1
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Hancock LP, Palmer JS, Allwood EG, Smaczynska-de Rooij II, Hodder AJ, Rowe ML, Williamson MP, Ayscough KR. Competitive binding of actin and SH3 domains at proline-rich regions of Las17/WASP regulates actin polymerisation. Commun Biol 2025; 8:759. [PMID: 40374776 DOI: 10.1038/s42003-025-08188-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2025] [Accepted: 05/07/2025] [Indexed: 05/18/2025] Open
Abstract
Eukaryotic actin filaments bind factors that regulate their assembly and disassembly creating a self-organising system, the actin cytoskeleton. Despite extensive knowledge of signals that modulate actin organisation, significant gaps remain in our understanding of spatiotemporal regulation of de novo filament initiation. Yeast Las17/WASP is essential for actin polymerisation initiation supporting membrane invagination in Saccharomyces cerevisiae endocytosis and therefore its tight regulation is critical. The adaptor protein Sla1 inhibits Las17 but mechanisms underpinning Las17 activation remain elusive. Here we show that Las17 binding of tandem Sla1 SH3 domains is >100-fold stronger than single domains. Furthermore, SH3 domains directly compete with G-actin for binding in the Las17 polyproline region, thus rationalising how SH3 interactions can affect actin polymerisation despite their distance from C-terminal actin-binding and Arp2/3-interacting VCA domains. Our data and proposed model also highlight the likely importance of multiple weak interactions that together ensure spatial and temporal regulation of endocytosis.
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Affiliation(s)
- Lewis P Hancock
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - John S Palmer
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Ellen G Allwood
- School of Biosciences, University of Sheffield, Sheffield, UK
| | | | | | - Michelle L Rowe
- School of Biosciences, University of Sheffield, Sheffield, UK
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2
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Defelipe LA, Veith K, Burastero O, Kupriianova T, Bento I, Skruzny M, Kölbel K, Uetrecht C, Thuenauer R, García-Alai MM. Subtleties in Clathrin heavy chain binding boxes provide selectivity among adaptor proteins of budding yeast. Nat Commun 2024; 15:9655. [PMID: 39511183 PMCID: PMC11543927 DOI: 10.1038/s41467-024-54037-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Accepted: 10/28/2024] [Indexed: 11/15/2024] Open
Abstract
Clathrin forms a triskelion, or three-legged, network that regulates cellular processes by facilitating cargo internalization and trafficking in eukaryotes. Its N-terminal domain is crucial for interacting with adaptor proteins, which link clathrin to the membrane and engage with specific cargo. The N-terminal domain contains up to four adaptor-binding sites, though their role in preferential occupancy by adaptor proteins remains unclear. In this study, we examine the binding hierarchy of adaptors for clathrin, using integrative biophysical and structural approaches, along with in vivo functional experiments. We find that yeast epsin Ent5 has the highest affinity for clathrin, highlighting its key role in cellular trafficking. Epsins Ent1 and Ent2, crucial for endocytosis but thought to have redundant functions, show distinct binding patterns. Ent1 exhibits stronger interactions with clathrin than Ent2, suggesting a functional divergence toward actin binding. These results offer molecular insights into adaptor protein selectivity, suggesting they competitively bind clathrin while also targeting three different clathrin sites.
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Affiliation(s)
- Lucas A Defelipe
- European Molecular Biology Laboratory - Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | - Katharina Veith
- European Molecular Biology Laboratory - Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | - Osvaldo Burastero
- European Molecular Biology Laboratory - Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | - Tatiana Kupriianova
- European Molecular Biology Laboratory - Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | - Isabel Bento
- European Molecular Biology Laboratory - Hamburg Unit, Hamburg, Germany
| | - Michal Skruzny
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Carl Zeiss Microscopy GmbH, Jena, Germany
| | - Knut Kölbel
- Centre for Structural Systems Biology, Hamburg, Germany
- Leibniz Institute of Virology (LIV), Hamburg, Germany
- Deutsches Elektronen Synchrotron - DESY, Hamburg, Germany
| | - Charlotte Uetrecht
- Centre for Structural Systems Biology, Hamburg, Germany
- Leibniz Institute of Virology (LIV), Hamburg, Germany
- Deutsches Elektronen Synchrotron - DESY, Hamburg, Germany
- Institute of Chemistry and Metabolomics, University of Lübeck, Lübeck, Germany
| | - Roland Thuenauer
- Centre for Structural Systems Biology, Hamburg, Germany
- Leibniz Institute of Virology (LIV), Hamburg, Germany
- Technology Platform Light Microscopy (TPLM), Universität Hamburg (UHH), Hamburg, Germany
| | - Maria M García-Alai
- European Molecular Biology Laboratory - Hamburg Unit, Hamburg, Germany.
- Centre for Structural Systems Biology, Hamburg, Germany.
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3
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Ren Y, Yang J, Fujita B, Zhang Y, Berro J. Cross-regulations of two connected domains form a mechanical circuit for steady force transmission during clathrin-mediated endocytosis. Cell Rep 2024; 43:114725. [PMID: 39276354 PMCID: PMC11476202 DOI: 10.1016/j.celrep.2024.114725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 07/01/2024] [Accepted: 08/21/2024] [Indexed: 09/17/2024] Open
Abstract
Mechanical forces are transmitted from the actin cytoskeleton to the membrane during clathrin-mediated endocytosis (CME) in the fission yeast Schizosaccharomyces pombe. End4p directly transmits force in CME by binding to both the membrane (through the AP180 N-terminal homology [ANTH] domain) and F-actin (through the talin-HIP1/R/Sla2p actin-tethering C-terminal homology [THATCH] domain). We show that 7 pN force is required for stable binding between THATCH and F-actin. We also characterized a domain in End4p, Rend (rod domain in End4p), that resembles R12 of talin. Membrane localization of Rend primes the binding of THATCH to F-actin, and force-induced unfolding of Rend at 15 pN terminates the transmission of force. We show that the mechanical properties (mechanical stability, unfolding extension, hysteresis) of Rend and THATCH are tuned to form a circuit for the initiation, transmission, and termination of force between the actin cytoskeleton and membrane. The mechanical circuit by Rend and THATCH may be conserved and coopted evolutionarily in cell adhesion complexes.
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Affiliation(s)
- Yuan Ren
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Nanobiology Institute, Yale University, West Haven, CT 06516, USA.
| | - Jie Yang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Barbara Fujita
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Nanobiology Institute, Yale University, West Haven, CT 06516, USA
| | - Yongli Zhang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Nanobiology Institute, Yale University, West Haven, CT 06516, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA.
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4
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Nieto-Fabregat F, Lenza MP, Marseglia A, Di Carluccio C, Molinaro A, Silipo A, Marchetti R. Computational toolbox for the analysis of protein-glycan interactions. Beilstein J Org Chem 2024; 20:2084-2107. [PMID: 39189002 PMCID: PMC11346309 DOI: 10.3762/bjoc.20.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 08/01/2024] [Indexed: 08/28/2024] Open
Abstract
Protein-glycan interactions play pivotal roles in numerous biological processes, ranging from cellular recognition to immune response modulation. Understanding the intricate details of these interactions is crucial for deciphering the molecular mechanisms underlying various physiological and pathological conditions. Computational techniques have emerged as powerful tools that can help in drawing, building and visualising complex biomolecules and provide insights into their dynamic behaviour at atomic and molecular levels. This review provides an overview of the main computational tools useful for studying biomolecular systems, particularly glycans, both in free state and in complex with proteins, also with reference to the principles, methodologies, and applications of all-atom molecular dynamics simulations. Herein, we focused on the programs that are generally employed for preparing protein and glycan input files to execute molecular dynamics simulations and analyse the corresponding results. The presented computational toolbox represents a valuable resource for researchers studying protein-glycan interactions and incorporates advanced computational methods for building, visualising and predicting protein/glycan structures, modelling protein-ligand complexes, and analyse MD outcomes. Moreover, selected case studies have been reported to highlight the importance of computational tools in studying protein-glycan systems, revealing the capability of these tools to provide valuable insights into the binding kinetics, energetics, and structural determinants that govern specific molecular interactions.
