1
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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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2
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Prokopchuk G, Butenko A, Dacks JB, Speijer D, Field MC, Lukeš J. Lessons from the deep: mechanisms behind diversification of eukaryotic protein complexes. Biol Rev Camb Philos Soc 2023; 98:1910-1927. [PMID: 37336550 PMCID: PMC10952624 DOI: 10.1111/brv.12988] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Genetic variation is the major mechanism behind adaptation and evolutionary change. As most proteins operate through interactions with other proteins, changes in protein complex composition and subunit sequence provide potentially new functions. Comparative genomics can reveal expansions, losses and sequence divergence within protein-coding genes, but in silico analysis cannot detect subunit substitutions or replacements of entire protein complexes. Insights into these fundamental evolutionary processes require broad and extensive comparative analyses, from both in silico and experimental evidence. Here, we combine data from both approaches and consider the gamut of possible protein complex compositional changes that arise during evolution, citing examples of complete conservation to partial and total replacement by functional analogues. We focus in part on complexes in trypanosomes as they represent one of the better studied non-animal/non-fungal lineages, but extend insights across the eukaryotes by extensive comparative genomic analysis. We argue that gene loss plays an important role in diversification of protein complexes and hence enhancement of eukaryotic diversity.
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Affiliation(s)
- Galina Prokopchuk
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
| | - Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
- Life Science Research Centre, Faculty of ScienceUniversity of OstravaChittussiho 983/10Ostrava71000Czech Republic
| | - Joel B. Dacks
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Division of Infectious Diseases, Department of MedicineUniversity of Alberta1‐124 Clinical Sciences Building, 11350‐83 AvenueEdmontonT6G 2R3AlbertaCanada
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and the EnvironmentUniversity College LondonDarwin Building, Gower StreetLondonWC1E 6BTUK
| | - Dave Speijer
- Medical Biochemistry, Amsterdam UMCUniversity of AmsterdamMeibergdreef 15Amsterdam1105 AZThe Netherlands
| | - Mark C. Field
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- School of Life SciencesUniversity of DundeeDow StreetDundeeDD1 5EHScotlandUK
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
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3
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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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4
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Küey C, Sittewelle M, Larocque G, Hernández-González M, Royle SJ. Recruitment of clathrin to intracellular membranes is sufficient for vesicle formation. eLife 2022; 11:78929. [PMID: 35852853 PMCID: PMC9337851 DOI: 10.7554/elife.78929] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
The formation of a clathrin-coated vesicle (CCV) is a major membrane remodeling process that is crucial for membrane traffic in cells. Besides clathrin, these vesicles contain at least 100 different proteins although it is unclear how many are essential for the formation of the vesicle. Here, we show that intracellular clathrin-coated formation can be induced in living cells using minimal machinery and that it can be achieved on various membranes, including the mitochondrial outer membrane. Chemical heterodimerization was used to inducibly attach a clathrin-binding fragment ‘hook’ to an ‘anchor’ protein targeted to a specific membrane. Endogenous clathrin assembled to form coated pits on the mitochondria, termed MitoPits, within seconds of induction. MitoPits are double-membraned invaginations that form preferentially on high curvature regions of the mitochondrion. Upon induction, all stages of CCV formation – initiation, invagination, and even fission – were faithfully reconstituted. We found no evidence for the functional involvement of accessory proteins in this process. In addition, fission of MitoPit-derived vesicles was independent of known scission factors including dynamins and dynamin-related protein 1 (Drp1), suggesting that the clathrin cage generates sufficient force to bud intracellular vesicles. Our results suggest that, following its recruitment, clathrin is sufficient for intracellular CCV formation.
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Affiliation(s)
- Cansu Küey
- Division of Biomedical Sciences, University of Warwick
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5
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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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6
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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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7
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Richardson E, Dacks JB. Distribution of Membrane Trafficking System Components Across Ciliate Diversity Highlights Heterogenous Organelle-Associated Machinery. Traffic 2022; 23:208-220. [PMID: 35128766 DOI: 10.1111/tra.12834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/24/2022] [Accepted: 02/03/2022] [Indexed: 11/29/2022]
Abstract
The ciliate phylum is a group of protists noted for their unusual membrane trafficking system and apparent environmental ubiquity; as highly successful microbial predators, they are found in all manner of environments and the ability for specific species to adapt to extremely challenging conditions makes them valued as bioindicators. Ciliates have also been used for many years as cell biological models due to their large cell size and ease of culturing, and for many fundamental cell structures, particularly membrane-bound organelles, ciliates were some of the earliest organisms in which these were observed via microscopy. In this study, we carried out a comparative genomic survey of selected membrane trafficking proteins in a pan-ciliate transcriptome and genome dataset. We observed considerable loss of membrane trafficking system (MTS) proteins that would indicate a loss of machinery that is generally conserved across eukaryotic diversity, even after controlling for potentially incomplete genome representation. In particular, the DSL1 complex was missing in all surveyed ciliates. This protein complex has been shown as involved in peroxisome biogenesis in some model systems, and a paucity of DSL1 components has been indicative of degenerate peroxisome. However, Tetrahymena thermophila (formerly Tetrahymena pyroformis) was one of the original models for visualising peroxisomes. Conversely, the AP3 complex essential for mucocyst maturation in T. thermophila, is poorly conserved despite the presence of secretory lysosome-related organelles across ciliate diversity. We discuss potential resolutions for these apparent paradoxes in the context of the heterogenous distribution of MTS machinery across the diversity of ciliates.
