51
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Moulay G, Lainé J, Lemaître M, Nakamori M, Nishino I, Caillol G, Mamchaoui K, Julien L, Dingli F, Loew D, Bitoun M, Leterrier C, Furling D, Vassilopoulos S. Alternative splicing of clathrin heavy chain contributes to the switch from coated pits to plaques. J Cell Biol 2021; 219:151930. [PMID: 32642759 PMCID: PMC7480091 DOI: 10.1083/jcb.201912061] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/14/2020] [Accepted: 05/15/2020] [Indexed: 12/18/2022] Open
Abstract
Clathrin function directly derives from its coat structure, and while endocytosis is mediated by clathrin-coated pits, large plaques contribute to cell adhesion. Here, we show that the alternative splicing of a single exon of the clathrin heavy chain gene (CLTC exon 31) helps determine the clathrin coat organization. Direct genetic control was demonstrated by forced CLTC exon 31 skipping in muscle cells that reverses the plasma membrane content from clathrin plaques to pits and by promoting exon inclusion that stimulated flat plaque assembly. Interestingly, mis-splicing of CLTC exon 31 found in the severe congenital form of myotonic dystrophy was associated with reduced plaques in patient myotubes. Moreover, forced exclusion of this exon in WT mice muscle induced structural disorganization and reduced force, highlighting the contribution of this splicing event for the maintenance of tissue homeostasis. This genetic control on clathrin assembly should influence the way we consider how plasticity in clathrin-coated structures is involved in muscle development and maintenance.
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Affiliation(s)
- Gilles Moulay
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France
| | - Jeanne Lainé
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France.,Sorbonne Université, Department of Physiology, Pitié-Salpêtrière Hospital, Paris, France
| | - Mégane Lemaître
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Phénotypage du petit animal - UMS 28, Paris, France
| | - Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Ghislaine Caillol
- Aix Marseille Université, Centre National de la Recherche Scientifique, NeuroCyto, Marseille, France
| | - Kamel Mamchaoui
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France
| | - Laura Julien
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France
| | - Florent Dingli
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Paris, France
| | - Damarys Loew
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, Paris, France
| | - Marc Bitoun
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France
| | - Christophe Leterrier
- Aix Marseille Université, Centre National de la Recherche Scientifique, NeuroCyto, Marseille, France
| | - Denis Furling
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France
| | - Stéphane Vassilopoulos
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS 974, Paris, France
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52
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Chen Z, Mino RE, Mettlen M, Michaely P, Bhave M, Reed DK, Schmid SL. Wbox2: A clathrin terminal domain-derived peptide inhibitor of clathrin-mediated endocytosis. J Cell Biol 2021; 219:151850. [PMID: 32520988 PMCID: PMC7480105 DOI: 10.1083/jcb.201908189] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 12/03/2019] [Accepted: 05/14/2020] [Indexed: 12/11/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) occurs via the formation of clathrin-coated vesicles from clathrin-coated pits (CCPs). Clathrin is recruited to CCPs through interactions between the AP2 complex and its N-terminal domain, which in turn recruits endocytic accessory proteins. Inhibitors of CME that interfere with clathrin function have been described, but their specificity and mechanisms of action are unclear. Here we show that overexpression of the N-terminal domain with (TDD) or without (TD) the distal leg inhibits CME and CCP dynamics by perturbing clathrin interactions with AP2 and SNX9. TDD overexpression does not affect clathrin-independent endocytosis or, surprisingly, AP1-dependent lysosomal trafficking from the Golgi. We designed small membrane–permeant peptides that encode key functional residues within the four known binding sites on the TD. One peptide, Wbox2, encoding residues along the W-box motif binding surface, binds to SNX9 and AP2 and potently and acutely inhibits CME.
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Affiliation(s)
- Zhiming Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Rosa E Mino
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Peter Michaely
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Madhura Bhave
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Dana Kim Reed
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, TX
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53
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Ma R, Berro J. Endocytosis against high turgor pressure is made easier by partial coating and freely rotating base. Biophys J 2021; 120:1625-1640. [PMID: 33675763 DOI: 10.1016/j.bpj.2021.02.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 01/27/2021] [Accepted: 02/11/2021] [Indexed: 02/02/2023] Open
Abstract
During clathrin-mediated endocytosis, a patch of flat plasma membrane is deformed into a vesicle. In walled cells, such as plants and fungi, the turgor pressure is high and pushes the membrane against the cell wall, thus hindering membrane internalization. In this work, we study how a patch of membrane is deformed against turgor pressure by force and by curvature-generating proteins. We show that a large amount of force is needed to merely start deforming the membrane and an even larger force is needed to pull a membrane tube. The magnitude of these forces strongly depends on how the base of the membrane is constrained and how the membrane is coated with curvature-generating proteins. In particular, these forces can be reduced by partially, but not fully, coating the membrane patch with curvature-generating proteins. Our theoretical results show excellent agreement with experimental data.
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Affiliation(s)
- Rui Ma
- Department of Physics, Xiamen University, Xiamen, China; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut; Nanobiology Institute, Yale University, West Haven, Connecticut.
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut; Nanobiology Institute, Yale University, West Haven, Connecticut; Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut.
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54
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Han Z, Hao X, Zhou CJ, Wang J, Wen X, Wang XY, Zhang DJ, Liang CG. Clathrin Heavy Chain 1 Plays Essential Roles During Oocyte Meiotic Spindle Formation and Early Embryonic Development in Sheep. Front Cell Dev Biol 2021; 9:609311. [PMID: 33718352 PMCID: PMC7946971 DOI: 10.3389/fcell.2021.609311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/28/2021] [Indexed: 11/24/2022] Open
Abstract
As a major protein of the polyhedral coat of coated pits and vesicles, clathrin molecules have been shown to play a stabilization role for kinetochore fibers of the mitotic spindle by acting as inter-microtubule bridges. Clathrin heavy chain 1 (CLTC), the basic subunit of the clathrin coat, plays vital roles in both spindle assembly and chromosome congression during somatic-cell mitosis. However, its function in oocyte meiotic maturation and early embryo development in mammals, especially in domesticated animals, has not been fully investigated. In this study, the expression profiles and functional roles of CLTC in sheep oocytes were investigated. Our results showed that the expression of CLTC was maintained at a high level from the germinal vesicle (GV) stage to metaphase II stage and that CLTC was distributed diffusely in the cytoplasm of cells at interphase, from the GV stage to the blastocyst stage. After GV breakdown (GVBD), CLTC co-localized with beta-tubulin during metaphase. Oocyte treatments with taxol, nocodazole, or cold did not affect CLTC expression levels but led to disorders of its distribution. Functional impairment of CLTC by specific morpholino injections in GV-stage oocytes led to disruptions in spindle assembly and chromosomal alignment, accompanied by impaired first polar body (PB1) emissions. In addition, knockdown of CLTC before parthenogenetic activation disrupted spindle formation and impaired early embryo development. Taken together, the results demonstrate that CLTC plays a vital role in sheep oocyte maturation via the regulation of spindle dynamics and an essential role during early embryo development.
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Affiliation(s)
- Zhe Han
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xin Hao
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Cheng-Jie Zhou
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Jun Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xin Wen
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xing-Yue Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - De-Jian Zhang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Cheng-Guang Liang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
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55
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Networks of interacting proteins contribute to membrane curvature sensing. Biophys J 2021; 120:752-753. [PMID: 33571433 DOI: 10.1016/j.bpj.2021.01.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/10/2021] [Accepted: 01/26/2021] [Indexed: 11/24/2022] Open
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56
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Clathrin senses membrane curvature. Biophys J 2021; 120:818-828. [PMID: 33524373 DOI: 10.1016/j.bpj.2020.12.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 11/21/2022] Open
Abstract
The ability of proteins to assemble at sites of high membrane curvature is essential to diverse membrane remodeling processes, including clathrin-mediated endocytosis. Multiple adaptor proteins within the clathrin pathway have been shown to sense regions of high membrane curvature, leading to local recruitment of the clathrin coat. Because clathrin triskelia do not bind to the membrane directly, it has remained unclear whether the clathrin coat plays an active role in sensing membrane curvature or is passively recruited by adaptor proteins. Using a synthetic tag to assemble clathrin directly on membrane surfaces, here we show that clathrin is a strong sensor of membrane curvature, comparable with previously studied adaptor proteins. Interestingly, this sensitivity arises from clathrin assembly rather than from the properties of unassembled triskelia, suggesting that triskelia have preferred angles of interaction, as predicted by earlier structural data. Furthermore, when clathrin is recruited by adaptors, its curvature sensitivity is amplified by 2- to 10-fold, such that the resulting protein complex is up to 100 times more likely to assemble on a highly curved surface compared with a flatter one. This exquisite sensitivity points to a synergistic relationship between the coat and its adaptor proteins, which enables clathrin to pinpoint sites of high membrane curvature, an essential step in ensuring robust membrane traffic. More broadly, these findings suggest that protein networks, rather than individual protein domains, are likely the most potent drivers of membrane curvature sensing.