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Affiliation(s)
- Ferran Nieto-Fabregat
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Maria Pia Lenza
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Angela Marseglia
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Cristina Di Carluccio
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
| | - Roberta Marchetti
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia 4, 80126, Italy
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5
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Ren Y, Yang J, Fujita B, Jin H, Zhang Y, Berro J. Force redistribution in clathrin-mediated endocytosis revealed by coiled-coil force sensors. SCIENCE ADVANCES 2023; 9:eadi1535. [PMID: 37831774 PMCID: PMC10575576 DOI: 10.1126/sciadv.adi1535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/13/2023] [Indexed: 10/15/2023]
Abstract
Forces are central to countless cellular processes, yet in vivo force measurement at the molecular scale remains difficult if not impossible. During clathrin-mediated endocytosis, forces produced by the actin cytoskeleton are transmitted to the plasma membrane by a multiprotein coat for membrane deformation. However, the magnitudes of these forces remain unknown. Here, we present new in vivo force sensors that induce protein condensation under force. We measured the forces on the fission yeast Huntingtin-Interacting Protein 1 Related (HIP1R) homolog End4p, a protein that links the membrane to the actin cytoskeleton. End4p is under ~19-piconewton force near the actin cytoskeleton, ~11 piconewtons near the clathrin lattice, and ~9 piconewtons near the plasma membrane. Our results demonstrate that forces are collected and redistributed across the endocytic machinery.
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Affiliation(s)
- Yuan Ren
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Nanobiology Institute, Yale University, West Haven, CT 06516, USA
| | - Jie Yang
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Barbara Fujita
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Nanobiology Institute, Yale University, West Haven, CT 06516, USA
| | - Huaizhou Jin
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yongli Zhang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Nanobiology Institute, Yale University, West Haven, CT 06516, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
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6
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Ren Y, Lin Q, Berro J. 2A peptide from ERBV-1 efficiently separates endogenous protein domains in the fission yeast Schizosaccharomyces pombe. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000941. [PMID: 37767365 PMCID: PMC10520729 DOI: 10.17912/micropub.biology.000941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/25/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023]
Abstract
2A peptides are widely used for polycistronic gene expression from vectors. In contrast, the separation of endogenous genes via 2A peptides has been largely unexplored. We show that in fission yeast Schizosaccharomyces pombe , the "cleaving" efficiency of the 2A peptide from ERBV-1 (Equine rhinitis B virus 1) range from ~70% to ~99% for End4 at different insertion sites. Our results suggest a high "cleaving" efficiency as well as considerable variation for using 2A peptide to separate endogenous protein domains in fission yeast. Verification of the "cleaving" efficiency of 2A peptides is advised for its application.
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Affiliation(s)
- Yuan Ren
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States
| | - Qun Lin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States
| | - Julien Berro
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States
- Nanobiology Institute, Yale University, West Haven, Connecticut, United States
- Department of Cell Biology, Yale University, New Haven, Connecticut, United States
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7
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Cheng A, Cai B, Fukunaga K, Sasaki T, Lakkaraju A. Feasibility and considerations of epsin2 as a candidate target for multiple system atrophy treatment. Expert Opin Ther Targets 2023; 27:1031-1034. [PMID: 37902421 DOI: 10.1080/14728222.2023.2277227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 10/26/2023] [Indexed: 10/31/2023]
Affiliation(s)
- An Cheng
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Bo Cai
- Department of chemistry, Purdue university, West Lafayett, IN, USA
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Takuya Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, USA
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8
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Liu JL, Zhang L, Huang Y, Li XH, Liu YF, Zhang SM, Zhao YE, Chen XJ, Liu Y, He LY, Dong Z, Liu FY, Sun L, Xiao L. Epsin1-mediated exosomal sorting of Dll4 modulates the tubular-macrophage crosstalk in diabetic nephropathy. Mol Ther 2023; 31:1451-1467. [PMID: 37016580 PMCID: PMC10188907 DOI: 10.1016/j.ymthe.2023.03.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 02/18/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023] Open
Abstract
Tubular epithelial cells (TECs) play critical roles in the development of diabetic nephropathy (DN), and can activate macrophages through the secretion of exosomes. However, the mechanism(s) of TEC-exosomes in macrophage activation under DN remains unknown. By mass spectrometry, 1,644 differentially expressed proteins, especially Dll4, were detected in the urine exosomes of DN patients compared with controls, which was confirmed by western blot assay. Elevated Epsin1 and Dll4/N1ICD expression was observed in kidney tissues in both DN patients and db/db mice and was positively associated with tubulointerstitial damage. Exosomes from high glucose (HG)-treated tubular cells (HK-2) with Epsin1 knockdown (KD) ameliorated macrophage activation, TNF-α, and IL-6 expression, and tubulointerstitial damage in C57BL/6 mice in vivo. In an in vitro study, enriched Dll4 was confirmed in HK-2 cells stimulated with HG, which was captured by THP-1 cells and promoted M1 macrophage activation. In addition, Epsin1 modulated the content of Dll4 in TEC-exosomes stimulated with HG. TEC-exosomes with Epsin1-KD significantly inhibited N1ICD activation and iNOS expression in THP-1 cells compared with incubation with HG alone. These findings suggested that Epsin1 could modulate tubular-macrophage crosstalk in DN by mediating exosomal sorting of Dll4 and Notch1 activation.
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Affiliation(s)
- Jia-Lu Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lei Zhang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ying Huang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiao-Hui Li
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yi-Fei Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shu-Min Zhang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yue-E Zhao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiao-Jun Chen
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yu Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li-Yu He
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zheng Dong
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA, USA; Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Fu-You Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lin Sun
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Xiao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
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9
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Ent2 Governs Morphogenesis and Virulence in Part through Regulation of the Cdc42 Signaling Cascade in the Fungal Pathogen Candida albicans. mBio 2023; 14:e0343422. [PMID: 36809010 PMCID: PMC10128014 DOI: 10.1128/mbio.03434-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
The ability to transition between yeast and filamentous growth states is critical for virulence of the leading human fungal pathogen Candida albicans. Large-scale genetic screens have identified hundreds of genes required for this morphological switch, but the mechanisms by which many of these genes orchestrate this developmental transition remain largely elusive. In this study, we characterized the role of Ent2 in governing morphogenesis in C. albicans. We showed that Ent2 is required for filamentous growth under a wide range of inducing conditions and is also required for virulence in a mouse model of systemic candidiasis. We found that the epsin N-terminal homology (ENTH) domain of Ent2 enables morphogenesis and virulence and does so via a physical interaction with the Cdc42 GTPase-activating protein (GAP) Rga2 and regulation of its localization. Further analyses revealed that overexpression of the Cdc42 effector protein Cla4 can overcome the requirement for the ENTH-Rga2 physical interaction, indicating that Ent2 functions, at least in part, to enable proper activation of the Cdc42-Cla4 signaling pathway in the presence of a filament-inducing cue. Overall, this work characterizes the mechanism by which Ent2 regulates hyphal morphogenesis in C. albicans, unveils the importance of this factor in enabling virulence in an in vivo model of systemic candidiasis and adds to the growing understanding of the genetic control of a key virulence trait. IMPORTANCE Candida albicans is a leading human fungal pathogen that can cause life-threatening infections in immunocompromised individuals, with mortality rates of ~40%. The ability of this organism to grow in both yeast and filamentous forms is critical for the establishment of systemic infection. Genomic screens have identified many genes required for this morphological transition, yet our understanding of the mechanisms that regulate this key virulence trait remains incomplete. In this study, we characterized Ent2 as a core regulator of C. albicans morphogenesis. We show that Ent2 regulates hyphal morphogenesis through an interaction between its ENTH domain and the Cdc42 GAP, Rga2, which signals through the Cdc42-Cla4 signaling pathway. Finally, we show that the Ent2 protein, and specifically its ENTH domain, is required for virulence in a mouse model of systemic candidiasis. Overall, this work identifies Ent2 as a key regulator of filamentation and virulence in C. albicans.
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10
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Niebling S, Burastero O, García-Alai M. Biophysical Characterization of Membrane Proteins. Methods Mol Biol 2023; 2652:215-230. [PMID: 37093478 DOI: 10.1007/978-1-0716-3147-8_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Membrane proteins are responsible for a large variety of tasks in organisms and of particular interesting as drug targets. At the same time, they are notoriously difficult to work with and require a thorough characterization before proceeding with structural studies. Here, we present a biophysical pipeline to characterize membrane proteins focusing on the optimization of stability, aggregation behavior, and homogeneity. The pipeline shown here is built on three biophysical techniques: differential scanning fluorimetry using native protein fluorescence (nano differential scanning fluorimetry), dynamic light scattering, and mass photometry. For each of these techniques, we provide detailed protocols for performing experiments and data analysis.
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Affiliation(s)
- Stephan Niebling
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Osvaldo Burastero
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - María García-Alai
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany.
