1
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Sun Y, Yeam A, Kuo J, Iwamoto Y, Hu G, Drubin DG. The conserved protein adaptors CALM/AP180 and FCHo1/2 cooperatively recruit Eps15 to promote the initiation of clathrin-mediated endocytosis in yeast. PLoS Biol 2024; 22:e3002833. [PMID: 39316607 DOI: 10.1371/journal.pbio.3002833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 10/04/2024] [Accepted: 09/05/2024] [Indexed: 09/26/2024] Open
Abstract
Clathrin-mediated endocytosis (CME) is a critical trafficking process that begins when an elaborate endocytic protein network is established at the plasma membrane. Interaction of early endocytic proteins with anionic phospholipids and/or cargo has been suggested to trigger CME initiation. However, the exact mechanism by which CME sites are initiated has not been fully elucidated. In the budding yeast Saccharomyces cerevisiae, higher levels of anionic phospholipids and cargo molecules exist in the newly formed daughter cell compared to the levels in the mother cell during polarized growth. Taking advantage of this asymmetry, we quantitatively compared CME proteins in S. cerevisiae mother versus daughter cells, observing differences in the dynamics and composition of key endocytic proteins. Our results show that CME site initiation occurs preferentially on regions of the plasma membrane with a relatively higher density of endocytic cargo and/or acidic phospholipids. Furthermore, our combined live cell-imaging and yeast genetics analysis provided evidence for a molecular mechanism in which CME sites are initiated when Yap1801 and Yap1802 (yeast CALM/AP180) and Syp1 (yeast FCHo1/2) coordinate with anionic phospholipids and cargo molecules to trigger Ede1 (yeast Eps15)-centric CME initiation complex assembly at the plasma membrane.
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Affiliation(s)
- Yidi Sun
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
| | - Albert Yeam
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
| | - Jonathan Kuo
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
| | - Yuichiro Iwamoto
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
| | - Gean Hu
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
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2
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Johnson A. Mechanistic divergences of endocytic clathrin-coated vesicle formation in mammals, yeasts and plants. J Cell Sci 2024; 137:jcs261847. [PMID: 39161994 PMCID: PMC11361644 DOI: 10.1242/jcs.261847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/21/2024] Open
Abstract
Clathrin-coated vesicles (CCVs), generated by clathrin-mediated endocytosis (CME), are essential eukaryotic trafficking organelles that transport extracellular and plasma membrane-bound materials into the cell. In this Review, we explore mechanisms of CME in mammals, yeasts and plants, and highlight recent advances in the characterization of endocytosis in plants. Plants separated from mammals and yeast over 1.5 billion years ago, and plant cells have distinct biophysical parameters that can influence CME, such as extreme turgor pressure. Plants can therefore provide a wider perspective on fundamental processes in eukaryotic cells. We compare key mechanisms that drive CCV formation and explore what these mechanisms might reveal about the core principles of endocytosis across the tree of life. Fascinatingly, CME in plants appears to more closely resemble that in mammalian cells than that in yeasts, despite plants being evolutionarily further from mammals than yeast. Endocytic initiation appears to be highly conserved across these three systems, requiring similar protein domains and regulatory processes. Clathrin coat proteins and their honeycomb lattice structures are also highly conserved. However, major differences are found in membrane-bending mechanisms. Unlike in mammals or yeast, plant endocytosis occurs independently of actin, highlighting that mechanistic assumptions about CME across different systems should be made with caution.
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Affiliation(s)
- Alexander Johnson
- Division of Anatomy, Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna 1090, Austria
- Medical Imaging Cluster (MIC), Medical University of Vienna, Vienna 1090, Austria
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
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3
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Lin Z, Mao Z, Ma R. Inferring biophysical properties of membranes during endocytosis using machine learning. SOFT MATTER 2024; 20:651-660. [PMID: 38164011 DOI: 10.1039/d3sm01221b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Endocytosis is a fundamental cellular process in eukaryotic cells that facilitates the transport of molecules into the cell. With the help of fluorescence microscopy and electron tomography, researchers have accumulated extensive geometric data of membrane shapes during endocytosis. These data contain rich information about the mechanical properties of membranes, which are hard to access via experiments due to the small dimensions of the endocytic patch. In this study, we propose an approach that combines machine learning with the Helfrich theory of membranes to infer the mechanical properties of membranes during endocytosis from a dataset of membrane shapes extracted from electron tomography. Our results demonstrate that machine learning can output solutions that both match the experimental profile and satisfy the membrane shape equations derived from Helfrich theory. The learning results show that during the early stage of endocytosis, the inferred membrane tension is negative, indicating the presence of strong compressive forces at the boundary of the endocytic invagination. Our method presents a generic framework for extracting membrane information from super-resolution imaging.
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Affiliation(s)
- Zhiwei Lin
- Department of Physics, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
| | - Zhiping Mao
- School of Mathematical Sciences, Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computing, Xiamen University, Xiamen 361005, China.
| | - Rui Ma
- Department of Physics, College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
- Fujian Provincial Key Laboratory for Soft Functional Materials Research, Research Institute for Biomimetics and Soft Matter, Xiamen University, Xiamen 361005, China
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4
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Stoops EH, Ferrin MA, Jorgens DM, Drubin DG. Self-organizing actin networks drive sequential endocytic protein recruitment and vesicle release on synthetic lipid bilayers. Proc Natl Acad Sci U S A 2023; 120:e2302622120. [PMID: 37216532 PMCID: PMC10235984 DOI: 10.1073/pnas.2302622120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/21/2023] [Indexed: 05/24/2023] Open
Abstract
Forces generated by actin assembly assist membrane invagination during clathrin-mediated endocytosis (CME). The sequential recruitment of core endocytic proteins and regulatory proteins, and assembly of the actin network, are well documented in live cells and are highly conserved from yeasts to humans. However, understanding of CME protein self-organization, as well as the biochemical and mechanical principles that underlie actin's role in CME, is lacking. Here, we show that supported lipid bilayers coated with purified yeast Wiskott Aldrich Syndrome Protein (WASP), an endocytic actin assembly regulator, and incubated in cytoplasmic yeast extracts, recruit downstream endocytic proteins and assemble actin networks. Time-lapse imaging of WASP-coated bilayers revealed sequential recruitment of proteins from different endocytic modules, faithfully replicating in vivo behavior. Reconstituted actin networks assemble in a WASP-dependent manner and deform lipid bilayers, as seen by electron microscopy. Time-lapse imaging revealed that vesicles are released from the lipid bilayers with a burst of actin assembly. Actin networks pushing on membranes have previously been reconstituted; here, we have reconstituted a biologically important variation of these actin networks that self-organize on bilayers and produce pulling forces sufficient to bud off membrane vesicles. We propose that actin-driven vesicle generation may represent an ancient evolutionary precursor to diverse vesicle forming processes adapted for a wide array of cellular environments and applications.
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Affiliation(s)
- Emily H. Stoops
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Michael A. Ferrin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | | | - David G. Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
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5
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Zhang X, Wang C, Qi L, Wang S, Chen Y, Kong Z, Li S, Zhang X, Zhang Z, Liu J, Wang D. The tandem EH domains of End3 cooperate to interact with dual XPF motifs of Sla1 for the connection of early and late stages in fungal endocytosis. Biochem Biophys Res Commun 2023; 663:147-153. [PMID: 37121125 DOI: 10.1016/j.bbrc.2023.04.075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 04/22/2023] [Indexed: 05/02/2023]
Abstract
Clathrin-mediated endocytosis (CME) is imperative for physiological processes in eukaryotic cells. In fungi, the Pan1/End3/Sla1 complex controls the transition between early and late stages of CME. Although it is acknowledged that End3 uses its N-terminal to interact with the C-terminal of Sla1, detailed mechanism remains obscure. Magnaporthe oryzae, the pathogenic fungus of rice, cause blast disease that threatens rice production worldwide. Here we report the detailed interaction mechanism between End3 and Sla1 of M. oryzae, i.e. MoEnd3 and MoSla1. The two EH domains of MoEnd3 (MoEnd3-EH1 and MoEnd3-EH2) is different both in evolution and calcium binding, but are indispensable for conformational stability of each other, an unreported effect of tandem-arranged EH domains. MoEnd3-EH1 and MoEnd3-EH2 interact with peptide MoSla11145-1155 containing a NPF motif with a conserved mode, and MoEnd3-EHs (containing both EH1 and EH2 domains) binds MoSla11145-1155 with a higher affinity, supporting the synergetic effect of EH domains. In addition, MoEnd3-EHs also recognize peptide MoSla1971-981 with a new MPF motif that has not been reported before, while Sla1 of yeast contains a DPF motif that bears EH domain interaction ability. Collectively, our research shows that the two EH domains of End3 synergize to interact with dual XPF motifs of Sla1, which conforms to a bivalent receptor-bivalent ligand model to improve both affinity and specificity.
