1
|
Vetal PV, Poirier Y. The Arabidopsis PHOSPHATE 1 exporter undergoes constitutive internalization via clathrin-mediated endocytosis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 116:1477-1491. [PMID: 37638714 DOI: 10.1111/tpj.16441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 08/29/2023]
Abstract
SUMMARYInorganic phosphate (Pi) homeostasis is essential for plant growth and depends on the transport of Pi across cells. In Arabidopsis thaliana, PHOSPHATE 1 (PHO1) is present in the root pericycle and xylem parenchyma where it exports Pi into the xylem apoplast for its transfer to shoots. PHO1 consists of a cytosolic SPX domain followed by membrane‐spanning α‐helices and ends with the EXS domain, which participates in the steady‐state localization of PHO1 to the Golgi and trans‐Golgi network (TGN). However, PHO1 exports Pi across the plasma membrane (PM), making its localization difficult to reconcile with its function. To investigate whether PHO1 transiently associates with the PM, we inhibited clathrin‐mediated endocytosis (CME) by overexpressing AUXILIN‐LIKE 2 or HUB1. Inhibiting CME resulted in PHO1 re‐localization from the Golgi/TGN to the PM when PHO1 was expressed in Arabidopsis root pericycle or epidermis or Nicotiana benthamiana leaf epidermal cells. A fusion protein between the PHO1 EXS region and GFP was stabilized at the PM by CME inhibition, indicating that the EXS domain plays an important role in sorting PHO1 to/from the PM. PHO1 internalization from the PM occurred independently of AP2 and was not influenced by Pi deficiency, the ubiquitin‐conjugating E2 PHO2, or the potential ubiquitination of cytosolic lysines in the EXS domain. PM‐stabilized PHO1 showed reduced root‐to‐shoot Pi export activity, indicating that CME of PHO1 may be important for its optimal Pi export activity and plant Pi homeostasis.
Collapse
Affiliation(s)
- Pallavi V Vetal
- Department of Plant Molecular Biology, University of Lausanne, 1015, Lausanne, Switzerland
| | - Yves Poirier
- Department of Plant Molecular Biology, University of Lausanne, 1015, Lausanne, Switzerland
| |
Collapse
|
2
|
A conformational switch in clathrin light chain regulates lattice structure and endocytosis at the plasma membrane of mammalian cells. Nat Commun 2023; 14:732. [PMID: 36759616 PMCID: PMC9911608 DOI: 10.1038/s41467-023-36304-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 01/25/2023] [Indexed: 02/11/2023] Open
Abstract
Conformational changes in endocytic proteins are regulators of clathrin-mediated endocytosis. Three clathrin heavy chains associated with clathrin light chains (CLC) assemble into triskelia that link into a geometric lattice that curves to drive endocytosis. Structural changes in CLC have been shown to regulate triskelia assembly in solution, yet the nature of these changes, and their effects on lattice growth, curvature, and endocytosis in cells are unknown. Here, we develop a new correlative fluorescence resonance energy transfer (FRET) and platinum replica electron microscopy method, named FRET-CLEM. With FRET-CLEM, we measure conformational changes in clathrin at thousands of individual morphologically distinct clathrin-coated structures. We discover that the N-terminus of CLC repositions away from the plasma membrane and triskelia vertex as coats curve. Preventing this conformational switch with chemical tools increases lattice sizes and inhibits endocytosis. Thus, a specific conformational switch in the light chain regulates lattice curvature and endocytosis in mammalian cells.
Collapse
|
3
|
Kim HS, Bae JH, Kim G, Song JJ, Kim HS. Construction and Functionalization of a Clathrin Assembly for a Targeted Protein Delivery. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2204620. [PMID: 36456203 DOI: 10.1002/smll.202204620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Protein assemblies have drawn much attention as platforms for biomedical applications, including gene/drug delivery and vaccine, due to biocompatibility and functional diversity. Here, the construction and functionalization of a protein assembly composed of human clathrin heavy chain and light chain for a targeted protein delivery, is presented. The clathrin heavy and light chains are redesigned and associated with each other, and the resulting triskelion unit further self-assembled into a clathrin assembly with the size of about 28 nm in diameter. The clathrin assembly is dual-functionalized with a protein cargo and a targeting moiety using two different orthogonal protein-ligand pairs through one-pot reaction. The functionalized clathrin assembly exhibits about a 900-fold decreased KD value for a cell-surface target due to avidity compared to a native targeting moiety. The utility of the clathrin assembly is demonstrated by an efficient delivery of a protein cargo into tumor cells in a target-specific manner, resulting in a strong cytotoxic effect. The present approach can be used in the creation of protein assemblies with multimodality.
Collapse
Affiliation(s)
- Hong-Sik Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jin-Ho Bae
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Gijeong Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hak-Sung Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| |
Collapse
|
4
|
Das J, Tiwari M, Subramanyam D. Clathrin Light Chains: Not to Be Taken so Lightly. Front Cell Dev Biol 2022; 9:774587. [PMID: 34970544 PMCID: PMC8712872 DOI: 10.3389/fcell.2021.774587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 11/12/2021] [Indexed: 01/31/2023] Open
Abstract
Clathrin is a cytosolic protein involved in the intracellular trafficking of a wide range of cargo. It is composed of three heavy chains and three light chains that together form a triskelion, the subunit that polymerizes to form a clathrin coated vesicle. In addition to its role in membrane trafficking, clathrin is also involved in various cellular and biological processes such as chromosomal segregation during mitosis and organelle biogenesis. Although the role of the heavy chains in regulating important physiological processes has been well documented, we still lack a complete understanding of how clathrin light chains regulate membrane traffic and cell signaling. This review highlights the importance and contributions of clathrin light chains in regulating clathrin assembly, vesicle formation, endocytosis of selective receptors and physiological and developmental processes.
Collapse
Affiliation(s)
- Jyoti Das
- National Centre for Cell Science, Pune, India.,Savitribai Phule Pune University, Pune, India
| | - Mahak Tiwari
- National Centre for Cell Science, Pune, India.,Savitribai Phule Pune University, Pune, India
| | | |
Collapse
|
5
|
Clathrin: the molecular shape shifter. Biochem J 2021; 478:3099-3123. [PMID: 34436540 DOI: 10.1042/bcj20200740] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 07/19/2021] [Accepted: 08/04/2021] [Indexed: 12/11/2022]
Abstract
Clathrin is best known for its contribution to clathrin-mediated endocytosis yet it also participates to a diverse range of cellular functions. Key to this is clathrin's ability to assemble into polyhedral lattices that include curved football or basket shapes, flat lattices or even tubular structures. In this review, we discuss clathrin structure and coated vesicle formation, how clathrin is utilised within different cellular processes including synaptic vesicle recycling, hormone desensitisation, spermiogenesis, cell migration and mitosis, and how clathrin's remarkable 'shapeshifting' ability to form diverse lattice structures might contribute to its multiple cellular functions.
Collapse
|
6
|
Redlingshöfer L, Brodsky FM. Antagonistic regulation controls clathrin-mediated endocytosis: AP2 adaptor facilitation vs restraint from clathrin light chains. Cells Dev 2021; 168:203714. [PMID: 34182181 DOI: 10.1016/j.cdev.2021.203714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/11/2021] [Accepted: 06/21/2021] [Indexed: 02/02/2023]
Abstract
Orchestration of a complex network of protein interactions drives clathrin-mediated endocytosis (CME). A central role for the AP2 adaptor complex beyond cargo recognition and clathrin recruitment has emerged in recent years. It is now apparent that AP2 serves as a pivotal hub for protein interactions to mediate clathrin coated pit maturation, and couples lattice formation to membrane deformation. As a key driver for clathrin assembly, AP2 complements the attenuating role of clathrin light chain subunits, which enable dynamic lattice rearrangement needed for budding. This review summarises recent insights into AP2 function with respect to CME dynamics and biophysics, and its relationship to the role of clathrin light chains in clathrin assembly.
Collapse
Affiliation(s)
- Lisa Redlingshöfer
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, United Kingdom; Institute for Structural and Molecular Biology, Birkbeck and University College London, London WC1E 7HX, United Kingdom.
| | - Frances M Brodsky
- Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, United Kingdom; Institute for Structural and Molecular Biology, Birkbeck and University College London, London WC1E 7HX, United Kingdom.
| |
Collapse
|
7
|
Souibgui E, Bruel C, Choquer M, de Vallée A, Dieryckx C, Dupuy JW, Latorse MP, Rascle C, Poussereau N. Clathrin Is Important for Virulence Factors Delivery in the Necrotrophic Fungus Botrytis cinerea. FRONTIERS IN PLANT SCIENCE 2021; 12:668937. [PMID: 34220891 PMCID: PMC8244658 DOI: 10.3389/fpls.2021.668937] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/19/2021] [Indexed: 06/13/2023]
Abstract
Fungi are the most prevalent plant pathogens, causing annually important damages. To infect and colonize their hosts, they secrete effectors including hydrolytic enzymes able to kill and macerate plant tissues. These secreted proteins are transported from the Endoplasmic Reticulum and the Golgi apparatus to the extracellular space through intracellular vesicles. In pathogenic fungi, intracellular vesicles were described but their biogenesis and their role in virulence remain unclear. In this study, we report the essential role of clathrin heavy chain (CHC) in the pathogenicity of Botrytis cinerea, the agent of gray mold disease. To investigate the importance of this protein involved in coat vesicles formation in eukaryotic cells, a T-DNA insertional mutant reduced in the expression of the CHC-encoding gene, and a mutant expressing a dominant-negative form of CHC were studied. Both mutants were strongly affected in pathogenicity. Characterization of the mutants revealed altered infection cushions and an important defect in protein secretion. This study demonstrates the essential role of clathrin in the infectious process of a plant pathogenic fungus and more particularly its role in virulence factors delivery.