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Affiliation(s)
- Elisabeth Richardson
- University of Alberta School of Public Health, Edmonton, Alberta, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Joel B Dacks
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.,Division of Infectious Diseases, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.,Department of Life Sciences, The Natural History Museum, London, UK
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8
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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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9
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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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10
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Welch MA, Jansen LAR, Baro DJ. SUMOylation of the Kv4.2 Ternary Complex Increases Surface Expression and Current Amplitude by Reducing Internalization in HEK 293 Cells. Front Mol Neurosci 2021; 14:757278. [PMID: 34795560 PMCID: PMC8593141 DOI: 10.3389/fnmol.2021.757278] [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: 08/11/2021] [Accepted: 10/05/2021] [Indexed: 11/29/2022] Open
Abstract
Kv4 α-subunits exist as ternary complexes (TC) with potassium channel interacting proteins (KChIP) and dipeptidyl peptidase-like proteins (DPLP); multiple ancillary proteins also interact with the α-subunits throughout the channel’s lifetime. Dynamic regulation of Kv4.2 protein interactions adapts the transient potassium current, IA, mediated by Kv4 α-subunits. Small ubiquitin-like modifier (SUMO) is an 11 kD peptide post-translationally added to lysine (K) residues to regulate protein–protein interactions. We previously demonstrated that when expressed in human embryonic kidney (HEK) cells, Kv4.2 can be SUMOylated at two K residues, K437 and K579. SUMOylation at K437 increased surface expression of electrically silent channels while SUMOylation at K579 reduced IA maximal conductance (Gmax) without altering surface expression. KChIP and DPLP subunits are known to modify the pattern of Kv4.2 post-translational decorations and/or their effects. In this study, co-expressing Kv4.2 with KChIP2a and DPP10c altered the effects of enhanced Kv4.2 SUMOylation. First, the effect of enhanced SUMOylation was the same for a TC containing either the wild-type Kv4.2 or the mutant K437R Kv4.2, suggesting that either the experimental manipulation no longer enhanced K437 SUMOylation or K437 SUMOylation no longer influenced Kv4.2 surface expression. Second, instead of decreasing IA Gmax, enhanced SUMOylation at K579 now produced a significant ∼37–70% increase in IA maximum conductance (Gmax) and a significant ∼30–50% increase in Kv4.2g surface expression that was accompanied by a 65% reduction in TC internalization. Blocking clathrin-mediated endocytosis (CME) in HEK cells expressing the Kv4.2 TC mimicked and occluded the effect of SUMO on IA Gmax; however, the amount of Kv4.2 associated with the major adaptor for constitutive CME, adaptor protein 2 (AP2), was not SUMO dependent. Thus, SUMOylation reduced Kv4.2 internalization by acting downstream of Kv4.2 recruitment into clathrin-coated pits. In sum, the two major findings of this study are: SUMOylation of Kv4.2 at K579 regulates TC internalization most likely by promoting channel recycling. Additionally, there is a reciprocity between Kv4.2 SUMOylation and the Kv4.2 interactome such that SUMOylation regulates the interactome and the interactome influences the pattern and effect of SUMOylation.
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Affiliation(s)
- Meghyn A Welch
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | | | - Deborah J Baro
- Department of Biology, Georgia State University, Atlanta, GA, United States.,Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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11
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The EMT activator ZEB1 accelerates endosomal trafficking to establish a polarity axis in lung adenocarcinoma cells. Nat Commun 2021; 12:6354. [PMID: 34732702 PMCID: PMC8566461 DOI: 10.1038/s41467-021-26677-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) is a transcriptionally governed process by which cancer cells establish a front-rear polarity axis that facilitates motility and invasion. Dynamic assembly of focal adhesions and other actin-based cytoskeletal structures on the leading edge of motile cells requires precise spatial and temporal control of protein trafficking. Yet, the way in which EMT-activating transcriptional programs interface with vesicular trafficking networks that effect cell polarity change remains unclear. Here, by utilizing multiple approaches to assess vesicular transport dynamics through endocytic recycling and retrograde trafficking pathways in lung adenocarcinoma cells at distinct positions on the EMT spectrum, we find that the EMT-activating transcription factor ZEB1 accelerates endocytosis and intracellular trafficking of plasma membrane-bound proteins. ZEB1 drives turnover of the MET receptor tyrosine kinase by hastening receptor endocytosis and transport to the lysosomal compartment for degradation. ZEB1 relieves a plus-end-directed microtubule-dependent kinesin motor protein (KIF13A) and a clathrin-associated adaptor protein complex subunit (AP1S2) from microRNA-dependent silencing, thereby accelerating cargo transport through the endocytic recycling and retrograde vesicular pathways, respectively. Depletion of KIF13A or AP1S2 mitigates ZEB1-dependent focal adhesion dynamics, front-rear axis polarization, and cancer cell motility. Thus, ZEB1-dependent transcriptional networks govern vesicular trafficking dynamics to effect cell polarity change. The way in which metastatic tumour cells control endocytic vesicular trafficking networks to establish a front-rear polarity axis that facilitates motility remains unclear. Here, the authors show that the EMT activator ZEB1 influences vesicular trafficking dynamics to execute cell polarity change.