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Affiliation(s)
- Xiaokang Zhang
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Chao Wang
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China; Zibo Academy of Agricultural Sciences, Shandong, 255000, China
| | - Linlu Qi
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Shiwei Wang
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Yitong Chen
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Zhiwei Kong
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Saijie Li
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Xin Zhang
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, The Key Laboratory of Plant Immunity, Nanjing Agricultural University, And Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Junfeng Liu
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China; Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, Beijing, 100193, China
| | - Dongli Wang
- Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
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6
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Stoops EH, Ferrin MA, Jorgens DM, Drubin DG. Self-organizing actin networks drive sequential endocytic protein recruitment and vesicle release on synthetic lipid bilayers. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528546. [PMID: 36824809 PMCID: PMC9949000 DOI: 10.1101/2023.02.14.528546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Forces generated by actin assembly assist membrane invagination during clathrin-mediated endocytosis (CME). The sequential recruitment of core endocytic proteins and regulatory proteins, and assembly of the actin network, are well documented in live cells and are highly conserved from yeasts to humans. However, understanding of CME protein self-organization, as well as the biochemical and mechanical principles that underlie actin’s role in CME, is lacking. Here, we show that supported lipid bilayers coated with purified yeast WASP, an endocytic actin assembly regulator, and incubated in cytoplasmic yeast extracts, recruit downstream endocytic proteins and assemble actin tails. Time-lapse imaging of WASP-coated bilayers revealed sequential recruitment of proteins from different endocytic modules, faithfully replicating in vivo behavior. Reconstituted actin networks assemble in a WASP-dependent manner and deform lipid bilayers, as seen by electron microscopy. Time-lapse imaging revealed that vesicles are released from the lipid bilayers with a burst of actin assembly. Actin networks pushing on membranes have previously been reconstituted; here, we have reconstituted a biologically important variation of these actin networks that self-organize on bilayers and produce pulling forces sufficient to bud off membrane vesicles. We propose that actin-driven vesicle generation may represent an ancient evolutionary precursor to diverse vesicle forming processes adapted for a wide array of cellular environments and applications. Significance Statement Actin filament assembly participates in many vesicle-forming processes. However, the underlying principles for how assembly is initiated and organized to effectively harness assembly forces remain elusive. To address this gap, we report a novel reconstitution of actin-driven vesicle release from supported lipid bilayers. Using real-time imaging, we observe sequential recruitment of endocytic proteins and, following a burst of actin assembly, vesicle release from bilayers. Given the absence of cargo or upstream endocytic regulatory proteins on the bilayers, and the participation of actin in many vesicle-forming processes, we posit that this mode of vesicle formation represents an early evolutionary precursor for multiple trafficking pathways. We expect that this assay will be of great use for future investigations of actin-mediated vesicle-forming processes.
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Affiliation(s)
- Emily H. Stoops
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Michael A. Ferrin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Danielle M. Jorgens
- Electron Microscope Laboratory, University of California, Berkeley, Berkeley, CA
| | - David G. Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
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7
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Insights of Endocytosis Signaling in Health and Disease. Int J Mol Sci 2023; 24:ijms24032971. [PMID: 36769293 PMCID: PMC9918140 DOI: 10.3390/ijms24032971] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/20/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Endocytosis in mammalian cells is a fundamental cellular machinery that regulates vital physiological processes, such as the absorption of metabolites, release of neurotransmitters, uptake of hormone cellular defense, and delivery of biomolecules across the plasma membrane. A remarkable characteristic of the endocytic machinery is the sequential assembly of the complex proteins at the plasma membrane, followed by internalization and fusion of various biomolecules to different cellular compartments. In all eukaryotic cells, functional characterization of endocytic pathways is based on dynamics of the protein complex and signal transduction modules. To coordinate the assembly and functions of the numerous parts of the endocytic machinery, the endocytic proteins interact significantly within and between the modules. Clathrin-dependent and -independent endocytosis, caveolar pathway, and receptor mediated endocytosis have been attributed to a greater variety of physiological and pathophysiological roles such as, autophagy, metabolism, cell division, apoptosis, cellular defense, and intestinal permeabilization. Notably, any defect or alteration in the endocytic machinery results in the development of pathological consequences associated with human diseases such as cancer, cardiovascular diseases, neurological diseases, and inflammatory diseases. In this review, an in-depth endeavor has been made to illustrate the process of endocytosis, and associated mechanisms describing pathological manifestation associated with dysregulated endocytosis machinery.
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8
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Wu X, Qiu H, Zhang M. Interactions between Membraneless Condensates and Membranous Organelles at the Presynapse: A Phase Separation View of Synaptic Vesicle Cycle. J Mol Biol 2023; 435:167629. [PMID: 35595170 DOI: 10.1016/j.jmb.2022.167629] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 02/04/2023]
Abstract
Action potential-induced neurotransmitter release in presynaptic boutons involves coordinated actions of a large list of proteins that are associated directly or indirectly with membrane structures including synaptic vesicles and plasma membranes. These proteins are often highly abundant in different synaptic bouton sub-compartments, and they rarely act alone. Instead, these proteins interact with each other forming intricate and distinct molecular complexes. Many of these complexes form condensed clusters on membrane surfaces. This review summarizes findings in recent years showing that many of presynaptic protein complex assemblies are formed via phase separation. These protein condensates extensively interact with lipid membranes via distinct modes, forming various mesoscale structures by different mode of organizations between membraneless condensates and membranous organelles. We discuss that such mesoscale interactions could have deep implications on mobilization, exocytosis, and retrieval of synaptic vesicles.
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Affiliation(s)
- Xiandeng Wu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Hua Qiu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen 518036, China; School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.
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9
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Shukla AK, Abidi SMS, Sharma C, Chand Saini T, Acharya A. Single-walled carbon nanotube conjugated cytochrome c as exogenous nano catalytic medicine to combat intracellular oxidative stress. Free Radic Biol Med 2022; 193:238-252. [PMID: 36257485 DOI: 10.1016/j.freeradbiomed.2022.10.276] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/04/2022] [Accepted: 10/12/2022] [Indexed: 10/31/2022]
Abstract
Mitochondrial dysfunction has been reported to be one of the main causes of many diseases including cancer, type2 diabetes, neurodegenerative disorders, cardiac ischemia, sepsis, muscular dystrophy, etc. Under in vitro conditions, Cytochrome C (Cyt C) maintains mitochondrial homeostasis and stimulates apoptosis, along with being a key participant in the life-supporting function of ATP synthesis. Hence, the medicinal importance of Cyt C as catalytic defense is immensely important in various mitochondrial disorders. Here, we have developed a nanomaterial via electrostatically conjugating oxidized single-wall carbon nanotube with Cyt C (Cyt C@cSWCNT) for the exogenous delivery of Cyt C. The chemical and morphological characterization of the developed Cyt C@cSWCNT was done using UV-vis, FTIR, XPS, powder XRD, TGA/DSC, TEM, etc. The developed Cyt C@cSWCNT exhibited bifunctional catalase and peroxidase activity with Km (∼ 642.7 μM and 351.6 μM) and Vmax (∼0.33 μM/s and 2.62 μM/s) values, respectively. Also, through this conjugation Cyt C was found to retain its catalytic activity even at 60 °C, excellent catalytic recyclability (at least up to 3 times), and wider pH activity (pH = 3 to 9). Cyt C@cSWCNT was found to promote intracellular ROS quenching and maintain mitochondrial membrane potential and cellular membrane integrity via Na+/K+ ion homeostasis during the H2O2 stress. Overall the present strategy provides an alternative approach for the exogenous delivery of Cyt C which can be used as nano catalytic medicine.
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Affiliation(s)
- Ashish K Shukla
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur (H.P.), 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Syed M S Abidi
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur (H.P.), 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Chandni Sharma
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur (H.P.), 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Trilok Chand Saini
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur (H.P.), 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - Amitabha Acharya
- Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur (H.P.), 176061, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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10
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Skruzny M. The endocytic protein machinery as an actin-driven membrane-remodeling machine. Eur J Cell Biol 2022; 101:151267. [PMID: 35970066 DOI: 10.1016/j.ejcb.2022.151267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 12/14/2022] Open
Abstract
In clathrin-mediated endocytosis, a principal membrane trafficking route of all eukaryotic cells, forces are applied to invaginate the plasma membrane and form endocytic vesicles. These forces are provided by specific endocytic proteins and the polymerizing actin cytoskeleton. One of the best-studied endocytic systems is endocytosis in yeast, known for its simplicity, experimental amenability, and overall similarity to human endocytosis. Importantly, the yeast endocytic protein machinery generates and transmits tremendous force to bend the plasma membrane, making this system beneficial for mechanistic studies of cellular force-driven membrane reshaping. This review summarizes important protein players, molecular functions, applied forces, and open questions and perspectives of this robust, actin-powered membrane-remodeling protein machine.
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Affiliation(s)
- Michal Skruzny
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany.
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11
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Enshoji M, Miyano Y, Yoshida N, Nagano M, Watanabe M, Kunihiro M, Siekhaus DE, Toshima JY, Toshima J. Eps15/Pan1p is a master regulator of the late stages of the endocytic pathway. J Cell Biol 2022; 221:213415. [PMID: 35984332 PMCID: PMC9396825 DOI: 10.1083/jcb.202112138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 06/30/2022] [Accepted: 08/03/2022] [Indexed: 11/22/2022] Open
Abstract
Endocytosis is a multistep process involving the sequential recruitment and action of numerous proteins. This process can be divided into two phases: an early phase, in which sites of endocytosis are formed, and a late phase in which clathrin-coated vesicles are formed and internalized into the cytosol, but how these phases link to each other remains unclear. In this study, we demonstrate that anchoring the yeast Eps15-like protein Pan1p to the peroxisome triggers most of the events occurring during the late phase at the peroxisome. At this ectopic location, Pan1p recruits most proteins that function in the late phases-including actin nucleation promoting factors-and then initiates actin polymerization. Pan1p also recruited Prk1 kinase and actin depolymerizing factors, thereby triggering disassembly immediately after actin assembly and inducing dissociation of endocytic proteins from the peroxisome. These observations suggest that Pan1p is a key regulator for initiating, processing, and completing the late phase of endocytosis.
