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Chen Y, Briant K, Camus MD, Brodsky FM. Clathrin light chains CLCa and CLCb have non-redundant roles in epithelial lumen formation. Life Sci Alliance 2024; 7:e202302175. [PMID: 37923360 PMCID: PMC10624596 DOI: 10.26508/lsa.202302175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 11/07/2023] Open
Abstract
To identify functional differences between vertebrate clathrin light chains (CLCa or CLCb), phenotypes of mice lacking genes encoding either isoform were characterised. Mice without CLCa displayed 50% neonatal mortality, reduced body weight, reduced fertility, and ∼40% of aged females developed uterine pyometra. Mice lacking CLCb displayed a less severe weight reduction phenotype compared with those lacking CLCa and had no survival or reproductive system defects. Analysis of female mice lacking CLCa that developed pyometra revealed ectopic expression of epithelial differentiation markers (FOXA2 and K14) and a reduced number of endometrial glands, indicating defects in the lumenal epithelium. Defects in lumen formation and polarity of epithelial cysts derived from uterine or gut cell lines were also observed when either CLCa or CLCb were depleted, with more severe effects from CLCa depletion. In cysts, the CLC isoforms had different distributions relative to each other, although they converge in tissue. Together, these findings suggest differential and cooperative roles for CLC isoforms in epithelial lumen formation, with a dominant function for CLCa.
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Affiliation(s)
- Yu Chen
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
- https://ror.org/02jx3x895 Institute of Structural and Molecular Biology, Birkbeck and University College London, London, UK
| | - Kit Briant
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
- https://ror.org/02jx3x895 Institute of Structural and Molecular Biology, Birkbeck and University College London, London, UK
| | - Marine D Camus
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
- https://ror.org/02jx3x895 Institute of Structural and Molecular Biology, Birkbeck and University College London, London, UK
| | - Frances M Brodsky
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
- https://ror.org/02jx3x895 Institute of Structural and Molecular Biology, Birkbeck and University College London, London, UK
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2
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Hood EM, Lipinski RAJ, Lipinski DM. Downregulation of lysosomal trafficking in ARPE19 cells leads to decreased transfection efficiency at high passage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550695. [PMID: 37546846 PMCID: PMC10402107 DOI: 10.1101/2023.07.26.550695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
PURPOSE ARPE19 cells are a commonly used cell culture model for the study of retinal pigment epithelial cell biology and pathologies. However, numerous studies have demonstrated that ARPE19 undergo morphologic, transcriptomic and genomic alterations over time and with increasing passage number. Herein, we explore the mechanisms underlying increased resistance to the delivery of exogenous genetic material via transfection in ARPE19 cells using mass spectrometry. METHODS ARPE19 cells (N=5 wells/reagent) were seeded in 6-well plates at passages 24 through 30. At 70% confluency an mCherry reporter construct was delivered via transfection using Lipofectamine 3000, Lipofectamine LTX, Lipofectamine Stem, or PEI (polyethylenimine) reagents. After 72 hours, transfection efficiency was quantified by fluorescence microscopy and flow cytometry. Mass spectrometry and immunofluorescence of ARPE19 cells were performed at passages 24 and 30 to evaluate altered protein synthesis and localization between passage numbers. RESULTS ARPE19 transfection showed a maximum transfection efficiency of 32.4% at P26 using Lipofectamine 3000 reagent. All lipofectamine based reagents demonstrated statistically significant decreases in transfection efficiency between passages 24 and 30. Mass spectrometry analysis revealed 18 differentially expressed proteins, including down-regulation of clathrin light chain B (CLTB) and legumain (LGMN) that was confirmed via immunofluorescence imaging, which indicated altered intracellular localization. CONCLUSIONS ARPE19 cells demonstrate passage number dependent changes in lipofectamine-based transfection efficiency. Mass spectrometry and immunofluorescence indicates the observed decrease in transfection efficiency involves the dysregulation of endocytosis and intracellular endolysosomal trafficking at later passages. TRANSLATIONAL RELEVANCE This study contributes to mounting evidence for changes in ARPE19 cell physiology with increasing passage number. This information is of value for the continued use of ARPE19 cells as a model system for RPE biology and the development of therapeutics.
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Affiliation(s)
- Erika M.S. Hood
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, WI, USA
| | | | - Daniel M. Lipinski
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, WI, USA
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, WI, USA
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3
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A conformational switch in clathrin light chain regulates lattice structure and endocytosis at the plasma membrane of mammalian cells. Nat Commun 2023; 14:732. [PMID: 36759616 PMCID: PMC9911608 DOI: 10.1038/s41467-023-36304-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 01/25/2023] [Indexed: 02/11/2023] Open
Abstract
Conformational changes in endocytic proteins are regulators of clathrin-mediated endocytosis. Three clathrin heavy chains associated with clathrin light chains (CLC) assemble into triskelia that link into a geometric lattice that curves to drive endocytosis. Structural changes in CLC have been shown to regulate triskelia assembly in solution, yet the nature of these changes, and their effects on lattice growth, curvature, and endocytosis in cells are unknown. Here, we develop a new correlative fluorescence resonance energy transfer (FRET) and platinum replica electron microscopy method, named FRET-CLEM. With FRET-CLEM, we measure conformational changes in clathrin at thousands of individual morphologically distinct clathrin-coated structures. We discover that the N-terminus of CLC repositions away from the plasma membrane and triskelia vertex as coats curve. Preventing this conformational switch with chemical tools increases lattice sizes and inhibits endocytosis. Thus, a specific conformational switch in the light chain regulates lattice curvature and endocytosis in mammalian cells.
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4
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Das J, Tiwari M, Subramanyam D. Clathrin Light Chains: Not to Be Taken so Lightly. Front Cell Dev Biol 2022; 9:774587. [PMID: 34970544 PMCID: PMC8712872 DOI: 10.3389/fcell.2021.774587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 11/12/2021] [Indexed: 01/31/2023] Open
Abstract
Clathrin is a cytosolic protein involved in the intracellular trafficking of a wide range of cargo. It is composed of three heavy chains and three light chains that together form a triskelion, the subunit that polymerizes to form a clathrin coated vesicle. In addition to its role in membrane trafficking, clathrin is also involved in various cellular and biological processes such as chromosomal segregation during mitosis and organelle biogenesis. Although the role of the heavy chains in regulating important physiological processes has been well documented, we still lack a complete understanding of how clathrin light chains regulate membrane traffic and cell signaling. This review highlights the importance and contributions of clathrin light chains in regulating clathrin assembly, vesicle formation, endocytosis of selective receptors and physiological and developmental processes.