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57
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Moo EV, van Senten JR, Bräuner-Osborne H, Møller TC. Arrestin-Dependent and -Independent Internalization of G Protein-Coupled Receptors: Methods, Mechanisms, and Implications on Cell Signaling. Mol Pharmacol 2021; 99:242-255. [PMID: 33472843 DOI: 10.1124/molpharm.120.000192] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/07/2021] [Indexed: 01/05/2023] Open
Abstract
Agonist-induced endocytosis is a key regulatory mechanism for controlling the responsiveness of the cell by changing the density of cell surface receptors. In addition to the role of endocytosis in signal termination, endocytosed G protein-coupled receptors (GPCRs) have been found to signal from intracellular compartments of the cell. Arrestins are generally believed to be the master regulators of GPCR endocytosis by binding to both phosphorylated receptors and adaptor protein 2 (AP-2) or clathrin, thus recruiting receptors to clathrin-coated pits to facilitate the internalization process. However, many other functions have been described for arrestins that do not relate to their role in terminating signaling. Additionally, there are now more than 30 examples of GPCRs that internalize independently of arrestins. Here we review the methods, pharmacological tools, and cellular backgrounds used to determine the role of arrestins in receptor internalization, highlighting their advantages and caveats. We also summarize key examples of arrestin-independent GPCR endocytosis in the literature and their suggested alternative endocytosis pathway (e.g., the caveolae-dependent and fast endophilin-mediated endocytosis pathways). Finally, we consider the possible function of arrestins recruited to GPCRs that are endocytosed independently of arrestins, including the catalytic arrestin activation paradigm. Technological improvements in recent years have advanced the field further, and, combined with the important implications of endocytosis on drug responses, this makes endocytosis an obvious parameter to include in molecular pharmacological characterization of ligand-GPCR interactions. SIGNIFICANCE STATEMENT: G protein-coupled receptor (GPCR) endocytosis is an important means to terminate receptor signaling, and arrestins play a central role in the widely accepted classical paradigm of GPCR endocytosis. In contrast to the canonical arrestin-mediated internalization, an increasing number of GPCRs are found to be endocytosed via alternate pathways, and the process appears more diverse than the previously defined "one pathway fits all."
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Affiliation(s)
- Ee Von Moo
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Jeffrey R van Senten
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Thor C Møller
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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58
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Frey F, Schwarz US. Competing pathways for the invagination of clathrin-coated membranes. SOFT MATTER 2020; 16:10723-10733. [PMID: 33107553 DOI: 10.1039/d0sm01375g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Clathrin-mediated endocytosis is the major pathway by which eukaryotic cells take up extracellular material, but it is still elusive which physical pathways are being taken during membrane invagination. From a continuum point of view, it can be driven by increases in coat stiffness, preferred curvature or line tension. Here we develop a comprehensive theoretical framework that can be solved analytically and that predicts the consequences of these different scenarios. We find that for the case of increasing stiffness or preferred curvature, curvature will be acquired gradually with growth, while for increasing line tension, the lattice must have grown to a certain size before a flat-to-curved transition can occur. At low membrane tension, the critical value for coat stiffness is 30 kBT, for preferred curvature it is 200 nm, and for line tension it is 6 pN. For high membrane tension, critical coat stiffness is 150 kBT and critical preferred curvature is 70 nm. In the mixed case when a coat with finite rigidity but increasing line tension is considered, a cup-to-sphere transition can occur for a line tension of 6 pN. The flat-to-curved and the cup-to-sphere transitions driven by line tension are both suppressed by high membrane tension.
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Affiliation(s)
- Felix Frey
- Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120 Heidelberg, Germany.
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59
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Rueda-Gensini L, Cifuentes J, Castellanos MC, Puentes PR, Serna JA, Muñoz-Camargo C, Cruz JC. Tailoring Iron Oxide Nanoparticles for Efficient Cellular Internalization and Endosomal Escape. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1816. [PMID: 32932957 PMCID: PMC7559083 DOI: 10.3390/nano10091816] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/05/2020] [Accepted: 09/07/2020] [Indexed: 12/16/2022]
Abstract
Iron oxide nanoparticles (IONs) have been widely explored for biomedical applications due to their high biocompatibility, surface-coating versatility, and superparamagnetic properties. Upon exposure to an external magnetic field, IONs can be precisely directed to a region of interest and serve as exceptional delivery vehicles and cellular markers. However, the design of nanocarriers that achieve an efficient endocytic uptake, escape lysosomal degradation, and perform precise intracellular functions is still a challenge for their application in translational medicine. This review highlights several aspects that mediate the activation of the endosomal pathways, as well as the different properties that govern endosomal escape and nuclear transfection of magnetic IONs. In particular, we review a variety of ION surface modification alternatives that have emerged for facilitating their endocytic uptake and their timely escape from endosomes, with special emphasis on how these can be manipulated for the rational design of cell-penetrating vehicles. Moreover, additional modifications for enhancing nuclear transfection are also included in the design of therapeutic vehicles that must overcome this barrier. Understanding these mechanisms opens new perspectives in the strategic development of vehicles for cell tracking, cell imaging and the targeted intracellular delivery of drugs and gene therapy sequences and vectors.
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Affiliation(s)
- Laura Rueda-Gensini
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
| | - Javier Cifuentes
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
| | - Maria Claudia Castellanos
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
| | - Paola Ruiz Puentes
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
| | - Julian A. Serna
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
| | - Carolina Muñoz-Camargo
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
| | - Juan C. Cruz
- Department of Biomedical Engineering, School of Engineering, Universidad de Los Andes, Carrera 1 No. 18A-12, 111711 Bogotá, Colombia; (L.R.-G.); (J.C.); (M.C.C.); (P.R.P.); (J.A.S.)
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide 5005, Australia
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60
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Clathrin light chain diversity regulates membrane deformation in vitro and synaptic vesicle formation in vivo. Proc Natl Acad Sci U S A 2020; 117:23527-23538. [PMID: 32907943 PMCID: PMC7519287 DOI: 10.1073/pnas.2003662117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
This study reveals that diversity of clathrin light chain (CLC) subunits alters clathrin properties and demonstrates that the two neuronal CLC subunits work together for optimal clathrin function in synaptic vesicle formation. Our findings establish a role for CLC diversity in synaptic transmission and illustrate how CLC variability expands the complexity of clathrin to serve tissue-specific functions. Clathrin light chain (CLC) subunits in vertebrates are encoded by paralogous genes CLTA and CLTB, and both gene products are alternatively spliced in neurons. To understand how this CLC diversity influences neuronal clathrin function, we characterized the biophysical properties of clathrin comprising individual CLC variants for correlation with neuronal phenotypes of mice lacking either CLC-encoding gene. CLC splice variants differentially influenced clathrin knee conformation within assemblies, and clathrin with neuronal CLC mixtures was more effective in membrane deformation than clathrin with single neuronal isoforms nCLCa or nCLCb. Correspondingly, electrophysiological recordings revealed that neurons from mice lacking nCLCa or nCLCb were both defective in synaptic vesicle replenishment. Mice with only nCLCb had a reduced synaptic vesicle pool and impaired neurotransmission compared to WT mice, while nCLCa-only mice had increased synaptic vesicle numbers, restoring normal neurotransmission. These findings highlight differences between the CLC isoforms and show that isoform mixing influences tissue-specific clathrin activity in neurons, which requires their functional balance.
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61
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Sakthivel NA, Shabaninezhad M, Sementa L, Yoon B, Stener M, Whetten RL, Ramakrishna G, Fortunelli A, Landman U, Dass A. The Missing Link: Au191(SPh-tBu)66 Janus Nanoparticle with Molecular and Bulk-Metal-like Properties. J Am Chem Soc 2020; 142:15799-15814. [DOI: 10.1021/jacs.0c05685] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Naga Arjun Sakthivel
- Department of Chemistry and Biochemistry, University of Mississippi, Oxford, Mississippi 38677, United States
| | - Masoud Shabaninezhad
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008, United States
| | - Luca Sementa
- CNR-ICCOM & IPCF, Consiglio Nazionale delle Ricerche, Pisa I-56124, Italy
| | - Bokwon Yoon
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Mauro Stener
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Trieste I-34127, Italy
| | - Robert L. Whetten
- Department of Applied Physics and Materials Science, Northern Arizona University, Flagstaff, Arizona 86011, United States
| | - Guda Ramakrishna
- Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States
| | | | - Uzi Landman
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Amala Dass
- Department of Chemistry and Biochemistry, University of Mississippi, Oxford, Mississippi 38677, United States
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62
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Kovtun O, Dickson VK, Kelly BT, Owen DJ, Briggs JAG. Architecture of the AP2/clathrin coat on the membranes of clathrin-coated vesicles. SCIENCE ADVANCES 2020; 6:eaba8381. [PMID: 32743075 PMCID: PMC7375805 DOI: 10.1126/sciadv.aba8381] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/17/2020] [Indexed: 05/19/2023]
Abstract
Clathrin-mediated endocytosis (CME) is crucial for modulating the protein composition of a cell's plasma membrane. Clathrin forms a cage-like, polyhedral outer scaffold around a vesicle, to which cargo-selecting clathrin adaptors are attached. Adaptor protein complex (AP2) is the key adaptor in CME. Crystallography has shown AP2 to adopt a range of conformations. Here, we used cryo-electron microscopy, tomography, and subtomogram averaging to determine structures, interactions, and arrangements of clathrin and AP2 at the key steps of coat assembly, from AP2 in solution to membrane-assembled clathrin-coated vesicles (CCVs). AP2 binds cargo and PtdIns(4,5)P 2 (phosphatidylinositol 4,5-bisphosphate)-containing membranes via multiple interfaces, undergoing conformational rearrangement from its cytosolic state. The binding mode of AP2 β2 appendage into the clathrin lattice in CCVs and buds implies how the adaptor structurally modulates coat curvature and coat disassembly.
