1
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Beyrent E, Wei DT, Beacham GM, Park S, Zheng J, Paszek MJ, Hollopeter G. Dimerization activates the Inversin complex in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594761. [PMID: 38798613 PMCID: PMC11118560 DOI: 10.1101/2024.05.17.594761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Genetic, colocalization, and biochemical studies suggest that the ankyrin repeat-containing proteins Inversin (INVS) and ANKS6 function with the NEK8 kinase to control tissue patterning and maintain organ physiology. It is unknown whether these three proteins assemble into a static "Inversin complex" or one that adopts multiple bioactive forms. Through characterization of hyperactive alleles in C. elegans , we discovered that the Inversin complex is activated by dimerization. Genome engineering of an RFP tag onto the nematode homologs of INVS (MLT-4) and NEK8 (NEKL-2) induced a gain-of-function, cyst-like phenotype that was suppressed by monomerization of the fluorescent tag. Stimulated dimerization of MLT-4 or NEKL-2 using optogenetics was sufficient to recapitulate the phenotype of a constitutively active Inversin complex. Further, dimerization of NEKL-2 bypassed a lethal MLT-4 mutant, demonstrating that the dimeric form is required for function. We propose that dynamic switching between at least two functionally distinct states-an active dimer and an inactive monomer-gates the output of the Inversin complex.
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2
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Jin M, Iwamoto Y, Shirazinejad C, Drubin DG. Intersectin1 promotes clathrin-mediated endocytosis by organizing and stabilizing endocytic protein interaction networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590579. [PMID: 38712149 PMCID: PMC11071352 DOI: 10.1101/2024.04.22.590579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
During clathrin-mediated endocytosis (CME), dozens of proteins are recruited to nascent CME sites on the plasma membrane. Coordination of endocytic protein recruitment in time and space is important for efficient CME. Here, we show that the multivalent scaffold protein intersectin1 (ITSN1) promotes CME by organizing and stabilizing endocytic protein interaction networks. By live-cell imaging of genome-edited cells, we observed that endogenously labeled ITSN1 is recruited to CME sites shortly after they begin to assemble. Knocking down ITSN1 impaired endocytic protein recruitment during the stabilization stage of CME site assembly. Artificially locating ITSN1 to the mitochondria surface was sufficient to assemble puncta consisting of CME initiation proteins, including EPS15, FCHO, adaptor proteins, the AP2 complex and epsin1 (EPN1), and the vesicle scission GTPase dynamin2 (DNM2). ITSN1 can form puncta and recruit DNM2 independently of EPS15/FCHO or EPN1. Our work redefines ITSN1's primary endocytic role as organizing and stabilizing the CME protein interaction networks rather than a previously suggested role in initiation and provides new insights into the multi-step and multi-zone organization of CME site assembly.
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Affiliation(s)
- Meiyan Jin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- Current Address: Department of Biology, University of Florida, Gainesville, Fl 32611, USA
| | - Yuichiro Iwamoto
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Cyna Shirazinejad
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - David G. Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
- Lead author
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3
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Dragwidge JM, Wang Y, Brocard L, De Meyer A, Hudeček R, Eeckhout D, Grones P, Buridan M, Chambaud C, Pejchar P, Potocký M, Winkler J, Vandorpe M, Serre N, Fendrych M, Bernard A, De Jaeger G, Pleskot R, Fang X, Van Damme D. Biomolecular condensation orchestrates clathrin-mediated endocytosis in plants. Nat Cell Biol 2024; 26:438-449. [PMID: 38347182 PMCID: PMC7615741 DOI: 10.1038/s41556-024-01354-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 01/10/2024] [Indexed: 02/16/2024]
Abstract
Clathrin-mediated endocytosis is an essential cellular internalization pathway involving the dynamic assembly of clathrin and accessory proteins to form membrane-bound vesicles. The evolutionarily ancient TSET-TPLATE complex (TPC) plays an essential, but ill-defined role in endocytosis in plants. Here we show that two highly disordered TPC subunits, AtEH1 and AtEH2, function as scaffolds to drive biomolecular condensation of the complex. These condensates specifically nucleate on the plasma membrane through interactions with anionic phospholipids, and facilitate the dynamic recruitment and assembly of clathrin, as well as early- and late-stage endocytic accessory proteins. Importantly, condensation promotes ordered clathrin assemblies. TPC-driven biomolecular condensation thereby facilitates dynamic protein assemblies throughout clathrin-mediated endocytosis. Furthermore, we show that a disordered region of AtEH1 controls the material properties of endocytic condensates in vivo. Alteration of these material properties disturbs the recruitment of accessory proteins, influences endocytosis dynamics and impairs plant responsiveness. Our findings reveal how collective interactions shape endocytosis.
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Affiliation(s)
- Jonathan Michael Dragwidge
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- VIB Center for Plant Systems Biology, Ghent, Belgium.
| | - Yanning Wang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lysiane Brocard
- Bordeaux Imaging Center, INSERM, CNRS, Université de Bordeaux, Bordeaux, France
| | - Andreas De Meyer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Roman Hudeček
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Peter Grones
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Matthieu Buridan
- Bordeaux Imaging Center, INSERM, CNRS, Université de Bordeaux, Bordeaux, France
| | - Clément Chambaud
- Laboratoire de Biogenèse Membranaire, CNRS, Université de Bordeaux, Bordeaux, France
| | - Přemysl Pejchar
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Potocký
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Joanna Winkler
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Michaël Vandorpe
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Nelson Serre
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Prague, Czech Republic
| | - Matyáš Fendrych
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Prague, Czech Republic
| | - Amelie Bernard
- Laboratoire de Biogenèse Membranaire, CNRS, Université de Bordeaux, Bordeaux, France
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Roman Pleskot
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Xiaofeng Fang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Daniël Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- VIB Center for Plant Systems Biology, Ghent, Belgium.
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4
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Durydivka O, Gazdarica M, Vecerkova K, Radenkovic S, Blahos J. Multiple Sgip1 splice variants inhibit cannabinoid receptor 1 internalization. Gene 2024; 892:147851. [PMID: 37783296 DOI: 10.1016/j.gene.2023.147851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/23/2023] [Accepted: 09/27/2023] [Indexed: 10/04/2023]
Abstract
Alternative splicing can often result in the expression of distinct protein isoforms from a single gene, with specific composition and properties. SH3-containing GRB2-like protein 3-interacting protein 1 (Sgip1) is a brain-enriched protein that regulates clathrin-mediated endocytosis and interferes with the internalization of cannabinoid receptor 1. Several research groups have studied the physiological importance of Sgip1, and four Sgip1 protein isoforms have been described to date, while the NCBI Gene database predicts the expression of 20 splice variants from the Sgip1 gene in mice. In this work, we cloned 15 Sgip1 splice variants from the mouse brain, including 11 novel splice variants. The cloned splice variants differed in exon composition within two Sgip1 regions: the membrane phospholipid-binding domain and the proline-rich region. All the Sgip1 splice isoforms had similar stability and comparable ability to inhibit the internalization of cannabinoid receptor 1. None of the isoforms influenced the internalization of the µ-opioid receptor. We confirm the expression of Sgip1 splice variants described in previous studies or predicted in silico. Our data provide a basis for further studies exploring the significance of Sgip1 splicing, and we suggest a new classification of Sgip1 splice variants to unify their nomenclature.
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Affiliation(s)
- Oleh Durydivka
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Matej Gazdarica
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Katerina Vecerkova
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic; Department of Informatics and Chemistry, University of Chemistry and Technology, Technicka 5, 166 28 Prague, Czech Republic
| | - Silvia Radenkovic
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Jaroslav Blahos
- Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic.
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5
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Kursel LE, Martinez JEA, Rog O. A suppressor screen in C. elegans identifies a multiprotein interaction that stabilizes the synaptonemal complex. Proc Natl Acad Sci U S A 2023; 120:e2314335120. [PMID: 38055743 PMCID: PMC10723054 DOI: 10.1073/pnas.2314335120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 10/23/2023] [Indexed: 12/08/2023] Open
Abstract
Successful chromosome segregation into gametes depends on tightly regulated interactions between the parental chromosomes. During meiosis, chromosomes are aligned end-to-end by an interface called the synaptonemal complex, which also regulates exchanges between them. However, despite the functional and ultrastructural conservation of this essential interface, how protein-protein interactions within the synaptonemal complex regulate chromosomal interactions remains poorly understood. Here, we describe a genetic interaction in the C. elegans synaptonemal complex, comprised of short segments of three proteins, SYP-1, SYP-3, and SYP-4. We identified the interaction through a saturated suppressor screen of a mutant that destabilizes the synaptonemal complex. The specificity and tight distribution of suppressors suggest a charge-based interface that promotes interactions between synaptonemal complex subunits and, in turn, allows intimate interactions between chromosomes. Our work highlights the power of genetic studies to illuminate the mechanisms that underlie meiotic chromosome interactions.
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Affiliation(s)
- Lisa E. Kursel
- School of Biological Sciences and Center for Cell and Genome Sciences, The University of Utah, Salt Lake City, UT84112
| | - Jesus E. Aguayo Martinez
- School of Biological Sciences and Center for Cell and Genome Sciences, The University of Utah, Salt Lake City, UT84112
| | - Ofer Rog
- School of Biological Sciences and Center for Cell and Genome Sciences, The University of Utah, Salt Lake City, UT84112
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6
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Zhang W, Lu CH, Nakamoto ML, Tsai CT, Roy AR, Lee CE, Yang Y, Jahed Z, Li X, Cui B. Curved adhesions mediate cell attachment to soft matrix fibres in three dimensions. Nat Cell Biol 2023; 25:1453-1464. [PMID: 37770566 PMCID: PMC10567576 DOI: 10.1038/s41556-023-01238-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 08/21/2023] [Indexed: 09/30/2023]
Abstract
Integrin-mediated focal adhesions are the primary architectures that transmit forces between the extracellular matrix (ECM) and the actin cytoskeleton. Although focal adhesions are abundant on rigid and flat substrates that support high mechanical tensions, they are sparse in soft three-dimensional (3D) environments. Here we report curvature-dependent integrin-mediated adhesions called curved adhesions. Their formation is regulated by the membrane curvatures imposed by the topography of ECM protein fibres. Curved adhesions are mediated by integrin ɑvβ5 and are molecularly distinct from focal adhesions and clathrin lattices. The molecular mechanism involves a previously unknown interaction between integrin β5 and a curvature-sensing protein, FCHo2. We find that curved adhesions are prevalent in physiological conditions, and disruption of curved adhesions inhibits the migration of some cancer cell lines in 3D fibre matrices. These findings provide a mechanism for cell anchorage to natural protein fibres and suggest that curved adhesions may serve as a potential therapeutic target.
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Affiliation(s)
- Wei Zhang
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
| | - Chih-Hao Lu
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
| | - Melissa L Nakamoto
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
| | - Ching-Ting Tsai
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
| | - Anish R Roy
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Christina E Lee
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
- Biophysics Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Yang Yang
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
| | - Zeinab Jahed
- Department of Chemistry, Stanford University, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA
- Department of Nanoengineering, University of California, San Diego, CA, USA
| | - Xiao Li
- Department of Chemistry, Stanford University, Stanford, CA, USA
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, CA, USA.
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University, Stanford, CA, USA.