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12
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Akisaka T. Platinum replicas of broken-open osteoclasts imaged by transmission electron microscopy. J Oral Biosci 2021; 63:307-318. [PMID: 34628004 DOI: 10.1016/j.job.2021.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/02/2021] [Accepted: 09/18/2021] [Indexed: 10/24/2022]
Abstract
BACKGROUND Preserving the cellular structure at the highest possible resolution is a prerequisite for morphological studies to deepen our understanding of cellular functions. A revival of interest in rapid-freezing methods combined with breaking-open techniques has taken place with the development of effective and informative approaches in platinum replica electron microscopy, thus providing new approaches to address unresolved issues in cell biology. HIGHLIGHT The images produced with platinum replicas revealed 3D structures of the cell interior: (1) cell membranes associated with highly organized cytoskeletons, including podosomes or geodomes, (2) heterogeneous clathrin assemblies and membrane skeletons on the inner side of the membrane, and (3) organization of the cytoskeleton after detergent extraction. CONCLUSION In this review, I will focus on the platinum replica method after brokenopen cells have been broken open with mechanical shearing or detergent extraction. Often forgotten nowadays is the use of platinum replicas with stereomicroscopic observations for transmission electron microscopy study; these "old-fashioned" imaging techniques, combined with the breaking-open technique represent a highly informative approach to deepen our understanding of the organization of the cell interior. These are still being pursued to answer outstanding biological questions.
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Affiliation(s)
- Toshitaka Akisaka
- Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Suita, Osaka, 565-0871, Japan.
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13
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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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14
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Aridor M, Owen DJ. Linton Mark Traub (1962-2020). J Cell Biol 2021; 220:e202011169. [PMID: 33404605 PMCID: PMC7791343 DOI: 10.1083/jcb.202011169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Meir Aridor and David Owen discuss the life and achievements of Linton Traub, who passed away on October 19, 2020.
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Affiliation(s)
- Meir Aridor
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - David J. Owen
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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15
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Akisaka T, Yoshida A. Surface distribution of heterogenous clathrin assemblies in resorbing osteoclasts. Exp Cell Res 2020; 399:112433. [PMID: 33359468 DOI: 10.1016/j.yexcr.2020.112433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/06/2020] [Accepted: 12/12/2020] [Indexed: 01/04/2023]
Abstract
Osteoclasts seeded on either glass coverslips or apatite pellets have at least two morphologically distinct substrate adhesion sites: actin-based adhesion structures including podosome belts and sealing zones, and adjacent clathrin sheets. Clathrin-coated structures are exclusively localized at the podosome belts and sealing zone, in both of which the plasma membrane forms a tight attachment to the substrate surface. When cultured on apatite osteoclasts can degrade the apatite leading to the formation of resorption lacunae. The sealing zone divides the ventral membrane into different domains, outside and inside of the sealing zones. The former facing the smooth-surfaced intact apatite contains relatively solitary or networks of larger flat clathrin structures; and the latter, facing the rough-surfaced degraded apatite in the resorption lacunae contain clathrin in various shapes and sizes. Clathrin assemblies on the membrane domain facing not only a resorption lacuna, or trails but also intact apatite indeed were observed to be heterogeneous in size and intensity, suggesting that they appeared to follow variations in the surface topography of the apatite surface. These results provide a detailed insight into the flat clathrin sheets that have been suggested to be the sites of adhesion and mechanosensing in co-operation with podosomes.
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Affiliation(s)
- Toshitaka Akisaka
- Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Japan.
| | - Atsushi Yoshida
- Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, Japan.
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16
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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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17
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Wang X, Chen Z, Mettlen M, Noh J, Schmid SL, Danuser G. DASC, a sensitive classifier for measuring discrete early stages in clathrin-mediated endocytosis. eLife 2020; 9:53686. [PMID: 32352376 PMCID: PMC7192580 DOI: 10.7554/elife.53686] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) in mammalian cells is driven by resilient machinery that includes >70 endocytic accessory proteins (EAP). Accordingly, perturbation of individual EAPs often results in minor effects on biochemical measurements of CME, thus providing inconclusive/misleading information regarding EAP function. Live-cell imaging can detect earlier roles of EAPs preceding cargo internalization; however, this approach has been limited because unambiguously distinguishing abortive coats (ACs) from bona fide clathrin-coated pits (CCPs) is required but unaccomplished. Here, we develop a thermodynamics-inspired method, “disassembly asymmetry score classification (DASC)”, that resolves ACs from CCPs based on single channel fluorescent movies. After extensive verification, we use DASC-resolved ACs and CCPs to quantify CME progression in 11 EAP knockdown conditions. We show that DASC is a sensitive detector of phenotypic variation in CCP dynamics that is uncorrelated to the variation in biochemical measurements of CME. Thus, DASC is an essential tool for uncovering EAP function.
