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Imoto Y, Xue J, Luo L, Raychaudhuri S, Itoh K, Ma Y, Craft GE, Kwan AH, Ogunmowo TH, Ho A, Mackay JP, Ha T, Watanabe S, Robinson PJ. Dynamin 1xA interacts with Endophilin A1 via its spliced long C-terminus for ultrafast endocytosis. EMBO J 2024:10.1038/s44318-024-00145-x. [PMID: 38907032 DOI: 10.1038/s44318-024-00145-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/26/2024] [Accepted: 05/24/2024] [Indexed: 06/23/2024] Open
Abstract
Dynamin 1 mediates fission of endocytic synaptic vesicles in the brain and has two major splice variants, Dyn1xA and Dyn1xB, which are nearly identical apart from the extended C-terminal region of Dyn1xA. Despite a similar set of binding partners, only Dyn1xA is enriched at endocytic zones and accelerates vesicle fission during ultrafast endocytosis. Here, we report that Dyn1xA achieves this localization by preferentially binding to Endophilin A1 through a newly defined binding site within its long C-terminal tail extension. Endophilin A1 binds this site at higher affinity than the previously reported site, and the affinity is determined by amino acids within the Dyn1xA tail but outside the binding site. This interaction is regulated by the phosphorylation state of two serine residues specific to the Dyn1xA variant. Dyn1xA and Endophilin A1 colocalize in patches near the active zone, and mutations disrupting Endophilin A binding to the long tail cause Dyn1xA mislocalization and stalled endocytic pits on the plasma membrane during ultrafast endocytosis. Together, these data suggest that the specificity for ultrafast endocytosis is defined by the phosphorylation-regulated interaction of Endophilin A1 with the C-terminal extension of Dyn1xA.
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Affiliation(s)
- Yuuta Imoto
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Jing Xue
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville, 2145, NSW, Australia
| | - Lin Luo
- Institute for Molecular Bioscience, Institute for Molecular Bioscience Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Sumana Raychaudhuri
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kie Itoh
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - George E Craft
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville, 2145, NSW, Australia
| | - Ann H Kwan
- School of Life and Environmental Sciences and Sydney Nano Institute, University of Sydney, Camperdown, NSW, Australia
| | - Tyler H Ogunmowo
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Annie Ho
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Joel P Mackay
- School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW, 2006, Australia
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA
- Howard Hughes Medical Institute, Baltimore, MD, USA
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville, 2145, NSW, Australia.
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2
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Romero MD, Carabeo RA. Dynamin-dependent entry of Chlamydia trachomatis is sequentially regulated by the effectors TarP and TmeA. Nat Commun 2024; 15:4926. [PMID: 38858371 PMCID: PMC11164928 DOI: 10.1038/s41467-024-49350-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 05/30/2024] [Indexed: 06/12/2024] Open
Abstract
Chlamydia invasion of epithelial cells is a pathogen-driven process involving two functionally distinct effectors - TarP and TmeA. They collaborate to promote robust actin dynamics at sites of entry. Here, we extend studies on the molecular mechanism of invasion by implicating the host GTPase dynamin 2 (Dyn2) in the completion of pathogen uptake. Importantly, Dyn2 function is modulated by TarP and TmeA at the levels of recruitment and activation through oligomerization, respectively. TarP-dependent recruitment requires phosphatidylinositol 3-kinase and the small GTPase Rac1, while TmeA has a post-recruitment role related to Dyn2 oligomerization. This is based on the rescue of invasion duration and efficiency in the absence of TmeA by the Dyn2 oligomer-stabilizing small molecule activator Ryngo 1-23. Notably, Dyn2 also regulated turnover of TarP- and TmeA-associated actin networks, with disrupted Dyn2 function resulting in aberrant turnover dynamics, thus establishing the interdependent functional relationship between Dyn2 and the effectors TarP and TmeA.
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Affiliation(s)
- Matthew D Romero
- Department of Pathology, Microbiology, and Immunology, College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Rey A Carabeo
- Department of Pathology, Microbiology, and Immunology, College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
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3
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Romero MD, Carabeo RA. Dynamin-dependent entry of Chlamydia trachomatis is sequentially regulated by the effectors TarP and TmeA. RESEARCH SQUARE 2023:rs.3.rs-3376558. [PMID: 37841835 PMCID: PMC10571596 DOI: 10.21203/rs.3.rs-3376558/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Chlamydia invasion of epithelial cells is a pathogen-driven process involving two functionally distinct effectors - TarP and TmeA. They collaborate to promote robust actin dynamics at sites of entry. Here, we extend studies on the molecular mechanism of invasion by implicating the host GTPase dynamin 2 (Dyn2) in the completion of pathogen uptake. Importantly, Dyn2 function is modulated by TarP and TmeA at the levels of recruitment and activation through oligomerization, respectively. TarP-dependent recruitment requires phosphatidylinositol 3-kinase and the small GTPase Rac1, while TmeA has a post-recruitment role related to Dyn2 oligomerization. This is based on the rescue of invasion duration and efficiency in the absence of TmeA by the Dyn2 oligomer-stabilizing small molecule activator Ryngo 1-23. Notably, Dyn2 also regulated turnover of TarP- and TmeA-associated actin networks, with disrupted Dyn2 function resulting in aberrant turnover dynamics, thus establishing the interdependent functional relationship between Dyn2 and the effectors TarP and TmeA.
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Affiliation(s)
- Matthew D. Romero
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, NE
| | - Rey A. Carabeo
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, NE
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4
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Imoto Y, Xue J, Luo L, Raychaudhuri S, Itoh K, Ma Y, Craft GE, Kwan AH, Mackay JP, Ha T, Watanabe S, Robinson PJ. Dynamin 1xA interacts with Endophilin A1 via its spliced long C-terminus for ultrafast endocytosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.21.558797. [PMID: 37790502 PMCID: PMC10542163 DOI: 10.1101/2023.09.21.558797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Dynamin 1 (Dyn1) has two major splice variants, xA and xB, with unique C-terminal extensions of 20 and 7 amino acids, respectively. Of these, only Dyn1xA is enriched at endocytic zones and accelerates vesicle fission during ultrafast endocytosis. Here, we report that the long tail variant, Dyn1xA, achieves this localization by preferentially binding to Endophilin A through a newly defined Class II binding site overlapping with its extension, at a site spanning the splice boundary. Endophilin binds this site at higher affinity than the previously reported site, and this affinity is determined by amino acids outside the binding sites acting as long distance elements within the xA tail. Their interaction is regulated by the phosphorylation state of two serine residues specific to the xA variant. Dyn1xA and Endophilin colocalize in patches near the active zone of synapses. Mutations selectively disrupting Endophilin binding to the long extension cause Dyn1xA mislocalization along axons. In these mutants, endocytic pits are stalled on the plasma membrane during ultrafast endocytosis. These data suggest that the specificity for ultrafast endocytosis is defined by the phospho-regulated interaction of Endophilin A through a newly identified site of Dyn1xA's long tail.
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Affiliation(s)
- Yuuta Imoto
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore MD, USA
| | - Jing Xue
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville 2145, NSW, Australia
| | - Lin Luo
- Institute for Molecular Bioscience, Institute for Molecular Bioscience Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sumana Raychaudhuri
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore MD, USA
| | - Kie Itoh
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore MD, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - George E. Craft
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville 2145, NSW, Australia
| | - Ann H. Kwan
- School of Life and Environmental Sciences and Sydney Nano Institute, University of Sydney, New South Wales, Australia
| | - Joel P. Mackay
- School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA
- Howard Hughes Medical Institute, Baltimore, MD, USA
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore MD, USA
- The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore MD, USA
| | - Phillip J. Robinson
- Cell Signalling Unit, Children’s Medical Research Institute, The University of Sydney, Locked Bag 23, Wentworthville 2145, NSW, Australia
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5
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Krishnan S, Klingauf J. The readily retrievable pool of synaptic vesicles. Biol Chem 2023; 404:385-397. [PMID: 36867726 DOI: 10.1515/hsz-2022-0298] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 02/16/2023] [Indexed: 03/05/2023]
Abstract
In the CNS communication between neurons occurs at synapses by secretion of neurotransmitter via exocytosis of synaptic vesicles (SVs) at the active zone. Given the limited number of SVs in presynaptic boutons a fast and efficient recycling of exocytosed membrane and proteins by triggered compensatory endocytosis is required to maintain neurotransmission. Thus, pre-synapses feature a unique tight coupling of exo- and endocytosis in time and space resulting in the reformation of SVs with uniform morphology and well-defined molecular composition. This rapid response requires early stages of endocytosis at the peri-active zone to be well choreographed to ensure reformation of SVs with high fidelity. The pre-synapse can address this challenge by a specialized membrane microcompartment, where a pre-sorted and pre-assembled readily retrievable pool (RRetP) of endocytic membrane patches is formed, consisting of the vesicle cargo, presumably bound within a nucleated Clathrin and adaptor complex. This review considers evidence for the RRetP microcompartment to be the primary organizer of presynaptic triggered compensatory endocytosis.