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Affiliation(s)
- Mariko Enshoji
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Yoshiko Miyano
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Nao Yoshida
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Makoto Nagano
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Minami Watanabe
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Mayumi Kunihiro
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Daria E. Siekhaus
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Junko Y. Toshima
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan,School of Health Science, Tokyo University of Technology, Ota-ku, Tokyo, Japan,Junko Y. Toshima:
| | - Jiro Toshima
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan,Correspondence to Jiro Toshima:
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12
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Kozak M, Kaksonen M. Condensation of Ede1 promotes the initiation of endocytosis. eLife 2022; 11:72865. [PMID: 35412456 PMCID: PMC9064294 DOI: 10.7554/elife.72865] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 04/01/2022] [Indexed: 11/27/2022] Open
Abstract
Clathrin-mediated endocytosis is initiated by a network of weakly interacting proteins through a poorly understood mechanism. Ede1, the yeast homolog of mammalian Eps15, is an early-arriving endocytic protein and a key initiation factor. In the absence of Ede1, most other early endocytic proteins lose their punctate localization and endocytic uptake is decreased. We show that in yeast cells, cytosolic concentration of Ede1 is buffered at a critical level. Excess amounts of Ede1 form large condensates which recruit other endocytic proteins and exhibit properties of phase-separated liquid droplets. We demonstrate that the central region of Ede1, containing a coiled-coil and a prion-like region, is essential for both the condensate formation and the function of Ede1 in endocytosis. The functionality of Ede1 mutants lacking the central region can be partially rescued by an insertion of heterologous prion-like domains. Conversely, fusion of a heterologous lipid-binding domain with the central region of Ede1 can promote clustering into stable plasma membrane domains. We propose that the ability of Ede1 to form condensed networks supports the clustering of early endocytic proteins and promotes the initiation of endocytosis.
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Affiliation(s)
- Mateusz Kozak
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Marko Kaksonen
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
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13
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Partlow EA, Cannon KS, Hollopeter G, Baker RW. Structural basis of an endocytic checkpoint that primes the AP2 clathrin adaptor for cargo internalization. Nat Struct Mol Biol 2022; 29:339-347. [PMID: 35347313 PMCID: PMC10116491 DOI: 10.1038/s41594-022-00749-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 02/16/2022] [Indexed: 11/08/2022]
Abstract
Clathrin-mediated endocytosis (CME) is the main route of internalization from the plasma membrane. It is known that the heterotetrameric AP2 clathrin adaptor must open to simultaneously engage membrane and endocytic cargo, yet it is unclear how transmembrane cargos are captured to catalyze CME. Using cryogenic-electron microscopy, we discover a new way in which mouse AP2 can reorganize to expose membrane- and cargo-binding pockets, which is not observed in clathrin-coated structures. Instead, it is stimulated by endocytic pioneer proteins called muniscins, which do not enter vesicles. Muniscin-engaged AP2 is primed to rearrange into the vesicle-competent conformation on binding the tyrosine cargo internalization motif (YxxΦ). We propose adaptor priming as a checkpoint to ensure cargo internalization.
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Affiliation(s)
- Edward A Partlow
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA
| | - Kevin S Cannon
- Department of Biochemistry and Biophysics, University of North Carolina (UNC) Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | | | - Richard W Baker
- Department of Biochemistry and Biophysics, University of North Carolina (UNC) Chapel Hill School of Medicine, Chapel Hill, NC, USA.
- UNC Lineberger Comprehensive Cancer Center, University of North Carolina (UNC) Chapel Hill School of Medicine, Chapel Hill, NC, USA.
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14
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Candida albicans END3 Mediates Endocytosis and Has Subsequent Roles in Cell Wall Integrity, Morphological Switching, and Tissue Invasion. Microbiol Spectr 2022; 10:e0188021. [PMID: 35234488 PMCID: PMC8941917 DOI: 10.1128/spectrum.01880-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of endocytosis in Candida albicans secretion, filamentation, and virulence remains poorly understood, despite its importance as a fundamental component of intracellular trafficking. Given that secretory mutants display defects in endocytosis, we have focused our attention on endocytic mutants to understand the interconnection between endocytosis and other secretory pathways. Using a reverse-genetic approach based upon CRISPR-Cas9 mediated gene deletion, we studied the functions of the gene END3, which plays a key role in clathrin-based endocytosis. In the end3Δ/Δ null mutant, clathrin-mediated endocytosis was substantially reduced. While in vitro growth, cell morphology, and vacuoles appeared normal, the mutant was impaired in actin patch formation, filamentous growth, biofilm formation, cell wall integrity, and extracellular protease secretion. In addition, susceptibility to various antifungal agents was altered. Consistent with the inability to form hyphae, in an in vitro keratinocyte infection model, the null mutant displayed reduced damage of mammalian adhesion zippers and host cell death. Thus, C. albicans END3 has a role in efficient endocytosis that is required for cell wall integrity, protein secretion, hyphal formation, and virulence-related processes. These findings suggest that impaired endocytosis subsequently affects other secretory pathways, providing evidence of the interconnection between these processes. IMPORTANCE Candida albicans is a fungal commensal organism that can cause serious opportunistic infections in immunocompromised patients leading to substantial complications and mortality. A better understanding of the microbe's biology to develop more effective therapeutic and diagnostic tools is required as invasive candidiasis is a problem of continued clinical importance. This study focuses on endocytosis, an important but incompletely understood cellular mechanism needed to uptake nutrients and communicate with a cell's environment. In this study, we have assessed the role of endocytosis in cell wall integrity, biofilm formation, and tissue invasion in C. albicans. These findings will improve our understanding of cellular mechanisms underlying endocytosis and will inform us of the interconnection with other intracellular transport processes.
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15
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Pashkova N, Gakhar L, Yu L, Schnicker NJ, Minard AY, Winistorfer S, Johnson IE, Piper RC. ANTH domains within CALM, HIP1R, and Sla2 recognize ubiquitin internalization signals. eLife 2021; 10:72583. [PMID: 34821552 PMCID: PMC8648300 DOI: 10.7554/elife.72583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 11/24/2021] [Indexed: 12/12/2022] Open
Abstract
Attachment of ubiquitin (Ub) to cell surface proteins serves as a signal for internalization via clathrin-mediated endocytosis (CME). How ubiquitinated membrane proteins engage the internalization apparatus remains unclear. The internalization apparatus contains proteins such as Epsin and Eps15, which bind Ub, potentially acting as adaptors for Ub-based internalization signals. Here, we show that additional components of the endocytic machinery including CALM, HIP1R, and Sla2 bind Ub via their N-terminal ANTH domain, a domain belonging to the superfamily of ENTH and VHS domains. Structural studies revealed that Ub binds with µM affinity to a unique C-terminal region within the ANTH domain not found in ENTH domains. Functional studies showed that combined loss of Ub-binding by ANTH-domain proteins and other Ub-binding domains within the yeast internalization apparatus caused defects in the Ub-dependent internalization of the GPCR Ste2 that was engineered to rely exclusively on Ub as an internalization signal. In contrast, these mutations had no effect on the internalization of Ste2 engineered to use an alternate Ub-independent internalization signal. These studies define new components of the internalization machinery that work collectively with Epsin and Eps15 to specify recognition of Ub as an internalization signal.
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Affiliation(s)
- Natalya Pashkova
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Lokesh Gakhar
- Carver College of Medicine Protein Crystallography Core, University of Iowa, Iowa City, United States.,Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, United States
| | - Liping Yu
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, United States.,Carver College of Medicine NMR Core, University of Iowa, Iowa City, United States
| | - Nicholas J Schnicker
- Carver College of Medicine Protein Crystallography Core, University of Iowa, Iowa City, United States
| | - Annabel Y Minard
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Stanley Winistorfer
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Ivan E Johnson
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
| | - Robert C Piper
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, United States
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16
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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.
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17
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Lizarrondo J, Klebl DP, Niebling S, Abella M, Schroer MA, Mertens HDT, Veith K, Thuenauer R, Svergun DI, Skruzny M, Sobott F, Muench SP, Garcia-Alai MM. Structure of the endocytic adaptor complex reveals the basis for efficient membrane anchoring during clathrin-mediated endocytosis. Nat Commun 2021; 12:2889. [PMID: 34001871 PMCID: PMC8129110 DOI: 10.1038/s41467-021-23151-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 04/13/2021] [Indexed: 12/13/2022] Open
Abstract
During clathrin-mediated endocytosis, a complex and dynamic network of protein-membrane interactions cooperate to achieve membrane invagination. Throughout this process in yeast, endocytic coat adaptors, Sla2 and Ent1, must remain attached to the plasma membrane to transmit force from the actin cytoskeleton required for successful membrane invagination. Here, we present a cryo-EM structure of a 16-mer complex of the ANTH and ENTH membrane-binding domains from Sla2 and Ent1 bound to PIP2 that constitutes the anchor to the plasma membrane. Detailed in vitro and in vivo mutagenesis of the complex interfaces delineate the key interactions for complex formation and deficient cell growth phenotypes demonstrate its biological relevance. A hetero-tetrameric unit binds PIP2 molecules at the ANTH-ENTH interfaces and can form larger assemblies to contribute to membrane remodeling. Finally, a time-resolved small-angle X-ray scattering study of the interaction of these adaptor domains in vitro suggests that ANTH and ENTH domains have evolved to achieve a fast subsecond timescale assembly in the presence of PIP2 and do not require further proteins to form a stable complex. Together, these findings provide a molecular understanding of an essential piece in the molecular puzzle of clathrin-coated endocytic sites.
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Affiliation(s)
- Javier Lizarrondo
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - David P Klebl
- School of Biomedical Sciences, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Stephan Niebling
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Marc Abella
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Martin A Schroer
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Haydyn D T Mertens
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Katharina Veith
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Roland Thuenauer
- Technology Platform Microscopy and Image Analysis, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Michal Skruzny
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Frank Sobott
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK.,Department of Chemistry, Biomolecular and Analytical Mass Spectrometry group, University of Antwerp, Antwerp, Belgium
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Maria M Garcia-Alai
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany. .,Centre for Structural Systems Biology, Hamburg, Germany.
