a simple mechanism for sustained torque production by ordered detachment of crosslinkers from a pair of parallel filaments.
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Affiliation(s)
- Rui Ma
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
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26
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Rosselli-Murai LK, Yates JA, Yoshida S, Bourg J, Ho KKY, White M, Prisby J, Tan X, Altemus M, Bao L, Wu ZF, Veatch SL, Swanson JA, Merajver SD, Liu AP. Loss of PTEN promotes formation of signaling-capable clathrin-coated pits. J Cell Sci 2018; 131:jcs.208926. [PMID: 29588397 DOI: 10.1242/jcs.208926] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 03/19/2018] [Indexed: 12/19/2022] Open
Abstract
Defective endocytosis and vesicular trafficking of signaling receptors has recently emerged as a multifaceted hallmark of malignant cells. Clathrin-coated pits (CCPs) display highly heterogeneous dynamics on the plasma membrane where they can take from 20 s to over 1 min to form cytosolic coated vesicles. Despite the large number of cargo molecules that traffic through CCPs, it is not well understood whether signaling receptors activated in cancer, such as epidermal growth factor receptor (EGFR), are regulated through a specific subset of CCPs. The signaling lipid phosphatidylinositol (3,4,5)-trisphosphate [PI(3,4,5)P3], which is dephosphorylated by phosphatase and tensin homolog (PTEN), is a potent tumorigenic signaling lipid. By using total internal reflection fluorescence microscopy and automated tracking and detection of CCPs, we found that EGF-bound EGFR and PTEN are enriched in a distinct subset of short-lived CCPs that correspond with clathrin-dependent EGF-induced signaling. We demonstrated that PTEN plays a role in the regulation of CCP dynamics. Furthermore, increased PI(3,4,5)P3 resulted in higher proportion of short-lived CCPs, an effect that recapitulates PTEN deletion. Altogether, our findings provide evidence for the existence of short-lived 'signaling-capable' CCPs.
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Affiliation(s)
| | - Joel A Yates
- Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109-5624, USA
| | - Sei Yoshida
- Department of Microbiology and Immunology of Michigan Medical School, University of Michigan, Ann Arbor, MI 48109-5620, USA
| | - Julia Bourg
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Kenneth K Y Ho
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Megan White
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Julia Prisby
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xinyu Tan
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Megan Altemus
- Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109-5624, USA.,Cancer Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Liwei Bao
- Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109-5624, USA
| | - Zhi-Fen Wu
- Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109-5624, USA
| | - Sarah L Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055, USA
| | - Joel A Swanson
- Department of Microbiology and Immunology of Michigan Medical School, University of Michigan, Ann Arbor, MI 48109-5620, USA
| | - Sofia D Merajver
- Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan, Ann Arbor, MI 48109-5624, USA .,Cell and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Allen P Liu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA .,Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055, USA.,Cell and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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27
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A noncanonical role for dynamin-1 in regulating early stages of clathrin-mediated endocytosis in non-neuronal cells. PLoS Biol 2018; 16:e2005377. [PMID: 29668686 PMCID: PMC5927468 DOI: 10.1371/journal.pbio.2005377] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/30/2018] [Accepted: 03/22/2018] [Indexed: 12/20/2022] Open
Abstract
Dynamin Guanosine Triphosphate hydrolases (GTPases) are best studied for their role in the terminal membrane fission process of clathrin-mediated endocytosis (CME), but they have also been proposed to regulate earlier stages of CME. Although highly enriched in neurons, dynamin-1 (Dyn1) is, in fact, widely expressed along with Dyn2 but inactivated in non-neuronal cells via phosphorylation by glycogen synthase kinase-3 beta (GSK3β) kinase. Here, we study the differential, isoform-specific functions of Dyn1 and Dyn2 as regulators of CME. Endogenously expressed Dyn1 and Dyn2 were fluorescently tagged either separately or together in two cell lines with contrasting Dyn1 expression levels. By quantitative live cell dual- and triple-channel total internal reflection fluorescence microscopy, we find that Dyn2 is more efficiently recruited to clathrin-coated pits (CCPs) than Dyn1, and that Dyn2 but not Dyn1 exhibits a pronounced burst of assembly, presumably into supramolecular collar-like structures that drive membrane scission and clathrin-coated vesicle (CCV) formation. Activation of Dyn1 by acute inhibition of GSK3β results in more rapid endocytosis of transferrin receptors, increased rates of CCP initiation, and decreased CCP lifetimes but did not significantly affect the extent of Dyn1 recruitment to CCPs. Thus, activated Dyn1 can regulate early stages of CME that occur well upstream of fission, even when present at low, substoichiometric levels relative to Dyn2. Under physiological conditions, Dyn1 is activated downstream of epidermal growth factor receptor (EGFR) signaling to alter CCP dynamics. We identify sorting nexin 9 (SNX9) as a preferred binding partner to activated Dyn1 that is partially required for Dyn1-dependent effects on early stages of CCP maturation. Together, we decouple regulatory and scission functions of dynamins and report a scission-independent, isoform-specific regulatory role for Dyn1 in CME. Clathrin-mediated endocytosis (CME), a major route for nutrient uptake, also controls signaling downstream of cell surface receptors. Recent studies have shown that signaling, in turn, can reciprocally regulate CME. CME is initiated by the assembly of clathrin-coated pits (CCPs) that mature to form deeply invaginated buds before the large Guanosine Triphosphate hydrolase (GTPase), dynamin, catalyzes membrane scission and clathrin-coated vesicle release. Here, we characterize an isoform-specific and noncanonical function for dynamin-1 (Dyn1) in regulating early stages of CME and show that Dyn1 and Dyn2 have nonredundant functions in CME. By genetically introducing fluorescent tags and using live-cell fluorescence imaging, we detected, tracked, and analyzed thousands of CCPs comprising up to three endocytic proteins in real time. We find that Dyn1, previously assumed to function only at neurological synapses, is expressed but maintained in an inactive state in non-neuronal cells through phosphorylation by glycogen synthase kinase-3 beta (GSK3β). We show that inhibition of GSK3β by a chemical inhibitor or downstream of epidermal growth factor receptor (EGFR) signaling activates Dyn1 and accelerates CCP assembly and maturation. These early effects are seen even when Dyn1 is barely detectable on CCPs. We conclude that Dyn1 is an important component of cross-communication between endocytosis and signaling.