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Affiliation(s)
- Sai Krishnan
- Institute of Medical Physics and Biophysics, University of Münster, Robert-Koch Strasse 31, D-48149, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, University of Münster, Robert-Koch Strasse 31, D-48149, Münster, Germany.,Center for Soft Nanoscience, Busso-Peus Strasse 10, D-48149, Münster, Germany
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6
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Kozlov MM, Taraska JW. Generation of nanoscopic membrane curvature for membrane trafficking. Nat Rev Mol Cell Biol 2023; 24:63-78. [PMID: 35918535 DOI: 10.1038/s41580-022-00511-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2022] [Indexed: 11/09/2022]
Abstract
Curved membranes are key features of intracellular organelles, and their generation involves dynamic protein complexes. Here we describe the fundamental mechanisms such as the hydrophobic insertion, scaffolding and crowding mechanisms these proteins use to produce membrane curvatures and complex shapes required to form intracellular organelles and vesicular structures involved in endocytosis and secretion. For each mechanism, we discuss its cellular functions as well as the underlying physical principles and the specific membrane properties required for the mechanism to be feasible. We propose that the integration of individual mechanisms into a highly controlled, robust process of curvature generation often relies on the assembly of proteins into coats. How cells unify and organize the curvature-generating factors at the nanoscale is presented for three ubiquitous coats central for membrane trafficking in eukaryotes: clathrin-coated pits, caveolae, and COPI and COPII coats. The emerging theme is that these coats arrange and coordinate curvature-generating factors in time and space to dynamically shape membranes to accomplish membrane trafficking within cells.
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Affiliation(s)
- Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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7
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Yang C, Colosi P, Hugelier S, Zabezhinsky D, Lakadamyali M, Svitkina T. Actin polymerization promotes invagination of flat clathrin-coated lattices in mammalian cells by pushing at lattice edges. Nat Commun 2022; 13:6127. [PMID: 36253374 PMCID: PMC9576739 DOI: 10.1038/s41467-022-33852-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/05/2022] [Indexed: 12/24/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) requires energy input from actin polymerization in mechanically challenging conditions. The roles of actin in CME are poorly understood due to inadequate knowledge of actin organization at clathrin-coated structures (CCSs). Using platinum replica electron microscopy of mammalian cells, we show that Arp2/3 complex-dependent branched actin networks, which often emerge from microtubule tips, assemble along the CCS perimeter, lack interaction with the apical clathrin lattice, and have barbed ends oriented toward the CCS. This structure is hardly compatible with the widely held "apical pulling" model describing actin functions in CME. Arp2/3 complex inhibition or epsin knockout produce large flat non-dynamic CCSs, which split into invaginating subdomains upon recovery from Arp2/3 inhibition. Moreover, epsin localization to CCSs depends on Arp2/3 activity. We propose an "edge pushing" model for CME, wherein branched actin polymerization promotes severing and invagination of flat CCSs in an epsin-dependent manner by pushing at the CCS boundary, thus releasing forces opposing the intrinsic curvature of clathrin lattices.
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Affiliation(s)
- Changsong Yang
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Patricia Colosi
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Siewert Hugelier
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Daniel Zabezhinsky
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Melike Lakadamyali
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Tatyana Svitkina
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
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8
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Imoto Y, Raychaudhuri S, Ma Y, Fenske P, Sandoval E, Itoh K, Blumrich EM, Matsubayashi HT, Mamer L, Zarebidaki F, Söhl-Kielczynski B, Trimbuch T, Nayak S, Iwasa JH, Liu J, Wu B, Ha T, Inoue T, Jorgensen EM, Cousin MA, Rosenmund C, Watanabe S. Dynamin is primed at endocytic sites for ultrafast endocytosis. Neuron 2022; 110:2815-2835.e13. [PMID: 35809574 PMCID: PMC9464723 DOI: 10.1016/j.neuron.2022.06.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 03/24/2022] [Accepted: 06/09/2022] [Indexed: 02/06/2023]
Abstract
Dynamin mediates fission of vesicles from the plasma membrane during endocytosis. Typically, dynamin is recruited from the cytosol to endocytic sites, requiring seconds to tens of seconds. However, ultrafast endocytosis in neurons internalizes vesicles as quickly as 50 ms during synaptic vesicle recycling. Here, we demonstrate that Dynamin 1 is pre-recruited to endocytic sites for ultrafast endocytosis. Specifically, Dynamin 1xA, a splice variant of Dynamin 1, interacts with Syndapin 1 to form molecular condensates on the plasma membrane. Single-particle tracking of Dynamin 1xA molecules confirms the liquid-like property of condensates in vivo. When Dynamin 1xA is mutated to disrupt its interaction with Syndapin 1, the condensates do not form, and consequently, ultrafast endocytosis slows down by 100-fold. Mechanistically, Syndapin 1 acts as an adaptor by binding the plasma membrane and stores Dynamin 1xA at endocytic sites. This cache bypasses the recruitment step and accelerates endocytosis at synapses.
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Affiliation(s)
- Yuuta Imoto
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Sumana Raychaudhuri
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Pascal Fenske
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Eduardo Sandoval
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Kie Itoh
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Eva-Maria Blumrich
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; The Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; Simons Initiatives for the Developing Brain, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK
| | - Hideaki T Matsubayashi
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Lauren Mamer
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Fereshteh Zarebidaki
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | - Thorsten Trimbuch
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Shraddha Nayak
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Janet H Iwasa
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Jian Liu
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK
| | - Bin Wu
- The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA
| | - Takanari Inoue
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Erik M Jorgensen
- HHMI, Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; The Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; Simons Initiatives for the Developing Brain, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK
| | - Christian Rosenmund
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA.
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9
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Jin M, Shirazinejad C, Wang B, Yan A, Schöneberg J, Upadhyayula S, Xu K, Drubin DG. Branched actin networks are organized for asymmetric force production during clathrin-mediated endocytosis in mammalian cells. Nat Commun 2022; 13:3578. [PMID: 35732852 PMCID: PMC9217951 DOI: 10.1038/s41467-022-31207-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 06/08/2022] [Indexed: 01/15/2023] Open
Abstract
Actin assembly facilitates vesicle formation in several trafficking pathways, including clathrin-mediated endocytosis (CME). Interestingly, actin does not assemble at all CME sites in mammalian cells. How actin networks are organized with respect to mammalian CME sites and how assembly forces are harnessed, are not fully understood. Here, branched actin network geometry at CME sites was analyzed using three different advanced imaging approaches. When endocytic dynamics of unperturbed CME sites are compared, sites with actin assembly show a distinct signature, a delay between completion of coat expansion and vesicle scission, indicating that actin assembly occurs preferentially at stalled CME sites. In addition, N-WASP and the Arp2/3 complex are recruited to one side of CME sites, where they are positioned to stimulate asymmetric actin assembly and force production. We propose that actin assembles preferentially at stalled CME sites where it pulls vesicles into the cell asymmetrically, much as a bottle opener pulls off a bottle cap.
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Affiliation(s)
- Meiyan Jin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Cyna Shirazinejad
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Biophysics Graduate Group, University of California Berkeley, Berkeley, CA, USA
| | - Bowen Wang
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - Amy Yan
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Johannes Schöneberg
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Department of Pharmacology, and Department of Chemistry and Biochemistry, University of California, San Diego, CA, USA
| | - Srigokul Upadhyayula
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Ke Xu
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
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10
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Abouelezz A, Almeida-Souza L. The mammalian endocytic cytoskeleton. Eur J Cell Biol 2022; 101:151222. [DOI: 10.1016/j.ejcb.2022.151222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/27/2022] Open
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11
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Alfonzo-Méndez MA, Sochacki KA, Strub MP, Taraska JW. Dual clathrin and integrin signaling systems regulate growth factor receptor activation. Nat Commun 2022; 13:905. [PMID: 35173166 PMCID: PMC8850434 DOI: 10.1038/s41467-022-28373-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 01/18/2022] [Indexed: 12/20/2022] Open
Abstract
The crosstalk between growth factor and adhesion receptors is key for cell growth and migration. In pathological settings, these receptors are drivers of cancer. Yet, how growth and adhesion signals are spatially organized and integrated is poorly understood. Here we use quantitative fluorescence and electron microscopy to reveal a mechanism where flat clathrin lattices partition and activate growth factor signals via a coordinated response that involves crosstalk between epidermal growth factor receptor (EGFR) and the adhesion receptor β5-integrin. We show that ligand-activated EGFR, Grb2, Src, and β5-integrin are captured by clathrin coated-structures at the plasma membrane. Clathrin structures dramatically grow in response to EGF into large flat plaques and provide a signaling platform that link EGFR and β5-integrin through Src-mediated phosphorylation. Disrupting this EGFR/Src/β5-integrin axis prevents both clathrin plaque growth and dampens receptor signaling. Our study reveals a reciprocal regulation between clathrin lattices and two different receptor systems to coordinate and enhance signaling. These findings have broad implications for the regulation of growth factor signaling, adhesion, and endocytosis.
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Affiliation(s)
- Marco A Alfonzo-Méndez
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Building 50, Bethesda, MD, 20892, USA
| | - Kem A Sochacki
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Building 50, Bethesda, MD, 20892, USA
| | - Marie-Paule Strub
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Building 50, Bethesda, MD, 20892, USA
| | - Justin W Taraska
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Building 50, Bethesda, MD, 20892, USA.