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18
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Fletcher E, Mercurio K, Walden EA, Baetz K. A yeast chemogenomic screen identifies pathways that modulate adipic acid toxicity. iScience 2021; 24:102327. [PMID: 33889823 PMCID: PMC8050732 DOI: 10.1016/j.isci.2021.102327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/19/2021] [Accepted: 03/15/2021] [Indexed: 11/18/2022] Open
Abstract
Adipic acid production by yeast fermentation is gaining attention as a renewable source of platform chemicals for making nylon products. However, adipic acid toxicity inhibits yeast growth and fermentation. Here, we performed a chemogenomic screen in Saccharomyces cerevisiae to understand the cellular basis of adipic acid toxicity. Our screen revealed that KGD1 (a key gene in the tricarboxylic acid cycle) deletion improved tolerance to adipic acid and its toxic precursor, catechol. Conversely, disrupting ergosterol biosynthesis as well as protein trafficking and vacuolar transport resulted in adipic acid hypersensitivity. Notably, we show that adipic acid disrupts the Membrane Compartment of Can1 (MCC) on the plasma membrane and impacts endocytosis. This was evidenced by the rapid internalization of Can1 for vacuolar degradation. As ergosterol is an essential component of the MCC and protein trafficking mechanisms are required for endocytosis, we highlight the importance of these cellular processes in modulating adipic acid toxicity. Deletion of the TCA cycle gene KGD1 improves tolerance to adipic acid and catechol Ergosterol and Pdr12 play non-overlapping roles protecting cell from adipic acid Adipic acid-induced plasma membrane localization of Pdr12 is independent of ergosterol Adipic acid disrupts the Membrane Compartment of Can1 (MCC) and induces endocytosis
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Affiliation(s)
- Eugene Fletcher
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Kevin Mercurio
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Elizabeth A. Walden
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Kristin Baetz
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
- Corresponding author
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19
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Pedersen RTA, Hassinger JE, Marchando P, Drubin DG. Spatial regulation of clathrin-mediated endocytosis through position-dependent site maturation. J Cell Biol 2020; 219:211446. [PMID: 33053166 PMCID: PMC7545360 DOI: 10.1083/jcb.202002160] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/08/2020] [Accepted: 09/04/2020] [Indexed: 12/17/2022] Open
Abstract
During clathrin-mediated endocytosis (CME), over 50 different proteins assemble on the plasma membrane to reshape it into a cargo-laden vesicle. It has long been assumed that cargo triggers local CME site assembly in Saccharomyces cerevisiae based on the discovery that cortical actin patches, which cluster near exocytic sites, are CME sites. Quantitative imaging data reported here lead to a radically different view of which CME steps are regulated and which steps are deterministic. We quantitatively and spatially describe progression through the CME pathway and pinpoint a cargo-sensitive regulatory transition point that governs progression from the initiation phase of CME to the internalization phase. Thus, site maturation, rather than site initiation, accounts for the previously observed polarized distribution of actin patches in this organism. While previous studies suggested that cargo ensures its own internalization by regulating either CME initiation rates or frequency of abortive events, our data instead identify maturation through a checkpoint in the pathway as the cargo-sensitive step.
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Affiliation(s)
- Ross T A Pedersen
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Julian E Hassinger
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA.,Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA
| | - Paul Marchando
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
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20
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Yin J, Hao C, Niu G, Wang W, Wang G, Xiang P, Xu JR, Zhang X. FgPal1 regulates morphogenesis and pathogenesis in Fusarium graminearum. Environ Microbiol 2020; 22:5373-5386. [PMID: 33000483 DOI: 10.1111/1462-2920.15266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/29/2020] [Indexed: 12/18/2022]
Abstract
Ascospores are the primary inoculum in Fusarium graminearum, a causal agent of wheat head blight. In a previous study, FgPAL1 was found to be upregulated in the Fgama1 mutant and important for ascosporogenesis. However, the biological function of this well-conserved gene in filamentous ascomycetes is not clear. In this study, we characterized its functions in growth, differentiation and pathogenesis. The Fgpal1 mutant had severe growth defects and often displayed abnormal hyphal tips. It was defective in infectious growth in rachis tissues and spreading in wheat heads. The Fgpal1 mutant produced conidia with fewer septa and more nuclei per compartment than the wild type. In actively growing hyphal tips, FgPal1-GFP mainly localized to the subapical collar and septa. The FgPal1 and LifeAct partially co-localized at the subapical region in an interdependent manner. The Fgpal1 mutant was normal in meiosis with eight nuclei in developing asci but most asci were aborted. Taken together, our results showed that FgPal1 plays a role in maintaining polarized tip growth and coordination between nuclear division and cytokinesis, and it is also important for infectious growth and developments of ascospores by the free cell formation process.
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Affiliation(s)
- Jinrong Yin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chaofeng Hao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Gang Niu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Wei Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Guanghui Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ping Xiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jin-Rong Xu
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Xue Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
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21
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Pascolutti R, Algisi V, Conte A, Raimondi A, Pasham M, Upadhyayula S, Gaudin R, Maritzen T, Barbieri E, Caldieri G, Tordonato C, Confalonieri S, Freddi S, Malabarba MG, Maspero E, Polo S, Tacchetti C, Haucke V, Kirchhausen T, Di Fiore PP, Sigismund S. Molecularly Distinct Clathrin-Coated Pits Differentially Impact EGFR Fate and Signaling. Cell Rep 2020; 27:3049-3061.e6. [PMID: 31167147 PMCID: PMC6581797 DOI: 10.1016/j.celrep.2019.05.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/04/2019] [Accepted: 05/02/2019] [Indexed: 12/22/2022] Open
Abstract
Adaptor protein 2 (AP2) is a major constituent of clathrin-coated pits (CCPs). Whether it is essential for all forms of clathrin-mediated endocytosis (CME) in mammalian cells is an open issue. Here, we demonstrate, by live TIRF microscopy, the existence of a subclass of relatively short-lived CCPs lacking AP2 under physiological, unperturbed conditions. This subclass is retained in AP2-knockout cells and is able to support the internalization of epidermal growth factor receptor (EGFR) but not of transferrin receptor (TfR). The AP2-independent internalization mechanism relies on the endocytic adaptors eps15, eps15L1, and epsin1. The absence of AP2 impairs the recycling of the EGFR to the cell surface, thereby augmenting its degradation. Accordingly, under conditions of AP2 ablation, we detected dampening of EGFR-dependent AKT signaling and cell migration, arguing that distinct classes of CCPs could provide specialized functions in regulating EGFR recycling and signaling. Distinct classes of CCPs exist, molecularly defined by the presence or lack of AP2 The AP2-negative CCPs support the internalization of EGFR but not of TfR The AP2-negative CCPs rely on the endocytic adaptors eps15/eps15L1 and epsin1 The two classes of CCPs determine distinct EGFR fates and signaling outputs
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Affiliation(s)
- Roberta Pascolutti
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy
| | - Veronica Algisi
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy
| | - Alexia Conte
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy
| | - Andrea Raimondi
- Experimental Imaging Centre, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), San Raffaele Scientific Institute, via Olgettina 58, 20132 Milan, Italy
| | - Mithun Pasham
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Srigokul Upadhyayula
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Raphael Gaudin
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Institut de Recherche en Infectiologie de Montpellier, UMR 9004, CNRS/UM, 1919 route de Mende, 34293 Montpellier cedex 5, France
| | - Tanja Maritzen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Elisa Barbieri
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy
| | - Giusi Caldieri
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy; Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, Via Santa Sofia 9/1, 20122 Milan, Italy
| | - Chiara Tordonato
- Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy
| | - Stefano Confalonieri
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy
| | - Stefano Freddi
- Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy
| | - Maria Grazia Malabarba
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy; Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, Via Santa Sofia 9/1, 20122 Milan, Italy
| | - Elena Maspero
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy
| | - Simona Polo
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, Via Santa Sofia 9/1, 20122 Milan, Italy
| | - Carlo Tacchetti
- Experimental Imaging Centre, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), San Raffaele Scientific Institute, via Olgettina 58, 20132 Milan, Italy; Università Vita-Salute San Raffaele, Milan, Italy
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Tom Kirchhausen
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Pier Paolo Di Fiore
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy; Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, Via Santa Sofia 9/1, 20122 Milan, Italy
| | - Sara Sigismund
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy; Istituto Europeo di Oncologia IRCCS, Via Ripamonti 435, 20141 Milan, Italy; Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, Via Santa Sofia 9/1, 20122 Milan, Italy.
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22
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Athanasopoulos A, André B, Sophianopoulou V, Gournas C. Fungal plasma membrane domains. FEMS Microbiol Rev 2020; 43:642-673. [PMID: 31504467 DOI: 10.1093/femsre/fuz022] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/25/2019] [Indexed: 12/11/2022] Open
Abstract
The plasma membrane (PM) performs a plethora of physiological processes, the coordination of which requires spatial and temporal organization into specialized domains of different sizes, stability, protein/lipid composition and overall architecture. Compartmentalization of the PM has been particularly well studied in the yeast Saccharomyces cerevisiae, where five non-overlapping domains have been described: The Membrane Compartments containing the arginine permease Can1 (MCC), the H+-ATPase Pma1 (MCP), the TORC2 kinase (MCT), the sterol transporters Ltc3/4 (MCL), and the cell wall stress mechanosensor Wsc1 (MCW). Additional cortical foci at the fungal PM are the sites where clathrin-dependent endocytosis occurs, the sites where the external pH sensing complex PAL/Rim localizes, and sterol-rich domains found in apically grown regions of fungal membranes. In this review, we summarize knowledge from several fungal species regarding the organization of the lateral PM segregation. We discuss the mechanisms of formation of these domains, and the mechanisms of partitioning of proteins there. Finally, we discuss the physiological roles of the best-known membrane compartments, including the regulation of membrane and cell wall homeostasis, apical growth of fungal cells and the newly emerging role of MCCs as starvation-protective membrane domains.