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany.
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11
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Skruzny M. The endocytic protein machinery as an actin-driven membrane-remodeling machine. Eur J Cell Biol 2022; 101:151267. [PMID: 35970066 DOI: 10.1016/j.ejcb.2022.151267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 12/14/2022] Open
Abstract
In clathrin-mediated endocytosis, a principal membrane trafficking route of all eukaryotic cells, forces are applied to invaginate the plasma membrane and form endocytic vesicles. These forces are provided by specific endocytic proteins and the polymerizing actin cytoskeleton. One of the best-studied endocytic systems is endocytosis in yeast, known for its simplicity, experimental amenability, and overall similarity to human endocytosis. Importantly, the yeast endocytic protein machinery generates and transmits tremendous force to bend the plasma membrane, making this system beneficial for mechanistic studies of cellular force-driven membrane reshaping. This review summarizes important protein players, molecular functions, applied forces, and open questions and perspectives of this robust, actin-powered membrane-remodeling protein machine.
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Affiliation(s)
- Michal Skruzny
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany.
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12
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Smith SM, Smith CJ. Capturing the mechanics of clathrin-mediated endocytosis. Curr Opin Struct Biol 2022; 75:102427. [PMID: 35872561 DOI: 10.1016/j.sbi.2022.102427] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/13/2022] [Accepted: 06/16/2022] [Indexed: 02/01/2023]
Abstract
Clathrin-mediated endocytosis enables selective uptake of molecules into cells in response to changing cellular needs. It occurs through assembly of coat components around the plasma membrane that determine vesicle contents and facilitate membrane bending to form a clathrin-coated transport vesicle. In this review we discuss recent cryo-electron microscopy structures that have captured a series of events in the life cycle of a clathrin-coated vesicle. Both single particle analysis and tomography approaches have revealed details of the clathrin lattice structure itself, how AP2 may interface with clathrin within a coated vesicle and the importance of PIP2 binding for assembly of the yeast adaptors Sla2 and Ent1 on the membrane. Within cells, cryo-electron tomography of clathrin in flat lattices and high-speed AFM studies provided new insights into how clathrin morphology can adapt during CCV formation. Thus, key mechanical processes driving clathrin-mediated endocytosis have been captured through multiple techniques working in partnership.
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Affiliation(s)
- Sarah M Smith
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Corinne J Smith
- School of Life Sciences, University of Warwick, Coventry, UK.
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13
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Niebling S, Veith K, Vollmer B, Lizarrondo J, Burastero O, Schiller J, Struve García A, Lewe P, Seuring C, Witt S, García-Alai M. Biophysical Screening Pipeline for Cryo-EM Grid Preparation of Membrane Proteins. Front Mol Biosci 2022; 9:882288. [PMID: 35813810 PMCID: PMC9259969 DOI: 10.3389/fmolb.2022.882288] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
Successful sample preparation is the foundation to any structural biology technique. Membrane proteins are of particular interest as these are important targets for drug design, but also notoriously difficult to work with. For electron cryo-microscopy (cryo-EM), the biophysical characterization of sample purity, homogeneity, and integrity as well as biochemical activity is the prerequisite for the preparation of good quality cryo-EM grids as these factors impact the result of the computational reconstruction. Here, we present a quality control pipeline prior to single particle cryo-EM grid preparation using a combination of biophysical techniques to address the integrity, purity, and oligomeric states of membrane proteins and its complexes to enable reproducible conditions for sample vitrification. Differential scanning fluorimetry following the intrinsic protein fluorescence (nDSF) is used for optimizing buffer and detergent conditions, whereas mass photometry and dynamic light scattering are used to assess aggregation behavior, reconstitution efficiency, and oligomerization. The data collected on nDSF and mass photometry instruments can be analyzed with web servers publicly available at spc.embl-hamburg.de. Case studies to optimize conditions prior to cryo-EM sample preparation of membrane proteins present an example quality assessment to corroborate the usefulness of our pipeline.
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Affiliation(s)
- Stephan Niebling
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Katharina Veith
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Benjamin Vollmer
- Centre for Structural Systems Biology (CSSB), Leibniz Institute of Virology (LIV), Hamburg, Germany
| | | | - Osvaldo Burastero
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Janina Schiller
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Angelica Struve García
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Philipp Lewe
- Centre for Structural Systems Biology (CSSB), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carolin Seuring
- Centre for Structural Systems Biology (CSSB), Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Susanne Witt
- Centre for Structural Systems Biology (CSSB), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - María García-Alai
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- *Correspondence: María García-Alai,
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14
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Opening opportunities for K d determination and screening of MHC peptide complexes. Commun Biol 2022; 5:488. [PMID: 35606511 PMCID: PMC9127112 DOI: 10.1038/s42003-022-03366-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/13/2022] [Indexed: 01/15/2023] Open
Abstract
An essential element of adaptive immunity is selective binding of peptide antigens by major histocompatibility complex (MHC) class I proteins and their presentation to cytotoxic T lymphocytes. Using native mass spectrometry, we analyze the binding of peptides to an empty disulfide-stabilized HLA-A*02:01 molecule and, due to its unique stability, we determine binding affinities of complexes loaded with truncated or charge-reduced peptides. We find that the two anchor positions can be stabilized independently, and we further analyze the contribution of additional amino acid positions to the binding strength. As a complement to computational prediction tools, our method estimates binding strength of even low-affinity peptides to MHC class I complexes quickly and efficiently. It has huge potential to eliminate binding affinity biases and thus accelerate drug discovery in infectious diseases, autoimmunity, vaccine design, and cancer immunotherapy. The authors present a sensitive and rapid method to determine the binding strength of MHC class 1 peptide complexes using native mass spectrometry.
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15
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Belessiotis-Richards A, Larsen AH, Higgins SG, Stevens MM, Alexander-Katz A. Coarse-Grained Simulations Suggest Potential Competing Roles of Phosphoinositides and Amphipathic Helix Structures in Membrane Curvature Sensing of the AP180 N-Terminal Homology Domain. J Phys Chem B 2022; 126:2789-2797. [PMID: 35394774 PMCID: PMC9036517 DOI: 10.1021/acs.jpcb.2c00239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/23/2022] [Indexed: 11/30/2022]
Abstract
The generation and sensing of membrane curvature by proteins has become of increasing interest to researchers with multiple mechanisms, from hydrophobic insertion to protein crowding, being identified. However, the role of charged lipids in the membrane curvature-sensing process is still far from understood. Many proteins involved in endocytosis bind phosphatidylinositol 4,5-bisphosphate (PIP2) lipids, allowing these proteins to accumulate at regions of local curvature. Here, using coarse-grained molecular dynamics simulations, we study the curvature-sensing behavior of the ANTH domain, a protein crucial for endocytosis. We selected three ANTH crystal structures containing either an intact, split, or truncated terminal amphipathic helix. On neutral membranes, the ANTH domain has innate curvature-sensing ability. In the presence of PIP2, however, only the domain with an intact helix senses curvature. Our work sheds light on the role of PIP2 and its modulation of membrane curvature sensing by proteins.
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Affiliation(s)
- Alexis Belessiotis-Richards
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, U.K.
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, U.K.
| | - Andreas H. Larsen
- Department
of Biochemistry, University of Oxford, Oxford OX1 3QU, U.K.
| | - Stuart G. Higgins
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, U.K.
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, U.K.
| | - Molly M. Stevens
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, U.K.
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, U.K.
| | - Alfredo Alexander-Katz
- Department
of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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16
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Abouelezz A, Almeida-Souza L. The mammalian endocytic cytoskeleton. Eur J Cell Biol 2022; 101:151222. [DOI: 10.1016/j.ejcb.2022.151222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/27/2022] Open
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17
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Kryshtafovych A, Moult J, Albrecht R, Chang GA, Chao K, Fraser A, Greenfield J, Hartmann MD, Herzberg O, Josts I, Leiman PG, Linden SB, Lupas AN, Nelson DC, Rees SD, Shang X, Sokolova ML, Tidow H, AlphaFold2 team. Computational models in the service of X-ray and cryo-electron microscopy structure determination. Proteins 2021; 89:1633-1646. [PMID: 34449113 PMCID: PMC8616789 DOI: 10.1002/prot.26223] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 01/20/2023]
Abstract
Critical assessment of structure prediction (CASP) conducts community experiments to determine the state of the art in computing protein structure from amino acid sequence. The process relies on the experimental community providing information about not yet public or about to be solved structures, for use as targets. For some targets, the experimental structure is not solved in time for use in CASP. Calculated structure accuracy improved dramatically in this round, implying that models should now be much more useful for resolving many sorts of experimental difficulties. To test this, selected models for seven unsolved targets were provided to the experimental groups. These models were from the AlphaFold2 group, who overall submitted the most accurate predictions in CASP14. Four targets were solved with the aid of the models, and, additionally, the structure of an already solved target was improved. An a posteriori analysis showed that, in some cases, models from other groups would also be effective. This paper provides accounts of the successful application of models to structure determination, including molecular replacement for X-ray crystallography, backbone tracing and sequence positioning in a cryo-electron microscopy structure, and correction of local features. The results suggest that, in future, there will be greatly increased synergy between computational and experimental approaches to structure determination.