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Affiliation(s)
- Oleksiy Kovtun
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg , Germany
| | - Veronica Kane Dickson
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Bernard T. Kelly
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
- Corresponding author. (B.T.K.); (D.J.O.); (J.A.G.B.)
| | - David J. Owen
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
- Corresponding author. (B.T.K.); (D.J.O.); (J.A.G.B.)
| | - John A. G. Briggs
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg , Germany
- Corresponding author. (B.T.K.); (D.J.O.); (J.A.G.B.)
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63
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Paraan M, Mendez J, Sharum S, Kurtin D, He H, Stagg SM. The structures of natively assembled clathrin-coated vesicles. SCIENCE ADVANCES 2020; 6:eaba8397. [PMID: 32743076 PMCID: PMC7375819 DOI: 10.1126/sciadv.aba8397] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 06/05/2020] [Indexed: 05/19/2023]
Abstract
Clathrin-coated vesicles mediate trafficking of proteins and nutrients in the cell and between organelles. Proteins included in the clathrin-coated vesicles (CCVs) category include clathrin heavy chain (CHC), clathrin light chain (CLC), and a variety of adaptor protein complexes. Much is known about the structures of the individual CCV components, but data are lacking about the structures of the fully assembled complexes together with membrane and in complex with cargo. Here, we determined the structures of natively assembled CCVs in a variety of geometries. We show that the adaptor β2 appendages crosslink adjacent CHC β-propellers and that the appendage densities are enriched in CCV hexagonal faces. We resolve how adaptor protein 2 and other associated factors in hexagonal faces form an assembly hub with an extensive web of interactions between neighboring β-propellers and propose a structural model that explains how adaptor binding can direct the formation of pentagonal and hexagonal faces.
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Affiliation(s)
- Mohammadreza Paraan
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - Joshua Mendez
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, FL 32306, USA
| | - Savanna Sharum
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - Danielle Kurtin
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - Huan He
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - Scott M. Stagg
- Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA
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Mazur E, Gallei M, Adamowski M, Han H, Robert HS, Friml J. Clathrin-mediated trafficking and PIN trafficking are required for auxin canalization and vascular tissue formation in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 293:110414. [PMID: 32081263 DOI: 10.1016/j.plantsci.2020.110414] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 06/10/2023]
Abstract
The flexible development of plants is characterized by a high capacity for post-embryonic organ formation and tissue regeneration, processes, which require tightly regulated intercellular communication and coordinated tissue (re-)polarization. The phytohormone auxin, the main driver for these processes, is able to establish polarized auxin transport channels, which are characterized by the expression and polar, subcellular localization of the PIN1 auxin transport proteins. These channels are demarcating the position of future vascular strands necessary for organ formation and tissue regeneration. Major progress has been made in the last years to understand how PINs can change their polarity in different contexts and thus guide auxin flow through the plant. However, it still remains elusive how auxin mediates the establishment of auxin conducting channels and the formation of vascular tissue and which cellular processes are involved. By the means of sophisticated regeneration experiments combined with local auxin applications in Arabidopsis thaliana inflorescence stems we show that (i) PIN subcellular dynamics, (ii) PIN internalization by clathrin-mediated trafficking and (iii) an intact actin cytoskeleton required for post-endocytic trafficking are indispensable for auxin channel formation, de novo vascular formation and vascular regeneration after wounding. These observations provide novel insights into cellular mechanism of coordinated tissue polarization during auxin canalization.
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Affiliation(s)
- Ewa Mazur
- Faculty of Natural Sciences, Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Jagiellońska 28, 40-032 Katowice, Poland; Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
| | - Michelle Gallei
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria
| | - Maciek Adamowski
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria
| | - Huibin Han
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria
| | - Hélène S Robert
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic
| | - Jiří Friml
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria.
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65
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Osuna-Pérez J, García-Ferreras R, Veiga E. From cellular microbiology to bacteria-based next generations of cancer immunotherapies. Cell Microbiol 2020; 22:e13187. [PMID: 32185897 DOI: 10.1111/cmi.13187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 12/24/2022]
Abstract
Pioneer work by Prof. Cossart among others, studying the interactions between pathogenic bacteria and host cells (this discipline was termed Cellular Microbiology), was fundamental to determine the bacterial infection processes and to improve our knowledge of different cellular mechanisms. The study of bacteria-host interactions also involves in vivo host immune responses, which can be manipulated by bacteria, being these last potent tools for different immunotherapies. During the last years, tumour immunotherapies, mainly the use of antibodies that target immune checkpoints [checkpoint inhibitors (CPI)], have been a revolution in oncology, allowing the treatment of tumours otherwise with very bad prognosis. In the same direction, bacteria inoculations have been used from long to treat some cancers; for example, non-muscle-invasive bladder cancer can be successfully treated with the bacterium Bacillus Calmette Guerin (BCG). More recently, it has been shown that microbiota could determine the success of CPI immunotherapies and intense research is being performed in order to use bacteria as immunotherapy tools due to their ability to activate the immune system. In this context, to expand the knowledge of the bacteria-immune system interactions will be fundamental to improve tumour immunotherapies.
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Affiliation(s)
- Jesús Osuna-Pérez
- Department of Molecular & Cellular Biology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Raquel García-Ferreras
- Department of Molecular & Cellular Biology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Esteban Veiga
- Department of Molecular & Cellular Biology, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
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66
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Rosenzweig R, Nillegoda NB, Mayer MP, Bukau B. The Hsp70 chaperone network. Nat Rev Mol Cell Biol 2020; 20:665-680. [PMID: 31253954 DOI: 10.1038/s41580-019-0133-3] [Citation(s) in RCA: 639] [Impact Index Per Article: 159.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The 70-kDa heat shock proteins (Hsp70s) are ubiquitous molecular chaperones that act in a large variety of cellular protein folding and remodelling processes. They function virtually at all stages of the life of proteins from synthesis to degradation and are thus crucial for maintaining protein homeostasis, with direct implications for human health. A large set of co-chaperones comprising J-domain proteins and nucleotide exchange factors regulate the ATPase cycle of Hsp70s, which is allosterically coupled to substrate binding and release. Moreover, Hsp70s cooperate with other cellular chaperone systems including Hsp90, Hsp60 chaperonins, small heat shock proteins and Hsp100 AAA+ disaggregases, together constituting a dynamic and functionally versatile network for protein folding, unfolding, regulation, targeting, aggregation and disaggregation, as well as degradation. In this Review we describe recent advances that have increased our understanding of the molecular mechanisms and working principles of the Hsp70 network. This knowledge showcases how the Hsp70 chaperone system controls diverse cellular functions, and offers new opportunities for the development of chemical compounds that modulate disease-related Hsp70 activities.
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Affiliation(s)
- Rina Rosenzweig
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
| | - Nadinath B Nillegoda
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany.,DKFZ-ZMBH Alliance, Heidelberg, Germany.,Australian Regenerative Medicine Institute (ARMI), Monash University, Clayton, VIC, Australia
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.,DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany. .,German Cancer Research Center (DKFZ), Heidelberg, Germany. .,DKFZ-ZMBH Alliance, Heidelberg, Germany.