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Affiliation(s)
- Alexandros Athanasopoulos
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Bruno André
- Molecular Physiology of the Cell laboratory, Université Libre de Bruxelles (ULB), Institut de Biologie et de Médecine Moléculaires, rue des Pr Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Vicky Sophianopoulou
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Christos Gournas
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
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23
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Han X, Chen L, Li W, Zhang L, Zhang L, Zou S, Liang Y, Yu J, Dong H. Endocytic FgEde1 regulates virulence and autophagy in Fusarium graminearum. Fungal Genet Biol 2020; 141:103400. [PMID: 32387406 DOI: 10.1016/j.fgb.2020.103400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/07/2020] [Accepted: 05/01/2020] [Indexed: 12/17/2022]
Abstract
Endocytosis plays critical roles in cellular processes, including nutrient uptake and signal transduction. Ede1 is an endocytic scaffolding protein that contributes to endocytic site initiation and maturation in yeast. However, the functions of Ede1 in phytopathogenic fungi are not known. Here, we identified functions of FgEde1 (FGSG_05182) in Fusarium graminearum. Deletion of FgEde1 resulted in defects in hyphal growth, conidiation and ascospore development. The FgEde1 deletion mutant showed reduced deoxynivalenol (DON) production and virulence in wheat. Furthermore, the FgEde1 deletion mutant also exhibited increased resistance to osmotic and oxidative stress as well as cell-wall perturbing agents. Importantly, deletion of FgEde1 increased the severity of autophagy in hyphae. Taken together, these results reveal that FgEde1 is involved in hyphal growth, asexual and sexual reproduction, virulence, stress responses, and autophagy in F. graminearum.
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Affiliation(s)
- Xuelian Han
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Lei Chen
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Weidong Li
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Li Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Liyuan Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Shenshen Zou
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Yuancun Liang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China.
| | - Jinfeng Yu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Hansong Dong
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
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24
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Manenschijn HE, Picco A, Mund M, Rivier-Cordey AS, Ries J, Kaksonen M. Type-I myosins promote actin polymerization to drive membrane bending in endocytosis. eLife 2019; 8:44215. [PMID: 31385806 PMCID: PMC6684269 DOI: 10.7554/elife.44215] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 07/23/2019] [Indexed: 12/24/2022] Open
Abstract
Clathrin-mediated endocytosis in budding yeast requires the formation of a dynamic actin network that produces the force to invaginate the plasma membrane against the intracellular turgor pressure. The type-I myosins Myo3 and Myo5 are important for endocytic membrane reshaping, but mechanistic details of their function remain scarce. Here, we studied the function of Myo3 and Myo5 during endocytosis using quantitative live-cell imaging and genetic perturbations. We show that the type-I myosins promote, in a dose-dependent way, the growth and expansion of the actin network, which controls the speed of membrane and coat internalization. We found that this myosin-activity is independent of the actin nucleation promoting activity of myosins, and cannot be compensated for by increasing actin nucleation. Our results suggest a new mechanism for type-I myosins to produce force by promoting actin filament polymerization.
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Affiliation(s)
- Hetty E Manenschijn
- Department of Biochemistry, University of Geneva, Geneva, Switzerland.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Andrea Picco
- Department of Biochemistry, University of Geneva, Geneva, Switzerland.,NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Markus Mund
- Department of Biochemistry, University of Geneva, Geneva, Switzerland.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | | | - Jonas Ries
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Marko Kaksonen
- Department of Biochemistry, University of Geneva, Geneva, Switzerland.,NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
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25
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Abstract
The entry of pathogens into nonphagocytic host cells has received much attention in the past three decades, revealing a vast array of strategies employed by bacteria and viruses. A method of internalization that has been extensively studied in the context of viral infections is the use of the clathrin-mediated pathway. More recently, a role for clathrin in the entry of some intracellular bacterial pathogens was discovered. Classically, clathrin-mediated endocytosis was thought to accommodate internalization only of particles smaller than 150 nm; however, this was challenged upon the discovery that Listeria monocytogenes requires clathrin to enter eukaryotic cells. Now, with discoveries that clathrin is required during other stages of some bacterial infections, another paradigm shift is occurring. There is a more diverse impact of clathrin during infection than previously thought. Much of the recent data describing clathrin utilization in processes such as bacterial attachment, cell-to-cell spread and intracellular growth may be due to newly discovered divergent roles of clathrin in the cell. Not only does clathrin act to facilitate endocytosis from the plasma membrane, but it also participates in budding from endosomes and the Golgi apparatus and in mitosis. Here, the manipulation of clathrin processes by bacterial pathogens, including its traditional role during invasion and alternative ways in which clathrin supports bacterial infection, is discussed. Researching clathrin in the context of bacterial infections will reveal new insights that inform our understanding of host-pathogen interactions and allow researchers to fully appreciate the diverse roles of clathrin in the eukaryotic cell.
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Affiliation(s)
- Eleanor A Latomanski
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Hayley J Newton
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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26
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Identification of Suppressor of Clathrin Deficiency-1 ( SCD1) and Its Connection to Clathrin-Mediated Endocytosis in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2019; 9:867-877. [PMID: 30679249 PMCID: PMC6404604 DOI: 10.1534/g3.118.200782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Clathrin is a major coat protein involved in vesicle formation during endocytosis and transport in the endosomal/trans Golgi system. Clathrin is required for normal growth of yeast (Saccharomyces cerevisiae) and in some genetic backgrounds deletion of the clathrin heavy chain gene (CHC1) is lethal. Our lab defined a locus referred to as “suppressor of clathrin deficiency” (SCD1). In the presence of the scd1-v allele (“v” – viable), yeast cells lacking clathrin heavy chain survive but grow slowly, are morphologically abnormal and have many membrane trafficking defects. In the presence of scd1-i (“i”- inviable), chc1∆ causes lethality. As a strategy to identify SCD1, we used pooled linkage analysis and whole genome sequencing. Here, we report that PAL2 (YHR097C) is the SCD1 locus. pal2∆ is synthetic lethal with chc1∆; whereas a deletion of its paralog, PAL1, is not synthetic lethal with clathrin deficiency. Like Pal1, Pal2 has two NPF motifs that are potential binding sites for EH domain proteins such as the early endocytic factor Ede1, and Pal2 associates with Ede1. Also, GFP-tagged Pal2p localizes to cortical patches containing other immobile phase endocytic coat factors. Overall, our data show that PAL2 is the SCD1 locus and the Pal2 protein has characteristics of an early factor involved in clathrin-mediated endocytosis.
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27
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Molecular mechanisms of contractile-ring constriction and membrane trafficking in cytokinesis. Biophys Rev 2018; 10:1649-1666. [PMID: 30448943 DOI: 10.1007/s12551-018-0479-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/06/2018] [Indexed: 12/14/2022] Open
Abstract
In this review, we discuss the molecular mechanisms of cytokinesis from plants to humans, with a focus on contribution of membrane trafficking to cytokinesis. Selection of the division site in fungi, metazoans, and plants is reviewed, as well as the assembly and constriction of a contractile ring in fungi and metazoans. We also provide an introduction to exocytosis and endocytosis, and discuss how they contribute to successful cytokinesis in eukaryotic cells. The conservation in the coordination of membrane deposition and cytoskeleton during cytokinesis in fungi, metazoans, and plants is highlighted.
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28
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Live-cell imaging of early coat protein dynamics during clathrin-mediated endocytosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1566-1578. [PMID: 30077636 DOI: 10.1016/j.bbamcr.2018.07.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/23/2018] [Accepted: 07/25/2018] [Indexed: 12/30/2022]
Abstract
Clathrin-mediated endocytosis is an essential process that is mediated by the stepwise appearance or disappearance of many different proteins at the plasma membrane. In the budding yeast, these proteins are categorized into at least five modules, according to their spatiotemporal dynamics. Among them, the dynamics of proteins in the late coat module are well characterized, but those in the early coat module still remain unclear because of the lack of a suitable fluorescent marker with sufficient brightness to allow analysis. To examine the dynamics of early coat proteins, in this study we tagged four representative early coat proteins with 3GFP, and expressed them in a single cell. This cell exhibited a significant increase in the fluorescence intensity of early coat proteins relative to that of each 3GFP-tagged protein. Using this strain, we performed a detailed analysis of early coat proteins, including their precise lifetime, changes in fluorescence intensity, and motility on the plasma membrane. We found that early coat proteins move on the plasma membrane before internalization. Additionally, we expressed these 3GFP-tagged proteins in mutants with deletion of genes related to endocytosis, and found four mutants - end3Δ, las17Δ, sla2Δ, and clc1Δ- in which the lifetime of early coat proteins was markedly increased. Interestingly, deletion of the CLC1 gene dramatically reduced the internalization of early coat proteins whereas internalization of actin patches was largely unchanged, suggesting that the clc1Δ mutant might have a defect in the link between the early coat and actin modules.