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Affiliation(s)
- Xinxin Wang
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Zhiming Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jungsik Noh
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
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18
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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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19
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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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20
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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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21
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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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22
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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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23
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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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24
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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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25
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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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26
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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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27
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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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28
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Snead WT, Zeno WF, Kago G, Perkins RW, Richter JB, Zhao C, Lafer EM, Stachowiak JC. BAR scaffolds drive membrane fission by crowding disordered domains. J Cell Biol 2018; 218:664-682. [PMID: 30504247 PMCID: PMC6363457 DOI: 10.1083/jcb.201807119] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/12/2018] [Accepted: 11/08/2018] [Indexed: 01/01/2023] Open
Abstract
Cylindrical protein scaffolds are thought to stabilize membrane tubules, preventing membrane fission. In contrast, Snead et al. find that when scaffold proteins assemble, bulky disordered domains within them become acutely concentrated, generating steric pressure that destabilizes tubules, driving fission. Cellular membranes are continuously remodeled. The crescent-shaped bin-amphiphysin-rvs (BAR) domains remodel membranes in multiple cellular pathways. Based on studies of isolated BAR domains in vitro, the current paradigm is that BAR domain–containing proteins polymerize into cylindrical scaffolds that stabilize lipid tubules. But in nature, proteins that contain BAR domains often also contain large intrinsically disordered regions. Using in vitro and live cell assays, here we show that full-length BAR domain–containing proteins, rather than stabilizing membrane tubules, are instead surprisingly potent drivers of membrane fission. Specifically, when BAR scaffolds assemble at membrane surfaces, their bulky disordered domains become crowded, generating steric pressure that destabilizes lipid tubules. More broadly, we observe this behavior with BAR domains that have a range of curvatures. These data suggest that the ability to concentrate disordered domains is a key driver of membrane remodeling and fission by BAR domain–containing proteins.
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Affiliation(s)
- Wilton T Snead
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - Wade F Zeno
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - Grace Kago
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX.,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX
| | - Ryan W Perkins
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - J Blair Richter
- Department of Biochemistry and Structural Biology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Chi Zhao
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX
| | - Eileen M Lafer
- Department of Biochemistry and Structural Biology, Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX .,Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX
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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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30
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Bucher D, Frey F, Sochacki KA, Kummer S, Bergeest JP, Godinez WJ, Kräusslich HG, Rohr K, Taraska JW, Schwarz US, Boulant S. Clathrin-adaptor ratio and membrane tension regulate the flat-to-curved transition of the clathrin coat during endocytosis. Nat Commun 2018; 9:1109. [PMID: 29549258 PMCID: PMC5856840 DOI: 10.1038/s41467-018-03533-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 02/15/2018] [Indexed: 12/03/2022] Open
Abstract
Although essential for many cellular processes, the sequence of structural and molecular events during clathrin-mediated endocytosis remains elusive. While it was long believed that clathrin-coated pits grow with a constant curvature, it was recently suggested that clathrin first assembles to form flat structures that then bend while maintaining a constant surface area. Here, we combine correlative electron and light microscopy and mathematical growth laws to study the ultrastructural rearrangements of the clathrin coat during endocytosis in BSC-1 mammalian cells. We confirm that clathrin coats initially grow flat and demonstrate that curvature begins when around 70% of the final clathrin content is acquired. We find that this transition is marked by a change in the clathrin to clathrin-adaptor protein AP2 ratio and that membrane tension suppresses this transition. Our results support the notion that BSC-1 mammalian cells dynamically regulate the flat-to-curved transition in clathrin-mediated endocytosis by both biochemical and mechanical factors. The sequence of structural and molecular events during clathrin-mediated endocytosis is unclear. Here the authors combine correlative microscopy and simple mathematical growth laws to demonstrate that the flat patch starts to curve when around 70% of the final clathrin content is reached.
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Affiliation(s)
- Delia Bucher
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany
| | - Felix Frey
- BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120, Heidelberg, Germany
| | - Kem A Sochacki
- National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Susann Kummer
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Jan-Philip Bergeest
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), Department of Bioinformatics and Functional Genomics, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - William J Godinez
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), Department of Bioinformatics and Functional Genomics, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Karl Rohr
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.,BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), Department of Bioinformatics and Functional Genomics, Heidelberg University, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany
| | - Justin W Taraska
- National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ulrich S Schwarz
- BioQuant Center, Im Neuenheimer Feld 267, 69120, Heidelberg, Germany. .,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120, Heidelberg, Germany.
| | - Steeve Boulant
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany. .,German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120, Heidelberg, Germany.