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7
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Kursel LE, Martinez JEA, Rog O. A suppressor screen in C. elegans identifies a multi-protein interaction interface that stabilizes the synaptonemal complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.554166. [PMID: 37662357 PMCID: PMC10473659 DOI: 10.1101/2023.08.21.554166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Successful chromosome segregation into gametes depends on tightly-regulated interactions between the parental chromosomes. During meiosis, chromosomes are aligned end-to-end by an interface called the synaptonemal complex, which also regulates exchanges between them. However, despite the functional and ultrastructural conservation of this essential interface, how protein-protein interactions within the synaptonemal complex regulate chromosomal interactions remains poorly understood. Here we describe a novel interaction interface in the C. elegans synaptonemal complex, comprised of short segments of three proteins, SYP-1, SYP-3 and SYP-4. We identified the interface through a saturated suppressor screen of a mutant that destabilizes the synaptonemal complex. The specificity and tight distribution of suppressors point to a charge-based interface that promotes interactions between synaptonemal complex subunits and, in turn, allows intimate interactions between chromosomes. Our work highlights the power of genetic studies to illuminate the mechanisms that underly meiotic chromosome interactions.
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Affiliation(s)
- Lisa E. Kursel
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, United States
| | - Jesus E. Aguayo Martinez
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, United States
| | - Ofer Rog
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, United States
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8
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Durydivka O, Mackie K, Blahos J. SGIP1 in axons prevents internalization of desensitized CB1R and modifies its function. Front Neurosci 2023; 17:1213094. [PMID: 37547151 PMCID: PMC10397514 DOI: 10.3389/fnins.2023.1213094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/04/2023] [Indexed: 08/08/2023] Open
Abstract
In the central nervous system (CNS), cannabinoid receptor 1 (CB1R) is preferentially expressed in axons where it has a unique property, namely resistance to agonist-driven endocytosis. This review aims to summarize what we know about molecular mechanisms of CB1R cell surface stability in axonal compartments, how these impact CB1R signaling, and to consider their physiological consequences. This review then focuses on a potential candidate for maintaining axonal CB1R at the cell surface, Src homology 3-domain growth factor receptor-bound 2-like endophilin interacting protein 1 (SGIP1). SGIP1 may contribute to the polarized distribution of CB1R and modify its signaling in axons. In addition, deletion of SGIP1 results in discrete behavioral changes in modalities controlled by the endocannabinoid system in vivo. Several drugs acting directly via CB1R have important therapeutic potential, however their adverse effects limit their clinical use. Future studies might reveal chemical approaches to target the SGIP1-CB1R interaction, with the aim to exploit the endocannabinoid system pharmaceutically in a discrete way, with minimized undesired consequences.
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Affiliation(s)
- Oleh Durydivka
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, IN, United States
| | - Jaroslav Blahos
- Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
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9
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Zhang W, Lu CH, Nakamoto ML, Tsai CT, Roy AR, Lee CE, Yang Y, Jahed Z, Li X, Cui B. Curved adhesions mediate cell attachment to soft matrix fibres in 3D. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.16.532975. [PMID: 36993504 PMCID: PMC10055138 DOI: 10.1101/2023.03.16.532975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Mammalian cells adhere to the extracellular matrix (ECM) and sense mechanical cues through integrin-mediated adhesions 1, 2 . Focal adhesions and related structures are the primary architectures that transmit forces between the ECM and the actin cytoskeleton. Although focal adhesions are abundant when cells are cultured on rigid substrates, they are sparse in soft environments that cannot support high mechanical tensions 3 . Here, we report a new class of integrin-mediated adhesions, curved adhesions, whose formation is regulated by membrane curvature instead of mechanical tension. In soft matrices made of protein fibres, curved adhesions are induced by membrane curvatures imposed by the fibre geometry. Curved adhesions are mediated by integrin ɑVβ5 and are molecularly distinct from focal adhesions and clathrin lattices. The molecular mechanism involves a previously unknown interaction between integrin β5 and a curvature-sensing protein FCHo2. We find that curved adhesions are prevalent in physiologically relevant environments. Disruption of curved adhesions by knocking down integrin β5 or FCHo2 abolishes the migration of multiple cancer cell lines in 3D matrices. These findings provide a mechanism of cell anchorage to natural protein fibres that are too soft to support the formation of focal adhesions. Given their functional importance for 3D cell migration, curved adhesions may serve as a therapeutic target for future development.
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Affiliation(s)
- Wei Zhang
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Chih-Hao Lu
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | | | - Ching-Ting Tsai
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Anish R. Roy
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Christina E. Lee
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Yang Yang
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Zeinab Jahed
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Xiao Li
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University; Stanford, CA 94305, USA
- Wu-Tsai Neuroscience Institute and ChEM-H institute, Stanford University; Stanford, CA 94305, USA
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10
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Krishnan S, Klingauf J. The readily retrievable pool of synaptic vesicles. Biol Chem 2023; 404:385-397. [PMID: 36867726 DOI: 10.1515/hsz-2022-0298] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 02/16/2023] [Indexed: 03/05/2023]
Abstract
In the CNS communication between neurons occurs at synapses by secretion of neurotransmitter via exocytosis of synaptic vesicles (SVs) at the active zone. Given the limited number of SVs in presynaptic boutons a fast and efficient recycling of exocytosed membrane and proteins by triggered compensatory endocytosis is required to maintain neurotransmission. Thus, pre-synapses feature a unique tight coupling of exo- and endocytosis in time and space resulting in the reformation of SVs with uniform morphology and well-defined molecular composition. This rapid response requires early stages of endocytosis at the peri-active zone to be well choreographed to ensure reformation of SVs with high fidelity. The pre-synapse can address this challenge by a specialized membrane microcompartment, where a pre-sorted and pre-assembled readily retrievable pool (RRetP) of endocytic membrane patches is formed, consisting of the vesicle cargo, presumably bound within a nucleated Clathrin and adaptor complex. This review considers evidence for the RRetP microcompartment to be the primary organizer of presynaptic triggered compensatory endocytosis.
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Affiliation(s)
- Sai Krishnan
- Institute of Medical Physics and Biophysics, University of Münster, Robert-Koch Strasse 31, D-48149, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, University of Münster, Robert-Koch Strasse 31, D-48149, Münster, Germany.,Center for Soft Nanoscience, Busso-Peus Strasse 10, D-48149, Münster, Germany
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11
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Oligomer-to-monomer transition underlies the chaperone function of AAGAB in AP1/AP2 assembly. Proc Natl Acad Sci U S A 2023; 120:e2205199120. [PMID: 36598941 PMCID: PMC9926252 DOI: 10.1073/pnas.2205199120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Assembly of protein complexes is facilitated by assembly chaperones. Alpha and gamma adaptin-binding protein (AAGAB) is a chaperone governing the assembly of the heterotetrameric adaptor complexes 1 and 2 (AP1 and AP2) involved in clathrin-mediated membrane trafficking. Here, we found that before AP1/2 binding, AAGAB exists as a homodimer. AAGAB dimerization is mediated by its C-terminal domain (CTD), which is critical for AAGAB stability and is missing in mutant proteins found in patients with the skin disease punctate palmoplantar keratoderma type 1 (PPKP1). We solved the crystal structure of the dimerization-mediating CTD, revealing an antiparallel dimer of bent helices. Interestingly, AAGAB uses the same CTD to recognize and stabilize the γ subunit in the AP1 complex and the α subunit in the AP2 complex, forming binary complexes containing only one copy of AAGAB. These findings demonstrate a dual role of CTD in stabilizing resting AAGAB and binding to substrates, providing a molecular explanation for disease-causing AAGAB mutations. The oligomerization state transition mechanism may also underlie the functions of other assembly chaperones.
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12
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Beacham GM, Wei DT, Beyrent E, Zhang Y, Zheng J, Camacho MMK, Florens L, Hollopeter G. The Caenorhabditis elegans ASPP homolog APE-1 is a junctional protein phosphatase 1 modulator. Genetics 2022; 222:iyac102. [PMID: 35792852 PMCID: PMC9434228 DOI: 10.1093/genetics/iyac102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/28/2022] [Indexed: 08/19/2023] Open
Abstract
How serine/threonine phosphatases are spatially and temporally tuned by regulatory subunits is a fundamental question in cell biology. Ankyrin repeat, SH3 domain, proline-rich-region-containing proteins are protein phosphatase 1 catalytic subunit binding partners associated with cardiocutaneous diseases. Ankyrin repeat, SH3 domain, proline-rich-region-containing proteins localize protein phosphatase 1 catalytic subunit to cell-cell junctions, but how ankyrin repeat, SH3 domain, proline-rich-region-containing proteins localize and whether they regulate protein phosphatase 1 catalytic subunit activity in vivo is unclear. Through a Caenorhabditis elegans genetic screen, we find that loss of the ankyrin repeat, SH3 domain, proline-rich-region-containing protein homolog, APE-1, suppresses a pathology called "jowls," providing us with an in vivo assay for APE-1 activity. Using immunoprecipitations and mass spectrometry, we find that APE-1 binds the protein phosphatase 1 catalytic subunit called GSP-2. Through structure-function analysis, we discover that APE-1's N-terminal half directs the APE-1-GSP-2 complex to intercellular junctions. Additionally, we isolated mutations in highly conserved residues of APE-1's ankyrin repeats that suppress jowls yet do not preclude GSP-2 binding, implying APE-1 does more than simply localize GSP-2. Indeed, in vivo reconstitution of APE-1 suggests the ankyrin repeats modulate phosphatase output, a function we find to be conserved among vertebrate homologs.
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Affiliation(s)
| | - Derek T Wei
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Erika Beyrent
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Ying Zhang
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jian Zheng
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Mari M K Camacho
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Gunther Hollopeter
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853, USA
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13
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Zaccai NR, Kadlecova Z, Dickson VK, Korobchevskaya K, Kamenicky J, Kovtun O, Umasankar PK, Wrobel AG, Kaufman JGG, Gray SR, Qu K, Evans PR, Fritzsche M, Sroubek F, Höning S, Briggs JAG, Kelly BT, Owen DJ, Traub LM. FCHO controls AP2's initiating role in endocytosis through a PtdIns(4,5)P 2-dependent switch. SCIENCE ADVANCES 2022; 8:eabn2018. [PMID: 35486718 PMCID: PMC9054013 DOI: 10.1126/sciadv.abn2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the main mechanism by which mammalian cells control their cell surface proteome. Proper operation of the pivotal CME cargo adaptor AP2 requires membrane-localized Fer/Cip4 homology domain-only proteins (FCHO). Here, live-cell enhanced total internal reflection fluorescence-structured illumination microscopy shows that FCHO marks sites of clathrin-coated pit (CCP) initiation, which mature into uniform-sized CCPs comprising a central patch of AP2 and clathrin corralled by an FCHO/Epidermal growth factor potential receptor substrate number 15 (Eps15) ring. We dissect the network of interactions between the FCHO interdomain linker and AP2, which concentrates, orients, tethers, and partially destabilizes closed AP2 at the plasma membrane. AP2's subsequent membrane deposition drives its opening, which triggers FCHO displacement through steric competition with phosphatidylinositol 4,5-bisphosphate, clathrin, cargo, and CME accessory factors. FCHO can now relocate toward a CCP's outer edge to engage and activate further AP2s to drive CCP growth/maturation.