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Affiliation(s)
| | - John Moult
- Institute for Bioscience and Biotechnology Research, Department of Cell Biology and Molecular genetics, University of Maryland, 9600 Gudelsky Drive, Rockville, MD 20850, USA
| | - Reinhard Albrecht
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Geoffrey A. Chang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA, 92093, USA
- Department of Pharmacology, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Kinlin Chao
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Alec Fraser
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics (SCSB), The University of Texas Medical Branch at Galveston, TX 77555, USA
| | - Julia Greenfield
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Marcus D. Hartmann
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Osnat Herzberg
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Inokentijs Josts
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR) & Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Petr G. Leiman
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics (SCSB), The University of Texas Medical Branch at Galveston, TX 77555, USA
| | - Sara B. Linden
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Andrei N. Lupas
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Daniel C. Nelson
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
- Department of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA
| | - Steven D. Rees
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, La Jolla, CA, 92093, USA
| | - Xiaoran Shang
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA
| | - Maria L. Sokolova
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 121205, Russia
| | - Henning Tidow
- The Hamburg Advanced Research Center for Bioorganic Chemistry (HARBOR) & Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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18
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Pashkova N, Gakhar L, Yu L, Schnicker NJ, Minard AY, Winistorfer S, Johnson IE, Piper RC. ANTH domains within CALM, HIP1R, and Sla2 recognize ubiquitin internalization signals. eLife 2021; 10:72583. [PMID: 34821552 PMCID: PMC8648300 DOI: 10.7554/elife.72583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/24/2021] [Indexed: 12/12/2022] Open
Abstract
Attachment of ubiquitin (Ub) to cell surface proteins serves as a signal for internalization via clathrin-mediated endocytosis (CME). How ubiquitinated membrane proteins engage the internalization apparatus remains unclear. The internalization apparatus contains proteins such as Epsin and Eps15, which bind Ub, potentially acting as adaptors for Ub-based internalization signals. Here, we show that additional components of the endocytic machinery including CALM, HIP1R, and Sla2 bind Ub via their N-terminal ANTH domain, a domain belonging to the superfamily of ENTH and VHS domains. Structural studies revealed that Ub binds with µM affinity to a unique C-terminal region within the ANTH domain not found in ENTH domains. Functional studies showed that combined loss of Ub-binding by ANTH-domain proteins and other Ub-binding domains within the yeast internalization apparatus caused defects in the Ub-dependent internalization of the GPCR Ste2 that was engineered to rely exclusively on Ub as an internalization signal. In contrast, these mutations had no effect on the internalization of Ste2 engineered to use an alternate Ub-independent internalization signal. These studies define new components of the internalization machinery that work collectively with Epsin and Eps15 to specify recognition of Ub as an internalization signal.
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Affiliation(s)
- Natalya Pashkova
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Lokesh Gakhar
- Carver College of Medicine Protein Crystallography Core, University of Iowa, Iowa City, United States.,Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, United States
| | - Liping Yu
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, United States.,Carver College of Medicine NMR Core, University of Iowa, Iowa City, United States
| | - Nicholas J Schnicker
- Carver College of Medicine Protein Crystallography Core, University of Iowa, Iowa City, United States
| | - Annabel Y Minard
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Stanley Winistorfer
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Ivan E Johnson
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Robert C Piper
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
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19
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Abella M, Andruck L, Malengo G, Skruzny M. Actin-generated force applied during endocytosis measured by Sla2-based FRET tension sensors. Dev Cell 2021; 56:2419-2426.e4. [PMID: 34473942 DOI: 10.1016/j.devcel.2021.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/27/2021] [Accepted: 08/11/2021] [Indexed: 11/17/2022]
Abstract
Mechanical forces are integral to many cellular processes, including clathrin-mediated endocytosis, a principal membrane trafficking route into the cell. During endocytosis, forces provided by endocytic proteins and the polymerizing actin cytoskeleton reshape the plasma membrane into a vesicle. Assessing force requirements of endocytic membrane remodeling is essential for understanding endocytosis. Here, we determined actin-generated force applied during endocytosis using FRET-based tension sensors inserted into the major force-transmitting protein Sla2 in yeast. We measured at least 8 pN force transmitted over Sla2 molecule, hence possibly more than 300-880 pN applied during endocytic vesicle formation. Importantly, decreasing cell turgor pressure and plasma membrane tension reduced force transmitted over the Sla2. The measurements in hypotonic conditions and mutants lacking BAR-domain membrane scaffolds then showed the limits of the endocytic force-transmitting machinery. Our study provides force values and force profiles critical for understanding the mechanics of endocytosis and potentially other key cellular membrane-remodeling processes.
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Affiliation(s)
- Marc Abella
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
| | - Lynell Andruck
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
| | - Gabriele Malengo
- Flow Cytometry and Imaging Facility, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
| | - Michal Skruzny
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany; LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany.
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20
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Overduin M, Kervin TA. The phosphoinositide code is read by a plethora of protein domains. Expert Rev Proteomics 2021; 18:483-502. [PMID: 34351250 DOI: 10.1080/14789450.2021.1962302] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION The proteins that decipher nucleic acid- and protein-based information are well known, however, those that read membrane-encoded information remain understudied. Here we report 70 different human, microbial and viral protein folds that recognize phosphoinositides (PIs), comprising the readers of a vast membrane code. AREAS COVERED Membrane recognition is best understood for FYVE, PH and PX domains, which exemplify hundreds of PI code readers. Comparable lipid interaction mechanisms may be mediated by kinases, adjacent C1 and C2 domains, trafficking arrestin, GAT and VHS modules, membrane-perturbing annexin, BAR, CHMP, ENTH, HEAT, syntaxin and Tubby helical bundles, multipurpose FERM, EH, MATH, PHD, PDZ, PROPPIN, PTB and SH2 domains, as well as systems that regulate receptors, GTPases and actin filaments, transfer lipids and assembled bacterial and viral particles. EXPERT OPINION The elucidation of how membranes are recognized has extended the genetic code to the PI code. Novel discoveries include PIP-stop and MET-stop residues to which phosphates and metabolites are attached to block phosphatidylinositol phosphate (PIP) recognition, memteins as functional membrane protein apparatuses, and lipidons as lipid "codons" recognized by membrane readers. At least 5% of the human proteome senses such membrane signals and allows eukaryotic organelles and pathogens to operate and replicate.
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Affiliation(s)
- Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Troy A Kervin
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
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21
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Protein Secondary Structure Affects Glycan Clustering in Native Mass Spectrometry. Life (Basel) 2021; 11:life11060554. [PMID: 34208397 PMCID: PMC8231113 DOI: 10.3390/life11060554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 01/01/2023] Open
Abstract
Infection by the humannoroviruses (hNoV), for the vast majority of strains, requires attachment of the viral capsid to histo blood group antigens (HBGAs). The HBGA-binding pocket is formed by dimers of the protruding domain (P dimers) of the capsid protein VP1. Several studies have focused on HBGA binding to P dimers, reporting binding affinities and stoichiometries. However, nuclear magnetic resonance spectroscopy (NMR) and native mass spectrometry (MS) analyses yielded incongruent dissociation constants (KD) for the binding of HBGAs to P dimers and, in some cases, disagreed on whether glycans bind at all. We hypothesized that glycan clustering during electrospray ionization in native MS critically depends on the physicochemical properties of the protein studied. It follows that the choice of a reference protein is crucial. We analysed carbohydrate clustering using various P dimers and eight non-glycan binding proteins serving as possible references. Data from native and ion mobility MS indicate that the mass fraction of β-sheets has a strong influence on the degree of glycan clustering. Therefore, the determination of specific glycan binding affinities from native MS must be interpreted cautiously.