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Affiliation(s)
- Jyoti Das
- National Centre for Cell Science, Pune, India.,Savitribai Phule Pune University, Pune, India
| | - Mahak Tiwari
- National Centre for Cell Science, Pune, India.,Savitribai Phule Pune University, Pune, India
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5
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Clathrin: the molecular shape shifter. Biochem J 2021; 478:3099-3123. [PMID: 34436540 DOI: 10.1042/bcj20200740] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 07/19/2021] [Accepted: 08/04/2021] [Indexed: 12/11/2022]
Abstract
Clathrin is best known for its contribution to clathrin-mediated endocytosis yet it also participates to a diverse range of cellular functions. Key to this is clathrin's ability to assemble into polyhedral lattices that include curved football or basket shapes, flat lattices or even tubular structures. In this review, we discuss clathrin structure and coated vesicle formation, how clathrin is utilised within different cellular processes including synaptic vesicle recycling, hormone desensitisation, spermiogenesis, cell migration and mitosis, and how clathrin's remarkable 'shapeshifting' ability to form diverse lattice structures might contribute to its multiple cellular functions.
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6
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Redlingshöfer L, Brodsky FM. Antagonistic regulation controls clathrin-mediated endocytosis: AP2 adaptor facilitation vs restraint from clathrin light chains. Cells Dev 2021; 168:203714. [PMID: 34182181 DOI: 10.1016/j.cdev.2021.203714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/11/2021] [Accepted: 06/21/2021] [Indexed: 02/02/2023]
Abstract
Orchestration of a complex network of protein interactions drives clathrin-mediated endocytosis (CME). A central role for the AP2 adaptor complex beyond cargo recognition and clathrin recruitment has emerged in recent years. It is now apparent that AP2 serves as a pivotal hub for protein interactions to mediate clathrin coated pit maturation, and couples lattice formation to membrane deformation. As a key driver for clathrin assembly, AP2 complements the attenuating role of clathrin light chain subunits, which enable dynamic lattice rearrangement needed for budding. This review summarises recent insights into AP2 function with respect to CME dynamics and biophysics, and its relationship to the role of clathrin light chains in clathrin assembly.
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Affiliation(s)
- Lisa Redlingshöfer
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, United Kingdom; Institute for Structural and Molecular Biology, Birkbeck and University College London, London WC1E 7HX, United Kingdom.
| | - Frances M Brodsky
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, United Kingdom; Institute for Structural and Molecular Biology, Birkbeck and University College London, London WC1E 7HX, United Kingdom.
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7
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Mukenhirn M, Muraca F, Bucher D, Asberger E, Cappio Barazzone E, Cavalcanti-Adam EA, Boulant S. Role of Clathrin Light Chains in Regulating Invadopodia Formation. Cells 2021; 10:cells10020451. [PMID: 33672612 PMCID: PMC7924216 DOI: 10.3390/cells10020451] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 02/02/2021] [Accepted: 02/17/2021] [Indexed: 12/31/2022] Open
Abstract
One of the most fundamental processes of the cell is the uptake of molecules from the surrounding environment. Clathrin-mediated endocytosis (CME) is the best-described uptake pathway and regulates nutrient uptake, protein and lipid turnover at the plasma membrane (PM), cell signaling, cell motility and cell polarity. The main protein in CME is clathrin, which assembles as a triskelion-looking building block made of three clathrin heavy chains and three clathrin light chains. Compared to clathrin heavy chains (CHCs), the role of the two isoforms of clathrin light chains (CLCA and CLCB) is poorly understood. Here, we confirm that the simultaneous deletion of both CLCA/B causes abnormal actin structures at the ventral PM and we describe them, for the first time, as functional invadopodia rather than disorganized actin-cytoskeleton assembly sites. Their identification is based on the occurrence of common invadopodia markers as well as functional invadopodia activity characterized by an increased local proteolytic activity of the extracellular matrix proteins. We demonstrate that CLCA/B deletion impacts the intracellular trafficking and recovery of the matrix metalloproteinase 14 (MMP14) leading to its accumulation at the plasma membrane and induction of invadopodia formation. Importantly, we show that invadopodia formation can be prevented by depletion of MMP14. As such, we propose that CLCA/B regulate invadopodia formation by regulating MMP14 delivery to the plasma membrane.
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Affiliation(s)
- Markus Mukenhirn
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany; (M.M.); (F.M.); (D.B.); (E.A.); (E.C.B.)
| | - Francesco Muraca
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany; (M.M.); (F.M.); (D.B.); (E.A.); (E.C.B.)
| | - Delia Bucher
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany; (M.M.); (F.M.); (D.B.); (E.A.); (E.C.B.)
| | - Edgar Asberger
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany; (M.M.); (F.M.); (D.B.); (E.A.); (E.C.B.)
| | - Elisa Cappio Barazzone
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany; (M.M.); (F.M.); (D.B.); (E.A.); (E.C.B.)
| | | | - Steeve Boulant
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 344, 69120 Heidelberg, Germany; (M.M.); (F.M.); (D.B.); (E.A.); (E.C.B.)
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Correspondence:
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8
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Ju Y, Guo H, Edman M, Hamm-Alvarez SF. Application of advances in endocytosis and membrane trafficking to drug delivery. Adv Drug Deliv Rev 2020; 157:118-141. [PMID: 32758615 PMCID: PMC7853512 DOI: 10.1016/j.addr.2020.07.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022]
Abstract
Multidisciplinary research efforts in the field of drug delivery have led to the development of a variety of drug delivery systems (DDS) designed for site-specific delivery of diagnostic and therapeutic agents. Since efficient uptake of drug carriers into target cells is central to effective drug delivery, a comprehensive understanding of the biological pathways for cellular internalization of DDS can facilitate the development of DDS capable of precise tissue targeting and enhanced therapeutic outcomes. Diverse methods have been applied to study the internalization mechanisms responsible for endocytotic uptake of extracellular materials, which are also the principal pathways exploited by many DDS. Chemical inhibitors remain the most commonly used method to explore endocytotic internalization mechanisms, although genetic methods are increasingly accessible and may constitute more specific approaches. This review highlights the molecular basis of internalization pathways most relevant to internalization of DDS, and the principal methods used to study each route. This review also showcases examples of DDS that are internalized by each route, and reviews the general effects of biophysical properties of DDS on the internalization efficiency. Finally, options for intracellular trafficking and targeting of internalized DDS are briefly reviewed, representing an additional opportunity for multi-level targeting to achieve further specificity and therapeutic efficacy.