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Affiliation(s)
- Nathan R. Zaccai
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Zuzana Kadlecova
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | | | - Kseniya Korobchevskaya
- Kennedy Institute of Rheumatology, University of Oxford, Roosevelt Drive, Oxford OX3 7FY, UK
| | - Jan Kamenicky
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - Oleksiy Kovtun
- MRC LMB Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Perunthottathu K. Umasankar
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Antoni G. Wrobel
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | | | - Sally R. Gray
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Kun Qu
- MRC LMB Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | | | - Marco Fritzsche
- Kennedy Institute of Rheumatology, University of Oxford, Roosevelt Drive, Oxford OX3 7FY, UK
- Rosalind Franklin Institute, Harwell Campus, Didcot, UK
| | - Filip Sroubek
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - Stefan Höning
- Institute for Biochemistry I, Medical Faculty, University of Cologne, Joseph-Stelzmann-Straße 52, 50931 Cologne, Germany
| | - John A. G. Briggs
- MRC LMB Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Bernard T. Kelly
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - David J. Owen
- CIMR, University of Cambridge, Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Linton M. Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, Pittsburgh, PA, USA
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14
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Partlow EA, Cannon KS, Hollopeter G, Baker RW. Structural basis of an endocytic checkpoint that primes the AP2 clathrin adaptor for cargo internalization. Nat Struct Mol Biol 2022; 29:339-347. [PMID: 35347313 PMCID: PMC10116491 DOI: 10.1038/s41594-022-00749-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 02/16/2022] [Indexed: 11/08/2022]
Abstract
Clathrin-mediated endocytosis (CME) is the main route of internalization from the plasma membrane. It is known that the heterotetrameric AP2 clathrin adaptor must open to simultaneously engage membrane and endocytic cargo, yet it is unclear how transmembrane cargos are captured to catalyze CME. Using cryogenic-electron microscopy, we discover a new way in which mouse AP2 can reorganize to expose membrane- and cargo-binding pockets, which is not observed in clathrin-coated structures. Instead, it is stimulated by endocytic pioneer proteins called muniscins, which do not enter vesicles. Muniscin-engaged AP2 is primed to rearrange into the vesicle-competent conformation on binding the tyrosine cargo internalization motif (YxxΦ). We propose adaptor priming as a checkpoint to ensure cargo internalization.
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Affiliation(s)
- Edward A Partlow
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA
| | - Kevin S Cannon
- Department of Biochemistry and Biophysics, University of North Carolina (UNC) Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | | | - Richard W Baker
- Department of Biochemistry and Biophysics, University of North Carolina (UNC) Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- UNC Lineberger Comprehensive Cancer Center, University of North Carolina (UNC) Chapel Hill School of Medicine, Chapel Hill, NC, USA.
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15
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Aniento F, Sánchez de Medina Hernández V, Dagdas Y, Rojas-Pierce M, Russinova E. Molecular mechanisms of endomembrane trafficking in plants. THE PLANT CELL 2022; 34:146-173. [PMID: 34550393 PMCID: PMC8773984 DOI: 10.1093/plcell/koab235] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/12/2021] [Indexed: 05/10/2023]
Abstract
Endomembrane trafficking is essential for all eukaryotic cells. The best-characterized membrane trafficking organelles include the endoplasmic reticulum (ER), Golgi apparatus, early and recycling endosomes, multivesicular body, or late endosome, lysosome/vacuole, and plasma membrane. Although historically plants have given rise to cell biology, our understanding of membrane trafficking has mainly been shaped by the much more studied mammalian and yeast models. Whereas organelles and major protein families that regulate endomembrane trafficking are largely conserved across all eukaryotes, exciting variations are emerging from advances in plant cell biology research. In this review, we summarize the current state of knowledge on plant endomembrane trafficking, with a focus on four distinct trafficking pathways: ER-to-Golgi transport, endocytosis, trans-Golgi network-to-vacuole transport, and autophagy. We acknowledge the conservation and commonalities in the trafficking machinery across species, with emphasis on diversity and plant-specific features. Understanding the function of organelles and the trafficking machinery currently nonexistent in well-known model organisms will provide great opportunities to acquire new insights into the fundamental cellular process of membrane trafficking.
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Affiliation(s)
| | - Víctor Sánchez de Medina Hernández
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030, Vienna, Austria
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16
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El Alaoui F, Casuso I, Sanchez-Fuentes D, Arpin-Andre C, Rathar R, Baecker V, Castro A, Lorca T, Viaud J, Vassilopoulos S, Carretero-Genevrier A, Picas L. Structural organization and dynamics of FCHo2 docking on membranes. eLife 2022; 11:e73156. [PMID: 35044298 PMCID: PMC8798043 DOI: 10.7554/elife.73156] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/18/2022] [Indexed: 11/24/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) is a central trafficking pathway in eukaryotic cells regulated by phosphoinositides. The plasma membrane phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) plays an instrumental role in driving CME initiation. The F-BAR domain-only protein 1 and 2 complex (FCHo1/2) is among the early proteins that reach the plasma membrane, but the exact mechanisms triggering its recruitment remain elusive. Here, we show the molecular dynamics of FCHo2 self-assembly on membranes by combining minimal reconstituted in vitro and cellular systems. Our results indicate that PI(4,5)P2 domains assist FCHo2 docking at specific membrane regions, where it self-assembles into ring-like-shaped protein patches. We show that the binding of FCHo2 on cellular membranes promotes PI(4,5)P2 clustering at the boundary of cargo receptors and that this accumulation enhances clathrin assembly. Thus, our results provide a mechanistic framework that could explain the recruitment of early PI(4,5)P2-interacting proteins at endocytic sites.
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Affiliation(s)
- Fatima El Alaoui
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS UMR 9004, Université de MontpellierMontpellierFrance
| | | | - David Sanchez-Fuentes
- Institut d'Électronique et des Systèmes (IES), CNRS UMR 5214, Université de MontpellierMontpellierFrance
| | - Charlotte Arpin-Andre
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS UMR 9004, Université de MontpellierMontpellierFrance
| | - Raissa Rathar
- Institut d'Électronique et des Systèmes (IES), CNRS UMR 5214, Université de MontpellierMontpellierFrance
| | - Volker Baecker
- Montpellier Ressources Imagerie, BioCampus Montpellier, CNRS, INSERM, Université de MontpellierMontpellierFrance
| | - Anna Castro
- Centre de Biologie Cellulaire de Montpellier (CRBM), CNRS UMR UMR 5237, Université de MontpellierMontpellierFrance
| | - Thierry Lorca
- Centre de Biologie Cellulaire de Montpellier (CRBM), CNRS UMR UMR 5237, Université de MontpellierMontpellierFrance
| | - Julien Viaud
- INSERM UMR1297, Institute of Metabolic and Cardiovascular Diseases (I2MC), University of Toulouse, Paul Sabatier UniversityToulouseFrance
| | - Stéphane Vassilopoulos
- Sorbonne Université, INSERM, Institute of Myology, Centre of Research in Myology, UMRS 974ParisFrance
| | - Adrian Carretero-Genevrier
- Institut d'Électronique et des Systèmes (IES), CNRS UMR 5214, Université de MontpellierMontpellierFrance
| | - Laura Picas
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS UMR 9004, Université de MontpellierMontpellierFrance
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17
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Lee SE, Cho E, Jeong S, Song Y, Kang S, Chang S. SGIP1α, but Not SGIP1, is an Ortholog of FCHo Proteins and Functions as an Endocytic Regulator. Front Cell Dev Biol 2022; 9:801420. [PMID: 35004694 PMCID: PMC8740024 DOI: 10.3389/fcell.2021.801420] [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: 10/25/2021] [Accepted: 12/01/2021] [Indexed: 11/24/2022] Open
Abstract
Src homology 3-domain growth factor receptor-bound 2-like interacting protein 1 (SGIP1), originally known as a regulator of energy homeostasis, was later found to be an ortholog of Fer/Cip4 homology domain-only (FCHo) proteins and to function during endocytosis. SGIP1α is a longer splicing variant in mouse brains that contains additional regions in the membrane phospholipid-binding domain (MP) and C-terminal region, but functional consequences with or without additional regions between SGIP1 and SGIP1α remain elusive. Moreover, many previous studies have either inadvertently used SGIP1 instead of SGIP1α or used the different isoforms with or without additional regions indiscriminately, resulting in further confusion. Here, we report that the additional region in the MP is essential for SGIP1α to deform membrane into tubules and for homo-oligomerization, and SGIP1, which lacks this region, fails to perform these functions. Moreover, only SGIP1α rescued endocytic defects caused by FCHo knock-down. Thus, our results indicate that SGIP1α, but not SGIP1, is the functional ortholog of FCHos, and SGIP1 and SGIP1α are not functionally redundant. These findings suggest that caution should be taken in interpreting the role of SGIP1 in endocytosis.
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Affiliation(s)
- Sang-Eun Lee
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Eunji Cho
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Soomin Jeong
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Yejij Song
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Seokjo Kang
- Department of Biochemistry and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
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18
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Abstract
Phosphoinositides are signalling lipids derived from phosphatidylinositol, a ubiquitous phospholipid in the cytoplasmic leaflet of eukaryotic membranes. Initially discovered for their roles in cell signalling, phosphoinositides are now widely recognized as key integrators of membrane dynamics that broadly impact on all aspects of cell physiology and on disease. The past decade has witnessed a vast expansion of our knowledge of phosphoinositide biology. On the endocytic and exocytic routes, phosphoinositides direct the inward and outward flow of membrane as vesicular traffic is coupled to the conversion of phosphoinositides. Moreover, recent findings on the roles of phosphoinositides in autophagy and the endolysosomal system challenge our view of lysosome biology. The non-vesicular exchange of lipids, ions and metabolites at membrane contact sites in between organelles has also been found to depend on phosphoinositides. Here we review our current understanding of how phosphoinositides shape and direct membrane dynamics to impact on cell physiology, and provide an overview of emerging concepts in phosphoinositide regulation.
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19
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Jean F, Stasiuk S, Maroilley T, Diao C, Galbraith A, Tarailo-Graovac M. Whole genome sequencing facilitates intragenic variant interpretation following modifier screening in C. elegans. BMC Genomics 2021; 22:820. [PMID: 34773966 PMCID: PMC8590768 DOI: 10.1186/s12864-021-08142-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/01/2021] [Indexed: 11/10/2022] Open
Abstract
Background Intragenic modifiers (in-phase, second-site variants) are known to have dramatic effects on clinical outcomes, affecting disease attributes such as severity or age of onset. However, despite their clinical importance, the focus of many genetic screens in model systems is on the discovery of extragenic variants, with many labs still relying upon more traditional methods to identify modifiers. However, traditional methods such as PCR and Sanger sequencing can be time-intensive and do not permit a thorough understanding of the intragenic modifier effects in the context of non-isogenic genomic backgrounds. Results Here, we apply high throughput approaches to identify and understand intragenic modifiers using Caenorhabditis elegans. Specifically, we applied whole genome sequencing (WGS) to a mutagen-induced forward genetic screen to identify intragenic suppressors of a temperature-sensitive zyg-1(it25) allele in C. elegans. ZYG-1 is a polo kinase that is important for centriole function and cell divisions, and mutations that truncate its human orthologue, PLK4, have been associated with microcephaly. Combining WGS and CRISPR/Cas9, we rapidly identify intragenic modifiers, show that these variants are distributed non-randomly throughout zyg-1 and that genomic context plays an important role on phenotypic outcomes. Conclusions Ultimately, our work shows that WGS facilitates high-throughput identification of intragenic modifiers in clinically relevant genes by reducing hands-on research time and overall costs and by allowing thorough understanding of the intragenic phenotypic effects in the context of different genetic backgrounds. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08142-8.