Collapse
Affiliation(s)
- Eytham Souibgui
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| | - Christophe Bruel
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| | - Mathias Choquer
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| | - Amélie de Vallée
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| | - Cindy Dieryckx
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| | - Jean William Dupuy
- Plateforme Protéome, Centre de Génomique Fonctionnelle, Université de Bordeaux, Bordeaux, France
| | | | - Christine Rascle
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| | - Nathalie Poussereau
- UMR 5240, CNRS MAP, INSA Lyon, Bayer SAS, UCBL, University Lyon, Lyon, France
| |
Collapse
|
8
|
Clathrin light chain diversity regulates membrane deformation in vitro and synaptic vesicle formation in vivo. Proc Natl Acad Sci U S A 2020; 117:23527-23538. [PMID: 32907943 PMCID: PMC7519287 DOI: 10.1073/pnas.2003662117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
This study reveals that diversity of clathrin light chain (CLC) subunits alters clathrin properties and demonstrates that the two neuronal CLC subunits work together for optimal clathrin function in synaptic vesicle formation. Our findings establish a role for CLC diversity in synaptic transmission and illustrate how CLC variability expands the complexity of clathrin to serve tissue-specific functions. Clathrin light chain (CLC) subunits in vertebrates are encoded by paralogous genes CLTA and CLTB, and both gene products are alternatively spliced in neurons. To understand how this CLC diversity influences neuronal clathrin function, we characterized the biophysical properties of clathrin comprising individual CLC variants for correlation with neuronal phenotypes of mice lacking either CLC-encoding gene. CLC splice variants differentially influenced clathrin knee conformation within assemblies, and clathrin with neuronal CLC mixtures was more effective in membrane deformation than clathrin with single neuronal isoforms nCLCa or nCLCb. Correspondingly, electrophysiological recordings revealed that neurons from mice lacking nCLCa or nCLCb were both defective in synaptic vesicle replenishment. Mice with only nCLCb had a reduced synaptic vesicle pool and impaired neurotransmission compared to WT mice, while nCLCa-only mice had increased synaptic vesicle numbers, restoring normal neurotransmission. These findings highlight differences between the CLC isoforms and show that isoform mixing influences tissue-specific clathrin activity in neurons, which requires their functional balance.
Collapse
|
9
|
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: 32] [Impact Index Per Article: 6.4] [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.
Collapse
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.
| |
Collapse
|
10
|
Cryo-EM of multiple cage architectures reveals a universal mode of clathrin self-assembly. Nat Struct Mol Biol 2019; 26:890-898. [PMID: 31582853 PMCID: PMC7100586 DOI: 10.1038/s41594-019-0292-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/02/2019] [Indexed: 01/10/2023]
Abstract
Clathrin forms diverse lattice and cage structures that change size and shape rapidly in response to the needs of eukaryotic cells during clathrin-mediated endocytosis and intracellular trafficking. We present the cryo-EM structure and molecular model of assembled porcine clathrin, providing insights into interactions that stabilize key elements of the clathrin lattice, namely, between adjacent heavy chains, at the light chain-heavy chain interface and within the trimerization domain. Furthermore, we report cryo-EM maps for five different clathrin cage architectures. Fitting structural models to three of these maps shows that their assembly requires only a limited range of triskelion leg conformations, yet inherent flexibility is required to maintain contacts. Analysis of the protein-protein interfaces shows remarkable conservation of contact sites despite architectural variation. These data reveal a universal mode of clathrin assembly that allows variable cage architecture and adaptation of coated vesicle size and shape during clathrin-mediated vesicular trafficking or endocytosis.
Collapse
|
11
|
Ekanayake G, LaMontagne ED, Heese A. Never Walk Alone: Clathrin-Coated Vesicle (CCV) Components in Plant Immunity. ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:387-409. [PMID: 31386597 DOI: 10.1146/annurev-phyto-080417-045841] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
At the host-pathogen interface, the protein composition of the plasma membrane (PM) has important implications for how a plant cell perceives and responds to invading microbial pathogens. A plant's ability to modulate its PM composition is critical for regulating the strength, duration, and integration of immune responses. One mechanism by which plant cells reprogram their cell surface is vesicular trafficking, including secretion and endocytosis. These trafficking processes add or remove cargo proteins (such as pattern-recognition receptors, transporters, and other proteins with immune functions) to or from the PM via small, membrane-bound vesicles. Clathrin-coated vesicles (CCVs) that form at the PM and trans-Golgi network/early endosomes have emerged as the prominent vesicle type in the regulation of plant immune responses. In this review, we discuss the roles of the CCV core, adaptors, and accessory components in plant defense signaling and immunity against various microbial pathogens.
Collapse
Affiliation(s)
- Gayani Ekanayake
- Division of Biochemistry, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211, USA; ,
| | - Erica D LaMontagne
- Division of Biochemistry, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211, USA; ,
| | - Antje Heese
- Division of Biochemistry, Interdisciplinary Plant Group, University of Missouri, Columbia, Missouri 65211, USA; ,
| |
Collapse
|
12
|
Gao J, Chaudhary A, Vaddepalli P, Nagel MK, Isono E, Schneitz K. The Arabidopsis receptor kinase STRUBBELIG undergoes clathrin-dependent endocytosis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3881-3894. [PMID: 31107531 PMCID: PMC6685663 DOI: 10.1093/jxb/erz190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 04/09/2019] [Indexed: 05/04/2023]
Abstract
Signaling mediated by cell surface receptor kinases is central to the coordination of growth patterns during organogenesis. Receptor kinase signaling is in part controlled through endocytosis and subcellular distribution of the respective receptor kinase. For the majority of plant cell surface receptors, the underlying trafficking mechanisms are not characterized. In Arabidopsis, tissue morphogenesis requires the atypical receptor kinase STRUBBELIG (SUB). Here, we studied the endocytic mechanism of SUB. Our data revealed that a functional SUB-enhanced green fluorescent protein (EGFP) fusion is ubiquitinated in vivo. We further showed that plasma membrane-bound SUB:EGFP becomes internalized in a clathrin-dependent fashion. We also found that SUB:EGFP associates with the trans-Golgi network and accumulates in multivesicular bodies and the vacuole. Co-immunoprecipitation experiments revealed that SUB:EGFP and clathrin are present within the same protein complex. Our genetic analysis showed that SUB and CLATHRIN HEAVY CHAIN (CHC) 2 regulate root hair patterning. By contrast, genetic reduction of CHC activity ameliorates the floral defects of sub mutants. Taken together, the data indicate that SUB undergoes clathrin-mediated endocytosis, that this process does not rely on stimulation of SUB signaling by an exogenous agent, and that SUB genetically interacts with clathrin-dependent pathways in a tissue-specific manner.
Collapse
Affiliation(s)
- Jin Gao
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Ajeet Chaudhary
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Prasad Vaddepalli
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
- Present address: Laboratory of Biochemistry, Wageningen University, Wageningen, the Netherlands
| | - Marie-Kristin Nagel
- Department of Biology, Chair of Plant Physiology and Biochemistry, University of Konstanz, Konstanz, Germany
| | - Erika Isono
- Department of Biology, Chair of Plant Physiology and Biochemistry, University of Konstanz, Konstanz, Germany
| | - Kay Schneitz
- Entwicklungsbiologie der Pflanzen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
- Correspondence:
| |
Collapse
|
13
|
Trusova SV, Teplova AD, Golyshev SA, Galiullina RA, Morozova EA, Chichkova NV, Vartapetian AB. Clathrin-Mediated Endocytosis Delivers Proteolytically Active Phytaspases Into Plant Cells. FRONTIERS IN PLANT SCIENCE 2019; 10:873. [PMID: 31379892 PMCID: PMC6657458 DOI: 10.3389/fpls.2019.00873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 06/19/2019] [Indexed: 06/10/2023]
Abstract
Phytaspases belong to the family of plant subtilisin-like proteases and are distinct from other family members, as they have strict and rarely occurring aspartate cleavage specificity and unusual localization dynamics. After being secreted into the apoplast of healthy plant tissues, phytaspases are able to return back into cells that have been committed to cell death due to a variety of biotic and abiotic stresses. It was recently discovered that retrograde transport of phytaspases involves clathrin-mediated endocytosis. Here, consequences of phytaspase internalization were studied. Proteolytic activity of phytaspases in the apoplast and intracellular protein fractions obtained from Nicotiana benthamiana leaves containing either endogenous phytaspase only or transiently producing Nicotiana tabacum phytaspase-EGFP protein (NtPhyt-EGFP) was determined. We demonstrated that triggering phytaspase internalization by antimycin A-induced oxidative stress is accompanied by re-distribution of phytaspase activity from the apoplast to the cell interior. Inhibition of clathrin-mediated endocytosis by co-production of the Hub protein prevented phytaspase internalization and phytaspase activity re-localization. Specificity of endocytic uptake of phytaspases was demonstrated by the co-production of an apoplast-targeted mRFP protein marker, which retained its apoplastic localization when phytaspase internalization was essentially complete. Overproduction of NtPhyt-EGFP, but not of the proteolytically inactive phytaspase mutant, per se caused moderate damage in young Nicotiana benthamiana seedlings, whereas antimycin A treatment induced a pronounced loss of cell viability independent of the NtPhyt-EGFP overproduction. Interestingly, inhibition of clathrin-mediated endocytosis abrogated cell death symptoms in both cases. In contrast to stress-induced internalization of tobacco phytaspase, Arabidopsis thaliana phytaspase-EGFP protein (AtPhyt-EGFP) was spontaneously internalized when transiently produced in N. benthamiana leaves. The AtPhyt-EGFP uptake was dependent on clathrin-mediated endocytosis as well, the internalized protein being initially visualized within the membranous vesicles. At later time points, the EGFP tag was cleaved off from AtPhyt, though the elevated level of intracellular AtPhyt proteolytic activity persisted. Our data, therefore, point to clathrin-mediated endocytosis as a means to deliver proteolytically active phytaspases into plant cells. It would be interesting to learn whether or not phytaspases are unique among the large family of plant subtilisin-like proteases in their ability to utilize retrograde trafficking.