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31
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32
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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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33
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34
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Schöneberg J, Lehmann M, Ullrich A, Posor Y, Lo WT, Lichtner G, Schmoranzer J, Haucke V, Noé F. Lipid-mediated PX-BAR domain recruitment couples local membrane constriction to endocytic vesicle fission. Nat Commun 2017. [PMID: 28627515 PMCID: PMC5481832 DOI: 10.1038/ncomms15873] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) involves membrane-associated scaffolds of the bin-amphiphysin-rvs (BAR) domain protein family as well as the GTPase dynamin, and is accompanied and perhaps triggered by changes in local lipid composition. How protein recruitment, scaffold assembly and membrane deformation is spatiotemporally controlled and coupled to fission is poorly understood. We show by computational modelling and super-resolution imaging that phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] synthesis within the clathrin-coated area of endocytic intermediates triggers selective recruitment of the PX-BAR domain protein SNX9, as a result of complex interactions of endocytic proteins competing for phospholipids. The specific architecture induces positioning of SNX9 at the invagination neck where its self-assembly regulates membrane constriction, thereby providing a template for dynamin fission. These data explain how lipid conversion at endocytic pits couples local membrane constriction to fission. Our work demonstrates how computational modelling and super-resolution imaging can be combined to unravel function and mechanisms of complex cellular processes. The spatiotemporal regulation of membrane scaffolds recruitment and coupling between membrane deformation and fission in endocytosis are unclear. Here the authors show that lipid conversion at endocytic pits recruits SNX9, which couples local membrane constriction to fission in endocytosis.
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Affiliation(s)
- Johannes Schöneberg
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin 14195, Germany
| | - Martin Lehmann
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, Berlin 13125, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany
| | - Alexander Ullrich
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin 14195, Germany
| | - York Posor
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, Berlin 13125, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany
| | - Wen-Ting Lo
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, Berlin 13125, Germany
| | - Gregor Lichtner
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin 14195, Germany.,Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, Berlin 13125, Germany
| | - Jan Schmoranzer
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, Berlin 13125, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany
| | - Volker Haucke
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Roessle-Straße 10, Berlin 13125, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany.,NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Virchowweg 6, Berlin 10117, Germany
| | - Frank Noé
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin 14195, Germany
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35
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Abstract
The earliest stages of clathrin-coated structure (CCS) assembly involve the recruitment and stabilization of clathrin-binding adaptor proteins and the clathrin coat. In this issue of Developmental Cell, Ma et al. (2016) now identify transient protein interactions that form the basis of AP-2 adaptor complex stabilization, key to initiating CCS formation.
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Affiliation(s)
- Derek C Prosser
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Mudd Hall, Room 48, Baltimore, MD 21218, USA
| | - Beverly Wendland
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Mudd Hall, Room 48, Baltimore, MD 21218, USA.
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36
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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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37
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The Effector Cig57 Hijacks FCHO-Mediated Vesicular Trafficking to Facilitate Intracellular Replication of Coxiella burnetii. PLoS Pathog 2016; 12:e1006101. [PMID: 28002452 PMCID: PMC5176192 DOI: 10.1371/journal.ppat.1006101] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/29/2016] [Indexed: 02/05/2023] Open
Abstract
Coxiella burnetii is an intracellular bacterial pathogen that infects alveolar macrophages and replicates within a unique lysosome-derived vacuole. When Coxiella is trafficked to a host cell lysosome the essential Dot/Icm type IV secretion system is activated allowing over 130 bacterial effector proteins to be translocated into the host cytosol. This cohort of effectors is believed to manipulate host cell functions to facilitate Coxiella-containing vacuole (CCV) biogenesis and bacterial replication. Transposon mutagenesis has demonstrated that the Dot/Icm effector Cig57 is required for CCV development and intracellular replication of Coxiella. Here, we demonstrate a role for Cig57 in subverting clathrin-mediated traffic through its interaction with FCHO2, an accessory protein of clathrin coated pits. A yeast two-hybrid screen identified FCHO2 as a binding partner of Cig57 and this interaction was confirmed during infection using immunoprecipitation experiments. The interaction between Cig57 and FCHO2 is dependent on one of three endocytic sorting motif encoded by Cig57. Importantly, complementation analysis demonstrated that this endocytic sorting motif is required for full function of Cig57. Consistent with the intracellular growth defect in cig57-disrupted Coxiella, siRNA gene silencing of FCHO2 or clathrin (CLTC) inhibits Coxiella growth and CCV biogenesis. Clathrin is recruited to the replicative CCV in a manner that is dependent on the interaction between Cig57 and FCHO2. Creation of an FCHO2 knockout cell line confirmed the importance of this protein for CCV expansion, intracellular replication of Coxiella and clathrin recruitment to the CCV. Collectively, these results reveal Cig57 to be a significant virulence factor that co-opts clathrin-mediated trafficking, via interaction with FCHO2, to facilitate the biogenesis of the fusogenic Coxiella replicative vacuole and enable intracellular success of this human pathogen. Human Q fever is caused by the intracellular bacterium Coxiella burnetii. Successful infection of human cells relies on a Dot/Icm secretion system and the translocation of effector proteins into the host cell cytosol. The functions of many Coxiella effector proteins, and their contribution to bacterial growth and host manipulation, remain unknown. We show that a unique effector, Cig57, has an important role in manipulation of host cellular clathrin-mediated trafficking. In particular, Cig57 binds FCHO2, a protein involved in formation of clathrin-coated vesicles, in a manner that is dependent on a tyrosine-based endocytic sorting motif. Through engaging proteins in the clathrin pathway, Cig57 facilitates expansion of the Coxiella replicative vacuole and enables the pathogen to replicate to large numbers. Thus, we identify a relationship between a host process and a key virulence protein that are required for pathogen success.