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Affiliation(s)
- Francesca Jean
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Susan Stasiuk
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Tatiana Maroilley
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Catherine Diao
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Andrew Galbraith
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Maja Tarailo-Graovac
- Departments of Biochemistry, Molecular Biology and Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. .,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.
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20
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Wan C, Crisman L, Wang B, Tian Y, Wang S, Yang R, Datta I, Nomura T, Li S, Yu H, Yin Q, Shen J. AAGAB is an assembly chaperone regulating AP1 and AP2 clathrin adaptors. J Cell Sci 2021; 134:272394. [PMID: 34494650 DOI: 10.1242/jcs.258587] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 08/31/2021] [Indexed: 11/20/2022] Open
Abstract
Multimeric cargo adaptors such as AP2 play central roles in intracellular membrane trafficking. We recently discovered that the assembly of the AP2 adaptor complex, a key player in clathrin-mediated endocytosis, is a highly organized process controlled by alpha- and gamma-adaptin-binding protein (AAGAB, also known as p34). In this study, we demonstrate that besides AP2, AAGAB also regulates the assembly of AP1, a cargo adaptor involved in clathrin-mediated transport between the trans-Golgi network and the endosome. However, AAGAB is not involved in the formation of other adaptor complexes, including AP3. AAGAB promotes AP1 assembly by binding and stabilizing the γ and σ subunits of AP1, and its mutation abolishes AP1 assembly and disrupts AP1-mediated cargo trafficking. Comparative proteomic analyses indicate that AAGAB mutation massively alters surface protein homeostasis, and its loss-of-function phenotypes reflect the synergistic effects of AP1 and AP2 deficiency. Taken together, these findings establish AAGAB as an assembly chaperone for both AP1 and AP2 adaptors and pave the way for understanding the pathogenesis of AAGAB-linked diseases.
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Affiliation(s)
- Chun Wan
- 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
| | - Bing Wang
- Department of Biological Sciences and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Yuan Tian
- Department of Biological Sciences and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Shifeng Wang
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Rui Yang
- Department of Biological Sciences and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Ishara Datta
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Toshifumi Nomura
- Department of Dermatology, University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Suzhao Li
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Haijia Yu
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Qian Yin
- Department of Biological Sciences and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Jingshi Shen
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
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21
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Ramesh ST, Navyasree KV, Sah S, Ashok AB, Qathoon N, Mohanty S, Swain RK, Umasankar PK. BMP2K phosphorylates AP-2 and regulates clathrin-mediated endocytosis. Traffic 2021; 22:377-396. [PMID: 34480404 DOI: 10.1111/tra.12814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 01/29/2023]
Abstract
Phosphorylation of the central adaptor protein complex, AP-2 is pivotal for clathrin-mediated endocytosis (CME). Here, we uncover the role of an uncharacterized kinase (BMP-2 inducible kinase-BMP2K) in AP-2 phosphorylation. We demonstrate that BMP2K can phosphorylate AP-2 in vitro and in vivo. Functional impairment of BMP2K impedes AP-2 phosphorylation leading to defects in clathrin-coated pit (CCP) morphology and cargo internalization. BMP2K engages AP-2 via its extended C-terminus and this interaction is important for its CCP localization and function. Notably, endogenous BMP2K levels decline upon functional impairment of AP-2 indicating AP-2 dependent BMP2K stabilization in cells. Further, functional inactivation of BMP2K in zebrafish embryos yields gastrulation phenotypes which mirror AP-2 loss-of-function suggesting physiological relevance of BMP2K in vertebrates. Together, our findings propose involvement of a novel kinase in AP-2 phosphorylation and in the operation of CME.
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Affiliation(s)
- Shikha T Ramesh
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Centre for Doctoral Studies, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Kolaparamba V Navyasree
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India.,Centre for Doctoral Studies, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Sneha Sah
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Anjitha B Ashok
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | - Nishada Qathoon
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
| | | | | | - Perunthottathu K Umasankar
- Intracellular Trafficking Laboratory, Transdisciplinary Biology Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India
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22
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Synaptic AP2 CCV life cycle regulation by the Eps15, ITSN1, Sgip1/AP2, synaptojanin1 interactome. Sci Rep 2021; 11:8007. [PMID: 33850201 PMCID: PMC8044098 DOI: 10.1038/s41598-021-87591-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/30/2021] [Indexed: 11/18/2022] Open
Abstract
The AP1/σ1B knockout causes impaired synaptic vesicle recycling and enhanced protein sorting into endosomes, leading to severe intellectual disability. These disturbances in synaptic protein sorting induce as a secondary phenotype the upregulation of AP2 CCV mediated endocytosis. Synapses contain canonical AP2 CCV and AP2 CCV with a more stable coat and thus extended life time. In AP1/σ1B knockout synapses, pool sizes of both CCV classes are doubled. Additionally, stable CCV of the knockout are more stabilised than stable wt CCV. One mechanism responsible for enhanced CCV stabilisation is the reduction of synaptojanin1 CCV levels, the PI-4,5-P2 phosphatase essential for AP2 membrane dissociation. To identify mechanisms regulating synaptojanin1 recruitment, we compared synaptojanin1 CCV protein interactome levels and CCV protein interactions between both CCV classes from wt and knockout mice. We show that ITSN1 determines synaptojanin1 CCV levels. Sgip1/AP2 excess hinders synaptojanin1 binding to ITSN1, further lowering its levels. ITSN1 levels are determined by Eps15, not Eps15L1. In addition, the data reveal that reduced amounts of pacsin1 can be counter balanced by its enhanced activation. These data exemplify the complexity of CCV life cycle regulation and indicate how cargo proteins determine the life cycle of their CCV.
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23
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Dvorakova M, Kubik-Zahorodna A, Straiker A, Sedlacek R, Hajkova A, Mackie K, Blahos J. SGIP1 is involved in regulation of emotionality, mood, and nociception and modulates in vivo signalling of cannabinoid CB 1 receptors. Br J Pharmacol 2021; 178:1588-1604. [PMID: 33491188 PMCID: PMC8795748 DOI: 10.1111/bph.15383] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/06/2020] [Accepted: 01/09/2021] [Indexed: 01/04/2023] Open
Abstract
Background and Purpose Src homology 3‐domain growth factor receptor‐bound 2‐like endophilin interacting protein 1 (SGIP1) interacts with cannabinoid CB1 receptors. SGIP1 is abundantly and principally expressed within the nervous system. SGIP1 and CB1 receptors co‐localize in axons and presynaptic boutons. SGIP1 interferes with the internalization of activated CB1 receptors in transfected heterologous cells. Consequently, the transient association of CB1 receptors with β‐arrestin2 is enhanced and prolonged, and CB1 receptor‐mediated ERK1/2 signalling is decreased. Because of these actions, SGIP1 may modulate affect, anxiety, pain processing, and other physiological processes controlled by the endocannabinoid system (ECS). Experimental Approach Using a battery of behavioural tests, we investigated the consequences of SGIP1 deletion in tasks regulated by the ECS in SGIP1 constitutive knockout (SGIP1−/−) mice. Key Results In SGIP1−/− mice, sensorimotor gating, exploratory levels, and working memory are unaltered. SGIP1−/− mice have decreased anxiety‐like behaviours. Fear extinction to tone is facilitated in SGIP1−/− females. Several cannabinoid tetrad behaviours are altered in the absence of SGIP1. SGIP1−/− males exhibit abnormal behaviours on Δ9‐tetrahydrocannabinol withdrawal. SGIP1 deletion also reduces acute nociception, and SGIP1−/− mice are more sensitive to analgesics. Conclusion and Implications SGIP1 was detected as a novel protein associated with CB1 receptors, and profoundly modified CB1 receptor signalling. Genetic deletion of SGIP1 particularly affected behavioural tests of mood‐related assessment and the cannabinoid tetrad. SGIP1−/− mice exhibit decreased nociception and augmented responses to CB1 receptor agonists and morphine. These in vivo findings suggest that SGIP1 is a novel modulator of CB1 receptor‐mediated behaviour.
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Affiliation(s)
- Michaela Dvorakova
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague 4, Czech Republic.,Department of Psychological and Brain Sciences, Gill Center for Molecular Bioscience, Indiana University, Bloomington, Indiana, USA
| | - Agnieszka Kubik-Zahorodna
- The Czech Center for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Alex Straiker
- Department of Psychological and Brain Sciences, Gill Center for Molecular Bioscience, Indiana University, Bloomington, Indiana, USA
| | - Radislav Sedlacek
- The Czech Center for Phenogenomics, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Alena Hajkova
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague 4, Czech Republic
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Gill Center for Molecular Bioscience, Indiana University, Bloomington, Indiana, USA
| | - Jaroslav Blahos
- Department of Molecular Pharmacology, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague 4, Czech Republic
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24
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Gerasymchuk D, Hubiernatorova A, Domanskyi A. MicroRNAs Regulating Cytoskeleton Dynamics, Endocytosis, and Cell Motility-A Link Between Neurodegeneration and Cancer? Front Neurol 2020; 11:549006. [PMID: 33240194 PMCID: PMC7680873 DOI: 10.3389/fneur.2020.549006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 10/06/2020] [Indexed: 12/13/2022] Open
Abstract
The cytoskeleton is one of the most mobile and complex cell structures. It is involved in cellular transport, cell division, cell shape formation and adaptation in response to extra- and intracellular stimuli, endo- and exocytosis, migration, and invasion. These processes are crucial for normal cellular physiology and are affected in several pathological processes, including neurodegenerative diseases, and cancer. Some proteins, participating in clathrin-mediated endocytosis (CME), play an important role in actin cytoskeleton reorganization, and formation of invadopodia in cancer cells and are also deregulated in neurodegenerative disorders. However, there is still limited information about the factors contributing to the regulation of their expression. MicroRNAs are potent negative regulators of gene expression mediating crosstalk between different cellular pathways in cellular homeostasis and stress responses. These molecules regulate numerous genes involved in neuronal differentiation, plasticity, and degeneration. Growing evidence suggests the role of microRNAs in the regulation of endocytosis, cell motility, and invasiveness. By modulating the levels of such microRNAs, it may be possible to interfere with CME or other processes to normalize their function. In malignancy, the role of microRNAs is undoubtful, and therefore changing their levels can attenuate the carcinogenic process. Here we review the current advances in our understanding of microRNAs regulating actin cytoskeleton dynamics, CME and cell motility with a special focus on neurodegenerative diseases, and cancer. We investigate whether current literature provides an evidence that microRNA-mediated regulation of essential cellular processes, such as CME and cell motility, is conserved in neurons, and cancer cells. We argue that more research effort should be addressed to study the neuron-specific functions on microRNAs. Disease-associated microRNAs affecting essential cellular processes deserve special attention both from the view of fundamental science and as future neurorestorative or anti-cancer therapies.