Collapse
Affiliation(s)
- Svetlana V. Trusova
- Department of Chemistry and Biochemistry of Nucleoproteins, Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Anastasia D. Teplova
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Sergei A. Golyshev
- Department of Chemistry and Biochemistry of Nucleoproteins, Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Raisa A. Galiullina
- Department of Chemistry and Biochemistry of Nucleoproteins, Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Ekaterina A. Morozova
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Nina V. Chichkova
- Department of Chemistry and Biochemistry of Nucleoproteins, Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Andrey B. Vartapetian
- Department of Chemistry and Biochemistry of Nucleoproteins, Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| |
Collapse
|
14
|
Lherbette M, Redlingshöfer L, Brodsky FM, Schaap IAT, Dannhauser PN. The AP2 adaptor enhances clathrin coat stiffness. FEBS J 2019; 286:4074-4085. [PMID: 31199077 PMCID: PMC6852553 DOI: 10.1111/febs.14961] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 03/22/2019] [Accepted: 06/10/2019] [Indexed: 12/30/2022]
Abstract
Deformation of the plasma membrane into clathrin-coated vesicles is a critical step in clathrin-mediated endocytosis and requires the orchestrated assembly of clathrin and endocytic adaptors into a membrane-associated protein coat. The individual role of these membrane-bending and curvature-stabilizing factors is subject to current debate. As such, it is unclear whether the clathrin coat itself is stiff enough to impose curvature and if so, whether this could be effectively transferred to the membrane by the linking adaptor proteins. We have recently demonstrated that clathrin alone is sufficient to form membrane buds in vitro. Here, we use atomic force microscopy to assess the contributions of clathrin and its membrane adaptor protein 2 (AP2) to clathrin coat stiffness, which determines the mechanics of vesicle formation. We found that clathrin coats are less than 10-fold stiffer than the membrane they enclose, suggesting a delicate balance between the forces harnessed from clathrin coat formation and those required for membrane bending. We observed that clathrin adaptor protein AP2 increased the stiffness of coats formed from native clathrin, but did not affect less-flexible coats formed from clathrin lacking the light chain subunits. We thus propose that clathrin light chains are important for clathrin coat flexibility and that AP2 facilitates efficient cargo sequestration during coated vesicle formation by modulating clathrin coat stiffness.
Collapse
Affiliation(s)
- Michael Lherbette
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Lisa Redlingshöfer
- Division of Biosciences, Research Department of Structural and Molecular Biology, Institute of Structural and Molecular Biology, University College London, UK
| | - Frances M Brodsky
- Division of Biosciences, Research Department of Structural and Molecular Biology, Institute of Structural and Molecular Biology, University College London, UK
| | - Iwan A T Schaap
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Philip N Dannhauser
- Division of Biosciences, Research Department of Structural and Molecular Biology, Institute of Structural and Molecular Biology, University College London, UK
| |
Collapse
|
15
|
Abstract
The unusual structure of clathrin, combined with its ability to assemble and disassemble rapidly in cells provides a model system for us to learn about the ways in which proteins can contribute mechanically to a functioning cell. In this article, we discuss the structural properties of clathrin cages and the triskelions which assemble to form them. The function of clathrin depends on the structure of these triskelions and the interactions they make both with each other during assembly and with the adaptor protein network that drives coated vesicle formation. The atomic resolution structure of clathrin domains has been revealed by X-ray crystallography while scattering studies have enabled the shape of a triskelion in solution to be deduced. Cryo-electron microscopy maps have shown the secondary structure of entire cages, how individual triskelion legs are arranged to form a cage and enabled some bound adaptor proteins to be located. Cage formation itself is energetically finely balanced and requires specific interactions between triskelion legs to be productive, as biochemical studies and in silico modeling have shown. Theoretical, structural and cell biological investigations over many years have contributed to our knowledge of clathrin structure and assembly. It now remains to determine the precise nature of the interactions which occur between clathrin triskelions, light chain and heavy chain and the adaptor protein network.
Collapse
Affiliation(s)
- Mary Halebian
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Kyle Morris
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Corinne Smith
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
| |
Collapse
|
16
|
Tu H, Li X, Yang Q, Peng L, Pan SQ. Real-Time Trafficking of Agrobacterium Virulence Protein VirE2 Inside Host Cells. Curr Top Microbiol Immunol 2018; 418:261-286. [PMID: 30182197 DOI: 10.1007/82_2018_131] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A. tumefaciens delivers T-DNA and virulence proteins, including VirE2, into host plant cells, where T-DNA is proposed to be protected by VirE2 molecules as a nucleoprotein complex (T-complex) and trafficked into the nucleus. VirE2 is a protein that can self-aggregate and contains targeting sequences so that it can efficiently move from outside of a cell to the nucleus. We adopted a split-GFP approach and generated a VirE2-GFP fusion which retains the self-aggregating property and the targeting sequences. The fusion protein is fully functional and can move inside cells in real time in a readily detectable format: fluorescent and unique filamentous aggregates. Upon delivery mediated by the bacterial type IV secretion system (T4SS), VirE2-GFP is internalized into the plant cells via clathrin adaptor complex AP2-mediated endocytosis. Subsequently, VirE2-GFP binds to membrane structures such as the endoplasmic reticulum (ER) and is trafficked within the cell. This enables us to observe the highly dynamic activities of the cell. If a compound, a gene, or a condition affects the cell, the cellular dynamics shown by the VirE2-GFP will be affected and thus readily observed by confocal microscopy. This represents an excellent model to study the delivery and trafficking of an exogenously produced and delivered protein inside a cell in a natural setting in real time. The model may be used to explore the theoretical and applied aspects of natural protein delivery and targeting.
Collapse
Affiliation(s)
- Haitao Tu
- School of Stomatology and Medicine, Foshan Institute of Molecular Bio-Engineering, Foshan University, 528000, Foshan, China
| | - Xiaoyang Li
- Department of Biological Sciences, National University of Singapore, 117543, Singapore, Singapore
| | - Qinghua Yang
- Department of Biological Sciences, National University of Singapore, 117543, Singapore, Singapore
| | - Ling Peng
- Department of Biological Sciences, National University of Singapore, 117543, Singapore, Singapore
| | - Shen Q Pan
- Department of Biological Sciences, National University of Singapore, 117543, Singapore, Singapore.
| |
Collapse
|
17
|
Ovarian expression and localization of clathrin (Cltc) components in cutthroat trout, Oncorhynchus clarki: Evidence for Cltc involvement in endocytosis of vitellogenin during oocyte growth. Comp Biochem Physiol A Mol Integr Physiol 2017; 212:24-34. [PMID: 28687414 DOI: 10.1016/j.cbpa.2017.06.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 11/24/2022]
Abstract
To evaluate potential involvement of clathrin in endocytosis of vitellogenin (Vtg) by teleost oocytes, cDNAs encoding clathrin heavy chain (cltc) were cloned from ovaries of cutthroat trout. Quantitative PCR revealed three types of cltc (cltc-a1, cltc-a2, cltc-b) to be expressed in 10 different tissues including the ovary. The cltc-a1 alone exhibited a significant decrease in ovarian expression during vitellogenesis; this was correlated with a corresponding decrease in transcripts encoding the major Vtg receptor (Vtgr). No development-related changes in ovarian cltc-a2 or cltc-b transcript levels were observed. In situ hybridization revealed a strong ctlc signal in pre-vitellogenic oocytes, but not in vitellogenic oocytes. Western blotting using a rabbit antiserum (a-Cltc) raised against a recombinant Cltc preparation detected a polypeptide band with an apparent mass of ~170kDa in vitellogenic ovary extracts. Immunohistochemistry using a-Cltc revealed Cltc to be uniformly distributed throughout the ooplasm of perinucleolus stage oocytes, translocated to the periphery of lipid droplet stage oocytes, and localized to the oolemma during vitellogenesis. These patterns of cltc/Cltc distribution and abundance during oogenesis, which are identical to those previously reported for vtgr/Vtgr in this species, constitute the first empirical evidence that cltc-a1/Cltc-a1 is involved in Vtg endocytosis via the Vtgr in teleost fish.
Collapse
|
18
|
Li X, Pan SQ. Agrobacterium delivers VirE2 protein into host cells via clathrin-mediated endocytosis. SCIENCE ADVANCES 2017; 3:e1601528. [PMID: 28345032 PMCID: PMC5362186 DOI: 10.1126/sciadv.1601528] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 02/09/2017] [Indexed: 05/20/2023]
Abstract
Agrobacterium tumefaciens can cause crown gall tumors on a wide range of host plants. As a natural genetic engineer, the bacterium can transfer both single-stranded DNA (ssDNA) [transferred DNA (T-DNA)] molecules and bacterial virulence proteins into various recipient cells. Among Agrobacterium-delivered proteins, VirE2 is an ssDNA binding protein that is involved in various steps of the transformation process. However, it is not clear how plant cells receive the T-DNA or protein molecules. Using a split-green fluorescent protein approach, we monitored the VirE2 delivery process inside plant cells in real time. We observed that A. tumefaciens delivered VirE2 from the bacterial lateral sides that were in close contact with plant membranes. VirE2 initially accumulated on plant cytoplasmic membranes at the entry points. VirE2-containing membranes were internalized through clathrin-mediated endocytosis to form endomembrane compartments. VirE2 colocalized with the early endosome marker SYP61 but not with the late endosome marker ARA6, suggesting that VirE2 escaped from early endosomes for subsequent trafficking inside the cells. Dual endocytic motifs at the carboxyl-terminal tail of VirE2 were involved in VirE2 internalization and could interact with the μ subunit of the plant clathrin-associated adaptor AP2 complex (AP2M). Both the VirE2 cargo motifs and AP2M were important for the transformation process. Because AP2-mediated endocytosis is well conserved, our data suggest that the A. tumefaciens pathogen hijacks conserved endocytic pathways to facilitate the delivery of virulence factors. This might be important for Agrobacterium to achieve both a wide host range and a high transformation efficiency.