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Affiliation(s)
- Yaping Ju
- Department of Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy, USA
| | - Hao Guo
- Department of Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy, USA
| | - Maria Edman
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, USA
| | - Sarah F Hamm-Alvarez
- Department of Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy, USA; Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, USA.
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9
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Penela P, Ribas C, Sánchez-Madrid F, Mayor F. G protein-coupled receptor kinase 2 (GRK2) as a multifunctional signaling hub. Cell Mol Life Sci 2019; 76:4423-4446. [PMID: 31432234 PMCID: PMC6841920 DOI: 10.1007/s00018-019-03274-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/06/2019] [Accepted: 08/12/2019] [Indexed: 12/18/2022]
Abstract
Accumulating evidence indicates that G protein-coupled receptor kinase 2 (GRK2) is a versatile protein that acts as a signaling hub by modulating G protein-coupled receptor (GPCR) signaling and also via phosphorylation or scaffolding interactions with an extensive number of non-GPCR cellular partners. GRK2 multifunctionality arises from its multidomain structure and from complex mechanisms of regulation of its expression levels, activity, and localization within the cell, what allows the precise spatio-temporal shaping of GRK2 targets. A better understanding of the GRK2 interactome and its modulation mechanisms is helping to identify the GRK2-interacting proteins and its substrates involved in the participation of this kinase in different cellular processes and pathophysiological contexts.
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Affiliation(s)
- Petronila Penela
- Departamento de Biología Molecular, Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain
| | - Catalina Ribas
- Departamento de Biología Molecular, Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain
| | - Francisco Sánchez-Madrid
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain
- Cell-Cell Communication Laboratory, Vascular Pathophysiology Area, Centro Nacional Investigaciones Cardiovasculares (CNIC), 28029, Madrid, Spain
| | - Federico Mayor
- Departamento de Biología Molecular, Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Universidad Autónoma de Madrid, C/Nicolás Cabrera 1, 28049, Madrid, Spain.
- Instituto de Investigación Sanitaria La Princesa, 28006, Madrid, Spain.
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), 28029, Madrid, Spain.
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10
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Biancospino M, Buel GR, Niño CA, Maspero E, Scotto di Perrotolo R, Raimondi A, Redlingshöfer L, Weber J, Brodsky FM, Walters KJ, Polo S. Clathrin light chain A drives selective myosin VI recruitment to clathrin-coated pits under membrane tension. Nat Commun 2019; 10:4974. [PMID: 31672988 PMCID: PMC6823378 DOI: 10.1038/s41467-019-12855-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/27/2019] [Indexed: 11/17/2022] Open
Abstract
Clathrin light chains (CLCa and CLCb) are major constituents of clathrin-coated vesicles. Unique functions for these evolutionary conserved paralogs remain elusive, and their role in clathrin-mediated endocytosis in mammalian cells is debated. Here, we find and structurally characterize a direct and selective interaction between CLCa and the long isoform of the actin motor protein myosin VI, which is expressed exclusively in highly polarized tissues. Using genetically-reconstituted Caco-2 cysts as proxy for polarized epithelia, we provide evidence for coordinated action of myosin VI and CLCa at the apical surface where these proteins are essential for fission of clathrin-coated pits. We further find that myosin VI and Huntingtin-interacting protein 1-related protein (Hip1R) are mutually exclusive interactors with CLCa, and suggest a model for the sequential function of myosin VI and Hip1R in actin-mediated clathrin-coated vesicle budding.
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Affiliation(s)
- Matteo Biancospino
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Gwen R Buel
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Carlos A Niño
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Elena Maspero
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | | | - Andrea Raimondi
- Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
| | - Lisa Redlingshöfer
- Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Janine Weber
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Frances M Brodsky
- Division of Biosciences, University College London, London, WC1E 6BT, UK.
| | - Kylie J Walters
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - Simona Polo
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy.
- Dipartimento di Oncologia ed Emato-oncologia, Universita' degli Studi di Milano, 20122, Milan, Italy.
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11
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The roles of grouper clathrin light chains in regulating the infection of a novel marine DNA virus, Singapore grouper iridovirus. Sci Rep 2019; 9:15647. [PMID: 31666545 PMCID: PMC6821850 DOI: 10.1038/s41598-019-51725-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 10/01/2019] [Indexed: 12/18/2022] Open
Abstract
Clathrins, composed of clathrin heavy chains (CHCs) and clathrin light chains (CLCs), are usually hijacked by viruses for infection. However, the role of CLCs, especially in regulating fish virus infection, remains poorly understood. Here, two isoforms of CLCs were cloned from the red-spotted grouper (Epinephelus akaara) (EaCLCa and EaCLCb). Both EaCLC transcripts were expressed in all examined tissues, and the expression of EaCLCa was much higher than that of EaCLCb. Over-expressing EaCLCa-W119R mutant significantly reduced Singapore grouper iridovirus (SGIV) infectivity. However, no effect of EaCLCb-W122R on SGIV infection was observed. The detailed steps were further studied, mainly including virus attachment, entry and the following transport to early endosomes. EaCLCa-W119R mutant notably inhibited internalization of SGIV particles with no effect on SGIV attachment. Furthermore, EaCLCa-W119R mutant obviously impaired the delivery of SGIV to early endosomes after virus internalization. In addition, the EaCLCa-W119R mutant markedly reduced the colocalization of SGIV and actin. However, EaCLCb is not required for such events during SGIV infection. Taken together, these results demonstrate for the first time that EaCLCa and EaCLCb exerted different impacts on iridovirus infection, providing a better understanding of the mechanisms of SGIV infection and opportunities for the design of new antiviral strategies.
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12
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Cryo-EM of multiple cage architectures reveals a universal mode of clathrin self-assembly. Nat Struct Mol Biol 2019; 26:890-898. [PMID: 31582853 PMCID: PMC7100586 DOI: 10.1038/s41594-019-0292-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/02/2019] [Indexed: 01/10/2023]
Abstract
Clathrin forms diverse lattice and cage structures that change size and shape rapidly in response to the needs of eukaryotic cells during clathrin-mediated endocytosis and intracellular trafficking. We present the cryo-EM structure and molecular model of assembled porcine clathrin, providing insights into interactions that stabilize key elements of the clathrin lattice, namely, between adjacent heavy chains, at the light chain-heavy chain interface and within the trimerization domain. Furthermore, we report cryo-EM maps for five different clathrin cage architectures. Fitting structural models to three of these maps shows that their assembly requires only a limited range of triskelion leg conformations, yet inherent flexibility is required to maintain contacts. Analysis of the protein-protein interfaces shows remarkable conservation of contact sites despite architectural variation. These data reveal a universal mode of clathrin assembly that allows variable cage architecture and adaptation of coated vesicle size and shape during clathrin-mediated vesicular trafficking or endocytosis.