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28
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Abstract
Clathrin-mediated endocytosis (CME) is the major endocytic pathway in mammalian cells. It is responsible for the uptake of transmembrane receptors and transporters, for remodeling plasma membrane composition in response to environmental changes, and for regulating cell surface signaling. CME occurs via the assembly and maturation of clathrin-coated pits that concentrate cargo as they invaginate and pinch off to form clathrin-coated vesicles. In addition to the major coat proteins, clathrin triskelia and adaptor protein complexes, CME requires a myriad of endocytic accessory proteins and phosphatidylinositol lipids. CME is regulated at multiple steps-initiation, cargo selection, maturation, and fission-and is monitored by an endocytic checkpoint that induces disassembly of defective pits. Regulation occurs via posttranslational modifications, allosteric conformational changes, and isoform and splice-variant differences among components of the CME machinery, including the GTPase dynamin. This review summarizes recent findings on the regulation of CME and the evolution of this complex process.
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Affiliation(s)
- Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Ping-Hung Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Saipraveen Srinivasan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , , .,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
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29
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Bucher D, Frey F, Sochacki KA, Kummer S, Bergeest JP, Godinez WJ, Kräusslich HG, Rohr K, Taraska JW, Schwarz US, Boulant S. Clathrin-adaptor ratio and membrane tension regulate the flat-to-curved transition of the clathrin coat during endocytosis. Nat Commun 2018; 9:1109. [PMID: 29549258 PMCID: PMC5856840 DOI: 10.1038/s41467-018-03533-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 02/15/2018] [Indexed: 12/03/2022] Open
Abstract
Although essential for many cellular processes, the sequence of structural and molecular events during clathrin-mediated endocytosis remains elusive. While it was long believed that clathrin-coated pits grow with a constant curvature, it was recently suggested that clathrin first assembles to form flat structures that then bend while maintaining a constant surface area. Here, we combine correlative electron and light microscopy and mathematical growth laws to study the ultrastructural rearrangements of the clathrin coat during endocytosis in BSC-1 mammalian cells. We confirm that clathrin coats initially grow flat and demonstrate that curvature begins when around 70% of the final clathrin content is acquired. We find that this transition is marked by a change in the clathrin to clathrin-adaptor protein AP2 ratio and that membrane tension suppresses this transition. Our results support the notion that BSC-1 mammalian cells dynamically regulate the flat-to-curved transition in clathrin-mediated endocytosis by both biochemical and mechanical factors. The sequence of structural and molecular events during clathrin-mediated endocytosis is unclear. Here the authors combine correlative microscopy and simple mathematical growth laws to demonstrate that the flat patch starts to curve when around 70% of the final clathrin content is reached.
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Affiliation(s)
- Delia Bucher
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany
| | - Felix Frey
- BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120, Heidelberg, Germany
| | - Kem A Sochacki
- National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Susann Kummer
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Jan-Philip Bergeest
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), Department of Bioinformatics and Functional Genomics, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - William J Godinez
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), Department of Bioinformatics and Functional Genomics, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Karl Rohr
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), Department of Bioinformatics and Functional Genomics, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - Justin W Taraska
- National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ulrich S Schwarz
- BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany. .,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120, Heidelberg, Germany.
| | - Steeve Boulant
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany. .,German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.