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22
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Lizarrondo J, Klebl DP, Niebling S, Abella M, Schroer MA, Mertens HDT, Veith K, Thuenauer R, Svergun DI, Skruzny M, Sobott F, Muench SP, Garcia-Alai MM. Structure of the endocytic adaptor complex reveals the basis for efficient membrane anchoring during clathrin-mediated endocytosis. Nat Commun 2021; 12:2889. [PMID: 34001871 PMCID: PMC8129110 DOI: 10.1038/s41467-021-23151-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 04/13/2021] [Indexed: 12/13/2022] Open
Abstract
During clathrin-mediated endocytosis, a complex and dynamic network of protein-membrane interactions cooperate to achieve membrane invagination. Throughout this process in yeast, endocytic coat adaptors, Sla2 and Ent1, must remain attached to the plasma membrane to transmit force from the actin cytoskeleton required for successful membrane invagination. Here, we present a cryo-EM structure of a 16-mer complex of the ANTH and ENTH membrane-binding domains from Sla2 and Ent1 bound to PIP2 that constitutes the anchor to the plasma membrane. Detailed in vitro and in vivo mutagenesis of the complex interfaces delineate the key interactions for complex formation and deficient cell growth phenotypes demonstrate its biological relevance. A hetero-tetrameric unit binds PIP2 molecules at the ANTH-ENTH interfaces and can form larger assemblies to contribute to membrane remodeling. Finally, a time-resolved small-angle X-ray scattering study of the interaction of these adaptor domains in vitro suggests that ANTH and ENTH domains have evolved to achieve a fast subsecond timescale assembly in the presence of PIP2 and do not require further proteins to form a stable complex. Together, these findings provide a molecular understanding of an essential piece in the molecular puzzle of clathrin-coated endocytic sites.
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Affiliation(s)
- Javier Lizarrondo
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - David P Klebl
- School of Biomedical Sciences, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Stephan Niebling
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Marc Abella
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Martin A Schroer
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Haydyn D T Mertens
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Katharina Veith
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Roland Thuenauer
- Technology Platform Microscopy and Image Analysis, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Michal Skruzny
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Frank Sobott
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK.,Department of Chemistry, Biomolecular and Analytical Mass Spectrometry group, University of Antwerp, Antwerp, Belgium
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Maria M Garcia-Alai
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany. .,Centre for Structural Systems Biology, Hamburg, Germany.
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23
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de Jong F, Munnik T. Attracted to membranes: lipid-binding domains in plants. PLANT PHYSIOLOGY 2021; 185:707-723. [PMID: 33793907 PMCID: PMC8133573 DOI: 10.1093/plphys/kiaa100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/11/2020] [Indexed: 05/18/2023]
Abstract
Membranes are essential for cells and organelles to function. As membranes are impermeable to most polar and charged molecules, they provide electrochemical energy to transport molecules across and create compartmentalized microenvironments for specific enzymatic and cellular processes. Membranes are also responsible for guided transport of cargoes between organelles and during endo- and exocytosis. In addition, membranes play key roles in cell signaling by hosting receptors and signal transducers and as substrates and products of lipid second messengers. Anionic lipids and their specific interaction with target proteins play an essential role in these processes, which are facilitated by specific lipid-binding domains. Protein crystallography, lipid-binding studies, subcellular localization analyses, and computer modeling have greatly advanced our knowledge over the years of how these domains achieve precision binding and what their function is in signaling and membrane trafficking, as well as in plant development and stress acclimation.
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Affiliation(s)
- Femke de Jong
- Cluster Green Life Sciences, Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Teun Munnik
- Cluster Green Life Sciences, Section Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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24
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Lee CT, Akamatsu M, Rangamani P. Value of models for membrane budding. Curr Opin Cell Biol 2021; 71:38-45. [PMID: 33706232 DOI: 10.1016/j.ceb.2021.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 12/16/2022]
Abstract
The budding of membranes and curvature generation is common to many forms of trafficking in cells. Clathrin-mediated endocytosis, as a prototypical example of trafficking, has been studied in great detail using a variety of experimental systems and methods. Recently, advances in experimental methods have led to great strides in insights on the molecular mechanisms and the spatiotemporal dynamics of the protein machinery associated with membrane curvature generation. These advances have been ably supported by computational models, which have given us insights into the underlying mechanical principles of clathrin-mediated endocytosis. On the other hand, targeted experimental perturbation of membranes has lagged behind that of proteins in cells. In this area, modeling is especially critical to interpret experimental measurements in a mechanistic context. Here, we discuss the contributions made by these models to our understanding of endocytosis and identify opportunities to strengthen the connections between models and experiments.
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Affiliation(s)
- Christopher T Lee
- Department of Mechanical and Aerospace Engineering, University of California San Diego Jacobs School of Engineering, 9500 Gilman Drive #0411, La Jolla, CA, 92093, USA
| | - Matthew Akamatsu
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego Jacobs School of Engineering, 9500 Gilman Drive #0411, La Jolla, CA, 92093, USA.
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25
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Abstract
Cellular membranes are anything but flat structures. They display a wide variety of complex and beautiful shapes, most of which have evolved for a particular physiological reason and are adapted to accommodate certain cellular demands. In membrane trafficking events, the dynamic remodelling of cellular membranes is apparent. In clathrin-mediated endocytosis for example, the plasma membrane undergoes heavy deformation to generate and internalize a highly curved clathrin-coated vesicle. This process has become a model system to study proteins with the ability to sense and induce membrane curvature and over the last two decades numerous membrane remodelling molecules and molecular mechanisms have been identified in this process. In this review, we discuss the interaction of epsin1 ENTH domain with membranes, which is one of the best-studied examples of a peripheral and transiently membrane bending protein important for clathrin-mediated endocytosis.
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Affiliation(s)
- Claudia Steinem
- Institute for Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany
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26
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Wang Y, Pedigo CE, Inoue K, Tian X, Cross E, Ebenezer K, Li W, Wang Z, Shin JW, Schwartze E, Groener M, Ishibe S. Murine Epsins Play an Integral Role in Podocyte Function. J Am Soc Nephrol 2020; 31:2870-2886. [PMID: 33051360 PMCID: PMC7790213 DOI: 10.1681/asn.2020050691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/30/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Epsins, a family of evolutionarily conserved membrane proteins, play an essential role in endocytosis and signaling in podocytes. METHODS Podocyte-specific Epn1, Epn2, Epn3 triple-knockout mice were generated to examine downstream regulation of serum response factor (SRF) by cell division control protein 42 homolog (Cdc42). RESULTS Podocyte-specific loss of epsins resulted in increased albuminuria and foot process effacement. Primary podocytes isolated from these knockout mice exhibited abnormalities in cell adhesion and spreading, which may be attributed to reduced activation of cell division control protein Cdc42 and SRF, resulting in diminished β1 integrin expression. In addition, podocyte-specific loss of Srf resulted in severe albuminuria and foot process effacement, and defects in cell adhesion and spreading, along with decreased β1 integrin expression. CONCLUSIONS Epsins play an indispensable role in maintaining properly functioning podocytes through the regulation of Cdc42 and SRF-dependent β1 integrin expression.
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Affiliation(s)
- Ying Wang
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
- Centre for Evidence-Based Chinese Medicine, Beijing University of Chinese Medicine, Chaoyang District, Beijing, 100029, China
| | - Christopher E Pedigo
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Kazunori Inoue
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Xuefei Tian
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Elizabeth Cross
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Karen Ebenezer
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Wei Li
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Zhen Wang
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Jee Won Shin
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Eike Schwartze
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Marwin Groener
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Shuta Ishibe
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut
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27
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Kroppen B, Teske N, Yambire KF, Denkert N, Mukherjee I, Tarasenko D, Jaipuria G, Zweckstetter M, Milosevic I, Steinem C, Meinecke M. Cooperativity of membrane-protein and protein-protein interactions control membrane remodeling by epsin 1 and affects clathrin-mediated endocytosis. Cell Mol Life Sci 2020; 78:2355-2370. [PMID: 32997199 PMCID: PMC7966211 DOI: 10.1007/s00018-020-03647-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 08/11/2020] [Accepted: 09/12/2020] [Indexed: 01/01/2023]
Abstract
Membrane remodeling is a critical process for many membrane trafficking events, including clathrin-mediated endocytosis. Several molecular mechanisms for protein-induced membrane curvature have been described in some detail. Contrary, the effect that the physico-chemical properties of the membrane have on these processes is far less well understood. Here, we show that the membrane binding and curvature-inducing ENTH domain of epsin1 is regulated by phosphatidylserine (PS). ENTH binds to membranes in a PI(4,5)P2-dependent manner but only induces curvature in the presence of PS. On PS-containing membranes, the ENTH domain forms rigid homo-oligomers and assembles into clusters. Membrane binding and membrane remodeling can be separated by structure-to-function mutants. Such oligomerization mutants bind to membranes but do not show membrane remodeling activity. In vivo, they are not able to rescue defects in epidermal growth factor receptor (EGFR) endocytosis in epsin knock-down cells. Together, these data show that the membrane lipid composition is important for the regulation of protein-dependent membrane deformation during clathrin-mediated endocytosis.