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13
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Abstract
The unusual structure of clathrin, combined with its ability to assemble and disassemble rapidly in cells provides a model system for us to learn about the ways in which proteins can contribute mechanically to a functioning cell. In this article, we discuss the structural properties of clathrin cages and the triskelions which assemble to form them. The function of clathrin depends on the structure of these triskelions and the interactions they make both with each other during assembly and with the adaptor protein network that drives coated vesicle formation. The atomic resolution structure of clathrin domains has been revealed by X-ray crystallography while scattering studies have enabled the shape of a triskelion in solution to be deduced. Cryo-electron microscopy maps have shown the secondary structure of entire cages, how individual triskelion legs are arranged to form a cage and enabled some bound adaptor proteins to be located. Cage formation itself is energetically finely balanced and requires specific interactions between triskelion legs to be productive, as biochemical studies and in silico modeling have shown. Theoretical, structural and cell biological investigations over many years have contributed to our knowledge of clathrin structure and assembly. It now remains to determine the precise nature of the interactions which occur between clathrin triskelions, light chain and heavy chain and the adaptor protein network.
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Affiliation(s)
- Mary Halebian
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Kyle Morris
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Corinne Smith
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
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14
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Tsygankova OM, Keen JH. A unique role for clathrin light chain A in cell spreading and migration. J Cell Sci 2019; 132:jcs.224030. [PMID: 30975920 DOI: 10.1242/jcs.224030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 04/01/2019] [Indexed: 12/12/2022] Open
Abstract
Clathrin heavy chain is the structural component of the clathrin triskelion, but unique functions for the two distinct and highly conserved clathrin light chains (CLCa and CLCb, also known as CLTA and CLTB, respectively) have been elusive. Here, we show that following detachment and replating, CLCa is uniquely responsible for promoting efficient cell spreading and migration. Selective depletion of CLCa, but not of CLCb, reduced the initial phase of isotropic spreading of HeLa, H1299 and HEK293 cells by 60-80% compared to siRNA controls, and wound closure and motility by ∼50%. Surface levels of β1-integrins were unaffected by CLCa depletion. However, CLCa was required for effective targeting of FAK (also known as PTK2) and paxillin to the adherent surface of spreading cells, for integrin-mediated activation of Src, FAK and paxillin, and for maturation of focal adhesions, but not their microtubule-based turnover. Depletion of CLCa also blocked the interaction of clathrin with the nucleation-promoting factor WAVE complex, and altered actin distribution. Furthermore, preferential recruitment of CLCa to budding protrusions was also observed. These results comprise the first identification of CLCa-specific functions, with implications for normal and neoplastic integrin-based signaling and cell migration.
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Affiliation(s)
- Oxana M Tsygankova
- Department of Biochemistry and Molecular Biology, Cell Biology and Signaling Program of the Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - James H Keen
- Department of Biochemistry and Molecular Biology, Cell Biology and Signaling Program of the Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
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15
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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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16
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Weinberg ZY, Puthenveedu MA. Regulation of G protein-coupled receptor signaling by plasma membrane organization and endocytosis. Traffic 2019; 20:121-129. [PMID: 30536564 PMCID: PMC6415975 DOI: 10.1111/tra.12628] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/27/2018] [Accepted: 12/05/2018] [Indexed: 12/11/2022]
Abstract
The trafficking of G protein coupled-receptors (GPCRs) is one of the most exciting areas in cell biology because of recent advances demonstrating that GPCR signaling is spatially encoded. GPCRs, acting in a diverse array of physiological systems, can have differential signaling consequences depending on their subcellular localization. At the plasma membrane, GPCR organization could fine-tune the initial stages of receptor signaling by determining the magnitude of signaling and the type of effectors to which receptors can couple. This organization is mediated by the lipid composition of the plasma membrane, receptor-receptor interactions, and receptor interactions with intracellular scaffolding proteins. GPCR organization is subsequently changed by ligand binding and the regulated endocytosis of these receptors. Activated GPCRs can modulate the dynamics of their own endocytosis through changing clathrin-coated pit dynamics, and through the scaffolding adaptor protein β-arrestin. This endocytic regulation has signaling consequences, predominantly through modulation of the MAPK cascade. This review explores what is known about receptor sorting at the plasma membrane, protein partners that control receptor endocytosis, and the ways in which receptor sorting at the plasma membrane regulates downstream trafficking and signaling.
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Affiliation(s)
- Zara Y Weinberg
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan
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17
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A new role of anterograde motor Kif5b in facilitating large clathrin-coated vesicle mediated endocytosis via regulating clathrin uncoating. Cell Discov 2019; 4:65. [PMID: 30603101 PMCID: PMC6305376 DOI: 10.1038/s41421-018-0067-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 11/30/2022] Open
Abstract
Kif5b-driven anterograde transport and clathrin-mediated endocytosis (CME) are responsible for opposite intracellular trafficking, contributing to plasma membrane homeostasis. However, whether and how the two trafficking processes coordinate remain unclear. Here, we show that Kif5b directly interacts with clathrin heavy chain (CHC) at a region close to that for uncoating catalyst (Hsc70) and preferentially localizes on relatively large clathrin-coated vesicles (CCVs). Uncoating in vitro is decreased for CCVs from the cortex of kif5b conditional knockout (mutant) mouse and facilitated by adding Kif5b fragments containing CHC-binding site, while cell peripheral distribution of CHC or Hsc70 keeps unaffected by Kif5b depletion. Furthermore, cellular entry of vesicular stomatitis virus that internalizes into large CCV is inhibited by Kif5b depletion or introducing a dominant-negative Kif5b fragment. These findings showed a new role of Kif5b in regulating large CCV-mediated CME via affecting CCV uncoating, indicating Kif5b as a molecular knot connecting anterograde transport to CME.