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38
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Wang L, Johnson A, Hanna M, Audhya A. Eps15 membrane-binding and -bending activity acts redundantly with Fcho1 during clathrin-mediated endocytosis. Mol Biol Cell 2016; 27:2675-87. [PMID: 27385343 PMCID: PMC5007088 DOI: 10.1091/mbc.e16-03-0151] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 06/29/2016] [Indexed: 11/11/2022] Open
Abstract
Clathrin-mediated endocytosis involves a network of proteins that direct cargo capture while simultaneously facilitating membrane remodeling. Eps15 is a critical factor that binds and bends membranes and acts redundantly with Fcho1 to ensure clathrin lattice stability during the initial stages of plasma membrane invagination. Clathrin coat assembly on membranes requires cytosolic adaptors and accessory proteins, which bridge triskeleons with the lipid bilayer and stabilize lattice architecture throughout the process of vesicle formation. In Caenorhabditis elegans, the prototypical AP-2 adaptor complex, which is activated by the accessory factor Fcho1 at the plasma membrane, is dispensable during embryogenesis, enabling us to define alternative mechanisms that facilitate clathrin-mediated endocytosis. Here we uncover a synthetic genetic interaction between C. elegans Fcho1 (FCHO-1) and Eps15 (EHS-1), suggesting that they function in a parallel and potentially redundant manner. Consistent with this idea, we find that the FCHO-1 EFC/F-BAR domain and the EHS-1 EH domains exhibit highly similar membrane-binding and -bending characteristics in vitro. Furthermore, we demonstrate a critical role for EHS-1 when FCHO-1 membrane-binding and -bending activity is specifically eliminated in vivo. Taken together, our data highlight Eps15 as an important membrane-remodeling factor, which acts in a partially redundant manner with Fcho proteins during the earliest stages of clathrin-mediated endocytosis.
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Affiliation(s)
- Lei Wang
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53706
| | - Adam Johnson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53706
| | - Michael Hanna
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53706
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53706
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Abstract
As cells grow, move, and divide, they must reorganize and rearrange their membranes and cytoskeleton. The F-BAR protein family links cellular membranes with actin cytoskeletal rearrangements in processes including endocytosis, cytokinesis, and cell motility. Here we review emerging information on mechanisms of F-BAR domain oligomerization and membrane binding, and how these activities are coordinated with additional domains to accomplish scaffolding and signaling functions.
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Affiliation(s)
- Nathan A McDonald
- a Department of Cell and Developmental Biology , Vanderbilt University , Nashville , TN , USA
| | - Kathleen L Gould
- a Department of Cell and Developmental Biology , Vanderbilt University , Nashville , TN , USA
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Ma L, Umasankar PK, Wrobel AG, Lymar A, McCoy AJ, Holkar SS, Jha A, Pradhan-Sundd T, Watkins SC, Owen DJ, Traub LM. Transient Fcho1/2⋅Eps15/R⋅AP-2 Nanoclusters Prime the AP-2 Clathrin Adaptor for Cargo Binding. Dev Cell 2016; 37:428-43. [PMID: 27237791 PMCID: PMC4921775 DOI: 10.1016/j.devcel.2016.05.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 04/08/2016] [Accepted: 05/02/2016] [Indexed: 11/26/2022]
Abstract
Clathrin-coated vesicles form by rapid assembly of discrete coat constituents into a cargo-sorting lattice. How the sequential phases of coat construction are choreographed is unclear, but transient protein-protein interactions mediated by short interaction motifs are pivotal. We show that arrayed Asp-Pro-Phe (DPF) motifs within the early-arriving endocytic pioneers Eps15/R are differentially decoded by other endocytic pioneers Fcho1/2 and AP-2. The structure of an Eps15/R⋅Fcho1 μ-homology domain complex reveals a spacing-dependent DPF triad, bound in a mechanistically distinct way from the mode of single DPF binding to AP-2. Using cells lacking FCHO1/2 and with Eps15 sequestered from the plasma membrane, we establish that without these two endocytic pioneers, AP-2 assemblies are fleeting and endocytosis stalls. Thus, distinct DPF-based codes within the unstructured Eps15/R C terminus direct the assembly of temporary Fcho1/2⋅Eps15/R⋅AP-2 ternary complexes to facilitate conformational activation of AP-2 by the Fcho1/2 interdomain linker to promote AP-2 cargo engagement. The endocytic pioneer protein Eps15 engages AP-2 and Fcho1/2 noncompetitively Structural analysis shows arrayed DPF motif triad in Eps15 for Fcho1/2 μHD binding DPF-based codes direct transient Fcho1/2⋅Eps15/R⋅AP-2 ternary complex formation In ternary complex, Fcho1 interdomain linker primes AP-2 for cargo capture
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Affiliation(s)
- Li Ma
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - Perunthottathu K Umasankar
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - Antoni G Wrobel
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Anastasia Lymar
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - Airlie J McCoy
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Sachin S Holkar
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - Anupma Jha
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - Tirthadipa Pradhan-Sundd
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA
| | - David J Owen
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Linton M Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, S312 BST, Pittsburgh, PA 15261, USA.