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30
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Delos Santos RC, Bautista S, Lucarelli S, Bone LN, Dayam RM, Abousawan J, Botelho RJ, Antonescu CN. Selective regulation of clathrin-mediated epidermal growth factor receptor signaling and endocytosis by phospholipase C and calcium. Mol Biol Cell 2017; 28:2802-2818. [PMID: 28814502 PMCID: PMC5638584 DOI: 10.1091/mbc.e16-12-0871] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 07/10/2017] [Accepted: 08/09/2017] [Indexed: 12/11/2022] Open
Abstract
Clathrin-mediated endocytosis is a major regulator of cell-surface protein internalization. Clathrin and other proteins assemble into small invaginating structures at the plasma membrane termed clathrin-coated pits (CCPs) that mediate vesicle formation. In addition, epidermal growth factor receptor (EGFR) signaling is regulated by its accumulation within CCPs. Given the diversity of proteins regulated by clathrin-mediated endocytosis, how this process may distinctly regulate specific receptors is a key question. We examined the selective regulation of clathrin-dependent EGFR signaling and endocytosis. We find that perturbations of phospholipase Cγ1 (PLCγ1), Ca2+, or protein kinase C (PKC) impair clathrin-mediated endocytosis of EGFR, the formation of CCPs harboring EGFR, and EGFR signaling. Each of these manipulations was without effect on the clathrin-mediated endocytosis of transferrin receptor (TfR). EGFR and TfR were recruited to largely distinct clathrin structures. In addition to control of initiation and assembly of CCPs, EGF stimulation also elicited a Ca2+- and PKC-dependent reduction in synaptojanin1 recruitment to clathrin structures, indicating broad control of CCP assembly by Ca2+ signals. Hence EGFR elicits PLCγ1-calcium signals to facilitate formation of a subset of CCPs, thus modulating its own signaling and endocytosis. This provides evidence for the versatility of CCPs to control diverse cellular processes.
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Affiliation(s)
- Ralph Christian Delos Santos
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Stephen Bautista
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Stefanie Lucarelli
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Leslie N Bone
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Roya M Dayam
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - John Abousawan
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Costin N Antonescu
- Department of Chemistry and Biology and Graduate Program in Molecular Science, Ryerson University, Toronto, ON M5B 2K3, Canada .,Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Toronto, ON M5B 1W8, Canada
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31
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Liu AP, Botelho RJ, Antonescu CN. The big and intricate dreams of little organelles: Embracing complexity in the study of membrane traffic. Traffic 2017; 18:567-579. [DOI: 10.1111/tra.12497] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Allen P. Liu
- Department of Mechanical Engineering University of Michigan Ann Arbor Michigan
- Department of Biomedical Engineering University of Michigan Ann Arbor Michigan
- Cellular and Molecular Biology Program University of Michigan Ann Arbor Michigan
- Biophysics Program University of Michigan Ann Arbor Michigan
| | - Roberto J. Botelho
- The Graduate Program in Molecular Science and Department of Chemistry and Biology Ryerson University Toronto Canada
| | - Costin N. Antonescu
- The Graduate Program in Molecular Science and Department of Chemistry and Biology Ryerson University Toronto Canada
- Keenan Research Centre for Biomedical Science St. Michael's Hospital Toronto Canada
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32
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Giani M, den Otter WK, Briels WJ. Early stages of clathrin aggregation at a membrane in coarse-grained simulations. J Chem Phys 2017; 146:155102. [DOI: 10.1063/1.4979985] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- M. Giani
- Multi Scale Mechanics, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Computational BioPhysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - W. K. den Otter
- Multi Scale Mechanics, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Computational BioPhysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - W. J. Briels
- Computational BioPhysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Forschungszentrum Jülich, ICS 3, D-52425 Jülich, Germany
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33
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Sochacki KA, Dickey AM, Strub MP, Taraska JW. Endocytic proteins are partitioned at the edge of the clathrin lattice in mammalian cells. Nat Cell Biol 2017; 19:352-361. [PMID: 28346440 DOI: 10.1038/ncb3498] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 02/23/2017] [Indexed: 12/15/2022]
Abstract
Dozens of proteins capture, polymerize and reshape the clathrin lattice during clathrin-mediated endocytosis (CME). How or if this ensemble of proteins is organized in relation to the clathrin coat is unknown. Here, we map key molecules involved in CME at the nanoscale using correlative super-resolution light and transmission electron microscopy. We localize 19 different endocytic proteins (amphiphysin1, AP2, β2-arrestin, CALM, clathrin, DAB2, dynamin2, EPS15, epsin1, epsin2, FCHO2, HIP1R, intersectin, NECAP, SNX9, stonin2, syndapin2, transferrin receptor, VAMP2) on thousands of individual clathrin structures, generating a comprehensive molecular architecture of endocytosis with nanoscale precision. We discover that endocytic proteins distribute into distinct spatial zones in relation to the edge of the clathrin lattice. The presence or concentrations of proteins within these zones vary at distinct stages of organelle development. We propose that endocytosis is driven by the recruitment, reorganization and loss of proteins within these partitioned nanoscale zones.