Collapse
Affiliation(s)
- Xiaoyang Li
- Department of Biological Sciences, National University of Singapore, 10 Science Drive 4, Singapore 117543, Singapore
| | - Shen Q. Pan
- Department of Biological Sciences, National University of Singapore, 10 Science Drive 4, Singapore 117543, Singapore
| |
Collapse
|
19
|
Boettner DR, Segarra VA, Moorthy BT, de León N, Creagh J, Collette JR, Malhotra A, Lemmon SK. Creating a chimeric clathrin heavy chain that functions independently of yeast clathrin light chain. Traffic 2016; 17:754-68. [PMID: 27062026 DOI: 10.1111/tra.12401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 04/05/2016] [Accepted: 04/05/2016] [Indexed: 01/20/2023]
Abstract
Clathrin facilitates vesicle formation during endocytosis and sorting in the trans-Golgi network (TGN)/endosomal system. Unlike in mammals, yeast clathrin function requires both the clathrin heavy (CHC) and clathrin light (CLC) chain, since Chc1 does not form stable trimers without Clc1. To further delineate clathrin subunit functions, we constructed a chimeric CHC protein (Chc-YR) , which fused the N-terminus of yeast CHC (1-1312) to the rat CHC residues 1318-1675, including the CHC trimerization region. The novel CHC-YR allele encoded a stable protein that fractionated as a trimer. CHC-YR also complemented chc1Δ slow growth and clathrin TGN/endosomal sorting defects. In strains depleted for Clc1 (either clc1Δ or chc1Δ clc1Δ), CHC-YR, but not CHC1, suppressed TGN/endosomal sorting and growth phenotypes. Chc-YR-GFP (green fluorescent protein) localized to the TGN and cortical patches on the plasma membrane, like Chc1 and Clc1. However, Clc1-GFP was primarily cytoplasmic in chc1Δ cells harboring pCHC-YR, indicating that Chc-YR does not bind yeast CLC. Still, some partial phenotypes persisted in cells with Chc-YR, which are likely due either to loss of CLC recruitment or chimeric HC lattice instability. Ultimately, these studies have created a tool to examine non-trimerization roles for the clathrin LC.
Collapse
Affiliation(s)
- Douglas R Boettner
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL, USA.,Current address: Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Verónica A Segarra
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL, USA.,Current Address: Department of Biology, High Point University, High Point, NC, USA
| | - Balaji T Moorthy
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL, USA
| | - Nagore de León
- Departamento de Microbiologıa y Genetica/IBFG, Universidad de Salamanca/CSIC, Salamanca, Spain
| | - John Creagh
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL, USA
| | - John R Collette
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL, USA.,Current address: Department of Pathology, Baylor College of Medicine, Houston, TX, USA
| | - Arun Malhotra
- Department of Biochemistry and Molecular Biology, University of Miami, Miami, FL, USA
| | - Sandra K Lemmon
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL, USA
| |
Collapse
|
20
|
Zwiewka M, Nodzyński T, Robert S, Vanneste S, Friml J. Osmotic Stress Modulates the Balance between Exocytosis and Clathrin-Mediated Endocytosis in Arabidopsis thaliana. MOLECULAR PLANT 2015; 8:1175-87. [PMID: 25795554 DOI: 10.1016/j.molp.2015.03.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 05/18/2023]
Abstract
The sessile life style of plants creates the need to deal with an often adverse environment, in which water availability can change on a daily basis, challenging the cellular physiology and integrity. Changes in osmotic conditions disrupt the equilibrium of the plasma membrane: hypoosmotic conditions increase and hyperosmotic environment decrease the cell volume. Here, we show that short-term extracellular osmotic treatments are closely followed by a shift in the balance between endocytosis and exocytosis in root meristem cells. Acute hyperosmotic treatments (ionic and nonionic) enhance clathrin-mediated endocytosis simultaneously attenuating exocytosis, whereas hypoosmotic treatments have the opposite effects. In addition to clathrin recruitment to the plasma membrane, components of early endocytic trafficking are essential during hyperosmotic stress responses. Consequently, growth of seedlings defective in elements of clathrin or early endocytic machinery is more sensitive to hyperosmotic treatments. We also found that the endocytotic response to a change of osmotic status in the environment is dominant over the presumably evolutionary more recent regulatory effect of plant hormones, such as auxin. These results imply that osmotic perturbation influences the balance between endocytosis and exocytosis acting through clathrin-mediated endocytosis. We propose that tension on the plasma membrane determines the addition or removal of membranes at the cell surface, thus preserving cell integrity.
Collapse
Affiliation(s)
- Marta Zwiewka
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Department of Plant Systems Biology, VIB and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Gent, Belgium
| | - Tomasz Nodzyński
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Department of Plant Systems Biology, VIB and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Gent, Belgium
| | - Stéphanie Robert
- Department of Plant Systems Biology, VIB and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Gent, Belgium
| | - Steffen Vanneste
- Department of Plant Systems Biology, VIB and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Gent, Belgium
| | - Jiří Friml
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic; Department of Plant Systems Biology, VIB and Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052 Gent, Belgium; Institute of Science and Technology (IST) Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
| |
Collapse
|
21
|
Ockenga W, Tikkanen R. Revisiting the endocytosis of the m2 muscarinic acetylcholine receptor. MEMBRANES 2015; 5:197-213. [PMID: 25985102 PMCID: PMC4496640 DOI: 10.3390/membranes5020197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/05/2015] [Indexed: 11/16/2022]
Abstract
The agonist-induced endocytosis of the muscarinic acetylcholine receptor M2 is different from that of the other members of the muscarinic receptor family. The uptake of the M2 receptor involves the adapter proteins of the β-arrestin family and the small GTPase ADP-ribosylation factor 6. However, it has remained inconclusive if M2 endocytosis is dependent on clathrin or the large GTPase dynamin. We here show by means of knocking down the clathrin heavy chain that M2 uptake upon agonist stimulation requires clathrin. The expression of various dominant-negative dynamin-2 mutants and the use of chemical inhibitors of dynamin function revealed that dynamin expression and membrane localization as such appear to be necessary for M2 endocytosis, whereas dynamin GTPase activity is not required for this process. Based on the data from the present and from previous studies, we propose that M2 endocytosis takes place by means of an atypical clathrin-mediated pathway that may involve a specific subset of clathrin-coated pits/vesicles.
Collapse
Affiliation(s)
- Wymke Ockenga
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, D-35392 Giessen, Germany.
| | - Ritva Tikkanen
- Institute of Biochemistry, Medical Faculty, University of Giessen, Friedrichstrasse 24, D-35392 Giessen, Germany.
| |
Collapse
|
22
|
Dannhauser PN, Platen M, Böning H, Ungewickell H, Schaap IA, Ungewickell EJ. Effect of Clathrin Light Chains on the Stiffness of Clathrin Lattices and Membrane Budding. Traffic 2015; 16:519-33. [DOI: 10.1111/tra.12263] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 01/19/2023]
Affiliation(s)
- Philip N. Dannhauser
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| | - Mitja Platen
- IIIrd Institute of Physics; Georg August University; Göttingen Germany
| | - Heike Böning
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| | - Huberta Ungewickell
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| | - Iwan A.T. Schaap
- IIIrd Institute of Physics; Georg August University; Göttingen Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB); Göttingen Germany
| | - Ernst J. Ungewickell
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| |
Collapse
|
23
|
Meister M, Zuk A, Tikkanen R. Role of dynamin and clathrin in the cellular trafficking of flotillins. FEBS J 2014; 281:2956-76. [PMID: 24809731 DOI: 10.1111/febs.12834] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/03/2014] [Accepted: 05/02/2014] [Indexed: 12/11/2022]
Abstract
Flotillin-1 and flotillin-2 are highly conserved, membrane-microdomain-associated proteins that have been shown to be involved in signal transduction, membrane trafficking and cell adhesion. Upon growth factor stimulation, flotillins are tyrosine phosphorylated and become endocytosed from the plasma membrane into endosomes from which they are recycled back to the plasma membrane. Although a role for flotillin-1 in the endocytosis of certain cargo proteins has been suggested, it is not known how the growth-factor-induced endocytosis of flotillins is regulated and which endocytosis pathway is used. However, this is likely to be different from the pathway used by flotillin-dependent cargo. In this study, we have addressed the mechanistic details of flotillin trafficking during growth factor signaling. We show that dynamin-2 activity is required for the uptake of flotillins from the plasma membrane upon epidermal growth factor stimulation, and inhibition of dynamin-2 GTPase activity impairs flotillin endocytosis. Surprisingly, recycling of flotillins from endosomes to the plasma membrane appears to require both dynamin-2 and clathrin. Upon overexpression of dynamin-2 mutants or depletion of clathrin heavy chain, flotillins are permanently trapped in endosomes. These data show that clathrin and dynamin are required for the endosomal sorting of flotillins, and the study provides a mechanistic dissection of the thus far poorly characterized endosomal trafficking of flotillins.
Collapse
|
24
|
Self-assembly of VPS41 promotes sorting required for biogenesis of the regulated secretory pathway. Dev Cell 2013; 27:425-37. [PMID: 24210660 DOI: 10.1016/j.devcel.2013.10.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 08/06/2013] [Accepted: 10/11/2013] [Indexed: 12/22/2022]
Abstract
The regulated release of polypeptides has a central role in physiology, behavior, and development, but the mechanisms responsible for production of the large dense core vesicles (LDCVs) capable of regulated release have remained poorly understood. Recent work has implicated cytosolic adaptor protein AP-3 in the recruitment of LDCV membrane proteins that confer regulated release. However, AP-3 in mammals has been considered to function in the endolysosomal pathway and in the biosynthetic pathway only in yeast. We now find that the mammalian homolog of yeast VPS41, a member of the homotypic fusion and vacuole protein sorting (HOPS) complex that delivers biosynthetic cargo to the endocytic pathway in yeast, promotes LDCV formation through a common mechanism with AP-3, indicating a conserved role for these proteins in the biosynthetic pathway. VPS41 also self-assembles into a lattice, suggesting that it acts as a coat protein for AP-3 in formation of the regulated secretory pathway.
Collapse
|
25
|
The role of clathrin in post-Golgi trafficking in Toxoplasma gondii. PLoS One 2013; 8:e77620. [PMID: 24147036 PMCID: PMC3795686 DOI: 10.1371/journal.pone.0077620] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 09/13/2013] [Indexed: 11/19/2022] Open
Abstract
Apicomplexan parasites are single eukaryotic cells with a highly polarised secretory system that contains unique secretory organelles (micronemes and rhoptries) that are required for host cell invasion. In contrast, the role of the endosomal system is poorly understood in these parasites. With many typical endocytic factors missing, we speculated that endocytosis depends exclusively on a clathrin-mediated mechanism. Intriguingly, in Toxoplasma gondii we were only able to observe the endogenous clathrin heavy chain 1 (CHC1) at the Golgi, but not at the parasite surface. For the functional characterisation of Toxoplasma gondii CHC1 we generated parasite mutants conditionally expressing the dominant negative clathrin Hub fragment and demonstrate that CHC1 is essential for vesicle formation at the trans-Golgi network. Consequently, the functional ablation of CHC1 results in Golgi aberrations, a block in the biogenesis of the unique secretory microneme and rhoptry organelles, and of the pellicle. However, we found no morphological evidence for clathrin mediating endocytosis in these parasites and speculate that they remodelled their vesicular trafficking system to adapt to an intracellular lifestyle.