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18
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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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19
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Endocytosis of G Protein-Coupled Receptors and Their Ligands: Is There a Role in Metal Trafficking? Cell Biochem Biophys 2018; 76:329-337. [PMID: 30022374 DOI: 10.1007/s12013-018-0850-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 07/03/2018] [Indexed: 12/22/2022]
Abstract
The prevalence of metal dysregulation in many neurodegenerative and neurocognitive disorders has compelled many studying such diseases to investigate the mechanisms underlying metal regulation in the central nervous system. Metal homoeostasis is often complex, with sophisticated, multilayered pathways in operation. G protein-coupled receptors are omnipresent on cell membranes and have intriguing mechanisms of endocytosis and trafficking that may be useful in metal homoeostasis. Indeed, many receptors and/or their cognate ligands are able to bind metals, and in many cases metals are considered to have neuromodulatory roles as a result of receptor binding. In this mini-review, we outline the structural and functional aspects of G protein-coupled receptors with a focus on the mechanisms leading to endocytosis and cellular trafficking. We further highlight how this may help in the trafficking of metal ions, notably copper.
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20
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Rule-based modelling provides an extendable framework for comparing candidate mechanisms underpinning clathrin polymerisation. Sci Rep 2018; 8:5658. [PMID: 29618727 PMCID: PMC5884807 DOI: 10.1038/s41598-018-23829-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 03/19/2018] [Indexed: 01/06/2023] Open
Abstract
Polymerisation of clathrin is a key process that underlies clathrin-mediated endocytosis. Clathrin-coated vesicles are responsible for cell internalization of external substances required for normal homeostasis and life –sustaining activity. There are several hypotheses describing formation of closed clathrin structures. According to one of the proposed mechanisms cage formation may start from a flat lattice buildup on the cellular membrane, which is later transformed into a curved structure. Creation of the curved surface requires rearrangement of the lattice, induced by additional molecular mechanisms. Different potential mechanisms require a modeling framework that can be easily modified to compare between them. We created an extendable rule-based model that describes polymerisation of clathrin molecules and various scenarios of cage formation. Using Global Sensitivity Analysis (GSA) we obtained parameter sets describing clathrin pentagon closure and the emergence/production and closure of large-size clathrin cages/vesicles. We were able to demonstrate that the model can reproduce budding of the clathrin cage from an initial flat array.
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21
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Maib H, Smythe E, Ayscough K. Forty years on: clathrin-coated pits continue to fascinate. Mol Biol Cell 2017; 28:843-847. [PMID: 28360213 PMCID: PMC5385932 DOI: 10.1091/mbc.e16-04-0213] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/23/2017] [Accepted: 01/30/2017] [Indexed: 01/01/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is a fundamental process in cell biology and has been extensively investigated over the past several decades. Every cell biologist learns about it at some point during his or her education, and the beauty of this process has led many of us to go deeper and make it the topic of our research. Great progress has been made toward elucidating the mechanisms of CME, and the field is becoming increasingly complex, with several hundred new publications every year. This makes it easy to get lost in the vast amount of literature and forget about the fundamentals of the field, which are based on the careful interpretation of simple observations made >40 years ago, as exemplified by a study performed by Anderson, Brown, and Goldstein in 1977. We examine how this seminal study was pivotal to our understanding of CME and its progression into ever-increasing complexity over the past four decades.
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Affiliation(s)
- Hannes Maib
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Elizabeth Smythe
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Kathryn Ayscough
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Sheffield S10 2TN, United Kingdom
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22
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Cunningham MR, Aungraheeta R, Mundell SJ. Pathophysiological consequences of receptor mistraffic: Tales from the platelet P2Y 12 receptor. Mol Cell Endocrinol 2017; 449:74-81. [PMID: 28212842 DOI: 10.1016/j.mce.2017.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 02/10/2017] [Accepted: 02/10/2017] [Indexed: 12/12/2022]
Abstract
Genetic variations in G protein-coupled receptor (GPCR) genes can disrupt receptor function in a wide variety of human genetic diseases, including platelet bleeding disorders. Platelets are critical for haemostasis with inappropriate platelet activation leading to the development of arterial thrombosis, which can result in heart attack and stroke whilst decreased platelet activity is associated with an increased risk of bleeding. GPCRs expressed on the surface of platelets play key roles in regulating platelet activity and therefore function. Receptors include purinergic receptors (P2Y1 and P2Y12), proteinase-activated receptor (PAR1 and PAR4) and thromboxane receptors (TPα), among others. Pharmacological blockade of these receptors forms a powerful therapeutic tool in the treatment and prevention of arterial thrombosis. With the advance of genomic technologies, there has been a substantial increase in the identification of naturally occurring rare and common GPCR variants. These variants include single-nucleotide polymorphisms (SNPs) and insertion or deletions that have the potential to alter GPCR expression or function. A number of defects in platelet GPCRs that disrupt receptor function have now been characterized in patients with mild bleeding disorders. This review will focus on rare, function-disrupting variants of platelet GPCRs with particular emphasis upon mutations in the P2Y12 receptor gene that affect receptor traffic to modulate platelet function. Further this review will outline how the identification and characterization of function-disrupting GPCR mutations provides an essential link in translating our detailed understanding of receptor traffic and function in cell line studies into relevant human biological systems.
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Affiliation(s)
- Margaret R Cunningham
- Strathclyde Institute for Pharmacy and Biomedical Sciences (SIPBS), University of Strathclyde, Glasgow, UK
| | - Riyaad Aungraheeta
- School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences, University of Bristol, Bristol, UK
| | - Stuart J Mundell
- School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences, University of Bristol, Bristol, UK.
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23
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Chen PH, Bendris N, Hsiao YJ, Reis CR, Mettlen M, Chen HY, Yu SL, Schmid SL. Crosstalk between CLCb/Dyn1-Mediated Adaptive Clathrin-Mediated Endocytosis and Epidermal Growth Factor Receptor Signaling Increases Metastasis. Dev Cell 2017; 40:278-288.e5. [PMID: 28171750 PMCID: PMC5740869 DOI: 10.1016/j.devcel.2017.01.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/15/2016] [Accepted: 01/09/2017] [Indexed: 01/18/2023]
Abstract
Signaling receptors are internalized and regulated by clathrin-mediated endocytosis (CME). Two clathrin light chain isoforms, CLCa and CLCb, are integral components of the endocytic machinery whose differential functions remain unknown. We report that CLCb is specifically upregulated in non-small-cell lung cancer (NSCLC) cells and is associated with poor patient prognosis. Engineered single CLCb-expressing NSCLC cells, as well as "switched" cells that predominantly express CLCb, exhibit increased rates of CME and altered clathrin-coated pit dynamics. This "adaptive CME" resulted from upregulation of dynamin-1 (Dyn1) and its activation through a positive feedback loop involving enhanced epidermal growth factor (EGF)-dependent Akt/GSK3β phosphorylation. CLCb/Dyn1-dependent adaptive CME selectively altered EGF receptor trafficking, enhanced cell migration in vitro, and increased the metastatic efficiency of NSCLC cells in vivo. We define molecular mechanisms for adaptive CME in cancer cells and a role for the reciprocal crosstalk between signaling and CME in cancer progression.