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12
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Tavares LA, Januário YC, daSilva LLP. HIV-1 Hijacking of Host ATPases and GTPases That Control Protein Trafficking. Front Cell Dev Biol 2021; 9:622610. [PMID: 34307340 PMCID: PMC8295591 DOI: 10.3389/fcell.2021.622610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 06/07/2021] [Indexed: 12/22/2022] Open
Abstract
The human immunodeficiency virus (HIV-1) modifies the host cell environment to ensure efficient and sustained viral replication. Key to these processes is the capacity of the virus to hijack ATPases, GTPases and the associated proteins that control intracellular protein trafficking. The functions of these energy-harnessing enzymes can be seized by HIV-1 to allow the intracellular transport of viral components within the host cell or to change the subcellular distribution of antiviral factors, leading to immune evasion. Here, we summarize how energy-related proteins deviate from their normal functions in host protein trafficking to aid the virus in different phases of its replicative cycle. Recent discoveries regarding the interplay among HIV-1 and host ATPases and GTPases may shed light on potential targets for pharmacological intervention.
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Affiliation(s)
- Lucas A Tavares
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Yunan C Januário
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Luis L P daSilva
- Department of Cell and Molecular Biology, Center for Virology Research, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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13
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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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14
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Tu C, Du Z, Zhang H, Feng Y, Qi Y, Zheng Y, Liu J, Wang J. Endocytic pathway inhibition attenuates extracellular vesicle-induced reduction of chemosensitivity to bortezomib in multiple myeloma cells. Am J Cancer Res 2021; 11:2364-2380. [PMID: 33500730 PMCID: PMC7797667 DOI: 10.7150/thno.47996] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 11/18/2020] [Indexed: 12/16/2022] Open
Abstract
Extracellular vesicles (EVs), including exosomes and microvesicles, derived from bone marrow stromal cells (BMSCs) have been demonstrated as key factors in the progression and drug resistance of multiple myeloma (MM). EV uptake involves a variety of mechanisms which largely depend on the vesicle origin and recipient cell type. The aim of the present study was to identify the mechanisms involved in the uptake of BMSC-derived small EVs (sEVs) by MM cells, and to evaluate the anti-MM effect of targeting this process. Methods: Human BMSC-derived sEVs were identified by transmission electron microscopy, nanoparticle tracking analysis, and western blot. The effects of chemical inhibitors and shRNA-mediated knockdown of endocytosis-associated genes on sEV uptake and cell apoptosis were analyzed by flow cytometry. The anti-MM effect of blocking sEV uptake was evaluated in vitro and in a xenograft MM mouse model. Results: sEVs derived from BMSC were taken up by MM cells in a time- and dose-dependent manner, and subsequently promoted MM cell cycling and reduced their chemosensitivity to bortezomib. Chemical endocytosis inhibitors targeting heparin sulphate proteoglycans, actin, tyrosine kinase, dynamin-2, sodium/proton exchangers, or phosphoinositide 3-kinases significantly reduced MM cell internalization of BMSC-derived sEVs. Moreover, shRNA-mediated knockdown of endocytosis-associated proteins, including caveolin-1, flotillin-1, clathrin heavy chain, and dynamin-2 in MM cells suppressed sEV uptake. Furthermore, an endocytosis inhibitor targeting dynamin-2 preferentially suppressed the uptake of sEV by primary MM cells ex vivo and enhanced the anti-MM effects of bortezomib in vitro and in a mouse model. Conclusion: Clathrin- and caveolin-dependent endocytosis and macropinocytosis are the predominant routes of sEV-mediated communication between BMSCs and MM cells, and inhibiting endocytosis attenuates sEV-induced reduction of chemosensitivity to bortezomib, and thus enhances its anti-MM properties.
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15
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Sposini S, Rosendale M, Claverie L, Van TNN, Jullié D, Perrais D. Imaging endocytic vesicle formation at high spatial and temporal resolutions with the pulsed-pH protocol. Nat Protoc 2020; 15:3088-3104. [PMID: 32807908 DOI: 10.1038/s41596-020-0371-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 06/04/2020] [Indexed: 11/09/2022]
Abstract
Endocytosis is a fundamental process occurring in all eukaryotic cells. Live cell imaging of endocytosis has helped to decipher many of its mechanisms and regulations. With the pulsed-pH (ppH) protocol, one can detect the formation of individual endocytic vesicles (EVs) with an unmatched temporal resolution of 2 s. The ppH protocol makes use of cargo protein (e.g., the transferrin receptor) coupled to a pH-sensitive fluorescent protein, such as superecliptic pHluorin (SEP), which is brightly fluorescent at pH 7.4 but not fluorescent at pH <6.0. If the SEP moiety is at the surface, its fluorescence will decrease when cells are exposed to a low pH (5.5) buffer. If the SEP moiety has been internalized, SEP will remain fluorescent even during application of the low pH buffer. Fast perfusion enables the complete exchange of low and high pH extracellular solutions every 2 s, defining the temporal resolution of the technique. Unlike other imaging-based endocytosis assays, the ppH protocol detects EVs without a priori hypotheses on the dynamics of vesicle formation. Here, we explain how the ppH protocol quantifies the endocytic activity of living cells and the recruitment of associated proteins in real time. We provide a step-by-step procedure for expression of the reporter proteins with transient transfection, live cell image acquisition with synchronized pH changes and automated analysis. The whole protocol can be performed in 2 d to provide quantitative information on the endocytic process being studied.
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Affiliation(s)
- Silvia Sposini
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France
| | - Morgane Rosendale
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,CNRS, Institut des Sciences Moléculaires, UMR 5255, Talence, France
| | - Léa Claverie
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,Euroquality, Bordeaux, France
| | - Thi Nhu Ngoc Van
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,Sys2diag, Montpellier, France
| | - Damien Jullié
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.,University of California, San Francisco, San Francisco, CA, USA
| | - David Perrais
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France. .,CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France.
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16
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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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17
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Molecular Biology of Escherichia Coli Shiga Toxins' Effects on Mammalian Cells. Toxins (Basel) 2020; 12:toxins12050345. [PMID: 32456125 PMCID: PMC7290813 DOI: 10.3390/toxins12050345] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Shiga toxins (Stxs), syn. Vero(cyto)toxins, are potent bacterial exotoxins and the principal virulence factor of enterohemorrhagic Escherichia coli (EHEC), a subset of Shiga toxin-producing E. coli (STEC). EHEC strains, e.g., strains of serovars O157:H7 and O104:H4, may cause individual cases as well as large outbreaks of life-threatening diseases in humans. Stxs primarily exert a ribotoxic activity in the eukaryotic target cells of the mammalian host resulting in rapid protein synthesis inhibition and cell death. Damage of endothelial cells in the kidneys and the central nervous system by Stxs is central in the pathogenesis of hemolytic uremic syndrome (HUS) in humans and edema disease in pigs. Probably even more important, the toxins also are capable of modulating a plethora of essential cellular functions, which eventually disturb intercellular communication. The review aims at providing a comprehensive overview of the current knowledge of the time course and the consecutive steps of Stx/cell interactions at the molecular level. Intervention measures deduced from an in-depth understanding of this molecular interplay may foster our basic understanding of cellular biology and microbial pathogenesis and pave the way to the creation of host-directed active compounds to mitigate the pathological conditions of STEC infections in the mammalian body.
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18
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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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19
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Jadli AS, Ballasy N, Edalat P, Patel VB. Inside(sight) of tiny communicator: exosome biogenesis, secretion, and uptake. Mol Cell Biochem 2020; 467:77-94. [PMID: 32088833 DOI: 10.1007/s11010-020-03703-z] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/14/2020] [Indexed: 01/07/2023]
Abstract
Discovered in the late 1980s as an extracellular vesicle of endosomal origin secreted from reticulocytes, exosomes recently gained scientific attention due to its role in intercellular communication. Exosomes have now been identified to carry cell-specific cargo of nucleic acids, proteins, lipids, and other biologically active molecules. Exosomes can be selectively taken up by neighboring or distant cells, which has shown to result in structural and functional responses in the recipient cells. Recent advances indicate the regulation of exosomes at various steps, including their biogenesis, selection of their cargo, as well as cell-specific uptake. This review will shed light on the differences between the type of extracellular vesicles. In this review, we discuss the recent progress in our understanding of the regulation of exosome biogenesis, secretion, and uptake.
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Affiliation(s)
- Anshul S Jadli
- Department of Physiology and Pharmacology, Cumming School of Medicine, The University of Calgary, HMRB-53, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.,Libin Cardiovascular Institute of Alberta, The University of Calgary, HMRB-71, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Noura Ballasy
- Department of Physiology and Pharmacology, Cumming School of Medicine, The University of Calgary, HMRB-53, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.,Libin Cardiovascular Institute of Alberta, The University of Calgary, HMRB-71, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Pariya Edalat
- Department of Physiology and Pharmacology, Cumming School of Medicine, The University of Calgary, HMRB-53, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.,Libin Cardiovascular Institute of Alberta, The University of Calgary, HMRB-71, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Vaibhav B Patel
- Department of Physiology and Pharmacology, Cumming School of Medicine, The University of Calgary, HMRB-53, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada. .,Libin Cardiovascular Institute of Alberta, The University of Calgary, HMRB-71, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
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20
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Narasimhan M, Johnson A, Prizak R, Kaufmann WA, Tan S, Casillas-Pérez B, Friml J. Evolutionarily unique mechanistic framework of clathrin-mediated endocytosis in plants. eLife 2020; 9:52067. [PMID: 31971511 PMCID: PMC7012609 DOI: 10.7554/elife.52067] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
In plants, clathrin mediated endocytosis (CME) represents the major route for cargo internalisation from the cell surface. It has been assumed to operate in an evolutionary conserved manner as in yeast and animals. Here we report characterisation of ultrastructure, dynamics and mechanisms of plant CME as allowed by our advancement in electron microscopy and quantitative live imaging techniques. Arabidopsis CME appears to follow the constant curvature model and the bona fide CME population generates vesicles of a predominantly hexagonal-basket type; larger and with faster kinetics than in other models. Contrary to the existing paradigm, actin is dispensable for CME events at the plasma membrane but plays a unique role in collecting endocytic vesicles, sorting of internalised cargos and directional endosome movement that itself actively promote CME events. Internalized vesicles display a strongly delayed and sequential uncoating. These unique features highlight the independent evolution of the plant CME mechanism during the autonomous rise of multicellularity in eukaryotes.