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41
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Dergai M, Iershov A, Novokhatska O, Pankivskyi S, Rynditch A. Evolutionary Changes on the Way to Clathrin-Mediated Endocytosis in Animals. Genome Biol Evol 2016; 8:588-606. [PMID: 26872775 PMCID: PMC4824007 DOI: 10.1093/gbe/evw028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Endocytic pathways constitute an evolutionarily ancient system that significantly contributed to the eukaryotic cell architecture and to the diversity of cell type-specific functions and signaling cascades, in particular of metazoans. Here we used comparative proteomic studies to analyze the universal internalization route in eukaryotes, clathrin-mediated endocytosis (CME), to address the issues of how this system evolved and what are its specific features. Among 35 proteins crucially required for animal CME, we identified a subset of 22 proteins common to major eukaryotic branches and 13 gradually acquired during evolution. Based on exploration of structure-function relationship between conserved homologs in sister, distantly related and early diverged branches, we identified novel features acquired during evolution of endocytic proteins on the way to animals: Elaborated way of cargo recruitment by multiple sorting proteins, structural changes in the core endocytic complex AP2, the emergence of the Fer/Cip4 homology domain-only protein/epidermal growth factor receptor substrate 15/intersectin functional complex as an additional interaction hub and activator of AP2, as well as changes in late endocytic stages due to recruitment of dynamin/sorting nexin 9 complex and involvement of the actin polymerization machinery. The evolutionary reconstruction showed the basis of the CME process and its subsequent step-by-step development. Documented changes imply more precise regulation of the pathway, as well as CME specialization for the uptake of specific cargoes and cell type-specific functions.
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Affiliation(s)
- Mykola Dergai
- Department of Functional Genomics, Institute of Molecular Biology and Genetics, NASU, Kyiv, Ukraine
| | - Anton Iershov
- Department of Biosynthesis of Nucleic Acids, Institute of Molecular Biology and Genetics, NASU, Kyiv, Ukraine
| | - Olga Novokhatska
- Department of Functional Genomics, Institute of Molecular Biology and Genetics, NASU, Kyiv, Ukraine
| | - Serhii Pankivskyi
- Department of Functional Genomics, Institute of Molecular Biology and Genetics, NASU, Kyiv, Ukraine
| | - Alla Rynditch
- Department of Functional Genomics, Institute of Molecular Biology and Genetics, NASU, Kyiv, Ukraine
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42
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Structural basis for the recognition of two consecutive mutually interacting DPF motifs by the SGIP1 μ homology domain. Sci Rep 2016; 6:19565. [PMID: 26822536 PMCID: PMC4731787 DOI: 10.1038/srep19565] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/10/2015] [Indexed: 12/24/2022] Open
Abstract
FCHo1, FCHo2, and SGIP1 are key regulators of clathrin-mediated endocytosis. Their μ homology domains (μHDs) interact with the C-terminal region of an endocytic scaffold protein, Eps15, containing fifteen Asp-Pro-Phe (DPF) motifs. Here, we show that the high-affinity μHD-binding site in Eps15 is a region encompassing six consecutive DPF motifs, while the minimal μHD-binding unit is two consecutive DPF motifs. We present the crystal structures of the SGIP1 μHD in complex with peptides containing two DPF motifs. The peptides bind to a novel ligand-binding site of the μHD, which is distinct from those of other distantly related μHD-containing proteins. The two DPF motifs, which adopt three-dimensional structures stabilized by sequence-specific intramotif and intermotif interactions, are extensively recognized by the μHD and are both required for binding. Thus, consecutive and singly scattered DPF motifs play distinct roles in μHD binding.
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43
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Robinson MS. Forty Years of Clathrin-coated Vesicles. Traffic 2015; 16:1210-38. [PMID: 26403691 DOI: 10.1111/tra.12335] [Citation(s) in RCA: 221] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022]
Abstract
The purification of coated vesicles and the discovery of clathrin by Barbara Pearse in 1975 was a landmark in cell biology. Over the past 40 years, work from many labs has uncovered the molecular details of clathrin and its associated proteins, including how they assemble into a coated vesicle and how they select cargo. Unexpected connections have been found with signalling, development, neuronal transmission, infection, immunity and genetic disorders. But there are still a number of unanswered questions, including how clathrin-mediated trafficking is regulated and how the machinery evolved.