Collapse
|
26
|
Hachez C, Besserer A, Chevalier AS, Chaumont F. Insights into plant plasma membrane aquaporin trafficking. TRENDS IN PLANT SCIENCE 2013; 18:344-52. [PMID: 23291163 DOI: 10.1016/j.tplants.2012.12.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 11/30/2012] [Accepted: 12/05/2012] [Indexed: 05/11/2023]
Abstract
Plasma membrane intrinsic proteins (PIPs) are plant aquaporins that facilitate the diffusion of water and small uncharged solutes through the cell membrane. Deciphering the network of interacting proteins that modulate PIP trafficking to and activity in the plasma membrane is essential to improve our knowledge about PIP regulation and function. This review highlights the most recent advances related to PIP subcellular routing and dynamic redistribution, identifies some key molecular interacting proteins, and indicates exciting directions for future research in this field. A better understanding of the mechanisms by which plants optimize water movement might help in identifying new molecular players of agronomical relevance involved in the control of cellular water uptake and drought tolerance.
Collapse
Affiliation(s)
- Charles Hachez
- Institut des Sciences de la Vie, Université Catholique de Louvain, Croix du Sud 4-L7.07.14, B-1348 Louvain-la-Neuve, Belgium
| | | | | | | |
Collapse
|
27
|
Agarwal S, Rastogi R, Gupta D, Patel N, Raje M, Mukhopadhyay A. Clathrin-mediated hemoglobin endocytosis is essential for survival of Leishmania. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1065-77. [DOI: 10.1016/j.bbamcr.2013.01.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 12/21/2012] [Accepted: 01/08/2013] [Indexed: 11/27/2022]
|
28
|
Wang C, Yan X, Chen Q, Jiang N, Fu W, Ma B, Liu J, Li C, Bednarek SY, Pan J. Clathrin light chains regulate clathrin-mediated trafficking, auxin signaling, and development in Arabidopsis. THE PLANT CELL 2013; 25:499-516. [PMID: 23424247 PMCID: PMC3608774 DOI: 10.1105/tpc.112.108373] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 01/21/2013] [Accepted: 01/31/2013] [Indexed: 05/18/2023]
Abstract
Plant clathrin-mediated membrane trafficking is involved in many developmental processes as well as in responses to environmental cues. Previous studies have shown that clathrin-mediated endocytosis of the plasma membrane (PM) auxin transporter PIN-FORMED1 is regulated by the extracellular auxin receptor AUXIN BINDING PROTEIN1 (ABP1). However, the mechanisms by which ABP1 and other factors regulate clathrin-mediated trafficking are poorly understood. Here, we applied a genetic strategy and time-resolved imaging to dissect the role of clathrin light chains (CLCs) and ABP1 in auxin regulation of clathrin-mediated trafficking in Arabidopsis thaliana. Auxin was found to differentially regulate the PM and trans-Golgi network/early endosome (TGN/EE) association of CLCs and heavy chains (CHCs) in an ABP1-dependent but TRANSPORT INHIBITOR RESPONSE1/AUXIN-BINDING F-BOX PROTEIN (TIR1/AFB)-independent manner. Loss of CLC2 and CLC3 affected CHC membrane association, decreased both internalization and intracellular trafficking of PM proteins, and impaired auxin-regulated endocytosis. Consistent with these results, basipetal auxin transport, auxin sensitivity and distribution, and root gravitropism were also found to be dramatically altered in clc2 clc3 double mutants, resulting in pleiotropic defects in plant development. These results suggest that CLCs are key regulators in clathrin-mediated trafficking downstream of ABP1-mediated signaling and thus play a critical role in membrane trafficking from the TGN/EE and PM during plant development.
Collapse
Affiliation(s)
- Chao Wang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
| | - Xu Yan
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
| | - Qian Chen
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Nan Jiang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
| | - Wei Fu
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
| | - Bojun Ma
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
| | - Jianzhong Liu
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | | | - Jianwei Pan
- College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang 321004, China
- Address correspondence to
| |
Collapse
|
29
|
Hom N, Mehta KR, Chou T, Foraker AB, Brodsky FM, Kirshenbaum K, Montclare JK. Anisotropic nanocrystal arrays organized on protein lattices formed by recombinant clathrin fragments. JOURNAL OF MATERIALS CHEMISTRY 2012; 22:23335-23339. [PMID: 23836951 PMCID: PMC3702375 DOI: 10.1039/c2jm35019j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Recombinant clathrin protein fragments form assemblies that template gold nanocrystals in an array across the latticed surface. The nanocrystals exhibit unusual anisotropic morphologies with long range ordering, both of which are dependent upon the presence of a hexahistidine tag on the clathrin heavy chain fragments.
Collapse
Affiliation(s)
- Nancy Hom
- Biomedical Chemistry Institute, Department of Chemistry, New York University, 100 Washington Square East, New York, New York, 10003;
| | - Kinjal R. Mehta
- Department of Chemical and Biomolecular Engineering, Polytechnic Institute of New York University, Brooklyn, NY, 11201;
| | - Tsengming Chou
- Laboratory for Multiscale Imaging, Stevens Institute of Technology, Hoboken, NJ, 07030
| | - Amy B. Foraker
- Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and the G.W. Hooper Foundation, University of California, San Francisco, San Francisco, CA, 94143
| | - Frances M. Brodsky
- Departments of Bioengineering and Therapeutic Sciences, Pharmaceutical Chemistry, Microbiology and Immunology and the G.W. Hooper Foundation, University of California, San Francisco, San Francisco, CA, 94143
| | - Kent Kirshenbaum
- Biomedical Chemistry Institute, Department of Chemistry, New York University, 100 Washington Square East, New York, New York, 10003;
| | - Jin K. Montclare
- Department of Chemical and Biomolecular Engineering, Polytechnic Institute of New York University, Brooklyn, NY, 11201;
| |
Collapse
|
30
|
Ybe JA, Fontaine SN, Stone T, Nix J, Lin X, Mishra S. Nuclear localization of clathrin involves a labile helix outside the trimerization domain. FEBS Lett 2012. [PMID: 23178717 DOI: 10.1016/j.febslet.2012.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Clathrin is a trimeric protein involved in receptor-mediated-endocytosis, but can function as a non-trimer outside of endocytosis. We have discovered that the subcellular distribution of a clathrin cysteine mutant we previously studied is altered and a proportion is also localized to nuclear spaces. MALS shows C1573A hub is a mixture of trimer-like and detrimerized molecules. The X-ray structure of the trimerization domain reveals that without light chains, a helix harboring cysteine-1573 is reoriented. We propose clathrin has a detrimerization switch, which suggests clathrin topology can be altered naturally for new functions.
Collapse
Affiliation(s)
- Joel A Ybe
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, 212 S. Hawthorne Drive, Bloomington, IN 47405, USA.
| | | | | | | | | | | |
Collapse
|
31
|
Adam T, Bouhidel K, Der C, Robert F, Najid A, Simon-Plas F, Leborgne-Castel N. Constitutive expression of clathrin hub hinders elicitor-induced clathrin-mediated endocytosis and defense gene expression in plant cells. FEBS Lett 2012; 586:3293-8. [PMID: 22796492 DOI: 10.1016/j.febslet.2012.06.053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 06/28/2012] [Indexed: 10/28/2022]
Abstract
Endocytosis has been recently implicated in the signaling network associated with the recognition of microbes by plants. In a previous study, we showed that the elicitor cryptogein was able to induce clathrin-mediated endocytosis (CME) in tobacco suspension cells. Herein, we investigate further the induced CME by means of a GFP-tagged clathrin light chain and a CME inhibitor, the hub domain of clathrin heavy chain. Hub constitutive expression does affect neither cell growth nor constitutive endocytosis but abolishes cryptogein-induced CME. Such an inhibition has no impact on early events in the cryptogein signaling pathway but reduces the expression of defense-associated genes.
Collapse
Affiliation(s)
- T Adam
- UMR Agroécologie 1347, AgroSup/INRA/Université de Bourgogne, Pôle Interaction Plantes Microorganismes, ERL6300 CNRS, Dijon, France
| | | | | | | | | | | | | |
Collapse
|
32
|
Scheuring D, Künzl F, Viotti C, Yan MSW, Jiang L, Schellmann S, Robinson DG, Pimpl P. Ubiquitin initiates sorting of Golgi and plasma membrane proteins into the vacuolar degradation pathway. BMC PLANT BIOLOGY 2012; 12:164. [PMID: 22970698 PMCID: PMC3534617 DOI: 10.1186/1471-2229-12-164] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 07/13/2012] [Indexed: 05/18/2023]
Abstract
BACKGROUND In yeast and mammals, many plasma membrane (PM) proteins destined for degradation are tagged with ubiquitin. These ubiquitinated proteins are internalized into clathrin-coated vesicles and are transported to early endosomal compartments. There, ubiquitinated proteins are sorted by the endosomal sorting complex required for transport (ESCRT) machinery into the intraluminal vesicles of multivesicular endosomes. Degradation of these proteins occurs after endosomes fuse with lysosomes/lytic vacuoles to release their content into the lumen. In plants, some PM proteins, which cycle between the PM and endosomal compartments, have been found to be ubiquitinated, but it is unclear whether ubiquitin is sufficient to mediate internalization and thus acts as a primary sorting signal for the endocytic pathway. To test whether plants use ubiquitin as a signal for the degradation of membrane proteins, we have translationally fused ubiquitin to different fluorescent reporters for the plasma membrane and analyzed their transport. RESULTS Ubiquitin-tagged PM reporters localized to endosomes and to the lumen of the lytic vacuole in tobacco mesophyll protoplasts and in tobacco epidermal cells. The internalization of these reporters was significantly reduced if clathrin-mediated endocytosis was inhibited by the coexpression of a mutant of the clathrin heavy chain, the clathrin hub. Surprisingly, a ubiquitin-tagged reporter for the Golgi was also transported into the lumen of the vacuole. Vacuolar delivery of the reporters was abolished upon inhibition of the ESCRT machinery, indicating that the vacuolar delivery of these reporters occurs via the endocytic transport route. CONCLUSIONS Ubiquitin acts as a sorting signal at different compartments in the endomembrane system to target membrane proteins into the vacuolar degradation pathway: If displayed at the PM, ubiquitin triggers internalization of PM reporters into the endocytic transport route, but it also mediates vacuolar delivery if displayed at the Golgi. In both cases, ubiquitin-tagged proteins travel via early endosomes and multivesicular bodies to the lytic vacuole. This suggests that vacuolar degradation of ubiquitinated proteins is not restricted to PM proteins but might also facilitate the turnover of membrane proteins in the early secretory pathway.