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Affiliation(s)
- Benjamin Kroppen
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Nelli Teske
- Institute for Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077, Göttingen, Germany
| | - King F Yambire
- European Neuroscience Institute, Göttingen - A Joint Initiative of the University Medical Center Göttingen and the Max-Planck-Society, Grisebachstr. 5, 37077, Göttingen, Germany
| | - Niels Denkert
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Indrani Mukherjee
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Daryna Tarasenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Garima Jaipuria
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Ira Milosevic
- European Neuroscience Institute, Göttingen - A Joint Initiative of the University Medical Center Göttingen and the Max-Planck-Society, Grisebachstr. 5, 37077, Göttingen, Germany
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, OX3 7BN, UK
| | - Claudia Steinem
- Institute for Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077, Göttingen, Germany.
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
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28
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Katan M, Cockcroft S. Phosphatidylinositol(4,5)bisphosphate: diverse functions at the plasma membrane. Essays Biochem 2020; 64:513-531. [PMID: 32844214 PMCID: PMC7517351 DOI: 10.1042/ebc20200041] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 07/25/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022]
Abstract
Phosphatidylinositol(4,5) bisphosphate (PI(4,5)P2) has become a major focus in biochemistry, cell biology and physiology owing to its diverse functions at the plasma membrane. As a result, the functions of PI(4,5)P2 can be explored in two separate and distinct roles - as a substrate for phospholipase C (PLC) and phosphoinositide 3-kinase (PI3K) and as a primary messenger, each having unique properties. Thus PI(4,5)P2 makes contributions in both signal transduction and cellular processes including actin cytoskeleton dynamics, membrane dynamics and ion channel regulation. Signalling through plasma membrane G-protein coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and immune receptors all use PI(4,5)P2 as a substrate to make second messengers. Activation of PI3K generates PI(3,4,5)P3 (phosphatidylinositol(3,4,5)trisphosphate), a lipid that recruits a plethora of proteins with pleckstrin homology (PH) domains to the plasma membrane to regulate multiple aspects of cellular function. In contrast, PLC activation results in the hydrolysis of PI(4,5)P2 to generate the second messengers, diacylglycerol (DAG), an activator of protein kinase C and inositol(1,4,5)trisphosphate (IP3/I(1,4,5)P3) which facilitates an increase in intracellular Ca2+. Decreases in PI(4,5)P2 by PLC also impact on functions that are dependent on the intact lipid and therefore endocytosis, actin dynamics and ion channel regulation are subject to control. Spatial organisation of PI(4,5)P2 in nanodomains at the membrane allows for these multiple processes to occur concurrently.
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Affiliation(s)
- Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, U.K
| | - Shamshad Cockcroft
- Department of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, 21 University Street, London WC1E 6JJ, U.K
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29
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Brod J, Hellwig A, Wieland FT. Epsin but not AP-2 supports reconstitution of endocytic clathrin-coated vesicles. FEBS Lett 2020; 594:2227-2239. [PMID: 32337703 DOI: 10.1002/1873-3468.13801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/05/2020] [Accepted: 04/10/2020] [Indexed: 12/12/2022]
Abstract
Formation of clathrin-coated vesicles (CCVs) in receptor-mediated endocytosis is a mechanistically well-established process, in which clathrin, the adaptor protein complex AP-2, and the large GTPase dynamin play crucial roles. In order to obtain more mechanistic insight into this process, here we established a giant unilamellar vesicle (GUV)-based in vitro CCV reconstitution system with chemically defined components and the full-length recombinant proteins clathrin, AP-2, epsin-1, and dynamin-2. Our results support the predominant model in which hydrolysis of GTP by dynamin is a prerequisite to generate CCVs. Strikingly, in this system at near physiological concentrations of reagents, epsin-1 alone does not have the propensity for scission but is required for bud formation, whereas AP-2 and clathrin are not sufficient. Thus, our study reveals that epsin-1 is an important factor for the maturation of clathrin coated buds, a prerequisite for vesicle generation.
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Affiliation(s)
- Jan Brod
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Germany
| | - Andrea Hellwig
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Germany
| | - Felix T Wieland
- Heidelberg University Biochemistry Center (BZH), University of Heidelberg, Germany
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30
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Skruzny M, Pohl E, Gnoth S, Malengo G, Sourjik V. The protein architecture of the endocytic coat analyzed by FRET microscopy. Mol Syst Biol 2020; 16:e9009. [PMID: 32400111 PMCID: PMC7218409 DOI: 10.15252/msb.20199009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 12/16/2022] Open
Abstract
Endocytosis is a fundamental cellular trafficking pathway, which requires an organized assembly of the multiprotein endocytic coat to pull the plasma membrane into the cell. Although the protein composition of the endocytic coat is known, its functional architecture is not well understood. Here, we determine the nanoscale organization of the endocytic coat by FRET microscopy in yeast Saccharomyces cerevisiae. We assessed pairwise proximities of 18 conserved coat-associated proteins and used clathrin subunits and protein truncations as molecular rulers to obtain a high-resolution protein map of the coat. Furthermore, we followed rearrangements of coat proteins during membrane invagination and their binding dynamics at the endocytic site. We show that the endocytic coat proteins are not confined inside the clathrin lattice, but form distinct functional layers above and below the lattice. Importantly, key endocytic proteins transverse the clathrin lattice deeply into the cytoplasm connecting thus the membrane and cytoplasmic parts of the coat. We propose that this design enables an efficient and regulated function of the endocytic coat during endocytic vesicle formation.
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Affiliation(s)
- Michal Skruzny
- Department of Systems and Synthetic MicrobiologyMax Planck Institute for Terrestrial MicrobiologyMarburgGermany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | - Emma Pohl
- Department of Systems and Synthetic MicrobiologyMax Planck Institute for Terrestrial MicrobiologyMarburgGermany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | - Sandina Gnoth
- Department of Systems and Synthetic MicrobiologyMax Planck Institute for Terrestrial MicrobiologyMarburgGermany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | - Gabriele Malengo
- Department of Systems and Synthetic MicrobiologyMax Planck Institute for Terrestrial MicrobiologyMarburgGermany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | - Victor Sourjik
- Department of Systems and Synthetic MicrobiologyMax Planck Institute for Terrestrial MicrobiologyMarburgGermany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
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31
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Hammond GRV, Burke JE. Novel roles of phosphoinositides in signaling, lipid transport, and disease. Curr Opin Cell Biol 2020; 63:57-67. [PMID: 31972475 PMCID: PMC7247936 DOI: 10.1016/j.ceb.2019.12.007] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/12/2019] [Accepted: 12/14/2019] [Indexed: 12/22/2022]
Abstract
Phosphoinositides (PPIns) are lipid signaling molecules that act as master regulators of cellular signaling. Recent studies have revealed novel roles of PPIns in myriad cellular processes and multiple human diseases mediated by misregulation of PPIn signaling. This review will present a timely summary of recent discoveries in PPIn biology, specifically their role in regulating unexpected signaling pathways, modification of signaling outcomes downstream of integral membrane proteins, and novel roles in lipid transport. This has revealed new roles of PPIns in regulating membrane trafficking, immunity, cell polarity, and response to extracellular signals. A specific focus will be on novel opportunities to target PPIn metabolism for treatment of human diseases, including cancer, pathogen infection, developmental disorders, and immune disorders.
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Affiliation(s)
- Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA.
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada.