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Affiliation(s)
- Dmytro Gerasymchuk
- Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland.,Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | | | - Andrii Domanskyi
- Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
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25
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Redpath GMI, Betzler VM, Rossatti P, Rossy J. Membrane Heterogeneity Controls Cellular Endocytic Trafficking. Front Cell Dev Biol 2020; 8:757. [PMID: 32850860 PMCID: PMC7419583 DOI: 10.3389/fcell.2020.00757] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 07/20/2020] [Indexed: 12/21/2022] Open
Abstract
Endocytic trafficking relies on highly localized events in cell membranes. Endocytosis involves the gathering of protein (cargo/receptor) at distinct plasma membrane locations defined by specific lipid and protein compositions. Simultaneously, the molecular machinery that drives invagination and eventually scission of the endocytic vesicle assembles at the very same place on the inner leaflet of the membrane. It is membrane heterogeneity - the existence of specific lipid and protein domains in localized regions of membranes - that creates the distinct molecular identity required for an endocytic event to occur precisely when and where it is required rather than at some random location within the plasma membrane. Accumulating evidence leads us to believe that the trafficking fate of internalized proteins is sealed following endocytosis, as this distinct membrane identity is preserved through the endocytic pathway, upon fusion of endocytic vesicles with early and sorting endosomes. In fact, just like at the plasma membrane, multiple domains coexist at the surface of these endosomes, regulating local membrane tubulation, fission and sorting to recycling pathways or to the trans-Golgi network via late endosomes. From here, membrane heterogeneity ensures that fusion events between intracellular vesicles and larger compartments are spatially regulated to promote the transport of cargoes to their intracellular destination.
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Affiliation(s)
- Gregory M I Redpath
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,The ANZAC Research Institute, Concord Repatriation General Hospital, Concord, NSW, Australia
| | - Verena M Betzler
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.,Biotechnology Institute Thurgau (BITg) at the University of Konstanz, Kreuzlingen, Switzerland
| | - Pascal Rossatti
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.,Biotechnology Institute Thurgau (BITg) at the University of Konstanz, Kreuzlingen, Switzerland
| | - Jérémie Rossy
- Biotechnology Institute Thurgau (BITg) at the University of Konstanz, Kreuzlingen, Switzerland.,Department of Biology, University of Konstanz, Konstanz, Germany
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26
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LaBella ML, Hujber EJ, Moore KA, Rawson RL, Merrill SA, Allaire PD, Ailion M, Hollien J, Bastiani MJ, Jorgensen EM. Casein Kinase 1δ Stabilizes Mature Axons by Inhibiting Transcription Termination of Ankyrin. Dev Cell 2020; 52:88-103.e18. [PMID: 31910362 DOI: 10.1016/j.devcel.2019.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/09/2019] [Accepted: 12/10/2019] [Indexed: 01/19/2023]
Abstract
After axon outgrowth and synapse formation, the nervous system transitions to a stable architecture. In C. elegans, this transition is marked by the appearance of casein kinase 1δ (CK1δ) in the nucleus. In CK1δ mutants, neurons continue to sprout growth cones into adulthood, leading to a highly ramified nervous system. Nervous system architecture in these mutants is completely restored by suppressor mutations in ten genes involved in transcription termination. CK1δ prevents termination by phosphorylating and inhibiting SSUP-72. SSUP-72 would normally remodel the C-terminal domain of RNA polymerase in anticipation of termination. The antitermination activity of CK1δ establishes the mature state of a neuron by promoting the expression of the long isoform of a single gene, the cytoskeleton protein Ankyrin.
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Affiliation(s)
- Matthew L LaBella
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Edward J Hujber
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Kristin A Moore
- Department of Biology, University of Utah, Salt Lake City, UT, USA
| | - Randi L Rawson
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Sean A Merrill
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Patrick D Allaire
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Julie Hollien
- Department of Biology, University of Utah, Salt Lake City, UT, USA
| | | | - Erik M Jorgensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA.
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27
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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: 36] [Impact Index Per Article: 9.0] [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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28
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Fletcher-Jones A, Hildick KL, Evans AJ, Nakamura Y, Henley JM, Wilkinson KA. Protein Interactors and Trafficking Pathways That Regulate the Cannabinoid Type 1 Receptor (CB1R). Front Mol Neurosci 2020; 13:108. [PMID: 32595453 PMCID: PMC7304349 DOI: 10.3389/fnmol.2020.00108] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 05/20/2020] [Indexed: 12/29/2022] Open
Abstract
The endocannabinoid system (ECS) acts as a negative feedback mechanism to suppress synaptic transmission and plays a major role in a diverse range of brain functions including, for example, the regulation of mood, energy balance, and learning and memory. The function and dysfunction of the ECS are strongly implicated in multiple psychiatric, neurological, and neurodegenerative diseases. Cannabinoid type 1 receptor (CB1R) is the most abundant G protein-coupled receptor (GPCR) expressed in the brain and, as for any synaptic receptor, CB1R needs to be in the right place at the right time to respond appropriately to changing synaptic circumstances. While CB1R is found intracellularly throughout neurons, its surface expression is highly polarized to the axonal membrane, consistent with its functional expression at presynaptic sites. Surprisingly, despite the importance of CB1R, the interacting proteins and molecular mechanisms that regulate the highly polarized distribution and function of CB1R remain relatively poorly understood. Here we set out what is currently known about the trafficking pathways and protein interactions that underpin the surface expression and axonal polarity of CB1R, and highlight key questions that still need to be addressed.
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Affiliation(s)
- Alexandra Fletcher-Jones
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Keri L Hildick
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Ashley J Evans
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Yasuko Nakamura
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Jeremy M Henley
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Kevin A Wilkinson
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
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29
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Łyszkiewicz M, Ziętara N, Frey L, Pannicke U, Stern M, Liu Y, Fan Y, Puchałka J, Hollizeck S, Somekh I, Rohlfs M, Yilmaz T, Ünal E, Karakukcu M, Patiroğlu T, Kellerer C, Karasu E, Sykora KW, Lev A, Simon A, Somech R, Roesler J, Hoenig M, Keppler OT, Schwarz K, Klein C. Human FCHO1 deficiency reveals role for clathrin-mediated endocytosis in development and function of T cells. Nat Commun 2020; 11:1031. [PMID: 32098969 PMCID: PMC7042371 DOI: 10.1038/s41467-020-14809-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 01/23/2020] [Indexed: 01/05/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is critical for internalisation of molecules across cell membranes. The FCH domain only 1 (FCHO1) protein is key molecule involved in the early stages of CME formation. The consequences of mutations in FCHO1 in humans were unknown. We identify ten unrelated patients with variable T and B cell lymphopenia, who are homozygous for six distinct mutations in FCHO1. We demonstrate that these mutations either lead to mislocalisation of the protein or prevent its interaction with binding partners. Live-cell imaging of cells expressing mutant variants of FCHO1 provide evidence of impaired formation of clathrin coated pits (CCP). Patient T cells are unresponsive to T cell receptor (TCR) triggering. Internalisation of the TCR receptor is severely perturbed in FCHO1-deficient Jurkat T cells but can be rescued by expression of wild-type FCHO1. Thus, we discovered a previously unrecognised critical role of FCHO1 and CME during T-cell development and function in humans. FCH domain only 1 (FCHO1) is a key molecule involved in clathrin-mediated endocytosis (CME). Here, the authors report homozygous FCHO1 mutations in individuals with variable T and B cell lymphopenia, which are associated with loss-of-function of FCHO1 and impaired formation of clathrin-coated pits in T cells.
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Affiliation(s)
- Marcin Łyszkiewicz
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany. .,Institute for Immunology, Biomedical Center Munich, Ludwig-Maximilians-Universität München, Planegg-Martinsried, 82152, Munich, Germany.
| | - Natalia Ziętara
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany.,Institute for Immunology, Biomedical Center Munich, Ludwig-Maximilians-Universität München, Planegg-Martinsried, 82152, Munich, Germany
| | - Laura Frey
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Ulrich Pannicke
- Institute for Transfusion Medicine, University of Ulm, Ulm, Germany
| | - Marcel Stern
- Max von Pettenkofer Institute, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany
| | - Yanshan Liu
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Yanxin Fan
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Jacek Puchałka
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Sebastian Hollizeck
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Ido Somekh
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Meino Rohlfs
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany
| | - Tuğba Yilmaz
- Department of Pediatrics, Division of Pediatric Hematology & Oncology, Erciyes University, Kayseri, Turkey
| | - Ekrem Ünal
- Department of Pediatrics, Division of Pediatric Hematology & Oncology, Erciyes University, Kayseri, Turkey
| | - Musa Karakukcu
- Department of Pediatrics, Division of Pediatric Hematology & Oncology, Erciyes University, Kayseri, Turkey
| | - Türkan Patiroğlu
- Department of Pediatrics, Division of Pediatric Hematology & Oncology, Erciyes University, Kayseri, Turkey.,Department of Pediatrics, Division of Pediatric Immunology, Erciyes University, Kayseri, Turkey
| | | | - Ebru Karasu
- Institute for Transfusion Medicine, University of Ulm, Ulm, Germany
| | - Karl-Walter Sykora
- Department of Pediatric Hematology/Oncology, Hannover Medical School, Hannover, Germany
| | - Atar Lev
- Pediatric Department A and the Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine Tel Aviv University, Tel Aviv, Israel
| | - Amos Simon
- Pediatric Department A and the Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine Tel Aviv University, Tel Aviv, Israel
| | - Raz Somech
- Pediatric Department A and the Immunology Service, Jeffrey Modell Foundation Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine Tel Aviv University, Tel Aviv, Israel
| | - Joachim Roesler
- Department of Pediatrics, Carl Gustav Carus Technical University Dresden, Dresden, Germany
| | - Manfred Hoenig
- Department of Pediatrics, University Medical Centre Ulm, Ulm, Germany
| | - Oliver T Keppler
- Max von Pettenkofer Institute, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU München, Munich, Germany.,German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
| | - Klaus Schwarz
- Institute for Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Service Baden-Wuerttemberg, Hessen, Germany
| | - Christoph Klein
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, LMU, Munich, Germany.
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30
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Joseph BB, Wang Y, Edeen P, Lažetić V, Grant BD, Fay DS. Control of clathrin-mediated endocytosis by NIMA family kinases. PLoS Genet 2020; 16:e1008633. [PMID: 32069276 PMCID: PMC7048319 DOI: 10.1371/journal.pgen.1008633] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/28/2020] [Accepted: 01/28/2020] [Indexed: 12/16/2022] Open
Abstract
Endocytosis, the process by which cells internalize plasma membrane and associated cargo, is regulated extensively by posttranslational modifications. Previous studies suggested the potential involvement of scores of protein kinases in endocytic control, of which only a few have been validated in vivo. Here we show that the conserved NIMA-related kinases NEKL-2/NEK8/9 and NEKL-3/NEK6/7 (the NEKLs) control clathrin-mediated endocytosis in C. elegans. Loss of NEKL-2 or NEKL-3 activities leads to penetrant larval molting defects and to the abnormal localization of trafficking markers in arrested larvae. Using an auxin-based degron system, we also find that depletion of NEKLs in adult-stage C. elegans leads to gross clathrin mislocalization and to a dramatic reduction in clathrin mobility at the apical membrane. Using a non-biased genetic screen to identify suppressors of nekl molting defects, we identified several components and regulators of AP2, the major clathrin adapter complex acting at the plasma membrane. Strikingly, reduced AP2 activity rescues both nekl mutant molting defects as well as associated trafficking phenotypes, whereas increased levels of active AP2 exacerbate nekl defects. Moreover, in a unique example of mutual suppression, NEKL inhibition alleviates defects associated with reduced AP2 activity, attesting to the tight link between NEKL and AP2 functions. We also show that NEKLs are required for the clustering and internalization of membrane cargo required for molting. Notably, we find that human NEKs can rescue molting and trafficking defects in nekl mutant worms, suggesting that the control of intracellular trafficking is an evolutionarily conserved function of NEK family kinases. In order to function properly, cells must continually import materials from the outside. This process, termed endocytosis, is necessary for the uptake of nutrients and for interpreting signals coming from the external environment or from within the body. These signals are critical during animal development but also affect many types of cell behaviors throughout life. In our current work, we show that several highly conserved proteins in the nematode Caenorhabditis elegans, NEKL-2 and NEKL-3, regulate endocytosis. The human counterparts of NEKL-2 and NEKL-3 have been implicated in cardiovascular and renal diseases as well as many types of cancers. However, their specific functions within cells is incompletely understood and very little is known about their role in endocytosis or how this role might impact disease processes. Here we use several complementary approaches to characterize the specific functions of C. elegans NEKL-2 and NEKL-3 in endocytosis and show that their human counterparts likely have very similar functions. This work paves the way to a better understanding of fundamental biological processes and to determining the cellular functions of proteins connected to human diseases.