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Affiliation(s)
- Kem A Sochacki
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Andrea M Dickey
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Marie-Paule Strub
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Justin W Taraska
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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34
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Lucarelli S, Delos Santos RC, Antonescu CN. Measurement of Epidermal Growth Factor Receptor-Derived Signals Within Plasma Membrane Clathrin Structures. Methods Mol Biol 2017; 1652:191-225. [PMID: 28791645 DOI: 10.1007/978-1-4939-7219-7_15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The epidermal growth factor (EGF) receptor (EGFR) is an important regulator of cell growth, proliferation, survival, migration, and metabolism. EGF binding to EGFR triggers the activation of the receptor's intrinsic kinase activity, in turn eliciting the recruitment of many secondary signaling proteins and activation of downstream signals, such as the activation of phosphatidylinositol-3-kinase (PI3K) and Akt, a process requiring the phosphorylation of Gab1. While the identity of many signals that can be activated by EGFR has been revealed, how the spatiotemporal organization of EGFR signaling within cells controls receptor outcome remains poorly understood. Upon EGF binding at the plasma membrane, EGFR is internalized by clathrin-mediated endocytosis following recruitment to clathrin-coated pits (CCPs). Further, plasma membrane CCPs, but not EGFR internalization, are required for EGF-stimulated Akt phosphorylation. Signaling intermediates such as phosphorylated Gab1, which lead to Akt phosphorylation, are enriched within CCPs upon EGF stimulation. These findings indicate that some plasma membrane CCPs also serve as signaling microdomains required for certain facets of EGFR signaling and are enriched in key EGFR signaling intermediates. Understanding how the spatiotemporal organization of EGFR signals within CCP microdomains controls receptor signaling outcome requires imaging methods that can systematically resolve and analyze the properties of CCPs, EGFR and key signaling intermediates. Here, we describe methods using total internal reflection fluorescence microscopy imaging and analysis to systematically study the enrichment of EGFR and key EGFR-derived signals within CCPs.
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Affiliation(s)
- Stefanie Lucarelli
- Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON, Canada, M5B 2K3.,Graduate Program in Molecular Science, Ryerson University, 350 Victoria Street, Toronto, ON, Canada, M5B 2K3
| | - Ralph Christian Delos Santos
- Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON, Canada, M5B 2K3.,Graduate Program in Molecular Science, Ryerson University, 350 Victoria Street, Toronto, ON, Canada, M5B 2K3
| | - Costin N Antonescu
- Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON, Canada, M5B 2K3. .,Graduate Program in Molecular Science, Ryerson University, 350 Victoria Street, Toronto, ON, Canada, M5B 2K3. .,Keenan Research Centre for Biomedical Science of St. Michael's Hospital, 30 Bond Street, Toronto, ON, Canada, M5B 1W8.
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35
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Kadlecova Z, Spielman SJ, Loerke D, Mohanakrishnan A, Reed DK, Schmid SL. Regulation of clathrin-mediated endocytosis by hierarchical allosteric activation of AP2. J Cell Biol 2016; 216:167-179. [PMID: 28003333 PMCID: PMC5223608 DOI: 10.1083/jcb.201608071] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/31/2016] [Accepted: 11/30/2016] [Indexed: 01/31/2023] Open
Abstract
The critical initiation phase of clathrin-mediated endocytosis (CME) determines where and when endocytosis occurs. Heterotetrameric adaptor protein 2 (AP2) complexes, which initiate clathrin-coated pit (CCP) assembly, are activated by conformational changes in response to phosphatidylinositol-4,5-bisphosphate (PIP2) and cargo binding at multiple sites. However, the functional hierarchy of interactions and how these conformational changes relate to distinct steps in CCP formation in living cells remains unknown. We used quantitative live-cell analyses to measure discrete early stages of CME and show how sequential, allosterically regulated conformational changes activate AP2 to drive both nucleation and subsequent stabilization of nascent CCPs. Our data establish that cargoes containing Yxxφ motif, but not dileucine motif, play a critical role in the earliest stages of AP2 activation and CCP nucleation. Interestingly, these cargo and PIP2 interactions are not conserved in yeast. Thus, we speculate that AP2 has evolved as a key regulatory node to coordinate CCP formation and cargo sorting and ensure high spatial and temporal regulation of CME.
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Affiliation(s)
- Zuzana Kadlecova
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Stephanie J Spielman
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA 19122
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208
| | - Aparna Mohanakrishnan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Dana Kim Reed
- Department of Cell Biology, 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
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36
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Fekri F, Delos Santos RC, Karshafian R, Antonescu CN. Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms. PLoS One 2016; 11:e0156754. [PMID: 27275866 PMCID: PMC4898768 DOI: 10.1371/journal.pone.0156754] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/19/2016] [Indexed: 01/24/2023] Open
Abstract
Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB) is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon USMB treatment are rapidly resealed, suggesting that other processes such as enhanced endocytosis may contribute to the enhanced material uptake by cells upon USMB treatment. How USMB regulates endocytic processes remains incompletely understood. Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME) for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR), and distinct mechanism(s) that mediate the majority of fluid-phase endocytosis. Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. Total internal reflection fluorescence microscopy experiments revealed that USMB treatment altered the assembly of clathrin-coated pits, the basic structural units of CME. In addition, the rate of fluid-phase endocytosis was enhanced, but with delayed onset upon USMB treatment relative to the enhancement of CME, suggesting that the two processes are distinctly regulated by USMB. Indeed, vacuolin-1 or desipramine treatment prevented the enhancement of CME but not of fluid phase endocytosis upon USMB, suggesting that lysosome exocytosis and acid sphingomyelinase, respectively, are required for the regulation of CME but not fluid phase endocytosis upon USMB treatment. These results indicate that USMB enhances both CME and fluid phase endocytosis through distinct signaling mechanisms, and suggest that strategies for potentiating the enhancement of endocytosis upon USMB treatment may improve targeted drug delivery.