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Affiliation(s)
| | - Alexander Johnson
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Roshan Prizak
- Institute of Science and Technology Austria, Klosterneuburg, Austria.,Institute of Biological and Chemical Systems - Biological Information Processing, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | | | - Shutang Tan
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | - Jiří Friml
- Institute of Science and Technology Austria, Klosterneuburg, Austria
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21
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Vasan R, Rudraraju S, Akamatsu M, Garikipati K, Rangamani P. A mechanical model reveals that non-axisymmetric buckling lowers the energy barrier associated with membrane neck constriction. SOFT MATTER 2020; 16:784-797. [PMID: 31830191 DOI: 10.1039/c9sm01494b] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Membrane neck formation is essential for scission, which, as recent experiments on tubules have demonstrated, can be location dependent. The diversity of biological machinery that can constrict a neck such as dynamin, actin, ESCRTs and BAR proteins, and the range of forces and deflection over which they operate, suggest that the constriction process is functionally mechanical and robust to changes in biological environment. In this study, we used a mechanical model of the lipid bilayer to systematically investigate the influence of location, symmetry constraints, and helical forces on membrane neck constriction. Simulations from our model demonstrated that the energy barriers associated with constriction of a membrane neck are location-dependent. Importantly, if symmetry restrictions are relaxed, then the energy barrier for constriction is dramatically lowered and the membrane buckles at lower values of forcing parameters. Our simulations also show that constriction due to helical proteins further reduces the energy barrier for neck formation when compared to cylindrical proteins. These studies establish that despite different molecular mechanisms of neck formation in cells, the mechanics of constriction naturally leads to a loss of symmetry that can lower the energy barrier to constriction.
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Affiliation(s)
- R Vasan
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA 92093, USA.
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22
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Functional recruitment of dynamin requires multimeric interactions for efficient endocytosis. Nat Commun 2019; 10:4462. [PMID: 31575863 PMCID: PMC6773865 DOI: 10.1038/s41467-019-12434-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/10/2019] [Indexed: 02/06/2023] Open
Abstract
During clathrin mediated endocytosis (CME), the concerted action of dynamin and its interacting partners drives membrane scission. Essential interactions occur between the proline/arginine-rich domain of dynamin (dynPRD) and the Src-homology domain 3 (SH3) of various proteins including amphiphysins. Here we show that multiple SH3 domains must bind simultaneously to dynPRD through three adjacent motifs for dynamin’s efficient recruitment and function. First, we show that mutant dynamins modified in a single motif, including the central amphiphysin SH3 (amphSH3) binding motif, partially rescue CME in dynamin triple knock-out cells. However, mutating two motifs largely prevents that ability. Furthermore, we designed divalent dynPRD-derived peptides. These ligands bind multimers of amphSH3 with >100-fold higher affinity than monovalent ones in vitro. Accordingly, dialyzing living cells with these divalent peptides through a patch-clamp pipette blocks CME much more effectively than with monovalent ones. We conclude that dynamin drives vesicle scission via multivalent interactions in cells. During clathrin mediated endocytosis (CME), membrane scission is achieved by the concerted action of dynamin and its interacting partners such as amphiphysins. Here authors show that efficient recruitment and function of dynamin requires simultaneous binding of multiple amphiphysin SH3 domains.
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23
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Karger A, Pérez-Núñez D, Urquiza J, Hinojar P, Alonso C, Freitas FB, Revilla Y, Le Potier MF, Montoya M. An Update on African Swine Fever Virology. Viruses 2019; 11:v11090864. [PMID: 31533244 PMCID: PMC6784044 DOI: 10.3390/v11090864] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/05/2019] [Accepted: 09/11/2019] [Indexed: 02/06/2023] Open
Abstract
Animal diseases constitute a continuing threat to animal health, food safety, national economy, and the environment. Among those, African swine fever (ASF) is one of the most devastating viruses affecting pigs and wild suids due to the lack of vaccine or effective treatment. ASF is endemic in countries in sub-Saharan Africa, but since its introduction to the Caucasus region in 2007, a highly virulent strain of ASF virus (ASFV) has continued to circulate and spread into Eastern Europe and Russia, and most recently into Western Europe, China, and various countries of Southeast Asia. Given the importance of this disease, this review will highlight recent discoveries in basic virology with special focus on proteomic analysis, replication cycle, and some recent data on genes involved in cycle progression and viral–host interactions, such as I215L (E2 ubiquitin-conjugating enzyme), EP402R (CD2v), A104R (histone-like protein), QP509L, and Q706L (RNA helicases) or P1192R (Topoisomerase II). Taking into consideration the large DNA genome of ASFV and its complex interactions with the host, more studies and new approaches are to be taken to understand the basic virus–host interaction for ASFV. Proteomic studies are just paving the way for future research.
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Affiliation(s)
- Axel Karger
- Institute of Molecular Virology and Cell Biology, Friedrich Loeffler Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany;
| | - Daniel Pérez-Núñez
- Virology Department, Centro Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain; (D.P.-N.); (Y.R.)
| | - Jesús Urquiza
- INIA, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28040 Madrid, Spain; (J.U.); (P.H.); (C.A.)
| | - Patricia Hinojar
- INIA, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28040 Madrid, Spain; (J.U.); (P.H.); (C.A.)
| | - Covadonga Alonso
- INIA, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, 28040 Madrid, Spain; (J.U.); (P.H.); (C.A.)
| | - Ferdinando B. Freitas
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, 1649-004 Lisboa, Portugal;
| | - Yolanda Revilla
- Virology Department, Centro Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain; (D.P.-N.); (Y.R.)
| | - Marie-Frédérique Le Potier
- ANSES, Laboratoire de Ploufragan/Plouzané/Niort, Unité Virologie Immunologie Porcines, Anses, 22440 Ploufragan, France;
| | - Maria Montoya
- Centro de Investigaciones Biológicas (CIB-CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain
- Correspondence:
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24
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Chen Y, Yong J, Martínez-Sánchez A, Yang Y, Wu Y, De Camilli P, Fernández-Busnadiego R, Wu M. Dynamic instability of clathrin assembly provides proofreading control for endocytosis. J Cell Biol 2019; 218:3200-3211. [PMID: 31451612 PMCID: PMC6781453 DOI: 10.1083/jcb.201804136] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/03/2019] [Accepted: 08/01/2019] [Indexed: 12/18/2022] Open
Abstract
Chen et al. reconstitute endocytosis in a cell-free system and show that cargo sorting requires the dynamic dissociation of clathrin during the growth phase of the clathrin-coated pit formation. Clathrin-mediated endocytosis depends on the formation of functional clathrin-coated pits that recruit cargos and mediate the uptake of those cargos into the cell. However, it remains unclear whether the cargos in the growing clathrin-coated pits are actively monitored by the coat assembly machinery. Using a cell-free reconstitution system, we report that clathrin coat formation and cargo sorting can be uncoupled, indicating that a checkpoint is required for functional cargo incorporation. We demonstrate that the ATPase Hsc70 and a dynamic exchange of clathrin during assembly are required for this checkpoint. In the absence of Hsc70 function, clathrin assembles into pits but fails to enrich cargo. Using single-molecule imaging, we further show that uncoating takes place throughout the lifetime of the growing clathrin-coated pits. Our results suggest that the dynamic exchange of clathrin, at the cost of the reduced overall assembly rates, primarily serves as a proofreading mechanism for quality control of endocytosis.
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Affiliation(s)
- Yan Chen
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore
| | - Jeffery Yong
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore
| | | | - Yang Yang
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore
| | - Yumei Wu
- Howard Hughes Medical Institute, Department of Cell Biology and Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Pietro De Camilli
- Howard Hughes Medical Institute, Department of Cell Biology and Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Rubén Fernández-Busnadiego
- Max Planck Institute for Biochemistry, Martinsried, Germany.,Department of Neuropathology, University Medical Center, Georg-August University Göttingen, Göttingen, Germany
| | - Min Wu
- Centre for Bioimaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore .,Mechanobiology Institute, National University of Singapore, Singapore
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25
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Reshetniak S, Rizzoli SO. Interrogating Synaptic Architecture: Approaches for Labeling Organelles and Cytoskeleton Components. Front Synaptic Neurosci 2019; 11:23. [PMID: 31507402 PMCID: PMC6716447 DOI: 10.3389/fnsyn.2019.00023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 08/02/2019] [Indexed: 01/06/2023] Open
Abstract
Synaptic transmission has been studied for decades, as a fundamental step in brain function. The structure of the synapse, and its changes during activity, turned out to be key aspects not only in the transfer of information between neurons, but also in cognitive processes such as learning and memory. The overall synaptic morphology has traditionally been studied by electron microscopy, which enables the visualization of synaptic structure in great detail. The changes in the organization of easily identified structures, such as the presynaptic active zone, or the postsynaptic density, are optimally studied via electron microscopy. However, few reliable methods are available for labeling individual organelles or protein complexes in electron microscopy. For such targets one typically relies either on combination of electron and fluorescence microscopy, or on super-resolution fluorescence microscopy. This review focuses on approaches and techniques used to specifically reveal synaptic organelles and protein complexes, such as cytoskeletal assemblies. We place the strongest emphasis on methods detecting the targets of interest by affinity binding, and we discuss the advantages and limitations of each method.