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Affiliation(s)
- Braveen B. Joseph
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming, United States of America
| | - Yu Wang
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey, United States of America
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Phil Edeen
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming, United States of America
| | - Vladimir Lažetić
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming, United States of America
| | - Barth D. Grant
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey, United States of America
| | - David S. Fay
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming, United States of America
- * E-mail:
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31
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Schwihla M, Korbei B. The Beginning of the End: Initial Steps in the Degradation of Plasma Membrane Proteins. FRONTIERS IN PLANT SCIENCE 2020; 11:680. [PMID: 32528512 PMCID: PMC7253699 DOI: 10.3389/fpls.2020.00680] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/30/2020] [Indexed: 05/05/2023]
Abstract
The plasma membrane (PM), as border between the inside and the outside of a cell, is densely packed with proteins involved in the sensing and transmission of internal and external stimuli, as well as transport processes and is therefore vital for plant development as well as quick and accurate responses to the environment. It is consequently not surprising that several regulatory pathways participate in the tight regulation of the spatiotemporal control of PM proteins. Ubiquitination of PM proteins plays a key role in directing their entry into the endo-lysosomal system, serving as a signal for triggering endocytosis and further sorting for degradation. Nevertheless, a uniting picture of the different roles of the respective types of ubiquitination in the consecutive steps of down-regulation of membrane proteins is still missing. The trans-Golgi network (TGN), which acts as an early endosome (EE) in plants receives the endocytosed cargo, and here the decision is made to either recycled back to the PM or further delivered to the vacuole for degradation. A multi-complex machinery, the endosomal sorting complex required for transport (ESCRT), concentrates ubiquitinated proteins and ushers them into the intraluminal vesicles of multi-vesicular bodies (MVBs). Several ESCRTs have ubiquitin binding subunits, which anchor and guide the cargos through the endocytic degradation route. Basic enzymes and the mode of action in the early degradation steps of PM proteins are conserved in eukaryotes, yet many plant unique components exist, which are often essential in this pathway. Thus, deciphering the initial steps in the degradation of ubiquitinated PM proteins, which is the major focus of this review, will greatly contribute to the larger question of how plants mange to fine-tune their responses to their environment.
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32
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Lehmann M, Lukonin I, Noé F, Schmoranzer J, Clementi C, Loerke D, Haucke V. Nanoscale coupling of endocytic pit growth and stability. SCIENCE ADVANCES 2019; 5:eaax5775. [PMID: 31807703 PMCID: PMC6881173 DOI: 10.1126/sciadv.aax5775] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 09/25/2019] [Indexed: 05/21/2023]
Abstract
Clathrin-mediated endocytosis, an essential process for plasma membrane homeostasis and cell signaling, is characterized by stunning heterogeneity in the size and lifetime of clathrin-coated endocytic pits (CCPs). If and how CCP growth and lifetime are coupled and how this relates to their physiological function are unknown. We combine computational modeling, automated tracking of CCP dynamics, electron microscopy, and functional rescue experiments to demonstrate that CCP growth and lifetime are closely correlated and mechanistically linked by the early-acting endocytic F-BAR protein FCHo2. FCHo2 assembles at the rim of CCPs to control CCP growth and lifetime by coupling the invagination of early endocytic intermediates to clathrin lattice assembly. Our data suggest a mechanism for the nanoscale control of CCP growth and stability that may similarly apply to other metastable structures in cells.
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Affiliation(s)
- Martin Lehmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Corresponding author. (V.H.); (M.L.)
| | - Ilya Lukonin
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Frank Noé
- Freie Universität Berlin, Department of Mathematics and Computer Science and Department of Physics, 14195 Berlin, Germany
- Center for Theoretical Biological Physics and Department of Chemistry, Rice University, Houston, TX 77005, USA
| | - Jan Schmoranzer
- Charité Universitätsmedizin Berlin, Virchowweg 6, 10117 Berlin, Germany
| | - Cecilia Clementi
- Freie Universität Berlin, Department of Mathematics and Computer Science and Department of Physics, 14195 Berlin, Germany
- Center for Theoretical Biological Physics and Department of Chemistry, Rice University, Houston, TX 77005, USA
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
- Freie Universität Berlin, Faculty of Biology, Chemistry, Pharmacy, 14195 Berlin, Germany
- Corresponding author. (V.H.); (M.L.)
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33
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Endocytic Adaptor Proteins in Health and Disease: Lessons from Model Organisms and Human Mutations. Cells 2019; 8:cells8111345. [PMID: 31671891 PMCID: PMC6912373 DOI: 10.3390/cells8111345] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/11/2022] Open
Abstract
Cells need to exchange material and information with their environment. This is largely achieved via cell-surface receptors which mediate processes ranging from nutrient uptake to signaling responses. Consequently, their surface levels have to be dynamically controlled. Endocytosis constitutes a powerful mechanism to regulate the surface proteome and to recycle vesicular transmembrane proteins that strand at the plasma membrane after exocytosis. For efficient internalization, the cargo proteins need to be linked to the endocytic machinery via adaptor proteins such as the heterotetrameric endocytic adaptor complex AP-2 and a variety of mostly monomeric endocytic adaptors. In line with the importance of endocytosis for nutrient uptake, cell signaling and neurotransmission, animal models and human mutations have revealed that defects in these adaptors are associated with several diseases ranging from metabolic disorders to encephalopathies. This review will discuss the physiological functions of the so far known adaptor proteins and will provide a comprehensive overview of their links to human diseases.
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34
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Mangione MC, Snider CE, Gould KL. The intrinsically disordered region of the cytokinetic F-BAR protein Cdc15 performs a unique essential function in maintenance of cytokinetic ring integrity. Mol Biol Cell 2019; 30:2790-2801. [PMID: 31509478 PMCID: PMC6789166 DOI: 10.1091/mbc.e19-06-0314] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/21/2019] [Accepted: 09/05/2019] [Indexed: 11/17/2022] Open
Abstract
Successful separation of two daughter cells (i.e., cytokinesis) is essential for life. Many eukaryotic cells divide using a contractile apparatus called the cytokinetic ring (CR) that associates dynamically with the plasma membrane (PM) and generates force that contributes to PM ingression between daughter cells. In Schizosaccharomyces pombe, important membrane-CR scaffolds include the paralogous F-BAR proteins Cdc15 and Imp2. Their conserved protein structure consists of the archetypal F-BAR domain linked to an SH3 domain by an intrinsically disordered region (IDR). Functions have been assigned to the F-BAR and SH3 domains. In this study we probed the function of the central IDR. We found that the IDR of Cdc15 is essential for viability and cannot be replaced by that of Imp2, whereas the F-BAR domain of Cdc15 can be swapped with several different F-BAR domains, including that of Imp2. Deleting part of the IDR results in CR defects and abolishes calcineurin phosphatase localization to the CR. Together these results indicate that Cdc15's IDR has a nonredundant essential function that coordinates regulation of CR architecture.
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Affiliation(s)
- MariaSanta C. Mangione
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Chloe E. Snider
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
| | - Kathleen L. Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240
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Partlow EA, Baker RW, Beacham GM, Chappie JS, Leschziner AE, Hollopeter G. A structural mechanism for phosphorylation-dependent inactivation of the AP2 complex. eLife 2019; 8:e50003. [PMID: 31464684 PMCID: PMC6739873 DOI: 10.7554/elife.50003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/28/2019] [Indexed: 01/05/2023] Open
Abstract
Endocytosis of transmembrane proteins is orchestrated by the AP2 clathrin adaptor complex. AP2 dwells in a closed, inactive state in the cytosol, but adopts an open, active conformation on the plasma membrane. Membrane-activated complexes are also phosphorylated, but the significance of this mark is debated. We recently proposed that NECAP negatively regulates AP2 by binding open and phosphorylated complexes (Beacham et al., 2018). Here, we report high-resolution cryo-EM structures of NECAP bound to phosphorylated AP2. The site of AP2 phosphorylation is directly coordinated by residues of the NECAP PHear domain that are predicted from genetic screens in C. elegans. Using membrane mimetics to generate conformationally open AP2, we find that a second domain of NECAP binds these complexes and cryo-EM reveals both domains of NECAP engaging closed, inactive AP2. Assays in vitro and in vivo confirm these domains cooperate to inactivate AP2. We propose that phosphorylation marks adaptors for inactivation.
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Affiliation(s)
- Edward A Partlow
- Department of Molecular MedicineCornell UniversityNew YorkUnited States
| | - Richard W Baker
- Department of Cellular and Molecular MedicineSchool of Medicine, University of California, San DiegoLa JollaUnited States
| | | | - Joshua S Chappie
- Department of Molecular MedicineCornell UniversityNew YorkUnited States
| | - Andres E Leschziner
- Department of Cellular and Molecular MedicineSchool of Medicine, University of California, San DiegoLa JollaUnited States
- Section of Molecular Biology, Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
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Wrobel AG, Kadlecova Z, Kamenicky J, Yang JC, Herrmann T, Kelly BT, McCoy AJ, Evans PR, Martin S, Müller S, Salomon S, Sroubek F, Neuhaus D, Höning S, Owen DJ. Temporal Ordering in Endocytic Clathrin-Coated Vesicle Formation via AP2 Phosphorylation. Dev Cell 2019; 50:494-508.e11. [PMID: 31430451 PMCID: PMC6706699 DOI: 10.1016/j.devcel.2019.07.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/18/2019] [Accepted: 07/15/2019] [Indexed: 11/23/2022]
Abstract
Clathrin-mediated endocytosis (CME) is key to maintaining the transmembrane protein composition of cells' limiting membranes. During mammalian CME, a reversible phosphorylation event occurs on Thr156 of the μ2 subunit of the main endocytic clathrin adaptor, AP2. We show that this phosphorylation event starts during clathrin-coated pit (CCP) initiation and increases throughout CCP lifetime. μ2Thr156 phosphorylation favors a new, cargo-bound conformation of AP2 and simultaneously creates a binding platform for the endocytic NECAP proteins but without significantly altering AP2's cargo affinity in vitro. We describe the structural bases of both. NECAP arrival at CCPs parallels that of clathrin and increases with μ2Thr156 phosphorylation. In turn, NECAP recruits drivers of late stages of CCP formation, including SNX9, via a site distinct from where NECAP binds AP2. Disruption of the different modules of this phosphorylation-based temporal regulatory system results in CCP maturation being delayed and/or stalled, hence impairing global rates of CME.