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67
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Faust O, Rosenzweig R. Structural and Biochemical Properties of Hsp40/Hsp70 Chaperone System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1243:3-20. [DOI: 10.1007/978-3-030-40204-4_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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68
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Francia V, Montizaan D, Salvati A. Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:338-353. [PMID: 32117671 PMCID: PMC7034226 DOI: 10.3762/bjnano.11.25] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/27/2020] [Indexed: 05/17/2023]
Abstract
Nano-sized materials have great potential as drug carriers for nanomedicine applications. Thanks to their size, they can exploit the cellular machinery to enter cells and be trafficked intracellularly, thus they can be used to overcome some of the cellular barriers to drug delivery. Nano-sized drug carriers of very different properties can be prepared, and their surface can be modified by the addition of targeting moieties to recognize specific cells. However, it is still difficult to understand how the material properties affect the subsequent interactions and outcomes at cellular level. As a consequence of this, designing targeted drugs remains a major challenge in drug delivery. Within this context, we discuss the current understanding of the initial steps in the interactions of nano-sized materials with cells in relation to nanomedicine applications. In particular, we focus on the difficult interplay between the initial adhesion of nano-sized materials to the cell surface, the potential recognition by cell receptors, and the subsequent mechanisms cells use to internalize them. The factors affecting these initial events are discussed. Then, we briefly describe the different pathways of endocytosis in cells and illustrate with some examples the challenges in understanding how nanomaterial properties, such as size, charge, and shape, affect the mechanisms cells use for their internalization. Technical difficulties in characterizing these mechanisms are presented. A better understanding of the first interactions of nano-sized materials with cells will help to design nanomedicines with improved targeting.
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Affiliation(s)
- Valentina Francia
- Groningen Research Institute of Pharmacy, University of Groningen, 9713AV Groningen, Netherlands
| | - Daphne Montizaan
- Groningen Research Institute of Pharmacy, University of Groningen, 9713AV Groningen, Netherlands
| | - Anna Salvati
- Groningen Research Institute of Pharmacy, University of Groningen, 9713AV Groningen, Netherlands
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69
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De novo CLTC variants are associated with a variable phenotype from mild to severe intellectual disability, microcephaly, hypoplasia of the corpus callosum, and epilepsy. Genet Med 2019; 22:797-802. [PMID: 31776469 DOI: 10.1038/s41436-019-0703-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/14/2019] [Accepted: 11/06/2019] [Indexed: 12/20/2022] Open
Abstract
PURPOSE To delineate the genotype-phenotype correlation in individuals with likely pathogenic variants in the CLTC gene. METHODS We describe 13 individuals with de novo CLTC variants. Causality of variants was determined by using the tolerance landscape of CLTC and computer-assisted molecular modeling where applicable. Phenotypic abnormalities observed in the individuals identified with missense and in-frame variants were compared with those with nonsense or frameshift variants in CLTC. RESULTS All de novo variants were judged to be causal. Combining our data with that of 14 previously reported affected individuals (n = 27), all had intellectual disability (ID), ranging from mild to moderate/severe, with or without additional neurologic, behavioral, craniofacial, ophthalmologic, and gastrointestinal features. Microcephaly, hypoplasia of the corpus callosum, and epilepsy were more frequently observed in individuals with missense and in-frame variants than in those with nonsense and frameshift variants. However, this difference was not significant. CONCLUSIONS The wide phenotypic variability associated with likely pathogenic CLTC variants seems to be associated with allelic heterogeneity. The detailed clinical characterization of a larger cohort of individuals with pathogenic CLTC variants is warranted to support the hypothesis that missense and in-frame variants exert a dominant-negative effect, whereas the nonsense and frameshift variants would result in haploinsufficiency.
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70
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Travis SM, Kokona B, Fairman R, Hughson FM. Roles of singleton tryptophan motifs in COPI coat stability and vesicle tethering. Proc Natl Acad Sci U S A 2019; 116:24031-24040. [PMID: 31712447 PMCID: PMC6883825 DOI: 10.1073/pnas.1909697116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coat protein I (COPI)-coated vesicles mediate retrograde transport from the Golgi to the endoplasmic reticulum (ER), as well as transport within the Golgi. Major progress has been made in defining the structure of COPI coats, in vitro and in vivo, at resolutions as high as 9 Å. Nevertheless, important questions remain unanswered, including what specific interactions stabilize COPI coats, how COPI vesicles recognize their target membranes, and how coat disassembly is coordinated with vesicle fusion and cargo delivery. Here, we use X-ray crystallography to identify a conserved site on the COPI subunit α-COP that binds to flexible, acidic sequences containing a single tryptophan residue. One such sequence, found within α-COP itself, mediates α-COP homo-oligomerization. Another such sequence is contained within the lasso of the ER-resident Dsl1 complex, where it helps mediate the tethering of Golgi-derived COPI vesicles at the ER membrane. Together, our findings suggest that α-COP homo-oligomerization plays a key role in COPI coat stability, with potential implications for the coordination of vesicle tethering, uncoating, and fusion.
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Affiliation(s)
- Sophie M Travis
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Bashkim Kokona
- Department of Biology, Haverford College, Haverford, PA 19041
- Department of Chemistry, Haverford College, Haverford, PA 19041
| | - Robert Fairman
- Department of Biology, Haverford College, Haverford, PA 19041
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71
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Biancospino M, Buel GR, Niño CA, Maspero E, Scotto di Perrotolo R, Raimondi A, Redlingshöfer L, Weber J, Brodsky FM, Walters KJ, Polo S. Clathrin light chain A drives selective myosin VI recruitment to clathrin-coated pits under membrane tension. Nat Commun 2019; 10:4974. [PMID: 31672988 PMCID: PMC6823378 DOI: 10.1038/s41467-019-12855-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/27/2019] [Indexed: 11/17/2022] Open
Abstract
Clathrin light chains (CLCa and CLCb) are major constituents of clathrin-coated vesicles. Unique functions for these evolutionary conserved paralogs remain elusive, and their role in clathrin-mediated endocytosis in mammalian cells is debated. Here, we find and structurally characterize a direct and selective interaction between CLCa and the long isoform of the actin motor protein myosin VI, which is expressed exclusively in highly polarized tissues. Using genetically-reconstituted Caco-2 cysts as proxy for polarized epithelia, we provide evidence for coordinated action of myosin VI and CLCa at the apical surface where these proteins are essential for fission of clathrin-coated pits. We further find that myosin VI and Huntingtin-interacting protein 1-related protein (Hip1R) are mutually exclusive interactors with CLCa, and suggest a model for the sequential function of myosin VI and Hip1R in actin-mediated clathrin-coated vesicle budding.
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Affiliation(s)
- Matteo Biancospino
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Gwen R Buel
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Carlos A Niño
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Elena Maspero
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | | | - Andrea Raimondi
- Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
| | - Lisa Redlingshöfer
- Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Janine Weber
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Frances M Brodsky
- Division of Biosciences, University College London, London, WC1E 6BT, UK.
| | - Kylie J Walters
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - Simona Polo
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy.
- Dipartimento di Oncologia ed Emato-oncologia, Universita' degli Studi di Milano, 20122, Milan, Italy.
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72
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Cryo-EM of multiple cage architectures reveals a universal mode of clathrin self-assembly. Nat Struct Mol Biol 2019; 26:890-898. [PMID: 31582853 PMCID: PMC7100586 DOI: 10.1038/s41594-019-0292-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/02/2019] [Indexed: 01/10/2023]
Abstract
Clathrin forms diverse lattice and cage structures that change size and shape rapidly in response to the needs of eukaryotic cells during clathrin-mediated endocytosis and intracellular trafficking. We present the cryo-EM structure and molecular model of assembled porcine clathrin, providing insights into interactions that stabilize key elements of the clathrin lattice, namely, between adjacent heavy chains, at the light chain-heavy chain interface and within the trimerization domain. Furthermore, we report cryo-EM maps for five different clathrin cage architectures. Fitting structural models to three of these maps shows that their assembly requires only a limited range of triskelion leg conformations, yet inherent flexibility is required to maintain contacts. Analysis of the protein-protein interfaces shows remarkable conservation of contact sites despite architectural variation. These data reveal a universal mode of clathrin assembly that allows variable cage architecture and adaptation of coated vesicle size and shape during clathrin-mediated vesicular trafficking or endocytosis.
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73
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The application of atomic force microscopy for viruses and protein shells: Imaging and spectroscopy. Adv Virus Res 2019; 105:161-187. [PMID: 31522704 DOI: 10.1016/bs.aivir.2019.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Atomic force microscopy (AFM) probes surface-adsorbed samples at the nanoscale by using a sharp stylus of nanometric size located at the end of a micro-cantilever. This technique can also work in a liquid environment and offers unique possibilities to study individual protein assemblies, such as viruses, under conditions that resemble their natural liquid milieu. Here, I show how AFM can be used to explore the topography of viruses and protein cages, including that of structures lacking a well-defined symmetry. AFM is not limited for imaging and allows the manipulation of individual viruses with force spectroscopy approaches, such as single indentation and mechanical fatigue assays. These pushing experiments deform the protein cages to obtain their mechanical information and can be used to monitor the structural changes induced by maturation or the exposure to different biochemical environments, such as pH variation. We discuss how studying capsid rupture and self-healing events offers insight into virus uncoating pathways. On the other hand, pulling tests can provide information about the virus-host interaction established between the viral fibers and the cell membrane.