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Affiliation(s)
- Sofiia Reshetniak
- Institute for Neuro- and Sensory Physiology, Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Göttingen, Germany
- International Max Planck Research School for Molecular Biology, Göttingen, Germany
| | - Silvio O. Rizzoli
- Institute for Neuro- and Sensory Physiology, Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Göttingen, Germany
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26
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Shi X, Duan F, Lin L, Xu Q, Xu T, Zhang R. WIP-1 and DBN-1 promote scission of endocytic vesicles by bridging actin and Dynamin-1 in the C. elegans intestine. J Cell Sci 2019; 132:jcs.228023. [PMID: 31118234 DOI: 10.1242/jcs.228023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 05/13/2019] [Indexed: 01/13/2023] Open
Abstract
There has been a consensus that actin plays an important role in scission of the clathrin-coated pits (CCPs) together with large GTPases of the dynamin family in metazoan cells. However, the recruitment, regulation and functional interdependence of actin and dynamin during this process remain inadequately understood. Here, based on small-scale screening and in vivo live-imaging techniques, we identified a novel set of molecules underlying CCP scission in the multicellular organism Caenorhabditis elegans We found that loss of Wiskott-Aldrich syndrome protein (WASP)-interacting protein (WIP-1) impaired CCP scission in a manner that is independent of the C. elegans homolog of WASP/N-WASP (WSP-1) and is mediated by direct binding to G-actin. Moreover, the cortactin-binding domain of WIP-1 serves as the binding interface for DBN-1 (also known in other organisms as Abp1), another actin-binding protein. We demonstrate that the interaction between DBN-1 and F-actin is essential for Dynamin-1 (DYN-1) recruitment at endocytic sites. In addition, the recycling regulator RME-1, a homolog of mammalian Eps15 homology (EH) domain-containing proteins, is increasingly recruited at the arrested endocytic intermediates induced by F-actin loss or DYN-1 inactivation, which further stabilizes the tubular endocytic intermediates. Our study provides new insights into the molecular network underlying F-actin participation in the scission of CCPs.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Xuemeng Shi
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Fengyun Duan
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Long Lin
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Qifeng Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Tao Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China .,National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Rongying Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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27
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Shigella promotes major alteration of gut epithelial physiology and tissue invasion by shutting off host intracellular transport. Proc Natl Acad Sci U S A 2019; 116:13582-13591. [PMID: 31209035 DOI: 10.1073/pnas.1902922116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Intracellular trafficking pathways in eukaryotic cells are essential to maintain organelle identity and structure, and to regulate cell communication with its environment. Shigella flexneri invades and subverts the human colonic epithelium by the injection of virulence factors through a type 3 secretion system (T3SS). In this work, we report the multiple effects of two S. flexneri effectors, IpaJ and VirA, which target small GTPases of the Arf and Rab families, consequently inhibiting several intracellular trafficking pathways. IpaJ and VirA induce large-scale impairment of host protein secretion and block the recycling of surface receptors. Moreover, these two effectors decrease clathrin-dependent and -independent endocytosis. Therefore, S. flexneri infection induces a global blockage of host cell intracellular transport, affecting the exchange between cells and their external environment. The combined action of these effectors disorganizes the epithelial cell polarity, disturbs epithelial barrier integrity, promotes multiple invasion events, and enhances the pathogen capacity to penetrate into the colonic tissue in vivo.
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28
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Zheng Y, Tu C, Zhang J, Wang J. Inhibition of multiple myeloma‑derived exosomes uptake suppresses the functional response in bone marrow stromal cell. Int J Oncol 2019; 54:1061-1070. [PMID: 30664188 DOI: 10.3892/ijo.2019.4685] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/07/2018] [Indexed: 11/06/2022] Open
Abstract
The communication between multiple myeloma (MM) cells and bone marrow stromal cells (BMSCs) serves a pivotal role in MM progression by supporting MM cell growth, proliferation and drug resistance. An exosomes‑based endogenous transport system has been determined as a novel mechanism of this communication by revealing the capacity for exchange of functional components between cells. An exosomes transfer‑mediated biological response in recipient cells is strongly determined by the detailed routes and mechanisms of exosomes internalization, which are diverse and can depend on surface molecules on the membrane of the vesicle and the recipient cell. Understanding the routes of exosomes uptake during MM cell‑BMSC communication is of great importance for the development of blocking strategies beneficial for MM treatment. In the present study, fluorescently‑labeled exosomes and pharmacological inhibitors, which are known to interfere with different internalization pathways, were used to characterize the cellular mechanisms involved in the uptake of MM cell‑derived exosomes by BMSCs. MM cell‑derived exosomes can promote BMSC viability and induce changes in multiple pro‑survival and pro‑proliferation pathways in BMSCs. As determined by flow cytometry and confocal microscopy, the uptake of MM cell‑derived exosomes proceeded primarily through endocytosis, via special caveolin‑dependent endocytosis, and partially through macropinocytosis and membrane fusion. Furthermore, treatment with endocytosis inhibitors suppressed the exosomes‑induced changes in pathways in BMSCs. Collectively, these results indicate that endocytosis is the primary route of internalization of MM cell‑derived exosomes by BMSCs and indicate that inhibition of exosomes uptake can interrupt the communication between MM cells and BMSCs and thus serve as a potential adjunctive strategy for MM treatment.
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Affiliation(s)
- Yongjiang Zheng
- Department of Hematology, The Third Affiliated Hospital of Sun Yat‑Sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Chenggong Tu
- Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
| | - Jingwen Zhang
- Department of Hematology, The Third Affiliated Hospital of Sun Yat‑Sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Jinheng Wang
- Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, Guangdong 511436, P.R. China
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29
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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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30
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Su P, Tian Y, Yang C, Ma X, Wang X, Pei J, Qian A. Mesenchymal Stem Cell Migration during Bone Formation and Bone Diseases Therapy. Int J Mol Sci 2018; 19:ijms19082343. [PMID: 30096908 PMCID: PMC6121650 DOI: 10.3390/ijms19082343] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/02/2018] [Accepted: 08/06/2018] [Indexed: 12/24/2022] Open
Abstract
During bone modeling, remodeling, and bone fracture repair, mesenchymal stem cells (MSCs) differentiate into chondrocyte or osteoblast to comply bone formation and regeneration. As multipotent stem cells, MSCs were used to treat bone diseases during the past several decades. However, most of these implications just focused on promoting MSC differentiation. Furthermore, cell migration is also a key issue for bone formation and bone diseases treatment. Abnormal MSC migration could cause different kinds of bone diseases, including osteoporosis. Additionally, for bone disease treatment, the migration of endogenous or exogenous MSCs to bone injury sites is required. Recently, researchers have paid more and more attention to two critical points. One is how to apply MSC migration to bone disease therapy. The other is how to enhance MSC migration to improve the therapeutic efficacy of bone diseases. Some considerable outcomes showed that enhancing MSC migration might be a novel trick for reversing bone loss and other bone diseases, such as osteoporosis, fracture, and osteoarthritis (OA). Although plenty of challenges need to be conquered, application of endogenous and exogenous MSC migration and developing different strategies to improve therapeutic efficacy through enhancing MSC migration to target tissue might be the trend in the future for bone disease treatment.
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Affiliation(s)
- Peihong Su
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Ye Tian
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Chaofei Yang
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Xiaoli Ma
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Xue Wang
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Jiawei Pei
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
| | - Airong Qian
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
- NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
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31
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Morris CE. Cytotoxic Swelling of Sick Excitable Cells - Impaired Ion Homeostasis and Membrane Tension Homeostasis in Muscle and Neuron. CURRENT TOPICS IN MEMBRANES 2018; 81:457-496. [PMID: 30243439 DOI: 10.1016/bs.ctm.2018.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
When they become simultaneously leaky to both Na+ and Cl-, excitable cells are vulnerable to potentially lethal cytotoxic swelling. Swelling ensues in spite of an isosmotic milieu because the entering ions add osmolytes to the cytoplasm's high concentration of impermeant anionic osmolytes. An influx of osmotically-obliged water is unavoidable. A cell that cannot stanch at least one the leaks will succumb to death by Donnan effect. "Sick excitable cells" are those injured through ischemia, trauma, inflammation, hyperactivity, genetically-impaired membrane skeletons and other insults, all of which foster bleb-damage to regions of the plasma membrane. Nav channels resident in damaged membrane exhibit left-shifted kinetics; the corresponding Nav window conductance constitutes a Na+-leak. In cortical neurons, sustained depolarization to ∼-20mV elicits a sustained lethal gCl. Underlying Vrest in skeletal muscle is a constitutively active gCl; not surprisingly therefore, dystrophic muscle fibers, which are prone to bleb damage and which exhibit Nav-leak and Na+-overload, are prone to cytotoxic swelling. To restore viability in cytotoxically swelling neurons and muscle, the imperative of fully functional ion homeostasis is well-recognized. However, as emphasized here, in a healthy excitable cell, fully functional membrane tension homeostasis is also imperative. ATPase-pumps keep plasma membrane batteries charged, and ATPase-motor proteins maintain membrane tone. In sick excitable cells, neither condition prevails.