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Affiliation(s)
- Ping-Hung Chen
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Nawal Bendris
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yi-Jing Hsiao
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei 10617, Taiwan
| | - Carlos R Reis
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marcel Mettlen
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Hsuan-Yu Chen
- Institute of Statistical Science, Academia Sinica, Taipei 11529, Taiwan
| | - Sung-Liang Yu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei 10617, Taiwan
| | - Sandra L Schmid
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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24
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Wu S, Majeed SR, Evans TM, Camus MD, Wong NML, Schollmeier Y, Park M, Muppidi JR, Reboldi A, Parham P, Cyster JG, Brodsky FM. Clathrin light chains' role in selective endocytosis influences antibody isotype switching. Proc Natl Acad Sci U S A 2016; 113:9816-21. [PMID: 27540116 PMCID: PMC5024586 DOI: 10.1073/pnas.1611189113] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clathrin, a cytosolic protein composed of heavy and light chain subunits, assembles into a vesicle coat, controlling receptor-mediated endocytosis. To establish clathrin light chain (CLC) function in vivo, we engineered mice lacking CLCa, the major CLC isoform in B lymphocytes, generating animals with CLC-deficient B cells. In CLCa-null mice, the germinal centers have fewer B cells, and they are enriched for IgA-producing cells. This enhanced switch to IgA production in the absence of CLCa was attributable to increased transforming growth factor β receptor 2 (TGFβR2) signaling resulting from defective endocytosis. Internalization of C-X-C chemokine receptor 4 (CXCR4), but not CXCR5, was affected in CLCa-null B cells, and CLC depletion from cell lines affected endocytosis of the δ-opioid receptor, but not the β2-adrenergic receptor, defining a role for CLCs in the uptake of a subset of signaling receptors. This instance of clathrin subunit deletion in vertebrates demonstrates that CLCs contribute to clathrin's role in vivo by influencing cargo selectivity, a function previously assigned exclusively to adaptor molecules.
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MESH Headings
- Animals
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Cerebral Cortex/cytology
- Cerebral Cortex/immunology
- Clathrin Light Chains/genetics
- Clathrin Light Chains/immunology
- Endocytosis/immunology
- Gene Deletion
- Gene Expression Regulation
- Humans
- Immunoglobulin A/biosynthesis
- Immunoglobulin A/genetics
- Immunoglobulin Class Switching
- Liver/cytology
- Liver/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myocardium/cytology
- Myocardium/immunology
- Organ Specificity
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/immunology
- Receptor, Transforming Growth Factor-beta Type II
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/immunology
- Receptors, CXCR4/genetics
- Receptors, CXCR4/immunology
- Receptors, Opioid, delta/genetics
- Receptors, Opioid, delta/immunology
- Receptors, Transforming Growth Factor beta/agonists
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/immunology
- Spleen/cytology
- Spleen/immunology
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
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Affiliation(s)
- Shuang Wu
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143
| | - Sophia R Majeed
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143
| | - Timothy M Evans
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143
| | - Marine D Camus
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143; Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Nicole M L Wong
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143
| | - Yvette Schollmeier
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143
| | - Minjong Park
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143
| | - Jagan R Muppidi
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - Andrea Reboldi
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - Peter Parham
- Department of Structural Biology, Stanford University, Stanford, CA 94305; Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Jason G Cyster
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143;
| | - Frances M Brodsky
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143; Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143; Department of Microbiology and Immunology, University of California, San Francisco, CA 94143; The G. W. Hooper Foundation, University of California, San Francisco, CA 94143; Division of Biosciences, University College London, London WC1E 6BT, United Kingdom;
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25
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Pal K, Hwang SH, Somatilaka B, Badgandi H, Jackson PK, DeFea K, Mukhopadhyay S. Smoothened determines β-arrestin-mediated removal of the G protein-coupled receptor Gpr161 from the primary cilium. J Cell Biol 2016; 212:861-75. [PMID: 27002170 PMCID: PMC4810300 DOI: 10.1083/jcb.201506132] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 02/11/2016] [Indexed: 02/08/2023] Open
Abstract
Dynamic changes in membrane protein composition of the primary cilium are central to development and homeostasis, but we know little about mechanisms regulating membrane protein flux. Stimulation of the sonic hedgehog (Shh) pathway in vertebrates results in accumulation and activation of the effector Smoothened within cilia and concomitant disappearance of a negative regulator, the orphan G protein-coupled receptor (GPCR), Gpr161. Here, we describe a two-step process determining removal of Gpr161 from cilia. The first step involves β-arrestin recruitment by the signaling competent receptor, which is facilitated by the GPCR kinase Grk2. An essential factor here is the ciliary trafficking and activation of Smoothened, which by increasing Gpr161-β-arrestin binding promotes Gpr161 removal, both during resting conditions and upon Shh pathway activation. The second step involves clathrin-mediated endocytosis, which functions outside of the ciliary compartment in coordinating Gpr161 removal. Mechanisms determining dynamic compartmentalization of Gpr161 in cilia define a new paradigm for down-regulation of GPCRs during developmental signaling from a specialized subcellular compartment.
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Affiliation(s)
- Kasturi Pal
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Bandarigoda Somatilaka
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Hemant Badgandi
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Peter K Jackson
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305
| | - Kathryn DeFea
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA 92521
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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26
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Robinson MS. Forty Years of Clathrin-coated Vesicles. Traffic 2015; 16:1210-38. [PMID: 26403691 DOI: 10.1111/tra.12335] [Citation(s) in RCA: 234] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022]
Abstract
The purification of coated vesicles and the discovery of clathrin by Barbara Pearse in 1975 was a landmark in cell biology. Over the past 40 years, work from many labs has uncovered the molecular details of clathrin and its associated proteins, including how they assemble into a coated vesicle and how they select cargo. Unexpected connections have been found with signalling, development, neuronal transmission, infection, immunity and genetic disorders. But there are still a number of unanswered questions, including how clathrin-mediated trafficking is regulated and how the machinery evolved.