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Affiliation(s)
- Farnaz Fekri
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
- Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Ralph Christian Delos Santos
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
- Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
| | - Raffi Karshafian
- Department of Medical Physics, Ryerson University, Toronto, Ontario, Canada
- Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
- Institute for Biomedical Engineering, Science and Technology (iBEST), a partnership between Ryerson University and St. Michael’s Hospital, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science of St. Michael’s Hospital, Toronto, Ontario, Canada
- * E-mail: (RK); (CNA)
| | - Costin N. Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, Ontario, Canada
- Graduate Program in Molecular Science, Ryerson University, Toronto, Ontario, Canada
- Keenan Research Centre for Biomedical Science of St. Michael’s Hospital, Toronto, Ontario, Canada
- * E-mail: (RK); (CNA)
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37
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Delgado-Peraza F, Nogueras-Ortiz C, Acevedo Canabal AM, Roman-Vendrell C, Yudowski GA. Imaging GPCRs trafficking and signaling with total internal reflection fluorescence microscopy in cultured neurons. Methods Cell Biol 2015; 132:25-33. [PMID: 26928537 PMCID: PMC5421379 DOI: 10.1016/bs.mcb.2015.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Total internal reflection fluorescence (TIRF) microscopy allows probing the cellular events occurring close and at the plasma membrane. Over the last decade, we have seen a significant increase in the number of publications applying TIRF microscopy to unravel some of the fundamental biological questions regarding G protein-coupled receptors (GPCRs) function such as the mechanisms controlling receptor trafficking, quaternary structure, and signaling among others. Most of the published work has been performed in heterologous systems such as HEK293 and CHO cells, where the imaging surface available is higher and smoother when compared with the narrow processes or the smaller cell bodies of neurons. However, some publications have expanded our understanding of these events to primary cell cultures, mostly rat hippocampal and striatal neuronal cultures. Results from these cells provide a bona fide model of the complex events controlling GPCR function in living cells. We believe more work needs to be performed in primary cultures and eventually in intact tissue to complement the knowledge obtained from heterologous cell models. Here, we described a step-by-step protocol to investigate the surface trafficking and signaling from GPCRs in rat hippocampal and striatal primary cultures.
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Affiliation(s)
- Francheska Delgado-Peraza
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901, USA
- Department of Anatomy & Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico 00901, USA
| | - Carlos Nogueras-Ortiz
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901, USA
| | - Agnes M. Acevedo Canabal
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901, USA
- Department of Anatomy & Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico 00901, USA
| | - Cristina Roman-Vendrell
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901, USA
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | - Guillermo A. Yudowski
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901, USA
- Department of Anatomy & Neurobiology, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico 00901, USA
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38
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Hong SH, Cortesio CL, Drubin DG. Machine-Learning-Based Analysis in Genome-Edited Cells Reveals the Efficiency of Clathrin-Mediated Endocytosis. Cell Rep 2015; 12:2121-30. [PMID: 26387943 DOI: 10.1016/j.celrep.2015.08.048] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 06/05/2015] [Accepted: 08/17/2015] [Indexed: 12/30/2022] Open
Abstract
Cells internalize various molecules through clathrin-mediated endocytosis (CME). Previous live-cell imaging studies suggested that CME is inefficient, with about half of the events terminated. These CME efficiency estimates may have been confounded by overexpression of fluorescently tagged proteins and inability to filter out false CME sites. Here, we employed genome editing and machine learning to identify and analyze authentic CME sites. We examined CME dynamics in cells that express fluorescent fusions of two defining CME proteins, AP2 and clathrin. Support vector machine classifiers were built to identify and analyze authentic CME sites. From inception until disappearance, authentic CME sites contain both AP2 and clathrin, have the same degree of limited mobility, continue to accumulate AP2 and clathrin over lifetimes >∼20 s, and almost always form vesicles as assessed by dynamin2 recruitment. Sites that contain only clathrin or AP2 show distinct dynamics, suggesting they are not part of the CME pathway.
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Affiliation(s)
- Sun Hae Hong
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Christa L Cortesio
- Department of Molecular and Cell Biology, 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.