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Affiliation(s)
- Catherine E Morris
- Senior Scientist Emeritus, Neuroscience, Ottawa Hospital Research Institute, Ottawa, ON, Canada
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32
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Dambournet D, Sochacki KA, Cheng AT, Akamatsu M, Taraska JW, Hockemeyer D, Drubin DG. Genome-edited human stem cells expressing fluorescently labeled endocytic markers allow quantitative analysis of clathrin-mediated endocytosis during differentiation. J Cell Biol 2018; 217:3301-3311. [PMID: 29980624 PMCID: PMC6123002 DOI: 10.1083/jcb.201710084] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/05/2017] [Accepted: 06/04/2018] [Indexed: 12/11/2022] Open
Abstract
We developed a general approach for investigation of how cellular processes become adapted for specific cell types during differentiation. Previous studies reported substantial differences in the morphology and dynamics of clathrin-mediated endocytosis (CME) sites. However, associating specific CME properties with distinct differentiated cell types and determining how these properties are developmentally specified during differentiation have been elusive. Using genome-edited human embryonic stem cells, and isogenic fibroblasts and neuronal progenitor cells derived from them, we established by live-cell imaging and platinum replica transmission electron microscopy that CME site dynamics and ultrastructure on the plasma membrane are precisely reprogrammed during differentiation. Expression levels for the endocytic adaptor protein AP2μ2 were found to underlie dramatic changes in CME dynamics and structure. Additionally, CME dependency on actin assembly and phosphoinositide-3 kinase activity are distinct for each cell type. Collectively, our results demonstrate that key CME properties are reprogrammed during differentiation at least in part through AP2μ2 expression regulation.
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Affiliation(s)
- Daphné Dambournet
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Kem A Sochacki
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | | | - Matthew Akamatsu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Justin W Taraska
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Dirk Hockemeyer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
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33
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Ripoll L, Heiligenstein X, Hurbain I, Domingues L, Figon F, Petersen KJ, Dennis MK, Houdusse A, Marks MS, Raposo G, Delevoye C. Myosin VI and branched actin filaments mediate membrane constriction and fission of melanosomal tubule carriers. J Cell Biol 2018; 217:2709-2726. [PMID: 29875258 PMCID: PMC6080934 DOI: 10.1083/jcb.201709055] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 03/16/2018] [Accepted: 05/09/2018] [Indexed: 01/19/2023] Open
Abstract
Vesicular and tubular transport intermediates regulate organellar cargo dynamics. Transport carrier release involves local and profound membrane remodeling before fission. Pinching the neck of a budding tubule or vesicle requires mechanical forces, likely exerted by the action of molecular motors on the cytoskeleton. Here, we show that myosin VI, together with branched actin filaments, constricts the membrane of tubular carriers that are then released from melanosomes, the pigment containing lysosome-related organelles of melanocytes. By combining superresolution fluorescence microscopy, correlative light and electron microscopy, and biochemical analyses, we find that myosin VI motor activity mediates severing by constricting the neck of the tubule at specific melanosomal subdomains. Pinching of the tubules involves the cooperation of the myosin adaptor optineurin and the activity of actin nucleation machineries, including the WASH and Arp2/3 complexes. The fission and release of these tubules allows for the export of components from melanosomes, such as the SNARE VAMP7, and promotes melanosome maturation and transfer to keratinocytes. Our data reveal a new myosin VI- and actin-dependent membrane fission mechanism required for organelle function.
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Affiliation(s)
- Léa Ripoll
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Xavier Heiligenstein
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Ilse Hurbain
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France.,Cell and Tissue Imaging Facility, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Lia Domingues
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Florent Figon
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France.,Master BioSciences, École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Karl J Petersen
- Structural Motility, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Megan K Dennis
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA.,Departments of Pathology and Laboratory Medicine and Physiology, University of Pennsylvania, Philadelphia, PA
| | - Anne Houdusse
- Structural Motility, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA.,Departments of Pathology and Laboratory Medicine and Physiology, University of Pennsylvania, Philadelphia, PA
| | - Graça Raposo
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France.,Cell and Tissue Imaging Facility, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Cédric Delevoye
- Structure and Membrane Compartments, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France .,Cell and Tissue Imaging Facility, Institut Curie, Paris Sciences & Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
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34
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Yoshida A, Sakai N, Uekusa Y, Imaoka Y, Itagaki Y, Suzuki Y, Yoshimura SH. Morphological changes of plasma membrane and protein assembly during clathrin-mediated endocytosis. PLoS Biol 2018; 16:e2004786. [PMID: 29723197 PMCID: PMC5953504 DOI: 10.1371/journal.pbio.2004786] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 05/15/2018] [Accepted: 03/29/2018] [Indexed: 12/21/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) proceeds through a series of morphological changes of the plasma membrane induced by a number of protein components. Although the spatiotemporal assembly of these proteins has been elucidated by fluorescence-based techniques, the protein-induced morphological changes of the plasma membrane have not been fully clarified in living cells. Here, we visualize membrane morphology together with protein localizations during CME by utilizing high-speed atomic force microscopy (HS-AFM) combined with a confocal laser scanning unit. The plasma membrane starts to invaginate approximately 30 s after clathrin starts to assemble, and the aperture diameter increases as clathrin accumulates. Actin rapidly accumulates around the pit and induces a small membrane swelling, which, within 30 s, rapidly covers the pit irreversibly. Inhibition of actin turnover abolishes the swelling and induces a reversible open–close motion of the pit, indicating that actin dynamics are necessary for efficient and irreversible pit closure at the end of CME. Cells communicate with their environments via the plasma membrane and various membrane proteins. Clathrin-mediated endocytosis (CME) plays a central role in such communication and proceeds with a series of multiprotein assembly, deformation of the plasma membrane, and production of a membrane vesicle that delivers extracellular signaling molecules into the cytoplasm. In this study, we utilized our home-built correlative imaging system comprising high-speed atomic force microscopy (HS-AFM) and confocal fluorescence microscopy to simultaneously image morphological changes of the plasma membrane and protein localization during CME in a living cell. The results revealed a tight correlation between the size of the pit and the amount of clathrin assembled. Actin dynamics play multiple roles in the assembly, maturation, and closing phases of the process, and affects membrane morphology, suggesting a close relationship between endocytosis and dynamic events at the cell cortex. Knock down of dynamin also affected the closing motion of the pit and showed functional correlation with actin.
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Affiliation(s)
- Aiko Yoshida
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | | | | | - Yuka Imaoka
- R&D Group, Olympus Corporation, Hachioji, Japan
| | | | - Yuki Suzuki
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan
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35
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Local actin polymerization during endocytic carrier formation. Biochem Soc Trans 2018; 46:565-576. [DOI: 10.1042/bst20170355] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/06/2018] [Accepted: 03/16/2018] [Indexed: 12/20/2022]
Abstract
Extracellular macromolecules, pathogens and cell surface proteins rely on endocytosis to enter cells. Key steps of endocytic carrier formation are cargo molecule selection, plasma membrane folding and detachment from the cell surface. While dedicated proteins mediate each step, the actin cytoskeleton contributes to all. However, its role can be indirect to the actual molecular events driving endocytosis. Here, we review our understanding of the molecular steps mediating local actin polymerization during the formation of endocytic carriers. Clathrin-mediated endocytosis is the least reliant on local actin polymerization, as it is only engaged to counter forces induced by membrane tension or cytoplasmic pressure. Two opposite situations are coated pit formation in yeast and at the basolateral surface of polarized mammalian cells which are, respectively, dependent and independent on actin polymerization. Conversely, clathrin-independent endocytosis forming both nanometer [CLIC (clathrin-independent carriers)/GEEC (glycosylphosphatidylinositol (GPI)-anchored protein enriched endocytic compartments), caveolae, FEME (fast endophilin-mediated endocytosis) and IL-2β (interleukin-2β) uptake] and micrometer carriers (macropinocytosis) are dependent on actin polymerization to power local membrane deformation and carrier budding. A variety of endocytic adaptors can recruit and activate the Cdc42/N-WASP or Rac1/WAVE complexes, which, in turn, engage the Arp2/3 complex, thereby mediating local actin polymerization at the membrane. However, the molecular steps for RhoA and formin-mediated actin bundling during endocytic pit formation remain unclear.
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36
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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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Milosevic I. Revisiting the Role of Clathrin-Mediated Endoytosis in Synaptic Vesicle Recycling. Front Cell Neurosci 2018; 12:27. [PMID: 29467622 PMCID: PMC5807904 DOI: 10.3389/fncel.2018.00027] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/17/2018] [Indexed: 12/11/2022] Open
Abstract
Without robust mechanisms to efficiently form new synaptic vesicles (SVs), the tens to hundreds of SVs typically present at the neuronal synapse would be rapidly used up, even at modest levels of neuronal activity. SV recycling is thus critical for synaptic physiology and proper function of sensory and nervous systems. Yet, more than four decades after it was originally proposed that the SVs are formed and recycled locally at the presynaptic terminals, the mechanisms of endocytic processes at the synapse are heavily debated. Clathrin-mediated endocytosis, a type of endocytosis that capitalizes on the clathrin coat, a number of adaptor and accessory proteins, and the GTPase dynamin, is well understood, while the contributions of clathrin-independent fast endocytosis, kiss-and-run, bulk endocytosis and ultrafast endocytosis are still being evaluated. This review article revisits and summarizes the current knowledge on the SV reformation with a focus on clathrin-mediated endocytosis, and it discusses the modes of SV formation from endosome-like structures at the synapse. Given the importance of this topic, future advances in this active field are expected to contribute to better comprehension of neurotransmission, and to have general implications for neuroscience and medicine.