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29
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Miao Y, Tipakornsaowapak T, Zheng L, Mu Y, Lewellyn E. Phospho-regulation of intrinsically disordered proteins for actin assembly and endocytosis. FEBS J 2018; 285:2762-2784. [PMID: 29722136 DOI: 10.1111/febs.14493] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/04/2018] [Accepted: 04/26/2018] [Indexed: 12/13/2022]
Abstract
Actin filament assembly contributes to the endocytic pathway pleiotropically, with active roles in clathrin-dependent and clathrin-independent endocytosis as well as subsequent endosomal trafficking. Endocytosis comprises a series of dynamic events, including the initiation of membrane curvature, bud invagination, vesicle abscission and subsequent vesicular transport. The ultimate success of endocytosis requires the coordinated activities of proteins that trigger actin polymerization, recruit actin-binding proteins (ABPs) and organize endocytic proteins (EPs) that promote membrane curvature through molecular crowding or scaffolding mechanisms. A particularly interesting phenomenon is that multiple EPs and ABPs contain a substantial percentage of intrinsically disordered regions (IDRs), which can contribute to protein coacervation and phase separation. In addition, intrinsically disordered proteins (IDPs) frequently contain sites for post-translational modifications (PTMs) such as phosphorylation, and these modifications exhibit a high preference for IDR residues [Groban ES et al. (2006) PLoS Comput Biol 2, e32]. PTMs are implicated in regulating protein function by modulating the protein conformation, protein-protein interactions and the transition between order and disorder states of IDPs. The molecular mechanisms by which IDRs of ABPs and EPs fine-tune actin assembly and endocytosis remain mostly unexplored and elusive. In this review, we analyze protein sequences of budding yeast EPs and ABPs, and discuss the potential underlying mechanisms for regulating endocytosis and actin assembly through the emerging concept of IDR-mediated protein multivalency, coacervation, and phase transition, with an emphasis on the phospho-regulation of IDRs. Finally, we summarize the current understanding of how these mechanisms coordinate actin cytoskeleton assembly and membrane curvature formation during endocytosis in budding yeast.
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Affiliation(s)
- Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | | | - Liangzhen Zheng
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yuguang Mu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Eric Lewellyn
- Department of Biology, Division of Natural Sciences, St Norbert College, De Pere, WI, USA
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30
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A Flow Cytometry-Based Phenotypic Screen To Identify Novel Endocytic Factors in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2018. [PMID: 29540444 PMCID: PMC5940143 DOI: 10.1534/g3.118.200102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Endocytosis is a fundamental process for internalizing material from the plasma membrane, including many transmembrane proteins that are selectively internalized depending on environmental conditions. In most cells, the main route of entry is clathrin-mediated endocytosis (CME), a process that involves the coordinated activity of over 60 proteins; however, there are likely as-yet unidentified proteins involved in cargo selection and/or regulation of endocytosis. We performed a mutagenic screen to identify novel endocytic genes in Saccharomyces cerevisiae expressing the methionine permease Mup1 tagged with pHluorin (pHl), a pH-sensitive GFP variant whose fluorescence is quenched upon delivery to the acidic vacuole lumen. We used fluorescence-activated cell sorting to isolate mutagenized cells with elevated fluorescence, resulting from failure to traffic Mup1-pHl cargo to the vacuole, and further assessed subcellular localization of Mup1-pHl to characterize the endocytic defects in 256 mutants. A subset of mutant strains was classified as having general endocytic defects based on mislocalization of additional cargo proteins. Within this group, we identified mutations in four genes encoding proteins with known roles in endocytosis: the endocytic coat components SLA2, SLA1, and EDE1, and the ARP3 gene, whose product is involved in nucleating actin filaments to form branched networks. All four mutants demonstrated aberrant dynamics of the endocytic machinery at sites of CME; moreover, the arp3R346H mutation showed reduced actin nucleation activity in vitro. Finally, whole genome sequencing of two general endocytic mutants identified mutations in conserved genes not previously implicated in endocytosis, KRE33 and IQG1, demonstrating that our screening approach can be used to identify new components involved in endocytosis.
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31
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Abstract
Clathrin-mediated endocytosis (CME) is the major endocytic pathway in mammalian cells. It is responsible for the uptake of transmembrane receptors and transporters, for remodeling plasma membrane composition in response to environmental changes, and for regulating cell surface signaling. CME occurs via the assembly and maturation of clathrin-coated pits that concentrate cargo as they invaginate and pinch off to form clathrin-coated vesicles. In addition to the major coat proteins, clathrin triskelia and adaptor protein complexes, CME requires a myriad of endocytic accessory proteins and phosphatidylinositol lipids. CME is regulated at multiple steps-initiation, cargo selection, maturation, and fission-and is monitored by an endocytic checkpoint that induces disassembly of defective pits. Regulation occurs via posttranslational modifications, allosteric conformational changes, and isoform and splice-variant differences among components of the CME machinery, including the GTPase dynamin. This review summarizes recent findings on the regulation of CME and the evolution of this complex process.
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Affiliation(s)
- Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Ping-Hung Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Saipraveen Srinivasan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , , .,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA; , , , ,
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32
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Tolsma TO, Cuevas LM, Di Pietro SM. The Sla1 adaptor-clathrin interaction regulates coat formation and progression of endocytosis. Traffic 2018. [PMID: 29542219 DOI: 10.1111/tra.12563] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Clathrin-mediated endocytosis is a fundamental transport pathway that depends on numerous protein-protein interactions. Testing the importance of the adaptor protein-clathrin interaction for coat formation and progression of endocytosis in vivo has been difficult due to experimental constrains. Here, we addressed this question using the yeast clathrin adaptor Sla1, which is unique in showing a cargo endocytosis defect upon substitution of 3 amino acids in its clathrin-binding motif (sla1AAA ) that disrupt clathrin binding. Live-cell imaging showed an impaired Sla1-clathrin interaction causes reduced clathrin levels but increased Sla1 levels at endocytic sites. Moreover, the rate of Sla1 recruitment was reduced indicating proper dynamics of both clathrin and Sla1 depend on their interaction. sla1AAA cells showed a delay in progression through the various stages of endocytosis. The Arp2/3-dependent actin polymerization machinery was present for significantly longer time before actin polymerization ensued, revealing a link between coat formation and activation of actin polymerization. Ultimately, in sla1AAA cells a larger than normal actin network was formed, dramatically higher levels of various machinery proteins other than clathrin were recruited, and the membrane profile of endocytic invaginations was longer. Thus, the Sla1-clathrin interaction is important for coat formation, regulation of endocytic progression and membrane bending.
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Affiliation(s)
- Thomas O Tolsma
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado
| | - Lena M Cuevas
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado
| | - Santiago M Di Pietro
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado
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33
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34
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Martzoukou O, Amillis S, Zervakou A, Christoforidis S, Diallinas G. The AP-2 complex has a specialized clathrin-independent role in apical endocytosis and polar growth in fungi. eLife 2017; 6. [PMID: 28220754 PMCID: PMC5338921 DOI: 10.7554/elife.20083] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 02/07/2017] [Indexed: 12/26/2022] Open
Abstract
Filamentous fungi provide excellent systems for investigating the role of the AP-2 complex in polar growth. Using Aspergillus nidulans, we show that AP-2 has a clathrin-independent essential role in polarity maintenance and growth. This is in line with a sequence analysis showing that the AP-2 β subunit (β2) of higher fungi lacks a clathrin-binding domain, and experiments showing that AP-2 does not co-localize with clathrin. We provide genetic and cellular evidence that AP-2 interacts with endocytic markers SlaBEnd4 and SagAEnd3 and the lipid flippases DnfA and DnfB in the sub-apical collar region of hyphae. The role of AP-2 in the maintenance of proper apical membrane lipid and cell wall composition is further supported by its functional interaction with BasA (sphingolipid biosynthesis) and StoA (apical sterol-rich membrane domains), and its essentiality in polar deposition of chitin. Our findings support that the AP-2 complex of dikarya has acquired, in the course of evolution, a specialized clathrin-independent function necessary for fungal polar growth. DOI:http://dx.doi.org/10.7554/eLife.20083.001
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Affiliation(s)
- Olga Martzoukou
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Sotiris Amillis
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Amalia Zervakou
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Savvas Christoforidis
- Institute of Molecular Biology and Biotechnology-Biomedical Research, Foundation for Research and Technology, Ioannina, Greece.,Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
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35
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Abstract
Clathrin-mediated endocytosis is an essential cellular process that involves the concerted assembly and disassembly of many different proteins at the plasma membrane. In yeast, live-cell imaging has shown that the spatiotemporal dynamics of these proteins is highly stereotypical. Recent work has focused on determining how the timing and functions of endocytic proteins are regulated. In this Cell Science at a Glance article and accompanying poster, we review our current knowledge of the timeline of endocytic site maturation and discuss recent works focusing on how phosphorylation, ubiquitylation and lipids regulate various aspects of the process.
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Affiliation(s)
- Rebecca Lu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Yidi Sun
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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36
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Lu R, Drubin DG. Selection and stabilization of endocytic sites by Ede1, a yeast functional homologue of human Eps15. Mol Biol Cell 2017; 28:567-575. [PMID: 28057762 PMCID: PMC5328616 DOI: 10.1091/mbc.e16-06-0391] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/09/2016] [Accepted: 12/29/2016] [Indexed: 12/19/2022] Open
Abstract
During clathrin-mediated endocytosis (CME), endocytic-site maturation can be divided into two stages corresponding to the arrival of the early and late proteins at the plasma membrane. The early proteins are required to capture cargo and position the late machinery, which includes proteins involved in actin assembly and membrane scission. However, the mechanism by which early-arriving proteins select and stabilize endocytic sites is not known. Ede1, one of the earliest proteins recruited to endocytic sites, facilitates site initiation and stabilization. Deletion of EDE1 results in fewer CME initiations and defects in the timing of vesicle maturation. Here we made truncation mutants of Ede1 to better understand how different domains contribute to its recruitment to CME sites, site selection, and site maturation. We found that the minimal domains required for efficient Ede1 localization at CME sites are the third EH domain, the proline-rich region, and the coiled-coil region. We also found that many strains expressing ede1 truncations could support a normal rate of site initiation but still had defects in site-maturation timing, indicating separation of Ede1 functions. When expressed in yeast, human Eps15 localized to the plasma membrane, where it recruited late-phase CME proteins and supported productive endocytosis, identifying it as an Ede1 functional homologue.