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Garay C, Judge G, Lucarelli S, Bautista S, Pandey R, Singh T, Antonescu CN. Epidermal growth factor-stimulated Akt phosphorylation requires clathrin or ErbB2 but not receptor endocytosis. Mol Biol Cell 2015; 26:3504-19. [PMID: 26246598 PMCID: PMC4591694 DOI: 10.1091/mbc.e14-09-1412] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 07/31/2015] [Indexed: 12/20/2022] Open
Abstract
Upon ligand binding, the epidermal growth factor receptor (EGFR) activates signaling and undergoes endocytosis. EGFR signaling leading to Akt activation is impaired by perturbation of clathrin but not by inhibition of internalization through perturbation of dynamin. Clathrin may thus directly regulate receptor signaling at the cell surface. Epidermal growth factor (EGF) binding to its receptor (EGFR) activates several signaling intermediates, including Akt, leading to control of cell survival and metabolism. Concomitantly, ligand-bound EGFR is incorporated into clathrin-coated pits—membrane structures containing clathrin and other proteins—eventually leading to receptor internalization. Whether clathrin might regulate EGFR signaling at the plasma membrane before vesicle scission is poorly understood. We compared the effect of clathrin perturbation (preventing formation of, or receptor recruitment to, clathrin structures) to that of dynamin2 (allowing formation of clathrin structures but preventing EGFR internalization) under conditions in which EGFR endocytosis is clathrin dependent. Clathrin perturbation by siRNA gene silencing, with the clathrin inhibitor pitstop2, or knocksideways silencing inhibited EGF-simulated Gab1 and Akt phosphorylation in ARPE-19 cells. In contrast, perturbation of dynamin2 with inhibitors or by siRNA gene silencing did not affect EGF-stimulated Gab1 or Akt phosphorylation. EGF stimulation enriched Gab1 and phospho-Gab1 within clathrin structures. ARPE-19 cells have low ErbB2 expression, and overexpression and knockdown experiments revealed that robust ErbB2 expression bypassed the requirement for clathrin for EGF-stimulated Akt phosphorylation. Thus clathrin scaffolds may represent unique plasma membrane signaling microdomains required for signaling by certain receptors, a function that can be separated from vesicle formation.
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Affiliation(s)
- Camilo Garay
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Gurjeet Judge
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Stefanie Lucarelli
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Stephen Bautista
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Rohan Pandey
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Tanveer Singh
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
| | - Costin N Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, ON M5B 2K3, Canada
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Picco A, Mund M, Ries J, Nédélec F, Kaksonen M. Visualizing the functional architecture of the endocytic machinery. eLife 2015; 4. [PMID: 25675087 PMCID: PMC4357291 DOI: 10.7554/elife.04535] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 02/10/2015] [Indexed: 01/08/2023] Open
Abstract
Clathrin-mediated endocytosis is an essential process that forms vesicles from the plasma membrane. Although most of the protein components of the endocytic protein machinery have been thoroughly characterized, their organization at the endocytic site is poorly understood. We developed a fluorescence microscopy method to track the average positions of yeast endocytic proteins in relation to each other with a time precision below 1 s and with a spatial precision of ∼10 nm. With these data, integrated with shapes of endocytic membrane intermediates and with superresolution imaging, we could visualize the dynamic architecture of the endocytic machinery. We showed how different coat proteins are distributed within the coat structure and how the assembly dynamics of N-BAR proteins relate to membrane shape changes. Moreover, we found that the region of actin polymerization is located at the base of the endocytic invagination, with the growing ends of filaments pointing toward the plasma membrane. DOI:http://dx.doi.org/10.7554/eLife.04535.001 Cells take up proteins and other useful material (called cargo) from their external environment through a process known as endocytosis. To start with, the cargo accumulates in a patch on the surface of the cell. On the inner side of the cell's membrane, a protein called clathrin gathers around the patch of cargo. Clathrin molecules and many other proteins bind together to make a lattice-like coat that causes the membrane to curve inwards and form a pocket that contains the cargo. This continues until the cargo is completely surrounded by membrane and eventually forms a bubble-like structure, or ‘vesicle’, that moves into the cell. More than 50 other proteins are involved in the endocytosis. These proteins arrive at the site of endocytosis in a particular order, complete their tasks and then move away to be used in further rounds of endocytosis. It is not clear how these proteins are organized to complete these steps because it is technically difficult to track the movements of many proteins at the same time. Here, Picco et al. developed a new fluorescence microscopy method that enabled them to track the positions of many of the proteins involved in endocytosis in yeast cells in real time. The experiments revealed when the proteins arrived at the site of endocytosis and how they assembled in relation to the membrane. For example, a group of proteins called N-BAR proteins formed an extended lattice covering the sides of the pocket that forms as the membrane curves inwards. To transform the flat membrane into a vesicle, a network of filaments made of a protein called actin needs to form at the site of endocytosis. The new method shows that the actin filaments grow in a small region at the base of the developing vesicle. By combining different types of microscopy data, Picco et al. were able to build a comprehensive model describing when the proteins involved in endocytosis move and assemble. The next challenge will be to understand the physics behind the molecular machine composed of these many proteins and the cell membrane. DOI:http://dx.doi.org/10.7554/eLife.04535.002
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Affiliation(s)
- Andrea Picco
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Markus Mund
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jonas Ries
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - François Nédélec
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Marko Kaksonen
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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Mechanisms Underlying Anomalous Diffusion in the Plasma Membrane. CURRENT TOPICS IN MEMBRANES 2015; 75:167-207. [DOI: 10.1016/bs.ctm.2015.03.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Mettlen M, Danuser G. Imaging and modeling the dynamics of clathrin-mediated endocytosis. Cold Spring Harb Perspect Biol 2014; 6:a017038. [PMID: 25167858 DOI: 10.1101/cshperspect.a017038] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Clathrin-mediated endocytosis (CME) plays a central role in cellular homeostasis and is mediated by clathrin-coated pits (CCPs). Live-cell imaging has revealed a remarkable heterogeneity in CCP assembly kinetics, which can be used as an intrinsic source of mechanistic information on CCP regulation but also poses several major problems for unbiased analysis of CME dynamics. The backbone of unveiling the molecular control of CME is an imaging-based inventory of the full diversity of individual CCP behaviors, which requires detection and tracking of structural fiduciaries and regulatory proteins with an accuracy of >99.9%, despite very low signals. This level of confidence can only be achieved by combining appropriate imaging modalities with self-diagnostic computational algorithms for image analysis and data mining.