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74
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Abstract
Protein coats are supramolecular complexes that assemble on the cytosolic face of membranes to promote cargo sorting and transport carrier formation in the endomembrane system of eukaryotic cells. Several types of protein coats have been described, including COPI, COPII, AP-1, AP-2, AP-3, AP-4, AP-5, and retromer, which operate at different stages of the endomembrane system. Defects in these coats impair specific transport pathways, compromising the function and viability of the cells. In humans, mutations in subunits of these coats cause various congenital diseases that are collectively referred to as coatopathies. In this article, we review the fundamental properties of protein coats and the diseases that result from mutation of their constituent subunits.
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Affiliation(s)
- Esteban C Dell'Angelica
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Juan S Bonifacino
- Cell Biology and Neurobiology Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland 20892, USA;
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75
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Gao J, Chaudhary A, Vaddepalli P, Nagel MK, Isono E, Schneitz K. The Arabidopsis receptor kinase STRUBBELIG undergoes clathrin-dependent endocytosis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3881-3894. [PMID: 31107531 PMCID: PMC6685663 DOI: 10.1093/jxb/erz190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 04/09/2019] [Indexed: 05/04/2023]
Abstract
Signaling mediated by cell surface receptor kinases is central to the coordination of growth patterns during organogenesis. Receptor kinase signaling is in part controlled through endocytosis and subcellular distribution of the respective receptor kinase. For the majority of plant cell surface receptors, the underlying trafficking mechanisms are not characterized. In Arabidopsis, tissue morphogenesis requires the atypical receptor kinase STRUBBELIG (SUB). Here, we studied the endocytic mechanism of SUB. Our data revealed that a functional SUB-enhanced green fluorescent protein (EGFP) fusion is ubiquitinated in vivo. We further showed that plasma membrane-bound SUB:EGFP becomes internalized in a clathrin-dependent fashion. We also found that SUB:EGFP associates with the trans-Golgi network and accumulates in multivesicular bodies and the vacuole. Co-immunoprecipitation experiments revealed that SUB:EGFP and clathrin are present within the same protein complex. Our genetic analysis showed that SUB and CLATHRIN HEAVY CHAIN (CHC) 2 regulate root hair patterning. By contrast, genetic reduction of CHC activity ameliorates the floral defects of sub mutants. Taken together, the data indicate that SUB undergoes clathrin-mediated endocytosis, that this process does not rely on stimulation of SUB signaling by an exogenous agent, and that SUB genetically interacts with clathrin-dependent pathways in a tissue-specific manner.
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Affiliation(s)
- Jin Gao
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Ajeet Chaudhary
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Prasad Vaddepalli
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
- Present address: Laboratory of Biochemistry, Wageningen University, Wageningen, the Netherlands
| | - Marie-Kristin Nagel
- Department of Biology, Chair of Plant Physiology and Biochemistry, University of Konstanz, Konstanz, Germany
| | - Erika Isono
- Department of Biology, Chair of Plant Physiology and Biochemistry, University of Konstanz, Konstanz, Germany
| | - Kay Schneitz
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
- Correspondence:
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76
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Beacham GM, Partlow EA, Hollopeter G. Conformational regulation of AP1 and AP2 clathrin adaptor complexes. Traffic 2019; 20:741-751. [PMID: 31313456 DOI: 10.1111/tra.12677] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/09/2019] [Accepted: 07/12/2019] [Indexed: 12/15/2022]
Abstract
Heterotetrameric clathrin adaptor protein complexes (APs) orchestrate the formation of coated vesicles for transport among organelles of the cell periphery. AP1 binds membranes enriched for phosphatidylinositol 4-phosphate, such as the trans Golgi network, while AP2 associates with phosphatidylinositol 4,5-bisphosphate of the plasma membrane. At their respective membranes, AP1 and AP2 bind the cytoplasmic tails of transmembrane protein cargo and clathrin triskelions, thereby coupling cargo recruitment to coat polymerization. Structural, biochemical and genetic studies have revealed that APs undergo conformational rearrangements and reversible phosphorylation to cycle between different activity states. While membrane, cargo and clathrin have been demonstrated to promote AP activation, growing evidence supports that membrane-associated proteins such as Arf1 and FCHo also stimulate this transition. APs may be returned to the inactive state via a regulated process involving phosphorylation and a protein called NECAP. Finally, because antiviral mechanisms often rely on appropriate trafficking of membrane proteins, viruses have evolved novel strategies to evade host defenses by influencing the conformation of APs. This review will cover recent advances in our understanding of the molecular inputs that stimulate AP1 and AP2 to adopt structurally and functionally distinct configurations.
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Affiliation(s)
| | - Edward A Partlow
- Department of Molecular Medicine, Cornell University, Ithaca, New York
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77
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Gulbranson DR, Crisman L, Lee M, Ouyang Y, Menasche BL, Demmitt BA, Wan C, Nomura T, Ye Y, Yu H, Shen J. AAGAB Controls AP2 Adaptor Assembly in Clathrin-Mediated Endocytosis. Dev Cell 2019; 50:436-446.e5. [PMID: 31353312 DOI: 10.1016/j.devcel.2019.06.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/29/2019] [Accepted: 06/20/2019] [Indexed: 12/26/2022]
Abstract
Multimeric adaptors are broadly involved in vesicle-mediated membrane trafficking. AP2 adaptor, in particular, plays a central role in clathrin-mediated endocytosis (CME) by recruiting cargo and clathrin to endocytic sites. It is generally thought that trafficking adaptors such as AP2 adaptor assemble spontaneously. In this work, however, we discovered that AP2 adaptor assembly is an ordered process controlled by alpha and gamma adaptin binding protein (AAGAB), an uncharacterized factor identified in our genome-wide genetic screen of CME. AAGAB guides the sequential association of AP2 subunits and stabilizes assembly intermediates. Without the assistance of AAGAB, AP2 subunits fail to form the adaptor complex, leading to their degradation. The function of AAGAB is abrogated by a mutation that causes punctate palmoplantar keratoderma type 1 (PPKP1), a human skin disease. Since other multimeric trafficking adaptors operate in an analogous manner to AP2 adaptor, their assembly likely involves a similar regulatory mechanism.
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Affiliation(s)
- Daniel R Gulbranson
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Lauren Crisman
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - MyeongSeon Lee
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Yan Ouyang
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Bridget L Menasche
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Brittany A Demmitt
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA; Institute for Behavioral Genetics, University of Colorado, Boulder, CO 80309, USA
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Toshifumi Nomura
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Haijia Yu
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA; Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
| | - Jingshi Shen
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
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78
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Peotter J, Kasberg W, Pustova I, Audhya A. COPII-mediated trafficking at the ER/ERGIC interface. Traffic 2019; 20:491-503. [PMID: 31059169 PMCID: PMC6640837 DOI: 10.1111/tra.12654] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/25/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022]
Abstract
Coat proteins play multiple roles in the life cycle of a membrane-bound transport intermediate, functioning in lipid bilayer remodeling, cargo selection and targeting to an acceptor compartment. The Coat Protein complex II (COPII) coat is known to act in each of these capacities, but recent work highlights the necessity for numerous accessory factors at all stages of transport carrier existence. Here, we review recent findings that highlight the roles of COPII and its regulators in the biogenesis of tubular COPII-coated carriers in mammalian cells that enable cargo transport between the endoplasmic reticulum and ER-Golgi intermediate compartments, the first step in a series of trafficking events that ultimately allows for the distribution of biosynthetic secretory cargoes throughout the entire endomembrane system.
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Affiliation(s)
- Jennifer Peotter
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - William Kasberg
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Iryna Pustova
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin
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79
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Deng H, Dutta P, Liu J. Entry modes of ellipsoidal nanoparticles on a membrane during clathrin-mediated endocytosis. SOFT MATTER 2019; 15:5128-5137. [PMID: 31190048 PMCID: PMC7570437 DOI: 10.1039/c9sm00751b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The membrane wrapping and internalization of nanoparticles, such as viruses and drug nanocarriers, through clathrin-mediated endocytosis (CME) are vitally important for intracellular transport. During CME, the shape of the particle plays crucial roles in the determination of particle-membrane interactions, but much of the previous work has been focused on spherical particles. In this work, we develop a stochastic model to study the CME of ellipsoidal particles. In our model, the deformation of the membrane and wrapping of the nanoparticles are driven by the accumulation of clathrin lattices, which is stimulated by the ligand-receptor interactions. Using our model, we systematically investigate the effect of particle shape (ellipsoids with different aspect ratios) on the CME. Our results show three entry modes: tip-first, tilted, and laying-down modes, used by ellipsoidal nanoparticles for internalization depending on the aspect ratio. Certain ellipsoids are able to take multiple entry modes for internalization. Interestingly, the prolate ellipsoid with an aspect ratio of 0.42 can be internalized with a significantly reduced number of ligand-receptor bonds. Particles which can be internalized with fewer bonds are excellent candidates for transcellular drug delivery. Moreover, our results demonstrate that internalization of ellipsoids with intermediate aspect ratios is easier than that of particles with low and high aspect ratios. Our model and simulations provide critical mechanistic insights into CME of ellipsoidal particles, and represent a viable platform for optimal design of nanoparticles for targeted drug delivery applications.