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Affiliation(s)
- Margaret S Robinson
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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27
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Muthusamy N, Chen YJ, Yin DM, Mei L, Bergson C. Complementary roles of the neuron-enriched endosomal proteins NEEP21 and calcyon in neuronal vesicle trafficking. J Neurochem 2015; 132:20-31. [PMID: 25376768 DOI: 10.1111/jnc.12989] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/17/2014] [Accepted: 10/23/2014] [Indexed: 01/18/2023]
Abstract
Understanding mechanisms governing the trafficking of transmembrane (TM) cargoes to synapses and other specialized membranes in neurons represents a long-standing challenge in cell biology. Investigation of the neuron-enriched endosomal protein of 21 kDa (NEEP21, or NSG1or P21) and Calcyon (Caly, or NSG3) indicates that the emergence of the NEEP21/Caly/P19 gene family could play a vital role in the success of these mechanisms in vertebrates. The upshot of a sizeable body of work is that the NEEP21 and Caly perform distinct endocytic and recycling functions, which impact (i) α amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor trafficking at excitatory synapses; (ii) transport to/in neuronal axons; as well as (iii) proteolytic processing of amyloid precursor protein and neuregulin 1, suggesting roles in neuron development, synaptic function, and neurodegeneration. We argue that their distinct effects on cargo endocytosis and recycling depend on interactions with vesicle trafficking and synaptic scaffolding proteins. As they play complementary, but opposing roles in cargo endocytosis, recycling, and degradation, balancing NEEP21 and Caly expression levels or activity could be important for homeostasis in a variety of signaling pathways, and also lead to a novel therapeutic strategy for disorders like Alzheimer's disease and schizophrenia. This review focuses on two closely related, neuron-enriched endosomal proteins: NEEP21 and Calcyon which perform distinct roles in regulating receptor endocytosis, recycling, and degradation. Based on an in-depth examination of the literature, we argue that these two proteins carry out complementary yet sometimes opposing vesicle trafficking functions that impact excitatory transmission, transcytosis, axonal transport, and also proteolytic processing by beta-secretase I (BACE1). Finally, we propose that balancing NEEP21 and Calcyon expression and/or activity could be important for homeostasis in a variety of signaling pathways, and also lead to a novel therapeutic strategy for disorders like Alzheimer's disease and schizophrenia. AMPA = α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor; NMDA = N-Methyl-D-aspartate.
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Affiliation(s)
- Nagendran Muthusamy
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
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28
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Fürthauer M, Smythe E. Systems dynamics in endocytosis. Traffic 2014; 15:338-46. [PMID: 24405722 DOI: 10.1111/tra.12147] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 12/22/2013] [Accepted: 01/09/2014] [Indexed: 11/28/2022]
Abstract
The endocytic system acts at the crossroads of different cellular activities to play a central role in the regulation of cell signaling and membrane dynamics. An European Molecular Biology Organization (EMBO) conference held in October 2013 in Villars-sur-Ollon gathered researchers from all over the world to present their latest findings on the endolysosomal system and identify major challenges for the future. The conference covered the entire spectrum of research in this rapidly evolving field ranging from the cellular mechanics of endocytosis to the role of proteins and lipids in the biogenesis and function of endolysosomal organelles and the analysis of higher order system properties in multicellular contexts. In particular, the meeting highlighted current efforts to complement the insights that can be gained by biochemical and cell biological approaches with the use of quantitative biophysics, systems biology and animal model systems to achieve an integrated view of the properties of the endomembrane system and its role in cellular information processing.
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Affiliation(s)
- Maximilian Fürthauer
- Institut de Biologie Valrose, CNRS UMR7277, INSERM 1091, University of Nice Sophia-Antipolis, Nice, France
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Pastuszka MK, Okamoto CT, Hamm-Alvarez SF, MacKay JA. Flipping the Switch on Clathrin-Mediated Endocytosis using Thermally Responsive Protein Microdomains. ADVANCED FUNCTIONAL MATERIALS 2014; 24:5340-5347. [PMID: 25419208 PMCID: PMC4235962 DOI: 10.1002/adfm.201400715] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A ubiquitous approach to study protein function is to knock down activity (gene deletions, siRNA, small molecule inhibitors, etc) and study the cellular effects. Using a new methodology, this manuscript describes how to rapidly and specifically switch off cellular pathways using thermally responsive protein polymers. A small increase in temperature stimulates cytosolic elastin-like polypeptides (ELPs) to assemble microdomains. We hypothesize that ELPs fused to a key effector in a target macromolecular complex will sequester the complex within these microdomains, which will bring the pathway to a halt. To test this hypothesis, we fused ELPs to clathrin-light chain (CLC), a protein associated with clathrin-mediated endocytosis. Prior to thermal stimulation, the ELP fusion is soluble and clathrin-mediated endocytosis remains 'on.' Increasing the temperature induces the assembly of ELP fusion proteins into organelle-sized microdomains that switches clathrin-mediated endocytosis 'off.' These microdomains can be thermally activated and inactivated within minutes, are reversible, do not require exogenous chemical stimulation, and are specific for components trafficked within the clathrin-mediated endocytosis pathway. This temperature-triggered cell switch system represents a new platform for the temporal manipulation of trafficking mechanisms in normal and disease cell models and has applications for manipulating other intracellular pathways.