Collapse
Affiliation(s)
- David Scheuring
- Department of Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
| | - Fabian Künzl
- Department of Developmental Genetics, Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, 72076, Germany
| | - Corrado Viotti
- Department of Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
- Plant Developmental Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
| | - Melody San Wan Yan
- School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin NT, Hong Kong, PR China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin NT, Hong Kong, PR China
| | - Swen Schellmann
- Botanical Institute, Biozentrum Köln, University of Cologne, Cologne, 50674, Germany
| | - David G Robinson
- Department of Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
| | - Peter Pimpl
- Department of Developmental Genetics, Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, 72076, Germany
- Department of Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany
| |
Collapse
|
33
|
Bonazzi M, Vasudevan L, Mallet A, Sachse M, Sartori A, Prevost MC, Roberts A, Taner SB, Wilbur JD, Brodsky FM, Cossart P. Clathrin phosphorylation is required for actin recruitment at sites of bacterial adhesion and internalization. ACTA ACUST UNITED AC 2012; 195:525-36. [PMID: 22042622 PMCID: PMC3206339 DOI: 10.1083/jcb.201105152] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Clathrin assembles at bacterial adhesion sites and its phosphorylation is required for actin recruitment during bacterial infection. Bacterial pathogens recruit clathrin upon interaction with host surface receptors during infection. Here, using three different infection models, we observed that host–pathogen interactions induce tyrosine phosphorylation of clathrin heavy chain. This modification was critical for recruitment of actin at bacteria–host adhesion sites during bacterial internalization or pedestal formation. At the bacterial interface, clathrin assembled to form coated pits of conventional size. Because such structures cannot internalize large particles such as bacteria, we propose that during infection, clathrin-coated pits serve as platforms to initiate actin rearrangements at bacteria–host adhesion sites. We then showed that the clathrin–actin interdependency is initiated by Dab2 and depends on the presence of clathrin light chain and its actin-binding partner Hip1R, and that the fully assembled machinery can recruit Myosin VI. Together, our study highlights a physiological role for clathrin heavy chain phosphorylation and reinforces the increasingly recognized function of clathrin in actin cytoskeletal organization in mammalian cells.
Collapse
Affiliation(s)
- Matteo Bonazzi
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Paris F-75015, France.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
|
35
|
Ito E, Fujimoto M, Ebine K, Uemura T, Ueda T, Nakano A. Dynamic behavior of clathrin in Arabidopsis thaliana unveiled by live imaging. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 69:204-16. [PMID: 21910772 DOI: 10.1111/j.1365-313x.2011.04782.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Clathrin-coated vesicles (CCV) are necessary for selective transport events, including receptor-mediated endocytosis on the plasma membrane and cargo molecule sorting in the trans-Golgi network (TGN). Components involved in CCV formation include clathrin heavy and light chains and several adaptor proteins that are conserved among plants. Clathrin-dependent endocytosis has been shown to play an integral part in plant endocytosis. However, little information is known about clathrin dynamics in living plant cells. In this study, we have visualized clathrin in Arabidopsis thaliana by tagging clathrin light chain with green fluorescent protein (CLC-GFP). Quantitative evaluations of colocalization demonstrate that the majority of CLC-GFP is localized to the TGN, and a minor population is associated with multivesicular endosomes and the Golgi trans-cisternae. Live imaging further demonstrated the presence of highly dynamic clathrin-positive tubules and vesicles, which appeared to mediate interactions between the TGNs. CLC-GFP is also targeted to cell plates and the plasma membrane. Although CLC-GFP colocalizes with a dynamin isoform at the plasma membrane, these proteins exhibit distinct distributions at newly forming cell plates. This finding indicates independent functions of CLC (clathrin light chains) and dynamin during the formation of cell plates. We have also found that brefeldin A and wortmannin treatment causes distinctly different alterations in the dynamics and distribution of clathrin-coated domains at the plasma membrane. This could account for the different effects of these drugs on plant endocytosis.
Collapse
Affiliation(s)
- Emi Ito
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | | | | | | | | |
Collapse
|
36
|
STAGSTED JAN. Journey beyond immunology. Regulation of receptor internalization by major histocompatibility complex class I (MHC-I) and effect of peptides derived from MHC-I. APMIS 2011. [DOI: 10.1111/j.1600-0463.1998.tb05657.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
37
|
Scheuring D, Viotti C, Krüger F, Künzl F, Sturm S, Bubeck J, Hillmer S, Frigerio L, Robinson DG, Pimpl P, Schumacher K. Multivesicular bodies mature from the trans-Golgi network/early endosome in Arabidopsis. THE PLANT CELL 2011; 23:3463-81. [PMID: 21934143 PMCID: PMC3203422 DOI: 10.1105/tpc.111.086918] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 08/19/2011] [Accepted: 08/31/2011] [Indexed: 05/17/2023]
Abstract
The plant trans-Golgi network/early endosome (TGN/EE) is a major hub for secretory and endocytic trafficking with complex molecular mechanisms controlling sorting and transport of cargo. Vacuolar transport from the TGN/EE to multivesicular bodies/late endosomes (MVBs/LEs) is assumed to occur via clathrin-coated vesicles, although direct proof for their participation is missing. Here, we present evidence that post-TGN transport toward lytic vacuoles occurs independently of clathrin and that MVBs/LEs are derived from the TGN/EE through maturation. We show that the V-ATPase inhibitor concanamycin A significantly reduces the number of MVBs and causes TGN and MVB markers to colocalize in Arabidopsis thaliana roots. Ultrastructural analysis reveals the formation of MVBs from the TGN/EE and their fusion with the vacuole. The localization of the ESCRT components VPS28, VPS22, and VPS2 at the TGN/EE and MVBs/LEs indicates that the formation of intraluminal vesicles starts already at the TGN/EE. Accordingly, a dominant-negative mutant of VPS2 causes TGN and MVB markers to colocalize and blocks vacuolar transport. RNA interference-mediated knockdown of the annexin ANNAT3 also yields the same phenotype. Together, these data indicate that MVBs originate from the TGN/EE in a process that requires the action of ESCRT for the formation of intraluminal vesicles and annexins for the final step of releasing MVBs as a transport carrier to the vacuole.
Collapse
Affiliation(s)
- David Scheuring
- Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Corrado Viotti
- Developmental Biology of Plants, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Falco Krüger
- Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Fabian Künzl
- Developmental Genetics, Centre for Plant Molecular Biology, University of Tübingen, 72076 Tuebingen, Germany
| | - Silke Sturm
- Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Julia Bubeck
- Developmental Biology of Plants, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Stefan Hillmer
- Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Lorenzo Frigerio
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - David G. Robinson
- Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| | - Peter Pimpl
- Plant Cell Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
- Developmental Genetics, Centre for Plant Molecular Biology, University of Tübingen, 72076 Tuebingen, Germany
- Address correspondence to
| | - Karin Schumacher
- Developmental Biology of Plants, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany
| |
Collapse
|
38
|
Boettner DR, Friesen H, Andrews B, Lemmon SK. Clathrin light chain directs endocytosis by influencing the binding of the yeast Hip1R homologue, Sla2, to F-actin. Mol Biol Cell 2011; 22:3699-714. [PMID: 21849475 PMCID: PMC3183023 DOI: 10.1091/mbc.e11-07-0628] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The clathrin light-chain (LC) N-terminal region interacts with the Sla2/Hip1/Hip1R family of ANTH/talin–like proteins. In vivo evidence shows that LC–Sla2 binding is important for releasing Sla2 attachments to actin in the endocytic coat. Loss of this regulation can suppress major actin defects during endocytosis. The role of clathrin light chain (CLC) in clathrin-mediated endocytosis is not completely understood. Previous studies showed that the CLC N-terminus (CLC-NT) binds the Hip1/Hip1R/Sla2 family of membrane/actin–binding factors and that overexpression of the CLC-NT in yeast suppresses endocytic defects of clathrin heavy-chain mutants. To elucidate the mechanistic basis for this suppression, we performed synthetic genetic array analysis with a clathrin CLC-NT deletion mutation (clc1-Δ19-76). clc1-Δ19-76 suppressed the internalization defects of null mutations in three late endocytic factors: amphiphysins (rvs161 and rvs167) and verprolin (vrp1). In actin sedimentation assays, CLC binding to Sla2 inhibited Sla2 interaction with F-actin. Furthermore, clc1-Δ19-76 suppression of the rvs and vrp phenotypes required the Sla2 actin-binding talin-Hip1/R/Sla2 actin-tethering C-terminal homology domain, suggesting that clc1-Δ19-76 promotes internalization by prolonging actin engagement by Sla2. We propose that CLC directs endocytic progression by pruning the Sla2-actin attachments in the clathrin lattice, providing direction for membrane internalization.