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Affiliation(s)
- Hua Deng
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99163, USA.
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80
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Abstract
The unusual structure of clathrin, combined with its ability to assemble and disassemble rapidly in cells provides a model system for us to learn about the ways in which proteins can contribute mechanically to a functioning cell. In this article, we discuss the structural properties of clathrin cages and the triskelions which assemble to form them. The function of clathrin depends on the structure of these triskelions and the interactions they make both with each other during assembly and with the adaptor protein network that drives coated vesicle formation. The atomic resolution structure of clathrin domains has been revealed by X-ray crystallography while scattering studies have enabled the shape of a triskelion in solution to be deduced. Cryo-electron microscopy maps have shown the secondary structure of entire cages, how individual triskelion legs are arranged to form a cage and enabled some bound adaptor proteins to be located. Cage formation itself is energetically finely balanced and requires specific interactions between triskelion legs to be productive, as biochemical studies and in silico modeling have shown. Theoretical, structural and cell biological investigations over many years have contributed to our knowledge of clathrin structure and assembly. It now remains to determine the precise nature of the interactions which occur between clathrin triskelions, light chain and heavy chain and the adaptor protein network.
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Affiliation(s)
- Mary Halebian
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Kyle Morris
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Corinne Smith
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
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81
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Hsp70 molecular chaperones: multifunctional allosteric holding and unfolding machines. Biochem J 2019; 476:1653-1677. [PMID: 31201219 DOI: 10.1042/bcj20170380] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 12/20/2022]
Abstract
The Hsp70 family of chaperones works with its co-chaperones, the nucleotide exchange factors and J-domain proteins, to facilitate a multitude of cellular functions. Central players in protein homeostasis, these jacks-of-many-trades are utilized in a variety of ways because of their ability to bind with selective promiscuity to regions of their client proteins that are exposed when the client is unfolded, either fully or partially, or visits a conformational state that exposes the binding region in a regulated manner. The key to Hsp70 functions is that their substrate binding is transient and allosterically cycles in a nucleotide-dependent fashion between high- and low-affinity states. In the past few years, structural insights into the molecular mechanism of this allosterically regulated binding have emerged and provided deep insight into the deceptively simple Hsp70 molecular machine that is so widely harnessed by nature for diverse cellular functions. In this review, these structural insights are discussed to give a picture of the current understanding of how Hsp70 chaperones work.
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82
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Fumagalli M, Camus SM, Diekmann Y, Burke A, Camus MD, Norman PJ, Joseph A, Abi-Rached L, Benazzo A, Rasteiro R, Mathieson I, Topf M, Parham P, Thomas MG, Brodsky FM. Genetic diversity of CHC22 clathrin impacts its function in glucose metabolism. eLife 2019; 8:41517. [PMID: 31159924 PMCID: PMC6548504 DOI: 10.7554/elife.41517] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 05/01/2019] [Indexed: 01/29/2023] Open
Abstract
CHC22 clathrin plays a key role in intracellular membrane traffic of the insulin-responsive glucose transporter GLUT4 in humans. We performed population genetic and phylogenetic analyses of the CHC22-encoding CLTCL1 gene, revealing independent gene loss in at least two vertebrate lineages, after arising from gene duplication. All vertebrates retained the paralogous CLTC gene encoding CHC17 clathrin, which mediates endocytosis. For vertebrates retaining CLTCL1, strong evidence for purifying selection supports CHC22 functionality. All human populations maintained two high frequency CLTCL1 allelic variants, encoding either methionine or valine at position 1316. Functional studies indicated that CHC22-V1316, which is more frequent in farming populations than in hunter-gatherers, has different cellular dynamics than M1316-CHC22 and is less effective at controlling GLUT4 membrane traffic, altering its insulin-regulated response. These analyses suggest that ancestral human dietary change influenced selection of allotypes that affect CHC22's role in metabolism and have potential to differentially influence the human insulin response.
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Affiliation(s)
- Matteo Fumagalli
- Department of Life Sciences, Imperial College London, Ascot, United Kingdom.,Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom.,Research Department of Genetics, Evolution and Environment, Division of Biosciences, University College London, London, United Kingdom.,UCL Genetics Institute, University College London, London, United Kingdom
| | - Stephane M Camus
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Yoan Diekmann
- Research Department of Genetics, Evolution and Environment, Division of Biosciences, University College London, London, United Kingdom.,UCL Genetics Institute, University College London, London, United Kingdom
| | - Alice Burke
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Marine D Camus
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Paul J Norman
- Division of Bioinformatics and Personalized Medicine, University of Colorado, Aurora, United States.,Department of Microbiology and Immunology, University of Colorado, Aurora, United States
| | - Agnel Joseph
- Institute of Structural and Molecular Biology, Birkbeck College and University College London, London, United Kingdom
| | - Laurent Abi-Rached
- Aix-Marseille Univ, IRD, MEPHI, IHU Méditerranée Infection, CNRS, Marseille, France
| | - Andrea Benazzo
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Rita Rasteiro
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Iain Mathieson
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck College and University College London, London, United Kingdom
| | - Peter Parham
- Department of Structural Biology, Stanford University, Stanford, CA, United States.,Department of Microbiology and Immunology, Stanford University, Stanford, CA, United States
| | - Mark G Thomas
- Research Department of Genetics, Evolution and Environment, Division of Biosciences, University College London, London, United Kingdom.,UCL Genetics Institute, University College London, London, United Kingdom
| | - Frances M Brodsky
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom.,Institute of Structural and Molecular Biology, Birkbeck College and University College London, London, United Kingdom
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83
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Abstract
The entry of pathogens into nonphagocytic host cells has received much attention in the past three decades, revealing a vast array of strategies employed by bacteria and viruses. A method of internalization that has been extensively studied in the context of viral infections is the use of the clathrin-mediated pathway. More recently, a role for clathrin in the entry of some intracellular bacterial pathogens was discovered. Classically, clathrin-mediated endocytosis was thought to accommodate internalization only of particles smaller than 150 nm; however, this was challenged upon the discovery that Listeria monocytogenes requires clathrin to enter eukaryotic cells. Now, with discoveries that clathrin is required during other stages of some bacterial infections, another paradigm shift is occurring. There is a more diverse impact of clathrin during infection than previously thought. Much of the recent data describing clathrin utilization in processes such as bacterial attachment, cell-to-cell spread and intracellular growth may be due to newly discovered divergent roles of clathrin in the cell. Not only does clathrin act to facilitate endocytosis from the plasma membrane, but it also participates in budding from endosomes and the Golgi apparatus and in mitosis. Here, the manipulation of clathrin processes by bacterial pathogens, including its traditional role during invasion and alternative ways in which clathrin supports bacterial infection, is discussed. Researching clathrin in the context of bacterial infections will reveal new insights that inform our understanding of host-pathogen interactions and allow researchers to fully appreciate the diverse roles of clathrin in the eukaryotic cell.
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Affiliation(s)
- Eleanor A Latomanski
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Hayley J Newton
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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84
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The Physics of Entropic Pulling: A Novel Model for the Hsp70 Motor Mechanism. Int J Mol Sci 2019; 20:ijms20092334. [PMID: 31083504 PMCID: PMC6539501 DOI: 10.3390/ijms20092334] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 01/04/2023] Open
Abstract
Hsp70s use ATP to generate forces that disassemble protein complexes and aggregates, and that translocate proteins into organelles. Entropic pulling has been proposed as a novel mechanism, distinct from the more familiar power-stroke and Brownian ratchet models, for how Hsp70s generate these forces. Experimental evidence supports entropic pulling, but this model may not be well understood among scientists studying these systems. In this review we address persistent misconceptions regarding the dynamics of proteins in solution that contribute to this lack of understanding, and we clarify the basic physics of entropic pulling with some simple analogies. We hope that increased understanding of the entropic pulling mechanism will inform future efforts to characterize how Hsp70s function as motors, and how they coordinate with their regulatory cochaperones in mechanochemical cycles that transduce the energy of ATP hydrolysis into physical changes in their protein substrates.
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85
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Markova EA, Zanetti G. Visualizing membrane trafficking through the electron microscope: cryo-tomography of coat complexes. Acta Crystallogr D Struct Biol 2019; 75:467-474. [PMID: 31063149 PMCID: PMC6503763 DOI: 10.1107/s2059798319005011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/12/2019] [Indexed: 11/23/2022] Open
Abstract
Coat proteins mediate vesicular transport between intracellular compartments, which is essential for the distribution of molecules within the eukaryotic cell. The global arrangement of coat proteins on the membrane is key to their function, and cryo-electron tomography and subtomogram averaging have been used to study membrane-bound coat proteins, providing crucial structural insight. This review outlines a workflow for the structural elucidation of coat proteins, incorporating recent developments in the collection and processing of cryo-electron tomography data. Recent work on coat protein I, coat protein II and retromer performed on in vitro reconstitutions or in situ is summarized. These studies have answered long-standing questions regarding the mechanisms of membrane binding, polymerization and assembly regulation of coat proteins.