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Affiliation(s)
| | | | - Jan Kamenicky
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - Ji-Chun Yang
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Torsten Herrmann
- University of Grenoble Alpes, CNRS, CEA, IBS, 38000 Grenoble, France
| | | | - Airlie J McCoy
- CIMR, WT/MRC Building, Hills Road, Cambridge CB2 0QQ, UK
| | - Philip R Evans
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Stephen Martin
- The Francis Crick Institute, 1 Midland Road, London NW1 1ST, UK
| | - Stefan Müller
- Center for Molecular Medicine (CMMC), University of Cologne, Robert-Koch-Straße 21, 50931 Cologne, Germany
| | - Susanne Salomon
- Institute for Biochemistry I, Medical Faulty, University of Cologne, Joseph-Stelzmann-Straße 52, 50931 Cologne, Germany
| | - Filip Sroubek
- Czech Academy of Sciences, Institute of Information Theory and Automation, Pod Vodarenskou vezi 4, 182 08 Prague 8, Czech Republic
| | - David Neuhaus
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Stefan Höning
- Institute for Biochemistry I, Medical Faulty, University of Cologne, Joseph-Stelzmann-Straße 52, 50931 Cologne, Germany.
| | - David J Owen
- CIMR, WT/MRC Building, Hills Road, Cambridge CB2 0QQ, UK
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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: 18] [Impact Index Per Article: 3.6] [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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Nance J, Frøkjær-Jensen C. The Caenorhabditis elegans Transgenic Toolbox. Genetics 2019; 212:959-990. [PMID: 31405997 PMCID: PMC6707460 DOI: 10.1534/genetics.119.301506] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/01/2019] [Indexed: 12/30/2022] Open
Abstract
The power of any genetic model organism is derived, in part, from the ease with which gene expression can be manipulated. The short generation time and invariant developmental lineage have made Caenorhabditis elegans very useful for understanding, e.g., developmental programs, basic cell biology, neurobiology, and aging. Over the last decade, the C. elegans transgenic toolbox has expanded considerably, with the addition of a variety of methods to control expression and modify genes with unprecedented resolution. Here, we provide a comprehensive overview of transgenic methods in C. elegans, with an emphasis on recent advances in transposon-mediated transgenesis, CRISPR/Cas9 gene editing, conditional gene and protein inactivation, and bipartite systems for temporal and spatial control of expression.
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Affiliation(s)
- Jeremy Nance
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York 10016
| | - Christian Frøkjær-Jensen
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division (BESE), KAUST Environmental Epigenetics Program (KEEP), Thuwal 23955-6900, Saudi Arabia
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Quantitative proteomics reveals reduction of endocytic machinery components in gliomas. EBioMedicine 2019; 46:32-41. [PMID: 31331834 PMCID: PMC6711119 DOI: 10.1016/j.ebiom.2019.07.039] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 02/04/2023] Open
Abstract
Background Gliomas are the most frequent and aggressive malignancies of the central nervous system. Decades of molecular analyses have demonstrated that gliomas accumulate genetic alterations that culminate in enhanced activity of receptor tyrosine kinases and downstream mediators. While the genetic alterations, like gene amplification or loss, have been well characterized, little information exists about changes in the proteome of gliomas of different grades. Methods We performed unbiased quantitative proteomics of human glioma biopsies by mass spectrometry followed by bioinformatic analysis. Findings Various pathways were found to be up- or downregulated. In particular, endocytosis as pathway was affected by a vast and concomitant reduction of multiple machinery components involved in initiation, formation, and scission of endocytic carriers. Both clathrin-dependent and -independent endocytosis were changed, since not only clathrin, AP-2 adaptins, and endophilins were downregulated, but also dynamin that is shared by both pathways. The reduction of endocytic machinery components caused increased receptor cell surface levels, a prominent phenotype of defective endocytosis. Analysis of additional biopsies revealed that depletion of endocytic machinery components was a common trait of various glioma grades and subclasses. Interpretation We propose that impaired endocytosis creates a selective advantage in glioma tumor progression due to prolonged receptor tyrosine kinase signaling from the cell surface. Fund This work was supported by Grants 316030-164105 (to P. Jenö), 31003A-162643 (to M. Spiess) and PP00P3-176974 (to G. Hutter) from the Swiss National Science Foundation. Further funding was received by the Department of Surgery from the University Hospital Basel.
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Lee SE, Jeong S, Lee U, Chang S. SGIP1α functions as a selective endocytic adaptor for the internalization of synaptotagmin 1 at synapses. Mol Brain 2019; 12:41. [PMID: 31053155 PMCID: PMC6499997 DOI: 10.1186/s13041-019-0464-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/16/2019] [Indexed: 11/10/2022] Open
Abstract
Proper sorting of exocytosed synaptic vesicle (SV) proteins into individual SVs during endocytosis is of the utmost importance for the fidelity of subsequent neurotransmission. Recent studies suggest that each SV protein is sorted into individual SVs by its own dedicated adaptors as well as by association between SV proteins. The SH3-containing GRB2-like protein 3-interacting protein 1 (SGIP1), an ortholog of Fer/Cip4 homology domain-only (FCHo) proteins, contains a μ-homology domain (μHD) and binds AP-2 and Eps15, thus functioning as an endocytic regulator of clathrin-mediated endocytosis (CME). Its longest isoform SGIP1α is predominantly expressed in the brain but the functional significance of SGIP1 in SV recycling remains unknown. Here, we found that SGIP1α, a brain-specific long isoform of SGIP1 binds synaptotagmin1 (Syt1) via its μHD and promotes the internalization of Syt1 on the neuronal surface. The small hairpin RNA (shRNA)-mediated knockdown (KD) of SGIP1α caused selective impairment of Syt1 internalization at hippocampal synapses and it was fully rescued by coexpression of the shRNA-resistant form of SGIP1α in KD neurons. We further found that the μHD of SGIP1α is structurally similar to those of AP-2 and stonin2, and mutations at Trp771 and Lys781, which correspond to Syt1-recognition motifs of AP-2 and stonin2, to Ala bound less efficiently to Syt1 and failed to rescue the endocytic defect of Syt1 caused by KD. Our results indicate that SGIP1α is an endocytic adaptor dedicated to the retrieval of surface-stranded Syt1. Since endocytic sorting of Syt1 is also mediated by the overlapping activities of synaptic vesicle glycoprotein 2A/B (SV2A/B) and stonin2, our results suggest that complementary fail-safe mechanism by these proteins ensures high fidelity of Syt1 retrieval.
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Affiliation(s)
- Sang-Eun Lee
- Department of Physiology and Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Soomin Jeong
- Department of Physiology and Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Unghwi Lee
- Department of Physiology and Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, South Korea.
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Traub LM. A nanobody-based molecular toolkit provides new mechanistic insight into clathrin-coat initiation. eLife 2019; 8:41768. [PMID: 31038455 PMCID: PMC6524969 DOI: 10.7554/elife.41768] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 04/24/2019] [Indexed: 12/21/2022] Open
Abstract
Besides AP-2 and clathrin triskelia, clathrin coat inception depends on a group of early-arriving proteins including Fcho1/2 and Eps15/R. Using genome-edited cells, we described the role of the unstructured Fcho linker in stable AP-2 membrane deposition. Here, expanding this strategy in combination with a new set of llama nanobodies against EPS15 shows an FCHO1/2–EPS15/R partnership plays a decisive role in coat initiation. A nanobody containing an Asn-Pro-Phe peptide within the complementarity-determining region 3 loop is a function-blocking pseudoligand for tandem EPS15/R EH domains. Yet, in living cells, EH domains gathered at clathrin-coated structures are poorly accessible, indicating residence by endogenous NPF-bearing partners. Forcibly sequestering cytosolic EPS15 in genome-edited cells with nanobodies tethered to early endosomes or mitochondria changes the subcellular location and availability of EPS15. This combined approach has strong effects on clathrin coat structure and function by dictating the stability of AP-2 assemblies at the plasma membrane.
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Affiliation(s)
- Linton M Traub
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, United States
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42
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Calzoni E, Platt CD, Keles S, Kuehn HS, Beaussant-Cohen S, Zhang Y, Pazmandi J, Lanzi G, Pala F, Tahiat A, Artac H, Heredia RJ, Dmytrus J, Reisli I, Uygun V, Uygun D, Bingol A, Basaran E, Djenouhat K, Benhalla N, Bendahmane C, Emiroglu M, Kirchhausen T, Pasham M, Jones J, Wallace JG, Zheng L, Boisson B, Porta F, Rosenzweig SD, Su H, Giliani S, Lenardo M, Geha RS, Boztug K, Chou J, Notarangelo LD. F-BAR domain only protein 1 (FCHO1) deficiency is a novel cause of combined immune deficiency in human subjects. J Allergy Clin Immunol 2019; 143:2317-2321.e12. [PMID: 30822429 DOI: 10.1016/j.jaci.2019.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/06/2019] [Accepted: 02/15/2019] [Indexed: 10/27/2022]
Affiliation(s)
- Enrica Calzoni
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md; "A. Nocivelli Institute for Molecular Medicine", Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Craig D Platt
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Sevgi Keles
- Division of Pediatric Immunology and Allergy, Meram Medical Faculty, Necmettin Erbakan University, Konya, Turkey
| | - Hye Sun Kuehn
- Immunology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Md
| | - Sarah Beaussant-Cohen
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Yu Zhang
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Julia Pazmandi
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria
| | - Gaetana Lanzi
- "A. Nocivelli Institute for Molecular Medicine", Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Francesca Pala
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Azzeddine Tahiat
- Laboratory of Medical Biology, Rouiba Hospital, Algiers, Algeria; Algiers Faculty of Medicine, University of Algiers 1, Algiers, Algeria
| | - Hasibe Artac
- Pediatric Immunology and Allergy, Selcuk University Medical Faculty, Konya, Turkey
| | | | - Jasmin Dmytrus
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria
| | - Ismail Reisli
- Division of Pediatric Immunology and Allergy, Meram Medical Faculty, Necmettin Erbakan University, Konya, Turkey
| | - Vedat Uygun
- Medical Park, Antalya Hospital, Pediatric Bone Marrow Transplantation Unit, Antalya, Turkey
| | - Dilara Uygun
- Department of Immunology-Allergy, Akdeniz University School of Medicine, Antalya, Turkey
| | - Aysen Bingol
- Department of Immunology-Allergy, Akdeniz University School of Medicine, Antalya, Turkey
| | - Erdem Basaran
- Department of Pediatric Pulmonology, Akdeniz University School of Medicine, Antalya, Turkey
| | - Kamel Djenouhat
- Laboratory of Medical Biology, Rouiba Hospital, Algiers, Algeria; Algiers Faculty of Medicine, University of Algiers 1, Algiers, Algeria
| | - Nafissa Benhalla
- Department of Pediatrics, Beni Messous University Hospital, Algiers, Algeria
| | | | - Melike Emiroglu
- Pediatric Infectious Diseases, Selcuk University Medical Faculty, Konya, Turkey
| | - Tomas Kirchhausen
- Department of Cell Biology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Mass
| | - Mithun Pasham
- Department of Cell Biology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Mass
| | - Jennifer Jones
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Jacqueline G Wallace
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Lixin Zheng
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Bertrand Boisson
- St Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, Rockefeller University, New York, NY; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Necker Hospital for Sick Children, Paris, France; Imagine Institute, Paris Descartes University, Paris, France
| | - Fulvio Porta
- Pediatric Onco-Haematology and BMT Unit, Children's Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Sergio D Rosenzweig
- Immunology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Md
| | - Helen Su
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Silvia Giliani
- "A. Nocivelli Institute for Molecular Medicine", Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Michael Lenardo
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md
| | - Raif S Geha
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Kaan Boztug
- Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria; CeMM Research Centre for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria; Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria; St Anna Children's Hospital and Children's Cancer Research Institute, Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Janet Chou
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md.