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Affiliation(s)
- Rebecca Lu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
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37
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Montoro AG, Bigliani G, Taubas JV. Transmembrane-domain shape is a novel endocytosis signal for single-spanning membrane proteins. J Cell Sci 2017; 130:3829-3838. [DOI: 10.1242/jcs.202937] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 09/27/2017] [Indexed: 02/03/2023] Open
Abstract
Endocytosis is crucial for all cells as it allows them to incorporate material from the extracellular space and control the availability of transmembrane proteins at the plasma membrane. In yeast, endocytosis followed by recycling to the plasma membrane results in a polarised distribution of membrane proteins by a kinetic mechanism. Here we report that increasing the volume of the residues that constitute the exoplasmic half of the transmembrane domain in the yeast SNARE Sso1, a type II membrane protein, results in its polarised distribution at the plasma membrane. Expression of this chimera in strains affected in either endocytosis or recycling revealed that this polarisation is achieved by endocytic cycling. A bioinformatics search of the Saccharomyces cerevisiae proteome identified several proteins with high-volume exoplasmic hemi-TMDs. Our experiments indicate that TMDs from these proteins can confer a polarised distribution to the Sso1 cytoplasmic domain, indicating that the shape of the TMD can act as a novel endocytosis and polarity signal in yeast. Additionally, a high-volume exoplasmic hemi-TMD can act as an endocytosis signal in a mammalian cell line.
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Affiliation(s)
- Ayelén González Montoro
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Current address: University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Gonzalo Bigliani
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Javier Valdez Taubas
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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38
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Kadlecova Z, Spielman SJ, Loerke D, Mohanakrishnan A, Reed DK, Schmid SL. Regulation of clathrin-mediated endocytosis by hierarchical allosteric activation of AP2. J Cell Biol 2016; 216:167-179. [PMID: 28003333 PMCID: PMC5223608 DOI: 10.1083/jcb.201608071] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 10/31/2016] [Accepted: 11/30/2016] [Indexed: 01/31/2023] Open
Abstract
The critical initiation phase of clathrin-mediated endocytosis (CME) determines where and when endocytosis occurs. Heterotetrameric adaptor protein 2 (AP2) complexes, which initiate clathrin-coated pit (CCP) assembly, are activated by conformational changes in response to phosphatidylinositol-4,5-bisphosphate (PIP2) and cargo binding at multiple sites. However, the functional hierarchy of interactions and how these conformational changes relate to distinct steps in CCP formation in living cells remains unknown. We used quantitative live-cell analyses to measure discrete early stages of CME and show how sequential, allosterically regulated conformational changes activate AP2 to drive both nucleation and subsequent stabilization of nascent CCPs. Our data establish that cargoes containing Yxxφ motif, but not dileucine motif, play a critical role in the earliest stages of AP2 activation and CCP nucleation. Interestingly, these cargo and PIP2 interactions are not conserved in yeast. Thus, we speculate that AP2 has evolved as a key regulatory node to coordinate CCP formation and cargo sorting and ensure high spatial and temporal regulation of CME.
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Affiliation(s)
- Zuzana Kadlecova
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Stephanie J Spielman
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA 19122
| | - Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208
| | - Aparna Mohanakrishnan
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Dana Kim Reed
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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39
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de León N, Valdivieso MH. The long life of an endocytic patch that misses AP-2. Curr Genet 2016; 62:765-770. [PMID: 27126383 DOI: 10.1007/s00294-016-0605-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 04/15/2016] [Indexed: 10/21/2022]
Abstract
Endocytosis is the process by which cells regulate extracellular fluid uptake and internalize molecules bound to their plasma membrane. This process requires the generation of protein-coated vesicles. In clathrin-mediated endocytosis (CME) the assembly polypeptide 2 (AP-2) adaptor facilitates rapid endocytosis of some plasma membrane receptors by mediating clathrin recruitment to the endocytic site and by connecting cargoes to the clathrin coat. While this adaptor is essential for early embryonic development in mammals, initial results suggested that it is dispensable for endocytosis in unicellular eukaryotes. The drastic effect of depleting AP-2 in metazoa and the mild effect of deleting AP-2 subunits in Saccharomyces cerevisiae have prevented a detailed analysis of the dynamics of endocytic patches in the absence of this adaptor. Using live-cell imaging of Schizosaccharomyces pombe endocytic sites we have shown that eliminating AP-2 perturbs the dynamics of endocytic patches beyond the moment of coat assembly. These perturbations affect the cell growth pattern and cell wall synthesis. Our results highlight the importance of using different model organisms to address the study of conserved aspects of CME.
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Affiliation(s)
- Nagore de León
- Departamento de Microbiología y Genética/Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain.,Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - M-Henar Valdivieso
- Departamento de Microbiología y Genética/Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain.
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40
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New Insight Into the Roles of Membrane Microdomains in Physiological Activities of Fungal Cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:119-80. [PMID: 27241220 DOI: 10.1016/bs.ircmb.2016.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The organization of biological membranes into structurally and functionally distinct lateral microdomains is generally accepted. From bacteria to mammals, laterally compartmentalized membranes seem to be a vital attribute of life. The crucial fraction of our current knowledge about the membrane microdomains has been gained from studies on fungi. In this review we summarize the evidence of the microdomain organization of membranes from fungal cells, with accent on their enormous diversity in composition, temporal dynamics, modes of formation, and recognized engagement in the cell physiology. A special emphasis is laid on the fact that in addition to their other biological functions, membrane microdomains also mediate the communication among different membranes within a eukaryotic cell and coordinate their functions. Involvement of fungal membrane microdomains in stress sensing, regulation of lipid homeostasis, and cell differentiation is discussed more in detail.
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de León N, Hoya M, Curto MA, Moro S, Yanguas F, Doncel C, Valdivieso MH. The AP-2 complex is required for proper temporal and spatial dynamics of endocytic patches in fission yeast. Mol Microbiol 2016; 100:409-24. [PMID: 26749213 DOI: 10.1111/mmi.13327] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2016] [Indexed: 12/27/2022]
Abstract
In metazoans the AP-2 complex has a well-defined role in clathrin-mediated endocytosis. By contrast, its direct role in endocytosis in unicellular eukaryotes has been questioned. Here, we report co- immunoprecipitation between the fission yeast AP-2 component Apl3p and clathrin, as well as the genetic interactions between apl3Δ and clc1 and sla2Δ/end4Δ mutants. Furthermore, a double clc1 apl3Δ mutant was found to be defective in FM4-64 uptake. In an otherwise wild-type strain, apl3Δ cells exhibit altered dynamics of the endocytic sites, with a heterogeneous and extended lifetime of early and late markers at the patches. Additionally, around 50% of the endocytic patches exhibit abnormal spatial dynamics, with immobile patches and patches that bounce backwards to the cell surface, showing a pervasive effect of the absence of AP-2. These alterations in the endocytic machinery result in abnormal cell wall synthesis and morphogenesis. Our results complement those found in budding yeast and confirm that a direct role of AP-2 in endocytosis has been conserved throughout evolution.
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Affiliation(s)
- Nagore de León
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Marta Hoya
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - M-Angeles Curto
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Sandra Moro
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Francisco Yanguas
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - Cristina Doncel
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
| | - M-Henar Valdivieso
- Departamento de Microbiología y Genética, Instituto de Biología Funcional y Genómica (IBFG), University of Salamanca/CSIC, Calle Zacarías González 2, 37007, Salamanca, Spain
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New Regulators of Clathrin-Mediated Endocytosis Identified in Saccharomyces cerevisiae by Systematic Quantitative Fluorescence Microscopy. Genetics 2015; 201:1061-70. [PMID: 26362318 DOI: 10.1534/genetics.115.180729] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/07/2015] [Indexed: 11/18/2022] Open
Abstract
Despite the importance of clathrin-mediated endocytosis (CME) for cell biology, it is unclear if all components of the machinery have been discovered and many regulatory aspects remain poorly understood. Here, using Saccharomyces cerevisiae and a fluorescence microscopy screening approach we identify previously unknown regulatory factors of the endocytic machinery. We further studied the top scoring protein identified in the screen, Ubx3, a member of the conserved ubiquitin regulatory X (UBX) protein family. In vivo and in vitro approaches demonstrate that Ubx3 is a new coat component. Ubx3-GFP has typical endocytic coat protein dynamics with a patch lifetime of 45 ± 3 sec. Ubx3 contains a W-box that mediates physical interaction with clathrin and Ubx3-GFP patch lifetime depends on clathrin. Deletion of the UBX3 gene caused defects in the uptake of Lucifer Yellow and the methionine transporter Mup1 demonstrating that Ubx3 is needed for efficient endocytosis. Further, the UBX domain is required both for localization and function of Ubx3 at endocytic sites. Mechanistically, Ubx3 regulates dynamics and patch lifetime of the early arriving protein Ede1 but not later arriving coat proteins or actin assembly. Conversely, Ede1 regulates the patch lifetime of Ubx3. Ubx3 likely regulates CME via the AAA-ATPase Cdc48, a ubiquitin-editing complex. Our results uncovered new components of the CME machinery that regulate this fundamental process.