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Affiliation(s)
- Margaret S Robinson
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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44
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Abstract
Coatomer consists of two subcomplexes: the membrane-targeting, ADP ribosylation factor 1 (Arf1):GTP-binding βγδζ-COP F-subcomplex, which is related to the adaptor protein (AP) clathrin adaptors, and the cargo-binding αβ'ε-COP B-subcomplex. We present the structure of the C-terminal μ-homology domain of the yeast δ-COP subunit in complex with the WxW motif from its binding partner, the endoplasmic reticulum-localized Dsl1 tether. The motif binds at a site distinct from that used by the homologous AP μ subunits to bind YxxΦ cargo motifs with its two tryptophan residues sitting in compatible pockets. We also show that the Saccharomyces cerevisiae Arf GTPase-activating protein (GAP) homolog Gcs1p uses a related WxxF motif at its extreme C terminus to bind to δ-COP at the same site in the same way. Mutations designed on the basis of the structure in conjunction with isothermal titration calorimetry confirm the mode of binding and show that mammalian δ-COP binds related tryptophan-based motifs such as that from ArfGAP1 in a similar manner. We conclude that δ-COP subunits bind Wxn(1-6)[WF] motifs within unstructured regions of proteins that influence the lifecycle of COPI-coated vesicles; this conclusion is supported by the observation that, in the context of a sensitizing domain deletion in Dsl1p, mutating the tryptophan-based motif-binding site in yeast causes defects in both growth and carboxypeptidase Y trafficking/processing.
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45
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Miller SE, Mathiasen S, Bright NA, Pierre F, Kelly BT, Kladt N, Schauss A, Merrifield CJ, Stamou D, Höning S, Owen DJ. CALM regulates clathrin-coated vesicle size and maturation by directly sensing and driving membrane curvature. Dev Cell 2015; 33:163-75. [PMID: 25898166 PMCID: PMC4406947 DOI: 10.1016/j.devcel.2015.03.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 01/23/2015] [Accepted: 03/01/2015] [Indexed: 02/06/2023]
Abstract
The size of endocytic clathrin-coated vesicles (CCVs) is remarkably uniform, suggesting that it is optimized to achieve the appropriate levels of cargo and lipid internalization. The three most abundant proteins in mammalian endocytic CCVs are clathrin and the two cargo-selecting, clathrin adaptors, CALM and AP2. Here we demonstrate that depletion of CALM causes a substantial increase in the ratio of “open” clathrin-coated pits (CCPs) to “necked”/“closed” CCVs and a doubling of CCP/CCV diameter, whereas AP2 depletion has opposite effects. Depletion of either adaptor, however, significantly inhibits endocytosis of transferrin and epidermal growth factor. The phenotypic effects of CALM depletion can be rescued by re-expression of wild-type CALM, but not with CALM that lacks a functional N-terminal, membrane-inserting, curvature-sensing/driving amphipathic helix, the existence and properties of which are demonstrated. CALM is thus a major factor in controlling CCV size and maturation and hence in determining the rates of endocytic cargo uptake. CALM loss increases size and frequency of early endocytic clathrin-coated structures Depletion of CALM slows endocytic clathrin-coated pit maturation and endocytic rate CALM possesses an N-terminal, membrane-curvature-sensing/driving amphipathic helix Clathrin-coated pit maturation is regulated by CALM’s N-terminal amphipathic helix
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Affiliation(s)
- Sharon E Miller
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.
| | - Signe Mathiasen
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Nicholas A Bright
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Fabienne Pierre
- Laboratoire d'Enzymologie et Biochimie Structurales, UPR3082 CNRS - Bat 34, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Bernard T Kelly
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Nikolay Kladt
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Astrid Schauss
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Christien J Merrifield
- Laboratoire d'Enzymologie et Biochimie Structurales, UPR3082 CNRS - Bat 34, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Dimitrios Stamou
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | - Stefan Höning
- Institute of Biochemistry I and Center for Molecular Medicine Cologne, University of Cologne, Joseph-Stelzmann-Str. 52, 50931 Cologne, Germany
| | - David J Owen
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.
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46
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Kokotos AC, Cousin MA. Synaptic vesicle generation from central nerve terminal endosomes. Traffic 2014; 16:229-40. [PMID: 25346420 DOI: 10.1111/tra.12235] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 01/01/2023]
Abstract
Central nerve terminals contain a small number of synaptic vesicles (SVs) that must sustain the fidelity of neurotransmission across a wide range of stimulation intensities. For this to be achieved, nerve terminals integrate a number of complementary endocytosis modes whose activation spans the breadth of these neuronal stimulation patterns. Two such modes are ultrafast endocytosis and activity-dependent bulk endocytosis, which are triggered by stimuli at either end of the physiological range. Both endocytosis modes generate endosomes directly from the nerve terminal plasma membrane, before the subsequent production of SVs from these structures. This review will discuss the current knowledge relating to the molecular mechanisms involved in the generation of SVs from nerve terminal endosomes, how this relates to other mechanisms of SV production and the functional role of such SVs.
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Affiliation(s)
- Alexandros C Kokotos
- Centre for Integrative Physiology, George Square, University of Edinburgh, Edinburgh, EH8 9XD, UK
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