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Affiliation(s)
- Martha K. Pastuszka
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California. 1985 Zonal Avenue, Los Angeles 90033-9121
| | - Curtis T. Okamoto
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California. 1985 Zonal Avenue, Los Angeles 90033-9121
| | - Sarah F. Hamm-Alvarez
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California. 1985 Zonal Avenue, Los Angeles 90033-9121
| | - J. Andrew MacKay
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California. 1985 Zonal Avenue, Los Angeles 90033-9121
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Cooke AE, Oldfield S, Krasel C, Mundell SJ, Henderson G, Kelly E. Morphine-induced internalization of the L83I mutant of the rat μ-opioid receptor. Br J Pharmacol 2014; 172:593-605. [PMID: 24697554 DOI: 10.1111/bph.12709] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 03/17/2014] [Accepted: 03/26/2014] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Naturally occurring single-nucleotide polymorphisms (SNPs) within GPCRs can result in alterations in various pharmacological parameters. Understanding the regulation and function of endocytic trafficking of the μ-opioid receptor (MOP receptor) is of great importance given its implication in the development of opioid tolerance. This study has compared the agonist-dependent trafficking and signalling of L83I, the rat orthologue of a naturally occurring variant of the MOP receptor. EXPERIMENTAL APPROACH Cell surface elisa, confocal microscopy and immunoprecipitation assays were used to characterize the trafficking properties of the MOP-L83I variant in comparison with the wild-type receptor in HEK 293 cells. Functional assays were used to compare the ability of the L83I variant to signal to several downstream pathways. KEY RESULTS Morphine-induced internalization of the L83I MOP receptor was markedly increased in comparison with the wild-type receptor. The altered trafficking of this variant was found to be specific to morphine and was both G-protein receptor kinase- and dynamin-dependent. The enhanced internalization of L83I variant in response to morphine was not due to increased phosphorylation of serine 375, arrestin association or an increased ability to signal. CONCLUSIONS AND IMPLICATIONS These results suggest that morphine promotes a specific conformation of the L83I variant that makes it more liable to internalize in response to morphine, unlike the wild-type receptor that undergoes significantly less morphine-stimulated internalization, providing an example of a ligand-selective biased receptor. The presence of this SNP within an individual may consequently affect the development of tolerance and analgesic responses. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
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Affiliation(s)
- A E Cooke
- School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK
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Clathrin light chains are required for the gyrating-clathrin recycling pathway and thereby promote cell migration. Nat Commun 2014; 5:3891. [PMID: 24852344 PMCID: PMC4050264 DOI: 10.1038/ncomms4891] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 04/14/2014] [Indexed: 02/07/2023] Open
Abstract
The clathrin light chain (CLC) subunits participate in several membrane traffic pathways involving both clathrin and actin, through binding the actin-organizing huntingtin-interacting proteins (Hip). However, CLCs are dispensable for clathrin-mediated endocytosis of many cargoes. Here we observe that CLC depletion affects cell migration through Hip binding and reduces surface expression of β1-integrin by interference with recycling following normal endocytosis of inactive β1-integrin. CLC depletion and expression of a modified CLC also inhibit the appearance of gyrating (G)-clathrin structures, known mediators of rapid recycling of transferrin receptor from endosomes. Expression of the modified CLC reduces β1-integrin and transferrin receptor recycling, as well as cell migration, implicating G-clathrin in these processes. Supporting a physiological role for CLC in migration, the CLCb isoform of CLC is upregulated in migratory human trophoblast cells during uterine invasion. Together, these studies establish CLCs as mediating clathrin–actin interactions needed for recycling by G-clathrin during migration. Clathrin light chain (CLC) subunits are dispensable for clathrin-mediated endocytosis of a number of cargoes. Majeed et al. report that CLCs are however required for gyrating-clathrin-dependent recycling of inactive β1-integrins, the absence of which impairs cell migration.
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Abstract
Many cellular membrane-bound structures exhibit distinct curvature that is driven by the physical properties of their lipid and protein constituents. Here we review how cells manipulate and control this curvature in the context of dynamic events such as vesicle-mediated membrane traffic. Lipids and cargo proteins each contribute energy barriers that must be overcome during vesicle formation. In contrast, protein coats and their associated accessory proteins drive membrane bending using a variety of interdependent physical mechanisms. We survey the energy costs and drivers involved in membrane curvature, and draw a contrast between the stochastic contributions of molecular crowding and the deterministic assembly of protein coats. These basic principles also apply to other cellular examples of membrane bending events, including important disease-related problems such as viral egress.
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Abstract
Platelets are critical for haemostasis, however inappropriate activation can lead to the development of arterial thrombosis, which can result in heart attack and stroke. ADP is a key platelet agonist that exerts its actions via stimulation of two surface GPCRs (G-protein-coupled receptors), P2Y(1) and P2Y(12). Similar to most GPCRs, P2Y receptor activity is tightly regulated by a number of complex mechanisms including receptor desensitization, internalization and recycling. In the present article, we review the molecular mechanisms that underlie P2Y(1) and P2Y(12) receptor regulation, with particular emphasis on the structural motifs within the P2Y(12) receptor, which are required to maintain regulatory protein interaction. The implications of these findings for platelet responsiveness are also discussed.
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Young A, Stoilova-McPhie S, Rothnie A, Vallis Y, Harvey-Smith P, Ranson N, Kent H, Brodsky FM, Pearse BMF, Roseman A, Smith CJ. Hsc70-induced changes in clathrin-auxilin cage structure suggest a role for clathrin light chains in cage disassembly. Traffic 2013; 14:987-96. [PMID: 23710728 PMCID: PMC3776051 DOI: 10.1111/tra.12085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 05/21/2013] [Accepted: 05/25/2013] [Indexed: 01/28/2023]
Abstract
The molecular chaperone, Hsc70, together with its co-factor, auxilin, facilitates the ATP-dependent removal of clathrin during clathrin-mediated endocytosis in cells. We have used cryo-electron microscopy to determine the 3D structure of a complex of clathrin, auxilin401-910 and Hsc70 at pH 6 in the presence of ATP, frozen within 20 seconds of adding Hsc70 in order to visualize events that follow the binding of Hsc70 to clathrin and auxilin before clathrin disassembly. In this map, we observe density beneath the vertex of the cage that we attribute to bound Hsc70. This density emerges asymmetrically from the clathrin vertex, suggesting preferential binding by Hsc70 for one of the three possible sites at the vertex. Statistical comparison with a map of whole auxilin and clathrin previously published by us reveals the location of statistically significant differences which implicate involvement of clathrin light chains in structural rearrangements which occur after Hsc70 is recruited. Clathrin disassembly assays using light scattering suggest that loss of clathrin light chains reduces the efficiency with which auxilin facilitates this reaction. These data support a regulatory role for clathrin light chains in clathrin disassembly in addition to their established role in regulating clathrin assembly.
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Affiliation(s)
- Anna Young
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
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Abstract
Clathrin is considered the prototype vesicle coat protein whose self-assembly mediates sorting of membrane cargo and recruitment of lipid modifiers. Detailed knowledge of clathrin biochemistry, structure, and interacting proteins has accumulated since the first observation, almost 50 years ago, of its role in receptor-mediated endocytosis of yolk protein. This review summarizes that knowledge, and focuses on properties of the clathrin heavy and light chain subunits and interaction of the latter with Hip proteins, to address the diversity of clathrin function beyond conventional receptor-mediated endocytosis. The distinct functions of the two human clathrin isoforms (CHC17 and CHC22) are discussed, highlighting CHC22's specialized involvement in traffic of the GLUT4 glucose transporter and consequent role in human glucose metabolism. Analysis of clathrin light chain function and interaction with the actin-binding Hip proteins during bacterial infection defines a novel actin-organizing function for CHC17 clathrin. By considering these diverse clathrin functions, along with intracellular sorting roles and influences on mitosis, further relevance of clathrin function to human health and disease is established.
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Affiliation(s)
- Frances M Brodsky
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94143-0552, USA.
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