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Sun Y, Leong NT, Wong T, Drubin DG. A Pan1/End3/Sla1 complex links Arp2/3-mediated actin assembly to sites of clathrin-mediated endocytosis. Mol Biol Cell 2015; 26:3841-56. [PMID: 26337384 PMCID: PMC4626068 DOI: 10.1091/mbc.e15-04-0252] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 08/27/2015] [Indexed: 01/06/2023] Open
Abstract
Eps15-related proteins couple the clathrin-mediated endocytic-site initiation and actin assembly phases and coordinate endocytic-site formation with cargo capture and actin assembly through their interaction with a CIN85-related protein. More than 60 highly conserved proteins appear sequentially at sites of clathrin-mediated endocytosis in yeast and mammals. The yeast Eps15-related proteins Pan1 and End3 and the CIN85-related protein Sla1 are known to interact with each other in vitro, and they all appear after endocytic-site initiation but before endocytic actin assembly, which facilitates membrane invagination/scission. Here we used live-cell imaging in parallel with genetics and biochemistry to explore comprehensively the dynamic interactions and functions of Pan1, End3, and Sla1. Our results indicate that Pan1 and End3 associate in a stable manner and appear at endocytic sites before Sla1. The End3 C-terminus is necessary and sufficient for its cortical localization via interaction with Pan1, whereas the End3 N-terminus plays a crucial role in Sla1 recruitment. We systematically examined the dynamic behaviors of endocytic proteins in cells in which Pan1 and End3 were simultaneously eliminated, using the auxin-inducible degron system. The results lead us to propose that endocytic-site initiation and actin assembly are separable processes linked by a Pan1/End3/Sla1 complex. Finally, our study provides mechanistic insights into how Pan1 and End3 function with Sla1 to coordinate cargo capture with actin assembly.
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Affiliation(s)
- Yidi Sun
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Nicole T Leong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - Tiffany Wong
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720 )
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Schultzhaus Z, Yan H, Shaw BD. Aspergillus nidulansflippase DnfA is cargo of the endocytic collar and plays complementary roles in growth and phosphatidylserine asymmetry with another flippase, DnfB. Mol Microbiol 2015; 97:18-32. [DOI: 10.1111/mmi.13019] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Zachary Schultzhaus
- Department of Plant Pathology and Microbiology; Texas A&M University; College Station TX USA
| | - Huijuan Yan
- Department of Plant Protection; Fujian Agricultural and Forestry University; Fuzhou Fujian China
| | - Brian D. Shaw
- Department of Plant Pathology and Microbiology; Texas A&M University; College Station TX USA
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Peng Y, Grassart A, Lu R, Wong CCL, Yates J, Barnes G, Drubin DG. Casein kinase 1 promotes initiation of clathrin-mediated endocytosis. Dev Cell 2015; 32:231-40. [PMID: 25625208 DOI: 10.1016/j.devcel.2014.11.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 06/11/2014] [Accepted: 11/10/2014] [Indexed: 12/22/2022]
Abstract
In budding yeast, over 60 proteins functioning in at least five modules are recruited to endocytic sites with predictable order and timing. However, how sites of clathrin-mediated endocytosis are initiated and stabilized is not well understood. Here, the casein kinase 1 (CK1) Hrr25 is shown to be an endocytic protein and to be among the earliest proteins to appear at endocytic sites. Hrr25 absence or overexpression decreases or increases the rate of endocytic site initiation, respectively. Ede1, an early endocytic Eps15-like protein important for endocytic initiation, is an Hrr25 target and is required for Hrr25 recruitment to endocytic sites. Hrr25 phosphorylation of Ede1 is required for Hrr25-Ede1 interaction and promotes efficient initiation of endocytic sites. These observations indicate that Hrr25 kinase and Ede1 cooperate to initiate and stabilize endocytic sites. Analysis of the mammalian homologs CK1δ/ε suggests a conserved role for these protein kinases in endocytic site initiation and stabilization.
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Affiliation(s)
- Yutian Peng
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Alexandre Grassart
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Rebecca Lu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Catherine C L Wong
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - John Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Georjana Barnes
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - David G Drubin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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Skruzny M, Desfosses A, Prinz S, Dodonova S, Gieras A, Uetrecht C, Jakobi A, Abella M, Hagen W, Schulz J, Meijers R, Rybin V, Briggs J, Sachse C, Kaksonen M. An Organized Co-assembly of Clathrin Adaptors Is Essential for Endocytosis. Dev Cell 2015; 33:150-62. [DOI: 10.1016/j.devcel.2015.02.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 11/29/2014] [Accepted: 02/25/2015] [Indexed: 10/23/2022]
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Boeke D, Trautmann S, Meurer M, Wachsmuth M, Godlee C, Knop M, Kaksonen M. Quantification of cytosolic interactions identifies Ede1 oligomers as key organizers of endocytosis. Mol Syst Biol 2014; 10:756. [PMID: 25366307 PMCID: PMC4299599 DOI: 10.15252/msb.20145422] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 09/11/2014] [Accepted: 10/01/2014] [Indexed: 01/08/2023] Open
Abstract
Clathrin-mediated endocytosis is a highly conserved intracellular trafficking pathway that depends on dynamic protein-protein interactions between up to 60 different proteins. However, little is known about the spatio-temporal regulation of these interactions. Using fluorescence (cross)-correlation spectroscopy in yeast, we tested 41 previously reported interactions in vivo and found 16 to exist in the cytoplasm. These detected cytoplasmic interactions included the self-interaction of Ede1, homolog of mammalian Eps15. Ede1 is the crucial scaffold for the organization of the early stages of endocytosis. We show that oligomerization of Ede1 through its central coiled coil domain is necessary for its localization to the endocytic site and we link the oligomerization of Ede1 to its function in locally concentrating endocytic adaptors and organizing the endocytic machinery. Our study sheds light on the importance of the regulation of protein-protein interactions in the cytoplasm for the assembly of the endocytic machinery in vivo.
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Affiliation(s)
- Dominik Boeke
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH) Deutsches Krebsforschungszentrum (DKFZ) DKFZ-ZMBH-Allianz, Heidelberg, Germany
| | - Susanne Trautmann
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH) Deutsches Krebsforschungszentrum (DKFZ) DKFZ-ZMBH-Allianz, Heidelberg, Germany
| | - Matthias Meurer
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH) Deutsches Krebsforschungszentrum (DKFZ) DKFZ-ZMBH-Allianz, Heidelberg, Germany
| | - Malte Wachsmuth
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Camilla Godlee
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Michael Knop
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH) Deutsches Krebsforschungszentrum (DKFZ) DKFZ-ZMBH-Allianz, Heidelberg, Germany
| | - Marko Kaksonen
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
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Umasankar PK, Ma L, Thieman JR, Jha A, Doray B, Watkins SC, Traub LM. A clathrin coat assembly role for the muniscin protein central linker revealed by TALEN-mediated gene editing. eLife 2014; 3. [PMID: 25303365 PMCID: PMC4215538 DOI: 10.7554/elife.04137] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/08/2014] [Indexed: 12/12/2022] Open
Abstract
Clathrin-mediated endocytosis is an evolutionarily ancient membrane transport system regulating cellular receptivity and responsiveness. Plasmalemma clathrin-coated structures range from unitary domed assemblies to expansive planar constructions with internal or flanking invaginated buds. Precisely how these morphologically-distinct coats are formed, and whether all are functionally equivalent for selective cargo internalization is still disputed. We have disrupted the genes encoding a set of early arriving clathrin-coat constituents, FCHO1 and FCHO2, in HeLa cells. Endocytic coats do not disappear in this genetic background; rather clustered planar lattices predominate and endocytosis slows, but does not cease. The central linker of FCHO proteins acts as an allosteric regulator of the prime endocytic adaptor, AP-2. By loading AP-2 onto the plasma membrane, FCHO proteins provide a parallel pathway for AP-2 activation and clathrin-coat fabrication. Further, the steady-state morphology of clathrin-coated structures appears to be a manifestation of the availability of the muniscin linker during lattice polymerization. DOI:http://dx.doi.org/10.7554/eLife.04137.001 Cells can take proteins and other molecules that are either embedded in, or attached to, their surface membrane and move them inside via a process called endocytosis. This process often involves a protein called clathrin working together with numerous other proteins. Early on, a complex of four proteins, called the adaptor protein-2 complex, interacts with both the ‘cargo’ molecules that are to be taken into the cell, and the cell membrane. Clathrin molecules then assemble into an ordered lattice-like coat, on top of the adaptor protein complex layer. This deforms a small patch of the cell membrane and curves it inwards. The clathrin molecules coat this pocket as it grows in size, until it engulfs the cargo. The pocket quickly pinches off from the membrane to form a bubble-like structure called a vesicle, which is brought into the cell. A family of proteins termed Muniscins were thought to be involved in the early stages of endocytosis and have to arrive at the membrane before the adaptor protein-2 complex and clathrin. But experiments to test this idea—that reduced, or ‘knocked-down’, the production of Muniscins—had given conflicting results. As such, it remained unclear how the small patches of membrane carrying cargo molecules are marked as being destined to become clathrin-coated vesicles. Now Umasankar et al. have studied the role that these proteins play in the early stages of endocytosis in human cells grown in a laboratory. A gene-editing approach was used to precisely disrupt a gene that codes for a Muniscin protein called FCHO2. Umasankar et al. observed that these ‘edited’ cells formed clathrin coats that were more irregular compared with those that form in normal cells. Nevertheless, clathrin-mediated vesicles still formed when this protein was absent, though the process of endocytosis was slower. Similar results were seen when Umasankar et al. used the same approach to disrupt the gene for a related protein called FCHO1 in the same cells. A short fragment of the Muniscin proteins, called the linker, was shown to bind to, and activate, the adaptor protein-2 complex. The linker then recruits this complex to the specific regions of the cell membrane where clathrin-coated vesicles will form. Several dozen other proteins also accumulate where clathrin pockets form; as such, one of the next challenges will be to investigate if this mechanism of locally activating the cargo-gathering machinery is common in living cells. DOI:http://dx.doi.org/10.7554/eLife.04137.002
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Affiliation(s)
| | - Li Ma
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - James R Thieman
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Anupma Jha
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Balraj Doray
- Department of Medicine, Washington University School of Medicine, St. Louis, United States
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Linton M Traub
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
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