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32
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Abriata LA, Lepore R, Dal Peraro M. About the need to make computational models of biological macromolecules available and discoverable. Bioinformatics 2020; 36:2952-2954. [DOI: 10.1093/bioinformatics/btaa086] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/13/2020] [Accepted: 02/06/2020] [Indexed: 12/19/2022] Open
Affiliation(s)
- Luciano A Abriata
- Laboratory for Biomolecular Modeling
- Protein Production and Structure Core Facility, School of Life Sciences, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne CH-1015, Switzerland
| | - Rosalba Lepore
- BSC-CNS Barcelona Supercomputing Center, Barcelona, Spain
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33
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Akamatsu M, Vasan R, Serwas D, Ferrin MA, Rangamani P, Drubin DG. Principles of self-organization and load adaptation by the actin cytoskeleton during clathrin-mediated endocytosis. eLife 2020; 9:49840. [PMID: 31951196 PMCID: PMC7041948 DOI: 10.7554/elife.49840] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 01/16/2020] [Indexed: 12/20/2022] Open
Abstract
Force generation by actin assembly shapes cellular membranes. An experimentally constrained multiscale model shows that a minimal branched actin network is sufficient to internalize endocytic pits against membrane tension. Around 200 activated Arp2/3 complexes are required for robust internalization. A newly developed molecule-counting method determined that ~200 Arp2/3 complexes assemble at sites of clathrin-mediated endocytosis in human cells. Simulations predict that actin self-organizes into a radial branched array with growing ends oriented toward the base of the pit. Long actin filaments bend between attachment sites in the coat and the base of the pit. Elastic energy stored in bent filaments, whose presence was confirmed by cryo-electron tomography, contributes to endocytic internalization. Elevated membrane tension directs more growing filaments toward the base of the pit, increasing actin nucleation and bending for increased force production. Thus, spatially constrained actin filament assembly utilizes an adaptive mechanism enabling endocytosis under varying physical constraints. The outer membrane of a cell is a tight but elastic barrier that controls what enters or leaves the cell. Large molecules typically cannot cross this membrane unaided. Instead, to enter the cell, they must be packaged into a pocket of the membrane that is then pulled inside. This process, called endocytosis, shuttles material into a cell hundreds of times a minute. Endocytosis relies on molecular machines that assemble and disassemble at the membrane as required. One component, a protein called actin, self-assembles near the membrane into long filaments with many repeated subunits. These filaments grow against the membrane, pulling it inwards. But it was not clear how actin filaments organize in such a way that allows them to pull on the membrane with enough force – and without a template to follow. Akamatsu et al. set about identifying how actin operates during endocytosis by using computer simulations that were informed by measurements made in living cells. The simulations included information about the location of actin and other essential molecules, along with the details of how these molecules work individually and together. Akamatsu et al. also developed a method to count the numbers of molecules of a key protein at individual sites of endocytosis. High-resolution imaging was then used to create 3D pictures of actin and endocytosis in action in human cells grown in the laboratory. The analysis showed the way actin filaments arrange themselves depends on the starting positions of a few key molecules that connect to actin. Imaging confirmed that, like a pole-vaulting pole, the flexible actin filaments bend to store energy and then release it to pull the membrane inwards during endocytosis. Finally, the simulations predicted that the collection of filaments adapts its shape and size in response to the resistance of the elastic membrane. This makes the system opportunistic and adaptable to the unpredictable environment within cells.
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Affiliation(s)
- Matthew Akamatsu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Ritvik Vasan
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, United States
| | - Daniel Serwas
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Michael A Ferrin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, United States
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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34
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Heidemann J, Kölbel K, Konijnenberg A, Van Dyck J, Garcia-Alai M, Meijers R, Sobott F, Uetrecht C. Further insights from structural mass spectrometry into endocytosis adaptor protein assemblies. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2020; 447:116240. [PMID: 33244295 PMCID: PMC7116418 DOI: 10.1016/j.ijms.2019.116240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
As a fundament in many biologically relevant processes, endocytosis in its different guises has been arousing interest for decades and still does so. This is true for the actual transport and its initiation alike. In clathrin-mediated endocytosis, a comparatively well understood endocytic pathway, a set of adaptor proteins bind specific lipids in the plasma membrane, subsequently assemble and thus form a crucial bridge from clathrin to actin for the ongoing process. These adaptor proteins are highly interesting themselves and the subject of this manuscript. Using many of the instruments that are available now in the mass spectrometry toolbox, we added some facets to the picture of how these minimal assemblies may look, how they form, and what influences the structure. Especially, lipids in the adaptor protein complexes result in reduced charging of a normal sized complex due to their specific binding position. The results further support our structural model of a double ring structure with interfacial lipids.
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Affiliation(s)
- Johannes Heidemann
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany
| | - Knut Kölbel
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany
| | - Albert Konijnenberg
- University of Antwerp, Biomolecular & Analytical Mass Spectrometry, Chemistry Dept. Campus Groenenborger V4, Groenenborgerlaan, 171 2020, Antwerp, Belgium
| | - Jeroen Van Dyck
- University of Antwerp, Biomolecular & Analytical Mass Spectrometry, Chemistry Dept. Campus Groenenborger V4, Groenenborgerlaan, 171 2020, Antwerp, Belgium
| | - Maria Garcia-Alai
- European Molecular Biology Laboratory (EMBL), Hamburg Outstation, Notkestrasse 85, 22607, Hamburg, Germany
| | - Rob Meijers
- European Molecular Biology Laboratory (EMBL), Hamburg Outstation, Notkestrasse 85, 22607, Hamburg, Germany
| | - Frank Sobott
- University of Antwerp, Biomolecular & Analytical Mass Spectrometry, Chemistry Dept. Campus Groenenborger V4, Groenenborgerlaan, 171 2020, Antwerp, Belgium
- Astbury Centre for Structural Molecular and Cellular Biology, School of Molecular and Cellular Biology, University of Leeds, LS3 9JT, United Kingdom
| | - Charlotte Uetrecht
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany
- European XFEL GmbH, Holzkoppel 4, 22869, Schenefeld, Germany
- Corresponding author. Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany.
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35
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Costa R, Bellesso S, Lualdi S, Manzoli R, Pistorio V, Filocamo M, Moro E. A transcriptional and post-transcriptional dysregulation of Dishevelled 1 and 2 underlies the Wnt signaling impairment in type I Gaucher disease experimental models. Hum Mol Genet 2019; 29:274-285. [DOI: 10.1093/hmg/ddz293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/02/2019] [Indexed: 02/07/2023] Open
Abstract
Abstract
Bone differentiation defects have been recently tied to Wnt signaling alterations occurring in vitro and in vivo Gaucher disease (GD) models. In this work, we provide evidence that the Wnt signaling multi-domain intracellular transducers Dishevelled 1 and 2 (DVL1 and DVL2) may be potential upstream targets of impaired beta glucosidase (GBA1) activity by showing their misexpression in different type 1 GD in vitro models. We also show that in Gba mutant fish a miR-221 upregulation is associated with reduced dvl2 expression levels and that in type I Gaucher patients single-nucleotide variants in the DVL2 3′ untranslated region are related to variable canonical Wnt pathway activity. Thus, we strengthen the recently outlined relation between bone differentiation defects and Wnt/β-catenin dysregulation in type I GD and further propose novel mechanistic insights of the Wnt pathway impairment caused by glucocerebrosidase loss of function.
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Affiliation(s)
- Roberto Costa
- Department of Biology, University of Padova, Padova I-35121, Italy
| | - Stefania Bellesso
- Department of Molecular Medicine, University of Padova, Padova I-35121, Italy
| | - Susanna Lualdi
- Centro di Diagnostica Genetica e Biochimica delle Malattie Metaboliche Giannina Gaslini Institute, Genova 16147, Italy
| | - Rosa Manzoli
- Department of Biology, University of Padova, Padova I-35121, Italy
- Department of Molecular Medicine, University of Padova, Padova I-35121, Italy
| | - Valeria Pistorio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80131, Italy
| | - Mirella Filocamo
- Centro di Diagnostica Genetica e Biochimica delle Malattie Metaboliche Giannina Gaslini Institute, Genova 16147, Italy
| | - Enrico Moro
- Department of Molecular Medicine, University of Padova, Padova I-35121, Italy
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36
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Biancospino M, Buel GR, Niño CA, Maspero E, Scotto di Perrotolo R, Raimondi A, Redlingshöfer L, Weber J, Brodsky FM, Walters KJ, Polo S. Clathrin light chain A drives selective myosin VI recruitment to clathrin-coated pits under membrane tension. Nat Commun 2019; 10:4974. [PMID: 31672988 PMCID: PMC6823378 DOI: 10.1038/s41467-019-12855-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/27/2019] [Indexed: 11/17/2022] Open
Abstract
Clathrin light chains (CLCa and CLCb) are major constituents of clathrin-coated vesicles. Unique functions for these evolutionary conserved paralogs remain elusive, and their role in clathrin-mediated endocytosis in mammalian cells is debated. Here, we find and structurally characterize a direct and selective interaction between CLCa and the long isoform of the actin motor protein myosin VI, which is expressed exclusively in highly polarized tissues. Using genetically-reconstituted Caco-2 cysts as proxy for polarized epithelia, we provide evidence for coordinated action of myosin VI and CLCa at the apical surface where these proteins are essential for fission of clathrin-coated pits. We further find that myosin VI and Huntingtin-interacting protein 1-related protein (Hip1R) are mutually exclusive interactors with CLCa, and suggest a model for the sequential function of myosin VI and Hip1R in actin-mediated clathrin-coated vesicle budding.