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Haucke V, Kozlov MM. Membrane remodeling in clathrin-mediated endocytosis. J Cell Sci 2018; 131:131/17/jcs216812. [PMID: 30177505 DOI: 10.1242/jcs.216812] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clathrin-mediated endocytosis is an essential cellular mechanism by which all eukaryotic cells regulate their plasma membrane composition to control processes ranging from cell signaling to adhesion, migration and morphogenesis. The formation of endocytic vesicles and tubules involves extensive protein-mediated remodeling of the plasma membrane that is organized in space and time by protein-protein and protein-phospholipid interactions. Recent studies combining high-resolution imaging with genetic manipulations of the endocytic machinery and with theoretical approaches have led to novel multifaceted phenomenological data of the temporal and spatial organization of the endocytic reaction. This gave rise to various - often conflicting - models as to how endocytic proteins and their association with lipids regulate the endocytic protein choreography to reshape the plasma membrane. In this Review, we discuss these findings in light of the hypothesis that endocytic membrane remodeling may be determined by an interplay between protein-protein interactions, the ability of proteins to generate and sense membrane curvature, and the ability of lipids to stabilize and reinforce the generated membrane shape through adopting their lateral distribution to the local membrane curvature.
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Affiliation(s)
- Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Straße 10, 13125 Berlin, Germany .,Freie Universität Berlin, Department of Biology, Chemistry, Pharmacy, Takustrasse 3, 14195 Berlin, Germany
| | - Michael M Kozlov
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Abstract
Clathrin-mediated endocytosis (CME) is the major endocytic pathway in mammalian cells. It is responsible for the uptake of transmembrane receptors and transporters, for remodeling plasma membrane composition in response to environmental changes, and for regulating cell surface signaling. CME occurs via the assembly and maturation of clathrin-coated pits that concentrate cargo as they invaginate and pinch off to form clathrin-coated vesicles. In addition to the major coat proteins, clathrin triskelia and adaptor protein complexes, CME requires a myriad of endocytic accessory proteins and phosphatidylinositol lipids. CME is regulated at multiple steps-initiation, cargo selection, maturation, and fission-and is monitored by an endocytic checkpoint that induces disassembly of defective pits. Regulation occurs via posttranslational modifications, allosteric conformational changes, and isoform and splice-variant differences among components of the CME machinery, including the GTPase dynamin. This review summarizes recent findings on the regulation of CME and the evolution of this complex process.
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Affiliation(s)
- Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Ping-Hung Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Saipraveen Srinivasan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , , .,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
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Beacham GM, Partlow EA, Lange JJ, Hollopeter G. NECAPs are negative regulators of the AP2 clathrin adaptor complex. eLife 2018; 7:32242. [PMID: 29345618 PMCID: PMC5785209 DOI: 10.7554/elife.32242] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/17/2018] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic cells internalize transmembrane receptors via clathrin-mediated endocytosis, but it remains unclear how the machinery underpinning this process is regulated. We recently discovered that membrane-associated muniscin proteins such as FCHo and SGIP initiate endocytosis by converting the AP2 clathrin adaptor complex to an open, active conformation that is then phosphorylated (Hollopeter et al., 2014). Here we report that loss of ncap-1, the sole C. elegans gene encoding an adaptiN Ear-binding Coat-Associated Protein (NECAP), bypasses the requirement for FCHO-1. Biochemical analyses reveal AP2 accumulates in an open, phosphorylated state in ncap-1 mutant worms, suggesting NECAPs promote the closed, inactive conformation of AP2. Consistent with this model, NECAPs preferentially bind open and phosphorylated forms of AP2 in vitro and localize with constitutively open AP2 mutants in vivo. NECAPs do not associate with phosphorylation-defective AP2 mutants, implying that phosphorylation precedes NECAP recruitment. We propose NECAPs function late in endocytosis to inactivate AP2.
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Affiliation(s)
| | - Edward A Partlow
- Department of Molecular Medicine, Cornell University, Ithaca, United States
| | - Jeffrey J Lange
- Stowers Institute for Medical Research, Kansas City, United States
| | - Gunther Hollopeter
- Department of Molecular Medicine, Cornell University, Ithaca, United States
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Li H, Santos MS, Park CK, Dobry Y, Voglmaier SM. VGLUT2 Trafficking Is Differentially Regulated by Adaptor Proteins AP-1 and AP-3. Front Cell Neurosci 2017; 11:324. [PMID: 29123471 PMCID: PMC5662623 DOI: 10.3389/fncel.2017.00324] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 09/28/2017] [Indexed: 01/25/2023] Open
Abstract
Release of the major excitatory neurotransmitter glutamate by synaptic vesicle exocytosis depends on glutamate loading into synaptic vesicles by vesicular glutamate transporters (VGLUTs). The two principal isoforms, VGLUT1 and 2, exhibit a complementary pattern of expression in adult brain that broadly distinguishes cortical (VGLUT1) and subcortical (VGLUT2) systems, and correlates with distinct physiological properties in synapses expressing these isoforms. Differential trafficking of VGLUT1 and 2 has been suggested to underlie their functional diversity. Increasing evidence suggests individual synaptic vesicle proteins use specific sorting signals to engage specialized biochemical mechanisms to regulate their recycling. We observed that VGLUT2 recycles differently in response to high frequency stimulation than VGLUT1. Here we further explore the trafficking of VGLUT2 using a pHluorin-based reporter, VGLUT2-pH. VGLUT2-pH exhibits slower rates of both exocytosis and endocytosis than VGLUT1-pH. VGLUT2-pH recycling is slower than VGLUT1-pH in both hippocampal neurons, which endogenously express mostly VGLUT1, and thalamic neurons, which endogenously express mostly VGLUT2, indicating that protein identity, not synaptic vesicle membrane or neuronal cell type, controls sorting. We characterize sorting signals in the C-terminal dileucine-like motif, which plays a crucial role in VGLUT2 trafficking. Disruption of this motif abolishes synaptic targeting of VGLUT2 and essentially eliminates endocytosis of the transporter. Mutational and biochemical analysis demonstrates that clathrin adaptor proteins (APs) interact with VGLUT2 at the dileucine-like motif. VGLUT2 interacts with AP-2, a well-studied adaptor protein for clathrin mediated endocytosis. In addition, VGLUT2 also interacts with the alternate adaptors, AP-1 and AP-3. VGLUT2 relies on distinct recycling mechanisms from VGLUT1. Abrogation of these differences by pharmacological and molecular inhibition reveals that these mechanisms are dependent on the adaptor proteins AP-1 and AP-3. Further, shRNA-mediated knockdown reveals differential roles for AP-1 and AP-3 in VGLUT2 recycling.
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Affiliation(s)
- Haiyan Li
- Department of Psychiatry, School of Medicine, Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States
| | - Magda S Santos
- Department of Psychiatry, School of Medicine, Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States
| | - Chihyung K Park
- Department of Psychiatry, School of Medicine, Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States
| | - Yuriy Dobry
- Department of Psychiatry, School of Medicine, Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States
| | - Susan M Voglmaier
- Department of Psychiatry, School of Medicine, Weill Institute for Neurosciences, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, United States
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Cousin MA. Integration of Synaptic Vesicle Cargo Retrieval with Endocytosis at Central Nerve Terminals. Front Cell Neurosci 2017; 11:234. [PMID: 28824381 PMCID: PMC5541026 DOI: 10.3389/fncel.2017.00234] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/25/2017] [Indexed: 12/12/2022] Open
Abstract
Central nerve terminals contain a limited number of synaptic vesicles (SVs) which mediate the essential process of neurotransmitter release during their activity-dependent fusion. The rapid and accurate formation of new SVs with the appropriate cargo is essential to maintain neurotransmission in mammalian brain. Generating SVs containing the correct SV cargo with the appropriate stoichiometry is a significant challenge, especially when multiple modes of endocytosis exist in central nerve terminals, which occur at different locations within the nerve terminals. These endocytosis modes include ultrafast endocytosis, clathrin-mediated endocytosis (CME) and activity-dependent bulk endocytosis (ADBE) which are triggered by specific patterns of neuronal activity. This review article will assess the evidence for the role of classical adaptor protein complexes in SV retrieval, discuss the role of monomeric adaptors and how interactions between specific SV cargoes can facilitate retrieval. In addition it will consider the evidence for preassembled plasma membrane cargo complexes and their role in facilitating these endocytosis modes. Finally it will present a unifying model for cargo retrieval at the presynapse, which integrates endocytosis modes in time and space.
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Affiliation(s)
- Michael A Cousin
- Centre for Integrative Physiology, University of EdinburghEdinburgh, United Kingdom
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Giani M, den Otter WK, Briels WJ. Early stages of clathrin aggregation at a membrane in coarse-grained simulations. J Chem Phys 2017; 146:155102. [DOI: 10.1063/1.4979985] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- M. Giani
- Multi Scale Mechanics, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Computational BioPhysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - W. K. den Otter
- Multi Scale Mechanics, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Computational BioPhysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - W. J. Briels
- Computational BioPhysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
- Forschungszentrum Jülich, ICS 3, D-52425 Jülich, Germany
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Abstract
The precise sequence of events promoting clathrin-coated vesicle assembly is still debated. In this issue, Kadlecova et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201608071) test structural models using quantitative microscopy in living cells to investigate the hierarchy and temporal importance of molecular events required for clathrin-coated pit initiation.
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Affiliation(s)
- Meredith N Frazier
- Department of Biological Sciences, Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
| | - Lauren P Jackson
- Department of Biological Sciences, Center for Structural Biology, Vanderbilt University, Nashville, TN 37232 .,Department of Biochemistry, Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
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Kadlecova Z, Spielman SJ, Loerke D, Mohanakrishnan A, Reed DK, Schmid SL. Regulation of clathrin-mediated endocytosis by hierarchical allosteric activation of AP2. J Cell Biol 2016; 216:167-179. [PMID: 28003333 PMCID: PMC5223608 DOI: 10.1083/jcb.201608071] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/31/2016] [Accepted: 11/30/2016] [Indexed: 01/31/2023] Open
Abstract
The critical initiation phase of clathrin-mediated endocytosis (CME) determines where and when endocytosis occurs. Heterotetrameric adaptor protein 2 (AP2) complexes, which initiate clathrin-coated pit (CCP) assembly, are activated by conformational changes in response to phosphatidylinositol-4,5-bisphosphate (PIP2) and cargo binding at multiple sites. However, the functional hierarchy of interactions and how these conformational changes relate to distinct steps in CCP formation in living cells remains unknown. We used quantitative live-cell analyses to measure discrete early stages of CME and show how sequential, allosterically regulated conformational changes activate AP2 to drive both nucleation and subsequent stabilization of nascent CCPs. Our data establish that cargoes containing Yxxφ motif, but not dileucine motif, play a critical role in the earliest stages of AP2 activation and CCP nucleation. Interestingly, these cargo and PIP2 interactions are not conserved in yeast. Thus, we speculate that AP2 has evolved as a key regulatory node to coordinate CCP formation and cargo sorting and ensure high spatial and temporal regulation of CME.
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Affiliation(s)
- Zuzana Kadlecova
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Stephanie J Spielman
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA 19122
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208
| | - Aparna Mohanakrishnan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Dana Kim Reed
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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