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Affiliation(s)
- Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75235-9039
| | - Gaudenz Danuser
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115
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43
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Ligand-specific endocytic dwell times control functional selectivity of the cannabinoid receptor 1. Nat Commun 2014; 5:4589. [PMID: 25081814 PMCID: PMC4227836 DOI: 10.1038/ncomms5589] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/03/2014] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are the major transducers of external stimuli and
key therapeutic targets in many pathological conditions. When activated by different
ligands, one receptor can elicit multiple signalling cascades that are mediated by G
proteins or β-arrestin, a process defined as functional selectivity or
ligand bias. However, the dynamic mechanisms underlying β-arrestin
signalling remain unknown. Here by studying the cannabinoid receptor 1 (CB1R), we identify ligand-specific endocytic dwell times, that
is, the time during which receptors are clustered into clathrin pits together with
β-arrestins before endocytosis, as the mechanism controlling
β-arrestin signalling. Agonists inducing short endocytic dwell times
produce little or no β-arrestin signalling, whereas those eliciting
prolonged dwell times induce robust signalling. Remarkably, extending CB1R dwell times by preventing endocytosis
substantially increased β-arrestin signalling. These studies reveal how
receptor activation translates into β-arrestin signalling and identify a
mechanism to control this pathway. G-protein coupled receptors can signal through G-proteins or through
β-arrestin, however mechanisms determining pathway selection remain unclear.
Here the authors show that the duration of cannabinoid receptor clustering in clathrin
coated pits prior to endocytosis determines the strength of β-arrestin
signalling.
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44
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Larson BT, Sochacki KA, Kindem JM, Taraska JW. Systematic spatial mapping of proteins at exocytic and endocytic structures. Mol Biol Cell 2014; 25:2084-93. [PMID: 24807904 PMCID: PMC4072581 DOI: 10.1091/mbc.e14-02-0771] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A quantitative cellular imaging and spatial mapping system is developed and used to measure a library of 78 proteins at calcium-regulated exocytic or clathrin-coated endocytic structures. Structures and proteins are randomly distributed. A steady-state network map is provided for studying the behavior of membrane-trafficking proteins. Vesicular secretion (exocytosis) involves the release and then compensatory recycling of vesicle components through endocytosis. This fundamental cellular process is controlled by the coordinated assembly and interactions of dozens of proteins at the plasma membrane. Understanding the molecular composition of individual exocytic and endocytic structures and their organization across the plasma membrane is critical to understanding the behavior and regulation of these two cellular processes. Here we develop a high-resolution and high-throughput fluorescence imaging–based approach for the unbiased mapping of 78 proteins at single exocytic vesicles and endocytic structures in neuroendocrine PC12 cells. This analysis uses two-color single-frame images to provide a systems-level map of the steady-state distributions of proteins at individual exocytic and endocytic structures in the cell. Along with this quantitative map, we find that both calcium-regulated exocytic vesicles (dense core vesicles) and endocytic structures (clathrin-coated structures) and the proteins associated with these structures exhibit a random spatial distribution in unstimulated neuroendocrine PC12 cells. This approach is broadly applicable for quantitatively mapping the molecular composition and spatial organization of discrete cellular processes with central molecular hubs.
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Affiliation(s)
- Ben T Larson
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Kem A Sochacki
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Jonathan M Kindem
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Justin W Taraska
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
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45
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Kirchhausen T, Owen D, Harrison SC. Molecular structure, function, and dynamics of clathrin-mediated membrane traffic. Cold Spring Harb Perspect Biol 2014; 6:a016725. [PMID: 24789820 DOI: 10.1101/cshperspect.a016725] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Clathrin is a molecular scaffold for vesicular uptake of cargo at the plasma membrane, where its assembly into cage-like lattices underlies the clathrin-coated pits of classical endocytosis. This review describes the structures of clathrin, major cargo adaptors, and other proteins that participate in forming a clathrin-coated pit, loading its contents, pinching off the membrane as a lattice-enclosed vesicle, and recycling the components. It integrates as much of the structural information as possible at the time of writing into a sketch of the principal steps in coated-pit and coated-vesicle formation.