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Affiliation(s)
- Matteo Biancospino
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Gwen R Buel
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Carlos A Niño
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Elena Maspero
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | | | - Andrea Raimondi
- Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
| | - Lisa Redlingshöfer
- Division of Biosciences, University College London, London, WC1E 6BT, UK
| | - Janine Weber
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Frances M Brodsky
- Division of Biosciences, University College London, London, WC1E 6BT, UK.
| | - Kylie J Walters
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - Simona Polo
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy.
- Dipartimento di Oncologia ed Emato-oncologia, Universita' degli Studi di Milano, 20122, Milan, Italy.
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37
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Remodeling Membrane Binding by Mono-Ubiquitylation. Biomolecules 2019; 9:biom9080325. [PMID: 31370222 PMCID: PMC6723200 DOI: 10.3390/biom9080325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/22/2019] [Accepted: 07/29/2019] [Indexed: 01/17/2023] Open
Abstract
Ubiquitin (Ub) receptors respond to ubiquitylation signals. They bind ubiquitylated substrates and exert their activity in situ. Intriguingly, Ub receptors themselves undergo rapid ubiquitylation and deubiquitylation. Here we asked what is the function of ubiquitylation of Ub receptors? We focused on yeast epsin, a Ub receptor that decodes the ubiquitylation signal of plasma membrane proteins into an endocytosis response. Using mass spectrometry, we identified lysine-3 as the major ubiquitylation site in the epsin plasma membrane binding domain. By projecting this ubiquitylation site onto our crystal structure, we hypothesized that this modification would compete with phosphatidylinositol-4,5-bisphosphate (PIP2) binding and dissociate epsin from the membrane. Using an E. coli-based expression of an authentic ubiquitylation apparatus, we purified ubiquitylated epsin. We demonstrated in vitro that in contrast to apo epsin, the ubiquitylated epsin does not bind to either immobilized PIPs or PIP2-enriched liposomes. To test this hypothesis in vivo, we mimicked ubiquitylation by the fusion of Ub at the ubiquitylation site. Live cell imaging demonstrated that the mimicked ubiquitylated epsin dissociates from the membrane. Our findings suggest that ubiquitylation of the Ub receptors dissociates them from their products to allow binding to a new ubiquitylated substrates, consequently promoting cyclic activity of the Ub receptors.
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38
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Enkavi G, Javanainen M, Kulig W, Róg T, Vattulainen I. Multiscale Simulations of Biological Membranes: The Challenge To Understand Biological Phenomena in a Living Substance. Chem Rev 2019; 119:5607-5774. [PMID: 30859819 PMCID: PMC6727218 DOI: 10.1021/acs.chemrev.8b00538] [Citation(s) in RCA: 196] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Indexed: 12/23/2022]
Abstract
Biological membranes are tricky to investigate. They are complex in terms of molecular composition and structure, functional over a wide range of time scales, and characterized by nonequilibrium conditions. Because of all of these features, simulations are a great technique to study biomembrane behavior. A significant part of the functional processes in biological membranes takes place at the molecular level; thus computer simulations are the method of choice to explore how their properties emerge from specific molecular features and how the interplay among the numerous molecules gives rise to function over spatial and time scales larger than the molecular ones. In this review, we focus on this broad theme. We discuss the current state-of-the-art of biomembrane simulations that, until now, have largely focused on a rather narrow picture of the complexity of the membranes. Given this, we also discuss the challenges that we should unravel in the foreseeable future. Numerous features such as the actin-cytoskeleton network, the glycocalyx network, and nonequilibrium transport under ATP-driven conditions have so far received very little attention; however, the potential of simulations to solve them would be exceptionally high. A major milestone for this research would be that one day we could say that computer simulations genuinely research biological membranes, not just lipid bilayers.
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Affiliation(s)
- Giray Enkavi
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Matti Javanainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy
of Sciences, Flemingovo naḿesti 542/2, 16610 Prague, Czech Republic
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Waldemar Kulig
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Tomasz Róg
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Ilpo Vattulainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
- MEMPHYS-Center
for Biomembrane Physics
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39
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Uetrecht C, Lorenzen K, Kitel M, Heidemann J, Robinson Spencer JH, Schlüter H, Schulz J. Native mass spectrometry provides sufficient ion flux for XFEL single-particle imaging. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:653-659. [PMID: 31074428 PMCID: PMC6510201 DOI: 10.1107/s1600577519002686] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/21/2019] [Indexed: 05/11/2023]
Abstract
The SPB/SFX instrument at the European XFEL provides unique conditions for single-particle imaging (SPI) experiments due to its high brilliance, nano-focus and unique pulse structure. Promising initial results provided by the international LCLS (Linac Coherent Light Source) SPI initiative highlight the potential of SPI. Current available injection methods generally have high sample consumption and do not provide any options for pulsing, selection or orientation of particles, which poses a problem for data evaluation. Aerosol-injector-based sample delivery is the current method of choice for SPI experiments, although, to a lesser extent, electrospray and electrospinning are used. Single particles scatter only a limited number of photons providing a single orientation for data evaluation, hence large datasets are required from particles in multiple orientations in order to reconstruct a structure. Here, a feasibility study demonstrates that nano-electrospray ionization, usually employed in biomolecular mass spectrometry, provides enough ion flux for SPI experiments. A novel instrument setup at the SPB/SFX instrument is proposed, which has the benefit of extremely low background while delivering mass over charge and conformation-selected ions for SPI.
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Affiliation(s)
- Charlotte Uetrecht
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistrasse 52, Hamburg 20251, Germany
- European XFEL GmbH, Holzkoppel 4, Schenefeld 22869, Germany
| | | | - Matthäus Kitel
- European XFEL GmbH, Holzkoppel 4, Schenefeld 22869, Germany
| | - Johannes Heidemann
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Martinistrasse 52, Hamburg 20251, Germany
| | - Jesse Huron Robinson Spencer
- European XFEL GmbH, Holzkoppel 4, Schenefeld 22869, Germany
- Institute for Clinical Chemistry, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, Hamburg 20246, Germany
| | - Hartmut Schlüter
- Institute for Clinical Chemistry, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, Hamburg 20246, Germany
| | - Joachim Schulz
- European XFEL GmbH, Holzkoppel 4, Schenefeld 22869, Germany
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40
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Structural basis for activation of plasma-membrane Ca 2+-ATPase by calmodulin. Commun Biol 2018; 1:206. [PMID: 30511020 PMCID: PMC6255812 DOI: 10.1038/s42003-018-0203-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 10/26/2018] [Indexed: 01/17/2023] Open
Abstract
Plasma-membrane Ca2+-ATPases expel Ca2+ from the cytoplasm and are key regulators of Ca2+ homeostasis in eukaryotes. They are autoinhibited under low Ca2+ concentrations. Calmodulin (CaM)-binding to a unique regulatory domain releases the autoinhibition and activates the pump. However, the structural basis for this activation, including the overall structure of this calcium pump and its complex with calmodulin, is unknown. We previously determined the high-resolution structure of calmodulin in complex with the regulatory domain of the plasma-membrane Ca2+-ATPase ACA8 and revealed a bimodular mechanism of calcium control in eukaryotes. Here we show that activation of ACA8 by CaM involves large conformational changes. Combining advanced modeling of neutron scattering data acquired from stealth nanodiscs and native mass spectrometry with detailed dissection of binding constants, we present a structural model for the full-length ACA8 Ca2+ pump in its calmodulin-activated state illustrating a displacement of the regulatory domain from the core enzyme. Julius Nitsche et al. demonstrate that binding of two calmodulin molecules displaces the regulatory domain of the plasma-membrane Ca2+-ATPase ACA8 to fully activate this Ca2+ pump by relieving the autoinhibition. This work provides structural evidence for the previously proposed bimodular activation mechanism.
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