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Affiliation(s)
- Ira Milosevic
- Synaptic Vesicle Dynamics Group, European Neuroscience Institute (ENI), University Medical Center Göttingen (UMG), Göttingen, Germany
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Membrane bending occurs at all stages of clathrin-coat assembly and defines endocytic dynamics. Nat Commun 2018; 9:419. [PMID: 29379015 PMCID: PMC5789089 DOI: 10.1038/s41467-018-02818-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/02/2018] [Indexed: 01/01/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) internalizes plasma membrane by reshaping small regions of the cell surface into spherical vesicles. The key mechanistic question of how coat assembly produces membrane curvature has been studied with molecular and cellular structural biology approaches, without direct visualization of the process in living cells; resulting in two competing models for membrane bending. Here we use polarized total internal reflection fluorescence microscopy (pol-TIRF) combined with electron, atomic force, and super-resolution optical microscopy to measure membrane curvature during CME. Surprisingly, coat assembly accommodates membrane bending concurrent with or after the assembly of the clathrin lattice. Once curvature began, CME proceeded to scission with robust timing. Four color pol-TIRF showed that CALM accumulated at high levels during membrane bending, implicating its auxiliary role in curvature generation. We conclude that clathrin-coat assembly is versatile and that multiple membrane-bending trajectories likely reflect the energetics of coat assembly relative to competing forces. Two distinct and opposing models for clathrin-mediated endocytosis have been inferred from EM and structural biology data. Here the authors develop an optical method to directly visualize membrane-bending dynamics and show that coat assembly accommodates membrane bending during or after the assembly of the clathrin lattice, which is not predicted by either model.
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Molinie N, Gautreau A. The Arp2/3 Regulatory System and Its Deregulation in Cancer. Physiol Rev 2017; 98:215-238. [PMID: 29212790 DOI: 10.1152/physrev.00006.2017] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 02/07/2023] Open
Abstract
The Arp2/3 complex is an evolutionary conserved molecular machine that generates branched actin networks. When activated, the Arp2/3 complex contributes the actin branched junction and thus cross-links the polymerizing actin filaments in a network that exerts a pushing force. The different activators initiate branched actin networks at the cytosolic surface of different cellular membranes to promote their protrusion, movement, or scission in cell migration and membrane traffic. Here we review the structure, function, and regulation of all the direct regulators of the Arp2/3 complex that induce or inhibit the initiation of a branched actin network and that controls the stability of its branched junctions. Our goal is to present recent findings concerning novel inhibitory proteins or the regulation of the actin branched junction and place these in the context of what was previously known to provide a global overview of how the Arp2/3 complex is regulated in human cells. We focus on the human set of Arp2/3 regulators to compare normal Arp2/3 regulation in untransformed cells to the deregulation of the Arp2/3 system observed in patients affected by various cancers. In many cases, these deregulations promote cancer progression and have a direct impact on patient survival.
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Affiliation(s)
- Nicolas Molinie
- Ecole Polytechnique, Université Paris-Saclay, CNRS UMR 7654, Palaiseau, France; and Moscow Institute of Physics and Technology, Life Sciences Center, Dolgoprudny, Russia
| | - Alexis Gautreau
- Ecole Polytechnique, Université Paris-Saclay, CNRS UMR 7654, Palaiseau, France; and Moscow Institute of Physics and Technology, Life Sciences Center, Dolgoprudny, Russia
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Dynamin-2 Stabilizes the HIV-1 Fusion Pore with a Low Oligomeric State. Cell Rep 2017; 18:443-453. [PMID: 28076788 PMCID: PMC5263234 DOI: 10.1016/j.celrep.2016.12.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/14/2016] [Accepted: 12/12/2016] [Indexed: 11/22/2022] Open
Abstract
One of the key research areas surrounding HIV-1 concerns the regulation of the fusion event that occurs between the virus particle and the host cell during entry. Even if it is universally accepted that the large GTPase dynamin-2 is important during HIV-1 entry, its exact role during the first steps of HIV-1 infection is not well characterized. Here, we have utilized a multidisciplinary approach to study the DNM2 role during fusion of HIV-1 in primary resting CD4 T and TZM-bl cells. We have combined advanced light microscopy and functional cell-based assays to experimentally assess the role of dynamin-2 during these processes. Overall, our data suggest that dynamin-2, as a tetramer, might help to establish hemi-fusion and stabilizes the pore during HIV-1 fusion. DNM2 is crucial for HIV-1 fusion in T Cells and reporter cells DNM2 is not necessarily linked with endocytosis DNM2 tetramer stabilizes the HIV-1 fusion pore
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Johannes L. Shiga Toxin-A Model for Glycolipid-Dependent and Lectin-Driven Endocytosis. Toxins (Basel) 2017; 9:toxins9110340. [PMID: 29068384 PMCID: PMC5705955 DOI: 10.3390/toxins9110340] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/15/2017] [Accepted: 10/20/2017] [Indexed: 12/27/2022] Open
Abstract
The cellular entry of the bacterial Shiga toxin and the related verotoxins has been scrutinized in quite some detail. This is due to their importance as a threat to human health. At the same time, the study of Shiga toxin has allowed the discovery of novel molecular mechanisms that also apply to the intracellular trafficking of endogenous proteins at the plasma membrane and in the endosomal system. In this review, the individual steps that lead to Shiga toxin uptake into cells will first be presented from a purely mechanistic perspective. Membrane-biological concepts will be highlighted that are often still poorly explored, such as fluctuation force-driven clustering, clathrin-independent membrane curvature generation, friction-driven scission, and retrograde sorting on early endosomes. It will then be explored whether and how these also apply to other pathogens, pathogenic factors, and cellular proteins. The molecular nature of Shiga toxin as a carbohydrate-binding protein and that of its cellular receptor as a glycosylated raft lipid will be an underlying theme in this discussion. It will thereby be illustrated how the study of Shiga toxin has led to the proposal of the GlycoLipid-Lectin (GL-Lect) hypothesis on the generation of endocytic pits in processes of clathrin-independent endocytosis.
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Affiliation(s)
- Ludger Johannes
- Cellular and Chemical Biology Department, Institut Curie, PSL Research University, U1143 INSERM, UMR3666 CNRS, 26 rue d'Ulm, 75248 Paris CEDEX 05, France.
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Flat clathrin lattices are dynamic actin-controlled hubs for clathrin-mediated endocytosis and signalling of specific receptors. Nat Commun 2017; 8:16068. [PMID: 28703125 PMCID: PMC5511353 DOI: 10.1038/ncomms16068] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 05/18/2017] [Indexed: 11/09/2022] Open
Abstract
Clathrin lattices at the plasma membrane coat both invaginated and flat regions forming clathrin-coated pits and clathrin plaques, respectively. The function and regulation of clathrin-coated pits in endocytosis are well understood but clathrin plaques remain enigmatic nanodomains. Here we use super-resolution microscopy, molecular genetics and cell biology to show that clathrin plaques contain the machinery for clathrin-mediated endocytosis and cell adhesion, and associate with both clathrin-coated pits and filamentous actin. We also find that actin polymerization promoted by N-WASP through the Arp2/3 complex is crucial for the regulation of plaques but not pits. Clathrin plaques oppose cell migration and undergo actin- and N-WASP-dependent disassembly upon activation of LPA receptor 1, but not EGF receptor. Most importantly, plaque disassembly correlates with the endocytosis of LPA receptor 1 and down-modulation of AKT activity. Thus, clathrin plaques serve as dynamic actin-controlled hubs for clathrin-mediated endocytosis and signalling that exhibit receptor specificity.
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Simunovic M, Manneville JB, Renard HF, Evergren E, Raghunathan K, Bhatia D, Kenworthy AK, Voth GA, Prost J, McMahon HT, Johannes L, Bassereau P, Callan-Jones A. Friction Mediates Scission of Tubular Membranes Scaffolded by BAR Proteins. Cell 2017. [PMID: 28648660 PMCID: PMC5576516 DOI: 10.1016/j.cell.2017.05.047] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Membrane scission is essential for intracellular trafficking. While BAR domain proteins such as endophilin have been reported in dynamin-independent scission of tubular membrane necks, the cutting mechanism has yet to be deciphered. Here, we combine a theoretical model, in vitro, and in vivo experiments revealing how protein scaffolds may cut tubular membranes. We demonstrate that the protein scaffold bound to the underlying tube creates a frictional barrier for lipid diffusion; tube elongation thus builds local membrane tension until the membrane undergoes scission through lysis. We call this mechanism friction-driven scission (FDS). In cells, motors pull tubes, particularly during endocytosis. Through reconstitution, we show that motors not only can pull out and extend protein-scaffolded tubes but also can cut them by FDS. FDS is generic, operating even in the absence of amphipathic helices in the BAR domain, and could in principle apply to any high-friction protein and membrane assembly.