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Affiliation(s)
- Tom Kirchhausen
- Department of Cell Biology, Harvard Medical School/PCMM, Boston, Massachusetts 02115
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46
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Quantifying the dynamic interactions between a clathrin-coated pit and cargo molecules. Proc Natl Acad Sci U S A 2013; 110:E4591-600. [PMID: 24218552 DOI: 10.1073/pnas.1315202110] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clathrin-mediated endocytosis takes place through the recruitment of cargo molecules into a growing clathrin-coated pit (CCP). Despite the importance of this process to all mammalian cells, little is yet known about the interaction dynamics between cargo and CCPs. These interactions are difficult to study because CCPs display a large degree of lifetime heterogeneity and the interactions with cargo molecules are time dependent. We use single-molecule total internal reflection fluorescence microscopy, in combination with automatic detection and tracking algorithms, to directly visualize the recruitment of individual voltage-gated potassium channels into forming CCPs in living cells. We observe association and dissociation of individual channels with a CCP and, occasionally, their internalization. Contrary to widespread ideas, cargo often escapes from a pit before abortive CCP termination or endocytic vesicle production. Thus, the binding times of cargo molecules associating to CCPs are much shorter than the overall endocytic process. By measuring tens of thousands of capturing events, we build the distribution of capture times and the times that cargo remains confined to a CCP. An analytical stochastic model is developed and compared with the measured distributions. Due to the dynamic nature of the pit, the model is non-Markovian and it displays long-tail power law statistics. The measured distributions and model predictions are in excellent agreement over more than five orders of magnitude. Our findings identify one source of the large heterogeneities in CCP dynamics and provide a mechanism for the anomalous diffusion of proteins in the plasma membrane.
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48
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Radhakrishnan K, Baltes J, Creemers JWM, Schu P. TGN morphology and sorting regulated by prolyl-oligopeptidase–like protein PREPL and AP-1 μ1A. J Cell Sci 2013; 126:1155-63. [DOI: 10.1242/jcs.116079] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The AP-1 complex recycles between membranes and the cytoplasm and dissociates from membranes during clathrin-coated-vesicle uncoating, but also independent of vesicular transport. The μ1A N-terminal seventy amino acids are involved in regulating AP-1 recycling. In a yeast-2-hybrid library screen we identified the cytoplasmic prolyl-oligopeptidase-like protein PREPL as an interaction partner of this domain. PREPL overexpression leads to reduced AP-1 membrane binding, whereas reduced PREPL expression increases membrane binding and it impairs AP-1 recycling. Altered AP-1 membrane binding in PREPL-deficient cells mirrors the membrane binding of the mutant AP-1* complex, not able to bind PREPL. Colocalisation of PREPL with residual membrane bound AP-1 can be demonstrated. Patient cell lines deficient in PREPL have an expanded TGN, which could be rescued by PREPL expression. These data demonstrate PREPL as an AP-1 effector, which takes part in the regulation of AP-1 membrane binding. PREPL is highly expressed in brain, and at lower levels also in muscle and kidney, and its deficiency causes hypotonia and growth hormone hyposecretion supporting essential PREPL functions in AP-1-dependent secretory pathways
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49
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Cocucci E, Aguet F, Boulant S, Kirchhausen T. The first five seconds in the life of a clathrin-coated pit. Cell 2012; 150:495-507. [PMID: 22863004 DOI: 10.1016/j.cell.2012.05.047] [Citation(s) in RCA: 279] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 01/12/2012] [Accepted: 05/31/2012] [Indexed: 10/28/2022]
Abstract
Coated pits assemble by growth of a clathrin lattice, which is linked by adaptors to the underlying membrane. How does this process start? We used live-cell TIRF imaging with single-molecule EGFP sensitivity and high temporal resolution to detect arrival of the clathrin triskelions and AP2 adaptors that initiate coat assembly. Unbiased object identification and trajectory tracking, together with a statistical model, yield the arrival times and numbers of individual proteins, as well as experimentally confirmed estimates of the extent of substitution of endogenous by expressed, fluorescently tagged proteins. Pits initiate by coordinated arrival of clathrin and AP2, which is usually detected as two sequential steps, each of one triskelion with two adaptors. PI-4,5-P2 is essential for initiation. The accessory proteins FCHo1/2 are not; instead, they are required for sustained growth. This objective picture of coated pit initiation also shows that methods outlined here will be broadly useful for studies of dynamic assemblies in living cells.
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Affiliation(s)
- Emanuele Cocucci
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
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50
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Banerjee A, Berezhkovskii A, Nossal R. Distributions of lifetime and maximum size of abortive clathrin-coated pits. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:031907. [PMID: 23030944 PMCID: PMC4264111 DOI: 10.1103/physreve.86.031907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Indexed: 06/01/2023]
Abstract
Clathrin-mediated endocytosis is a complex process through which eukaryotic cells internalize nutrients, antigens, growth factors, pathogens, etc. The process occurs via the formation of invaginations on the cell membrane, called clathrin-coated pits (CCPs). Over the years, much has been learned about the mechanism of CCP assembly, but a complete understanding of the assembly process still remains elusive. In recent years, using fluorescence microscopy, studies have been done to determine the statistical properties of CCP formation. In this paper, using a recently proposed coarse-grained, stochastic model of CCP assembly [Banerjee, Berezhkovskii, and Nossal, Biophys. J. 102, 2725 (2012)], we suggest new ways of analyzing such experimental data. To be more specific, we derive analytical expressions for the distribution of maximum size of abortive CCPs, and the probability density of their lifetimes. Our results show how these functions depend on the kinetic and energetic parameters characterizing the assembly process, and therefore could be useful in extracting information about the mechanism of CCP assembly from experimental data. We find excellent agreement between our analytical results and those obtained from kinetic Monte Carlo simulations of the assembly process.
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Affiliation(s)
- Anand Banerjee
- Program in Physical Biology, Eunice Kennedy Shriver Institute of Child Health, and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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