Collapse
Affiliation(s)
- Douglas R Boettner
- Department of Molecular and Cellular Pharmacology, University of Miami, Miami, FL 33101, USA
| | | | | | | |
Collapse
|
39
|
Kitakura S, Vanneste S, Robert S, Löfke C, Teichmann T, Tanaka H, Friml J. Clathrin mediates endocytosis and polar distribution of PIN auxin transporters in Arabidopsis. THE PLANT CELL 2011; 23:1920-31. [PMID: 21551390 PMCID: PMC3123958 DOI: 10.1105/tpc.111.083030] [Citation(s) in RCA: 242] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 03/15/2011] [Accepted: 04/18/2011] [Indexed: 05/18/2023]
Abstract
Endocytosis is a crucial mechanism by which eukaryotic cells internalize extracellular and plasma membrane material, and it is required for a multitude of cellular and developmental processes in unicellular and multicellular organisms. In animals and yeast, the best characterized pathway for endocytosis depends on the function of the vesicle coat protein clathrin. Clathrin-mediated endocytosis has recently been demonstrated also in plant cells, but its physiological and developmental roles remain unclear. Here, we assessed the roles of the clathrin-mediated mechanism of endocytosis in plants by genetic means. We interfered with clathrin heavy chain (CHC) function through mutants and dominant-negative approaches in Arabidopsis thaliana and established tools to manipulate clathrin function in a cell type-specific manner. The chc2 single mutants and dominant-negative CHC1 (HUB) transgenic lines were defective in bulk endocytosis as well as in internalization of prominent plasma membrane proteins. Interference with clathrin-mediated endocytosis led to defects in constitutive endocytic recycling of PIN auxin transporters and their polar distribution in embryos and roots. Consistent with this, these lines had altered auxin distribution patterns and associated auxin transport-related phenotypes, such as aberrant embryo patterning, imperfect cotyledon specification, agravitropic growth, and impaired lateral root organogenesis. Together, these data demonstrate a fundamental role for clathrin function in cell polarity, growth, patterning, and organogenesis in plants.
Collapse
Affiliation(s)
- Saeko Kitakura
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, B-9052 Ghent, Belgium
| | - Steffen Vanneste
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, B-9052 Ghent, Belgium
| | - Stéphanie Robert
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, B-9052 Ghent, Belgium
| | - Christian Löfke
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Gottingen, Germany
| | - Thomas Teichmann
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Gottingen, Germany
| | - Hirokazu Tanaka
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, B-9052 Ghent, Belgium
| | - Jiří Friml
- Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent University, B-9052 Ghent, Belgium
- Address correspondence to
| |
Collapse
|
40
|
Human immunodeficiency virus type 1 and related primate lentiviruses engage clathrin through Gag-Pol or Gag. J Virol 2011; 85:3792-801. [PMID: 21289110 DOI: 10.1128/jvi.02329-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Gag-Pol polyprotein of human immunodeficiency virus type 1 (HIV-1) is not required for efficient viral particle production. However, premature termination codons in pol, particularly in the integrase (IN)-coding region, can markedly impair HIV-1 particle formation, apparently due to the premature activation of the viral protease (PR). We now report that the IN domain of Gag-Pol is required for the incorporation of clathrin into HIV-1 virions. Significantly, PR-dependent effects of point mutations in IN on particle production correlated strictly with their effects on clathrin incorporation. A possible interpretation of these findings is that certain IN mutations impair particle production in a PR-dependent manner by promoting Gag-Pol dimerization, which also occludes a binding site for clathrin. Consistently with this model, the reverse transcriptase (RT) inhibitor efavirenz, which is thought to promote Gag-Pol dimerization, inhibited the incorporation of clathrin into HIV-1 virions. Clathrin-depleted cells produced normal amounts of HIV-1 virions; however, their infectivity was reduced. We also observed that HIV-2 and the simian immunodeficiency virus SIVmac interact with clathrin through one or two copies of a peptide motif in the p6 domain of Gag that resembles the clathrin box of cellular adaptor proteins. Furthermore, the substitution of the hydrophobic residues in the single clathrin box motif of SIVmac caused a replication defect in primary cells. Taken together, our results indicate that primate lentiviruses from two different subgroups functionally interact with clathrin during assembly.
Collapse
|
41
|
Park M, Jürgens G. Membrane traffic and fusion at post-Golgi compartments. FRONTIERS IN PLANT SCIENCE 2011; 2:111. [PMID: 22645561 PMCID: PMC3355779 DOI: 10.3389/fpls.2011.00111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 12/19/2011] [Indexed: 05/18/2023]
Abstract
Complete sequencing of the Arabidopsis genome a decade ago has facilitated the functional analysis of various biological processes including membrane traffic by which many proteins are delivered to their sites of action and turnover. In particular, membrane traffic between post-Golgi compartments plays an important role in cell signaling, taking care of receptor-ligand interaction and inactivation, which requires secretion, endocytosis, and recycling or targeting to the vacuole for degradation. Here, we discuss recent studies that address the identity of post-Golgi compartments, the machinery involved in traffic and fusion or functionally characterized cargo proteins that are delivered to or pass through post-Golgi compartments. We also provide an outlook on future challenges in this area of research.
Collapse
Affiliation(s)
- Misoon Park
- Entwicklungsgenetik, Zentrum für Molekularbiologie der Pflanzen, University of TübingenTübingen, Germany
| | - Gerd Jürgens
- Entwicklungsgenetik, Zentrum für Molekularbiologie der Pflanzen, University of TübingenTübingen, Germany
- *Correspondence: Gerd Jürgens, Entwicklungsgenetik, Zentrum für Molekularbiologie der Pflanzen, University of Tübingen, Auf der Morgenstelle 3, 72076 Tübingen, Germany. e-mail:
| |
Collapse
|
42
|
Zhao Y, Yan A, Feijó JA, Furutani M, Takenawa T, Hwang I, Fu Y, Yang Z. Phosphoinositides regulate clathrin-dependent endocytosis at the tip of pollen tubes in Arabidopsis and tobacco. THE PLANT CELL 2010; 22:4031-44. [PMID: 21189293 PMCID: PMC3027160 DOI: 10.1105/tpc.110.076760] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 11/23/2010] [Accepted: 12/06/2010] [Indexed: 05/18/2023]
Abstract
Using the tip-growing pollen tube of Arabidopsis thaliana and Nicotiana tabacum as a model to investigate endocytosis mechanisms, we show that phosphatidylinositol-4-phosphate 5-kinase 6 (PIP5K6) regulates clathrin-dependent endocytosis in pollen tubes. Green fluorescent protein-tagged PIP5K6 was preferentially localized to the subapical plasma membrane (PM) in pollen tubes where it apparently converts phosphatidylinositol 4-phosphate (PI4P) to phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)]. RNA interference-induced suppression of PIP5K6 expression impaired tip growth and inhibited clathrin-dependent endocytosis in pollen tubes. By contrast, PIP5K6 overexpression induced massive aggregation of the PM in pollen tube tips. This PM abnormality was apparently due to excessive clathrin-dependent membrane invagination because this defect was suppressed by the expression of a dominant-negative mutant of clathrin heavy chain. These results support a role for PI(4,5)P(2) in promoting early stages of clathrin-dependent endocytosis (i.e., membrane invagination). Interestingly, the PIP5K6 overexpression-induced PM abnormality was partially suppressed not only by the overexpression of PLC2, which breaks down PI(4,5)P(2), but also by that of PI4Kβ1, which increases the pool of PI4P. Based on these observations, we propose that a proper balance between PI4P and PI(4,5)P(2) is required for clathrin-dependent endocytosis in the tip of pollen tubes.
Collapse
Affiliation(s)
- Yan Zhao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- China Agricultural University–University of California-Riverside Joint Center for Biological Sciences and Biotechnology, China Agricultural University, Beijing 100193, China
- Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - An Yan
- Center for Plant Cell Biology, Department of Botany and Sciences, University of California, Riverside, California 92521
| | - José A. Feijó
- Seccao de Biologia Vegetal, Faculdade de Ciencias, Universidade de Lisboa 1700, Lisbon P-1749-016, Portugal
- Instituto Gulbenkian de Ciencia, 2780-156 Oeiras, Portugal
| | - Masahiro Furutani
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Tadaomi Takenawa
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Inhwan Hwang
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Ying Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhenbiao Yang
- China Agricultural University–University of California-Riverside Joint Center for Biological Sciences and Biotechnology, China Agricultural University, Beijing 100193, China
- Center for Plant Cell Biology, Department of Botany and Sciences, University of California, Riverside, California 92521
| |
Collapse
|
43
|
Robert S, Kleine-Vehn J, Barbez E, Sauer M, Paciorek T, Baster P, Vanneste S, Zhang J, Simon S, Čovanová M, Hayashi K, Dhonukshe P, Yang Z, Bednarek SY, Jones AM, Luschnig C, Aniento F, Zažímalová E, Friml J. ABP1 mediates auxin inhibition of clathrin-dependent endocytosis in Arabidopsis. Cell 2010; 143:111-21. [PMID: 20887896 DOI: 10.1016/j.cell.2010.09.027] [Citation(s) in RCA: 346] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 05/10/2010] [Accepted: 09/14/2010] [Indexed: 01/25/2023]
Abstract
Spatial distribution of the plant hormone auxin regulates multiple aspects of plant development. These self-regulating auxin gradients are established by the action of PIN auxin transporters, whose activity is regulated by their constitutive cycling between the plasma membrane and endosomes. Here, we show that auxin signaling by the auxin receptor AUXIN-BINDING PROTEIN 1 (ABP1) inhibits the clathrin-mediated internalization of PIN proteins. ABP1 acts as a positive factor in clathrin recruitment to the plasma membrane, thereby promoting endocytosis. Auxin binding to ABP1 interferes with this action and leads to the inhibition of clathrin-mediated endocytosis. Our study demonstrates that ABP1 mediates a nontranscriptional auxin signaling that regulates the evolutionarily conserved process of clathrin-mediated endocytosis and suggests that this signaling may be essential for the developmentally important feedback of auxin on its own transport.