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Affiliation(s)
- Evgenia A. Markova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, England
| | - Giulia Zanetti
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London WC1E 7HX, England
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86
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Reconstitution of Clathrin Coat Disassembly for Fluorescence Microscopy and Single-Molecule Analysis. Methods Mol Biol 2019; 1847:121-146. [PMID: 30129014 DOI: 10.1007/978-1-4939-8719-1_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
The disassembly of the clathrin lattice surrounding coated vesicles is the obligatory last step in their life cycle. It is mediated by the coordinated recruitment of auxilin and Hsc70, an ATP-driven molecular clamp. Here, we describe the preparation of reagents and the single-particle fluorescence microscopy imaging assay in which we visualize directly the Hsc70-driven uncoating of synthetic clathrin coats or clathrin-coated vesicles.
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87
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Abstract
![]()
Ordered
protein assemblies are attracting interest as next-generation
biomaterials with a remarkable range of structural and functional
properties, leading to potential applications in biocatalysis, materials
templating, drug delivery and vaccine development. This Review covers
ordered protein assemblies including protein nanowires/nanofibrils,
nanorings, nanotubes, designed two- and three-dimensional ordered
protein lattices and protein-like cages including polyhedral virus-like
cage structures. The main focus is on designed ordered protein assemblies,
in which the spatial organization of the proteins is controlled by
tailored noncovalent interactions (including metal ion binding interactions,
electrostatic interactions and ligand–receptor interactions
among others) or by careful design of modified (mutant) proteins or de novo constructs. The modification of natural protein
assemblies including bacterial S-layers and cage-like and rod-like
viruses to impart novel function, e.g. enzymatic activity, is also
considered. A diversity of structures have been created using distinct
approaches, and this Review provides a summary of the state-of-the-art
in the development of these systems, which have exceptional potential
as advanced bionanomaterials for a diversity of applications.
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Affiliation(s)
- Ian W Hamley
- Department of Chemistry , University of Reading , Whiteknights , Reading RG6 6AD , United Kingdom
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88
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From Flat to Curved Clathrin: Controlling a Plastic Ratchet. Trends Cell Biol 2019; 29:241-256. [DOI: 10.1016/j.tcb.2018.12.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/04/2018] [Accepted: 12/09/2018] [Indexed: 01/13/2023]
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89
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Disulfide-mediated conversion of 8-mer bowl-like protein architecture into three different nanocages. Nat Commun 2019; 10:778. [PMID: 30770832 PMCID: PMC6377661 DOI: 10.1038/s41467-019-08788-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/23/2019] [Indexed: 01/16/2023] Open
Abstract
Constructing different protein nanostructures with high-order discrete architectures by using one single building block remains a challenge. Here, we present a simple, effective disulfide-mediated approach to prepare a set of protein nanocages with different geometries from single building block. By genetically deleting an inherent intra-subunit disulfide bond, we can render the conversion of an 8-mer bowl-like protein architecture (NF-8) into a 24-mer ferritin-like nanocage in solution, while selective insertion of an inter-subunit disulfide bond into NF-8 triggers its conversion into a 16-mer lenticular nanocage. Deletion of the same intra-subunit disulfide bond and insertion of the inter-subunit disulfide bond results in the conversion of NF-8 into a 48-mer protein nanocage in solution. Thus, in the laboratory, simple mutation of one protein building block can generate three different protein nanocages in a manner that is highly reminiscent of natural pentamer building block originating from viral capsids that self-assemble into protein assemblies with different symmetries.
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90
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A new role of anterograde motor Kif5b in facilitating large clathrin-coated vesicle mediated endocytosis via regulating clathrin uncoating. Cell Discov 2019; 4:65. [PMID: 30603101 PMCID: PMC6305376 DOI: 10.1038/s41421-018-0067-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 11/30/2022] Open
Abstract
Kif5b-driven anterograde transport and clathrin-mediated endocytosis (CME) are responsible for opposite intracellular trafficking, contributing to plasma membrane homeostasis. However, whether and how the two trafficking processes coordinate remain unclear. Here, we show that Kif5b directly interacts with clathrin heavy chain (CHC) at a region close to that for uncoating catalyst (Hsc70) and preferentially localizes on relatively large clathrin-coated vesicles (CCVs). Uncoating in vitro is decreased for CCVs from the cortex of kif5b conditional knockout (mutant) mouse and facilitated by adding Kif5b fragments containing CHC-binding site, while cell peripheral distribution of CHC or Hsc70 keeps unaffected by Kif5b depletion. Furthermore, cellular entry of vesicular stomatitis virus that internalizes into large CCV is inhibited by Kif5b depletion or introducing a dominant-negative Kif5b fragment. These findings showed a new role of Kif5b in regulating large CCV-mediated CME via affecting CCV uncoating, indicating Kif5b as a molecular knot connecting anterograde transport to CME.
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91
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Extracting lipid vesicles from plasma membranes via self-assembly of clathrin-inspired scaffolding nanoparticles. Colloids Surf B Biointerfaces 2019; 176:239-248. [PMID: 30623811 DOI: 10.1016/j.colsurfb.2019.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/27/2018] [Accepted: 01/02/2019] [Indexed: 11/22/2022]
Abstract
Single-cell analysis is a new and rapidly expanding field, the goal of which is obtaining fresh information from individual cells to understand the regulatory mechanisms of cell development and diseases. Conventional approaches generally rely on the cell lysis which, however, is destructive to cells and against multiple sampling from the living cell. Here, we propose and design a scaffolding nanoparticle (NP) system that enables us to sample cytoplasmic contents without rupturing the cellular membrane, by mimicking the unusual features of clathrin. Our simulation results reveal the design principles, following which scaffolding NPs can extract lipid vesicles from plasma membranes, with both the pathway and the mechanism resembling the clathrin-mediated endocytosis, i.e. multiple NPs deposit at the membrane, assembling into cage-like structures to deform the membrane into a vesicle shape. As important design parameters, the interaction between different NPs should be properly stronger than that between each NP and the membrane to ensure the cage formation, and optimal NP concentration and the membrane surface tension are also requisite for extracting lipid vesicles. Our results provide useful guidelines for design of bio-inspired scaffolding NPs as an intelligent machine for practical use in but not limited to the single-cell analysis.
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92
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Chen H, Zhou K, Wang Y, Zang J, Zhao G. Self-assembly of engineered protein nanocages into reversible ordered 3D superlattices mediated by zinc ions. Chem Commun (Camb) 2019; 55:11299-11302. [DOI: 10.1039/c9cc06262a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Zinc ion triggered self-assembly of re-engineered Dps nanocages into highly ordered architectures with a bcc structure.
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Affiliation(s)
- H. Chen
- Beijing Advanced Innovation Center for Food Nutrition and Human Health
- College of Food Science & Nutritional Engineering
- China Agricultural University
- Beijing Key Laboratory of Functional Food from Plant Resources
- Beijing
| | - K. Zhou
- Beijing Advanced Innovation Center for Food Nutrition and Human Health
- College of Food Science & Nutritional Engineering
- China Agricultural University
- Beijing Key Laboratory of Functional Food from Plant Resources
- Beijing
| | - Y. Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health
- College of Food Science & Nutritional Engineering
- China Agricultural University
- Beijing Key Laboratory of Functional Food from Plant Resources
- Beijing
| | - J. Zang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health
- College of Food Science & Nutritional Engineering
- China Agricultural University
- Beijing Key Laboratory of Functional Food from Plant Resources
- Beijing
| | - G. Zhao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health
- College of Food Science & Nutritional Engineering
- China Agricultural University
- Beijing Key Laboratory of Functional Food from Plant Resources
- Beijing
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93
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de Pablo PJ, Schaap IAT. Atomic Force Microscopy of Viruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1215:159-179. [PMID: 31317500 DOI: 10.1007/978-3-030-14741-9_8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Atomic force microscopy employs a nanometric tip located at the end of a micro-cantilever to probe surface-mounted samples at nanometer resolution. Because the technique can also work in a liquid environment it offers unique possibilities to study individual viruses under conditions that mimic their natural milieu. Here, we review how AFM imaging can be used to study the surface structure of viruses including that of viruses lacking a well-defined symmetry. Beyond imaging, AFM enables the manipulation of single viruses by force spectroscopy experiments. Pulling experiments can provide information about the early events of virus-host interaction between the viral fibers and the cell membrane receptors. Pushing experiments measure the mechanical response of the viral capsid and its contents and can be used to show how virus maturation and exposure to different pH values change the mechanical response of the viruses and the interaction between the capsid and genome. Finally, we discuss how studying capsid rupture and self-healing events offers insight in virus uncoating pathways.
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Affiliation(s)
- P J de Pablo
- Department of Condensed Matter Physics and Solid Condensed Matter Institute IFIMAC, Universidad Autónoma de Madrid, Madrid, Spain.