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Affiliation(s)
- Mijo Simunovic
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC University Paris 06, 75005 Paris, France; Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago, 5735 S. Ellis Avenue, Chicago, IL 60637, USA
| | - Jean-Baptiste Manneville
- Subcellular Structure and Cellular Dynamics Unit, Institut Curie, PSL Research University, CNRS UMR144, 75005 Paris, France
| | - Henri-François Renard
- Chemical Biology of Membranes and Therapeutic Delivery Unit, Institut Curie, PSL Research University, CNRS UMR3666, INSERM U1143, 75005 Paris, France
| | - Emma Evergren
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; Centre for Cancer Research and Cell Biology, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Krishnan Raghunathan
- Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, 718 Light Hall, Nashville, TN 37232, USA
| | - Dhiraj Bhatia
- Chemical Biology of Membranes and Therapeutic Delivery Unit, Institut Curie, PSL Research University, CNRS UMR3666, INSERM U1143, 75005 Paris, France
| | - Anne K Kenworthy
- Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, 718 Light Hall, Nashville, TN 37232, USA
| | - Gregory A Voth
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago, 5735 S. Ellis Avenue, Chicago, IL 60637, USA
| | - Jacques Prost
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC University Paris 06, 75005 Paris, France; Mechanobiology Institute, National University of Singapore, Singapore 119077, Singapore
| | - Harvey T McMahon
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Ludger Johannes
- Chemical Biology of Membranes and Therapeutic Delivery Unit, Institut Curie, PSL Research University, CNRS UMR3666, INSERM U1143, 75005 Paris, France
| | - Patricia Bassereau
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC University Paris 06, 75005 Paris, France.
| | - Andrew Callan-Jones
- Laboratoire Matière et Systèmes Complexes, CNRS UMR7057, 75205 Paris, France.
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Mordue KE, Hawley BR, Satchwell TJ, Toye AM. CD47 surface stability is sensitive to actin disruption prior to inclusion within the band 3 macrocomplex. Sci Rep 2017; 7:2246. [PMID: 28533511 PMCID: PMC5440412 DOI: 10.1038/s41598-017-02356-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/10/2017] [Indexed: 02/04/2023] Open
Abstract
CD47 is an important 'marker of self' protein with multiple isoforms produced though alternative splicing that exhibit tissue-specific expression. Mature erythrocytes express CD47 isoform 2 only, with membrane stability of this version dependent on inclusion within the band 3 macrocomplex, via protein 4.2. At present a paucity of information exists regarding the associations and trafficking of the CD47 isoforms during erythropoiesis. We show that CD47 isoform 2 is the predominant version maintained at the surface of expanding and terminally differentiating erythroblasts. CD47 isoforms 3 and 4 are expressed in all cell types tested except mature erythrocytes, but do not reach the plasma membrane in erythroblasts and are degraded by the orthochromatic stage of differentiation. To identify putative CD47 interactants, immunoprecipitation combined with Nano LC-MS/MS mass spectrometry was conducted on the erythroleukaemic K562 cell line, expanding and terminally differentiating primary erythroblasts and mature erythrocytes. Results indicate that prior to incorporation into the band 3 macrocomplex, CD47 associates with actin-binding proteins and we confirm that CD47 membrane stability is sensitive to actin disrupting drugs. Maintenance of CD47 at the cell surface was also influenced by dynamin, with sensitivity to dynamin disruption prolonged relative to that of actin during erythropoiesis.
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Affiliation(s)
- Kathryn E Mordue
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, United Kingdom
- Bristol Institute of Transfusion Sciences, NHSBT, Filton, BS34 7QH, United Kingdom
| | - Bethan R Hawley
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, United Kingdom
- Bristol Institute of Transfusion Sciences, NHSBT, Filton, BS34 7QH, United Kingdom
- National Institute for Health Research (NIHR) Blood and Transplant Unit in Red Blood Cell Products at the University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Timothy J Satchwell
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, United Kingdom
- Bristol Institute of Transfusion Sciences, NHSBT, Filton, BS34 7QH, United Kingdom
- National Institute for Health Research (NIHR) Blood and Transplant Unit in Red Blood Cell Products at the University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ashley M Toye
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, United Kingdom.
- Bristol Institute of Transfusion Sciences, NHSBT, Filton, BS34 7QH, United Kingdom.
- National Institute for Health Research (NIHR) Blood and Transplant Unit in Red Blood Cell Products at the University of Bristol, Bristol, BS8 1TD, United Kingdom.
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45
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Stamatovic SM, Johnson AM, Sladojevic N, Keep RF, Andjelkovic AV. Endocytosis of tight junction proteins and the regulation of degradation and recycling. Ann N Y Acad Sci 2017; 1397:54-65. [PMID: 28415156 DOI: 10.1111/nyas.13346] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 12/31/2022]
Abstract
Internalization of tight junction (TJ) proteins from the plasma membrane is a pivotal mechanism regulating TJ plasticity and function in both epithelial and endothelial barrier tissues. Once internalized, the TJ proteins enter complex vesicular machinery, where further trafficking is directly dependent on the initiating stimulus and downstream signaling pathways that regulate the sorting and destiny of TJ proteins, as well as on cell and barrier responses. The destiny of internalized TJ proteins is recycling to the plasma membrane or sorting to late endosomes and degradation. This review highlights recent advances in our knowledge of endocytosis and vesicular trafficking of TJ proteins in both epithelial and endothelial cells. A greater understanding of these processes may allow for the development of methods to modulate barrier permeability for drug delivery or prevent barrier dysfunction in disease states.
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Affiliation(s)
| | | | | | - Richard F Keep
- Neurosurgery.,Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
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46
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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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47
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Marzook NB, Newsome TP. Viruses That Exploit Actin-Based Motility for Their Replication and Spread. Handb Exp Pharmacol 2016; 235:237-261. [PMID: 27757755 DOI: 10.1007/164_2016_41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The actin cytoskeleton is a crucial part of the eukaryotic cell. Viruses depend on host cells for their replication, and, as a result, many have developed ways of manipulating the actin network to promote their spread. This chapter reviews the various ways in which viruses utilize the actin cytoskeleton at discrete steps in their life cycle, from entry into the host cell, replication, and assembly of new progeny to virus release. Various actin inhibitors that function in different ways to affect proper actin dynamics can be used to parse the role of actin at these steps.
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Affiliation(s)
- N Bishara Marzook
- The School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Timothy P Newsome
- The School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.
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Abstract
Cancer diagnosis and therapy is steadily improving. Still, diagnosis is frequently late and diagnosis and follow-up procedures mostly are time-consuming and expensive. Searching for tumor-derived exosomes (TEX) in body fluids may provide an alternative, minimally invasive, yet highly reliable diagnostic tool. Beyond this, there is strong evidence that TEX could become a potent therapeutics. Exosomes, small vesicles delivered by many cells of the organism, are found in all body fluids. Exosomes are characterized by lipid composition, common and donor cell specific proteins, mRNA, small non-coding RNA including miRNA and DNA. Particularly the protein and miRNA markers received much attention as they may allow for highly specific diagnosis and can provide hints toward tumor aggressiveness and progression, where exosome-based diagnosis and follow-up is greatly facilitated by the recovery of exosomes in body fluids, particularly the peripheral blood. Beyond this, exosomes are the most important intercellular communicators that modulate, instruct, and reprogram their surrounding as well as distant organs. In concern about TEX this includes message transfer from tumor cells toward the tumor stroma, the premetastatic niche, the hematopoietic system and, last but not least, the instruction of non-cancer stem cells by cancer-initiating cells (CIC). Taking this into account, it becomes obvious that "tailored" exosomes offer themselves as potent therapeutic delivery system. In brief, during the last 4-5 years there is an ever-increasing, overwhelming interest in exosome research. This boom appears fully justified provided the content of the exosomes becomes most thoroughly analyzed and their mode of intercellular interaction can be unraveled in detail as this knowledge will open new doors toward cancer diagnosis and therapy including immunotherapy and CIC reprogramming.
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Affiliation(s)
- Margot Zöller
- Tumor Cell Biology, University Hospital of Surgery, im Neuenheimer Feld 365, 69120, Heidelberg, Germany.
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49
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Lampe M, Vassilopoulos S, Merrifield C. Clathrin coated pits, plaques and adhesion. J Struct Biol 2016; 196:48-56. [DOI: 10.1016/j.jsb.2016.07.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 07/11/2016] [Accepted: 07/13/2016] [Indexed: 11/27/2022]
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50
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Boye TL, Nylandsted J. Annexins in plasma membrane repair. Biol Chem 2016; 397:961-9. [DOI: 10.1515/hsz-2016-0171] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/14/2016] [Indexed: 01/01/2023]
Abstract
Abstract
Disruption of the plasma membrane poses deadly threat to eukaryotic cells and survival requires a rapid membrane repair system. Recent evidence reveal various plasma membrane repair mechanisms, which are required for cells to cope with membrane lesions including membrane fusion and replacement strategies, remodeling of cortical actin cytoskeleton and vesicle wound patching. Members of the annexin protein family, which are Ca2+-triggered phospholipid-binding proteins emerge as important components of the plasma membrane repair system. Here, we discuss the mechanisms of plasma membrane repair involving annexins spanning from yeast to human cancer cells.
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