Collapse
|
44
|
Neumann-Staubitz P, Hall SL, Kuo J, Jackson AP. Characterization of a temperature-sensitive vertebrate clathrin heavy chain mutant as a tool to study clathrin-dependent events in vivo. PLoS One 2010; 5:e12017. [PMID: 20700507 PMCID: PMC2917355 DOI: 10.1371/journal.pone.0012017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2008] [Accepted: 07/15/2010] [Indexed: 01/27/2023] Open
Abstract
Clathrin and clathrin-dependent events are evolutionary conserved although it is believed that there are differences in the requirement for clathrin in yeast and higher vertebrates. Clathrin is a long-lived protein and thus, with clathrin knockdowns only long-term consequences of clathrin depletion can be studied. Here, we characterize the first vertebrate temperature-sensitive clathrin heavy chain mutant as a tool to investigate responses to rapid clathrin inactivation in higher eukaryotes. Although we created this mutant using a clathrin cryo-electron microscopy model and a yeast temperature-sensitive mutant as a guide, the resulting temperature-sensitive clathrin showed an altered phenotype compared to the corresponding yeast temperature-sensitive clathrin. First, it seemed to form stable triskelions at the non-permissive temperature although endocytosis was impaired under these conditions. Secondly, as a likely consequence of the stable triskelions at the non-permissive temperature, clathrin also localized correctly to its target membranes. Thirdly, we did not observe missorting of the lysosomal enzyme beta-glucuronidase which could indicate that the temperature-sensitive clathrin is still operating at the non-permissive temperature at the Golgi or, that, like in yeast, more than one TGN trafficking pathway exists. Fourthly, in contrast to yeast, actin does not appear to actively compensate in general endocytosis. Thus, there seem to be differences between vertebrates and yeast which can be studied in further detail with this newly created tool.
Collapse
|
45
|
Wilbur JD, Hwang PK, Ybe JA, Lane M, Sellers BD, Jacobson MP, Fletterick RJ, Brodsky FM. Conformation switching of clathrin light chain regulates clathrin lattice assembly. Dev Cell 2010; 18:841-8. [PMID: 20493816 DOI: 10.1016/j.devcel.2010.04.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 01/25/2010] [Accepted: 03/05/2010] [Indexed: 11/19/2022]
Abstract
Clathrin-coated vesicle formation is responsible for membrane traffic to and from the endocytic pathway during receptor-mediated endocytosis and organelle biogenesis, influencing how cells relate to their environment. Generating these vesicles involves self-assembly of clathrin molecules into a latticed coat on membranes that recruits receptors and organizes protein machinery necessary for budding. Here we define a molecular mechanism regulating clathrin lattice formation by obtaining structural information from co-crystals of clathrin subunits. Low resolution X-ray diffraction data (7.9-9.0 A) was analyzed using a combination of molecular replacement with an energy-minimized model and noncrystallographic symmetry averaging. Resulting topological information revealed two conformations of the regulatory clathrin light chain bound to clathrin heavy chain. Based on protein domain positions, mutagenesis, and biochemical assays, we identify an electrostatic interaction between the clathrin subunits that allows the observed conformational variation in clathrin light chains to alter the conformation of the clathrin heavy chain and thereby regulates assembly.
Collapse
Affiliation(s)
- Jeremy D Wilbur
- Graduate Program in Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Hölzenspies JJ, Roelen BAJ, Colenbrander B, Romijn RAP, Hemrika W, Stoorvogel W, van Haeften T. Clathrin is essential for meiotic spindle function in oocytes. Reproduction 2010; 140:223-33. [PMID: 20522479 DOI: 10.1530/rep-10-0045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the mammalian ovary, oocytes are arrested at prophase of meiosis I until a hormonal stimulus triggers resumption of meiosis. During the subsequent meiotic maturation process, which includes completion of the first meiotic division and formation of the second metaphase spindle, oocytes acquire competence for fertilization. Recently, it was shown that clathrin, a cytosolic protein complex originally defined for its role in intracellular membrane traffic, is also involved in the stabilization of kinetochore fibers in mitotic spindles of dividing somatic cells. However, whether clathrin has a similar function in meiotic spindles in oocytes has not been investigated previously. Our results show that endogenous clathrin associates with the meiotic spindles in oocytes. To study the function of clathrin during meiotic maturation, we microinjected green fluorescent protein-tagged C-terminal and N-terminal dominant-negative clathrin protein constructs into isolated porcine oocytes prior to in vitro maturation. Both protein constructs associated with meiotic spindles similar to endogenous clathrin, but induced misalignment and clumping of chromosomes, occurrence of cytoplasmic chromatin and failure of polar body extrusion. These data demonstrate that clathrin plays a crucial role in meiotic spindle function in maturing oocytes, possibly through spindle stabilization.
Collapse
Affiliation(s)
- Jurriaan J Hölzenspies
- Departments of Farm Animal Health Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
47
|
Two Distantly Spaced Basic Patches in the Flexible Domain of Huntingtin-Interacting Protein 1 (HIP1) Are Essential for the Binding of Clathrin Light Chain. Res Lett Biochem 2009; 2009:256124. [PMID: 22820750 PMCID: PMC3005887 DOI: 10.1155/2009/256124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Accepted: 02/24/2009] [Indexed: 11/17/2022] Open
Abstract
The interaction between HIP family proteins (HIP1 and HIP12/1R) and clathrin is fundamental to endocytosis. We used circular dichroism (CD) to study the stability of an HIP1 subfragment (aa468-530) that is splayed open. CD thermal melts show HIP1 468-530 is only stable at low temperatures, but this HIP1 fragment contains a structural unit that does not melt out even at 83°C. We then created HIP1 mutants to probe our hypothesis that a short hydrophobic path in the opened region is the binding site for clathrin light chain. We found that the binding of hub/LCb was sensitive to mutating two distantly separated basic residues (K474 and K494). The basic patches marked by K474 and K494 are conserved in HIP12/1R. The lack of conservation in sla2p (S. cerevisiae), HIP1 from D. melanogaster, and HIP1 homolog ZK370.3 from C. elegans implies the binding of HIP1 and HIP1 homologs to clathrin light chain may be different in these organisms.
Collapse
|
48
|
Differential requirements for clathrin in receptor-mediated endocytosis and maintenance of synaptic vesicle pools. Proc Natl Acad Sci U S A 2009; 106:1139-44. [PMID: 19151157 DOI: 10.1073/pnas.0809541106] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clathrin is a coat protein involved in vesicle budding from several membrane-bound compartments within the cell. Here we present an analysis of a temperature-sensitive (ts) mutant of clathrin heavy chain (CHC) in a multicellular animal. As expected Caenorhabditis elegans chc-1(b1025ts) mutant animals are defective in receptor-mediated endocytosis and arrest development soon after being shifted to the restrictive temperature. Steady-state clathrin levels in these mutants are reduced by more than 95% at all temperatures. Hub interactions and membrane associations are lost at the restrictive temperature. chc-1(b1025ts) animals become paralyzed within minutes of exposure to the restrictive temperature because of a defect in the nervous system. Surprisingly synaptic vesicle number is not reduced in chc-1(b1025ts) animals. Consistent with the normal number of vesicles, postsynaptic miniature currents occur at normal frequencies. Taken together, these results indicate that a high level of CHC activity is required for receptor-mediated endocytosis in nonneuronal cells but is largely dispensable for maintenance of synaptic vesicle pools.
Collapse
|
49
|
Salt-stress-induced association of phosphatidylinositol 4,5-bisphosphate with clathrin-coated vesicles in plants. Biochem J 2008; 415:387-99. [PMID: 18721128 DOI: 10.1042/bj20081306] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Plants exposed to hyperosmotic stress undergo changes in membrane dynamics and lipid composition to maintain cellular integrity and avoid membrane leakage. Various plant species respond to hyperosmotic stress with transient increases in PtdIns(4,5)P(2); however, the physiological role of such increases is unresolved. The plasma membrane represents the outermost barrier between the symplast of plant cells and its apoplastic surroundings. In the present study, the spatio-temporal dynamics of stress-induced changes in phosphoinositides were analysed in subcellular fractions of Arabidopsis leaves to delineate possible physiological roles. Unlabelled lipids were separated by TLC and quantified by gas-chromatographic detection of associated fatty acids. Transient PtdIns(4,5)P(2) increases upon exposure to hyperosmotic stress were detected first in enriched plasmamembrane fractions, however, at later time points, PtdIns(4,5)P(2) was increased in the endomembrane fractions of the corresponding two-phase systems. When major endomembranes were enriched from rosette leaves prior to hyperosmotic stress and during stimulation for 60 min, no stress-induced increases in the levels of PtdIns(4,5)P(2) were found in fractions enriched for endoplasmic reticulum, nuclei or plastidial membranes. Instead, increased PtdIns(4,5)P(2) was found in CCVs (clathrin-coated vesicles), which proliferated several-fold in mass within 60 min of hyperosmotic stress, according to the abundance of CCV-associated proteins and lipids. Monitoring the subcellular distribution of fluorescence-tagged reporters for clathrin and PtdIns(4,5)P(2) during transient co-expression in onion epidermal cells indicates rapid stress-induced co-localization of clathrin with PtdIns(4,5)P(2) at the plasma membrane. The results indicate that PtdIns(4,5)P(2) may act in stress-induced formation of CCVs in plant cells, highlighting the evolutionary conservation of the phosphoinositide system between organismic kingdoms.
Collapse
|
50
|
Wilbur JD, Chen CY, Manalo V, Hwang PK, Fletterick RJ, Brodsky FM. Actin binding by Hip1 (huntingtin-interacting protein 1) and Hip1R (Hip1-related protein) is regulated by clathrin light chain. J Biol Chem 2008; 283:32870-9. [PMID: 18790740 DOI: 10.1074/jbc.m802863200] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The huntingtin-interacting protein family members (Hip1 and Hip1R in mammals and Sla2p in yeast) link clathrin-mediated membrane traffic to actin cytoskeleton dynamics. Genetic data in yeast have implicated the light chain subunit of clathrin in regulating this link. To test this hypothesis, the biophysical properties of mammalian Hip1 and Hip1R and their interaction with clathrin light chain and actin were analyzed. The coiled-coil domains (clathrin light chain-binding) of Hip1 and Hip1R were found to be stable homodimers with no propensity to heterodimerize in vitro. Homodimers were also predominant in vivo, accounting for cellular segregation of Hip1 and Hip1R functions. Coiled-coil domains of Hip1 and Hip1R differed in their stability and flexibility, correlating with slightly different affinities for clathrin light chain and more markedly with effects of clathrin light chain binding on Hip protein-actin interactions. Clathrin light chain binding induced a compact conformation of both Hip1 and Hip1R and significantly reduced actin binding by their THATCH domains. Thus, clathrin is a negative regulator of Hip-actin interactions. These observations necessarily change models proposed for Hip protein function.
Collapse
Affiliation(s)
- Jeremy D Wilbur
- Graduate Program in Biophysics, University of California, San Francisco, California 94143-0552, USA
| | | | | | | | | | | |
Collapse
|