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94
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Panahandeh S, Li S, Zandi R. The equilibrium structure of self-assembled protein nano-cages. NANOSCALE 2018; 10:22802-22809. [PMID: 30516220 DOI: 10.1039/c8nr07202g] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Understanding how highly symmetric, robust, monodisperse protein nano-cages self-assemble can have major applications in various areas of bio-nanotechnology, such as drug delivery, biomedical imaging and gene therapy. We develop a model to investigate the assembly of protein subunits into the structures with different sizes and symmetries. Using Monte Carlo simulation, we obtain global minimum energy structures. Our results suggest that the physical properties including the spontaneous curvature, flexibility and bending rigidity of coat proteins are sufficient to predict the size, symmetry and shape selectivity of the assembly products. Further, on a thermodynamic basis, we discuss the polymorphism of nano-cages observed in assembly experiments.
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Affiliation(s)
- Sanaz Panahandeh
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA.
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95
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Johnson ME. Modeling the Self-Assembly of Protein Complexes through a Rigid-Body Rotational Reaction-Diffusion Algorithm. J Phys Chem B 2018; 122:11771-11783. [PMID: 30256109 DOI: 10.1021/acs.jpcb.8b08339] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The reaction-diffusion equations provide a powerful framework for modeling nonequilibrium, cell-scale dynamics over the long time scales that are inaccessible by traditional molecular modeling approaches. Single-particle reaction-diffusion offers the highest resolution technique for tracking such dynamics, but it has not been applied to the study of protein self-assembly due to its treatment of reactive species as single-point particles. Here, we develop a relatively simple but accurate approach for building rigid structure and rotation into single-particle reaction-diffusion methods, providing a rate-based method for studying protein self-assembly. Our simplifying assumption is that reactive collisions can be evaluated purely on the basis of the separations between the sites, and not their orientations. The challenge of evaluating reaction probabilities can then be performed using well-known equations based on translational diffusion in both 3D and 2D, by employing an effective diffusion constant we derive here. We show how our approach reproduces both the kinetics of association, which is altered by rotational diffusion, and the equilibrium of reversible association, which is not. Importantly, the macroscopic kinetics of association can be predicted on the basis of the microscopic parameters of our structurally resolved model, allowing for critical comparisons with theory and other rate-based simulations. We demonstrate this method for efficient, rate-based simulations of self-assembly of clathrin trimers, highlighting how formation of regular lattices impacts the kinetics of association.
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Affiliation(s)
- Margaret E Johnson
- TC Jenkins Department of Biophysics , The Johns Hopkins University , 3400 North Charles Street , Baltimore , Maryland 21218 , United States
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96
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Gupta S, Singh R, Kumar V, Shukla P, Joshi KB. Ornamentation of Triskelion Peptide Nanotori to Produce Gold Nanoparticle (AuNP)-Embedded Peptide Nanobangles. Chem Asian J 2018; 13:3285-3295. [DOI: 10.1002/asia.201801270] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Shradhey Gupta
- Department of Chemistry, School of Chemical Science and Technology; Dr. Harisingh Gour Central University; Sagar, MP 470003 India
| | - Ramesh Singh
- Department of Chemistry, School of Chemical Science and Technology; Dr. Harisingh Gour Central University; Sagar, MP 470003 India
| | - Vikas Kumar
- Current address: BIOPEP group; Stellenbosch University; Stellenbosch 7600 South Africa
| | - Prashant Shukla
- Department of Physics; Dr. Harisingh Gour Central University; Sagar, MP 470003 India
| | - Khashti Ballabh Joshi
- Department of Chemistry, School of Chemical Science and Technology; Dr. Harisingh Gour Central University; Sagar, MP 470003 India
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97
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From the resolution revolution to evolution: structural insights into the evolutionary relationships between vesicle coats and the nuclear pore. Curr Opin Struct Biol 2018; 52:32-40. [PMID: 30103204 DOI: 10.1016/j.sbi.2018.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 11/22/2022]
Abstract
Nuclear pores and coated vesicles are elaborate multi-component protein complexes that oligomerize on membranes, and stabilize or induce membrane curvature. Their components, nucleoporins and coat proteins, respectively, share similar structural folds and some principles of how they interact with membranes. The protocoatomer hypothesis postulates that this is due to divergent evolution from a common ancestor. It therefore has been suggested that nucleoporins and coat proteins have similar higher order architectures. Here, we review recent work that relied on technical advances in cryo-electron microscopy and integrative structural biology to take a fresh look on how these proteins form membrane coats in situ. We discuss the relationship between the architectures of nuclear pores and coated vesicles, and their evolutionary origins.
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98
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Simunovic M, Bassereau P, Voth GA. Organizing membrane-curving proteins: the emerging dynamical picture. Curr Opin Struct Biol 2018; 51:99-105. [PMID: 29609179 PMCID: PMC6165709 DOI: 10.1016/j.sbi.2018.03.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/16/2018] [Accepted: 03/19/2018] [Indexed: 11/30/2022]
Abstract
Lipid membranes play key roles in cells, such as in trafficking, division, infection, remodeling of organelles, among others. The key step in all these processes is creating membrane curvature, typically under the control of many anchored, adhered or included proteins. However, it has become clear that the membrane itself can mediate the interactions among proteins to produce highly ordered assemblies. Computer simulations are ideally suited to investigate protein organization and the dynamics of membrane remodeling at near-micron scales, something that is extremely challenging to tackle experimentally. We review recent computational efforts in modeling protein-caused membrane deformation mechanisms, specifically focusing on coarse-grained simulations. We highlight work that exposed the membrane-mediated ordering of proteins into lines, meshwork, spirals and other assemblies, in what seems to be a very generic mechanism driven by a combination of short and long-ranged forces. Modulating the mechanical properties of membranes is an underexplored signaling mechanism in various processes deserving of more attention in the near future.
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Affiliation(s)
- Mijo Simunovic
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute and Computation Institute, The University of Chicago, Chicago, IL 60637, USA; Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris, France; Center for Studies in Physics and Biology, The Rockefeller University, New York, NY 10065, USA.
| | - Patricia Bassereau
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, 75005 Paris, France; Sorbonne Universités, UPMC Univ Paris 06, 75005 Paris, France
| | - Gregory A Voth
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute and Computation Institute, The University of Chicago, Chicago, IL 60637, USA.
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99
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Picco A, Kaksonen M. Quantitative imaging of clathrin-mediated endocytosis. Curr Opin Cell Biol 2018; 53:105-110. [PMID: 30025292 DOI: 10.1016/j.ceb.2018.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 04/24/2018] [Accepted: 06/11/2018] [Indexed: 11/29/2022]
Abstract
Clathrin-mediated endocytosis is a process by which eukaryotic cells bend a small region of their plasma membrane to form a transport vesicle that carries specific cargo molecules into the cell. Endocytosis controls the composition of the plasma membrane, imports nutrients and regulates many signalling pathways. The roles of most of the proteins involved in endocytosis have been thoroughly characterised. However, how these proteins cooperate in the cell to drive the endocytic process is not well understood. Microscopy methods have been instrumental in describing the dynamics and the molecular mechanism of endocytosis. Here, we will review the challenges and the recent advances in visualising the endocytic machinery and we will reflect on how the integration of current imaging technologies can lead us toward a quantitative understanding of the molecular mechanisms of endocytosis.
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Affiliation(s)
- Andrea Picco
- Department of Biochemistry and NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Marko Kaksonen
- Department of Biochemistry and NCCR Chemical Biology, University of Geneva, Geneva, Switzerland.
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100
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Stochastic simulations of nanoparticle internalization through transferrin receptor dependent clathrin-mediated endocytosis. Biochim Biophys Acta Gen Subj 2018; 1862:2104-2111. [PMID: 29959983 DOI: 10.1016/j.bbagen.2018.06.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/14/2018] [Accepted: 06/26/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND Receptor dependent clathrin-mediated endocytosis (CME) is one of the most important endocytic pathways for the internalization of bioparticles into cells. During CME, the ligand-receptor interactions, development of clathrin-coated pit (CCP) and membrane evolution all act together to drive the internalization of bioparticles. In this work, we develop a stochastic computational model to investigate the CME based on the Metropolis Monte Carlo simulations. METHODS The model is based on the combination of a stochastic particle binding model with a membrane model. The energetic costs of membrane bending, CCP formation and ligand-receptor interactions are systematically linked together. RESULTS We implement our model to investigate the effects of particle size, ligand density and membrane stiffness on the overall process of CME from the drug delivery perspectives. Consistent with some experiments, our results show that the intermediate particle size and ligand density favor the particle internalization. Moreover, our results show that it is easier for a particle to enter a cell with softer membrane. CONCLUSIONS The model presented here is able to provide mechanistic insights into CME and can be readily modified to include other important factors, such as actins. The predictions from the model will aid in the therapeutic design of intracellular/transcellular drug delivery and antiviral interventions.
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