1
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Yuan F, Gollapudi S, Day KJ, Ashby G, Sangani A, Malady BT, Wang L, Lafer EM, Huibregtse JM, Stachowiak JC. Ubiquitin-driven protein condensation stabilizes clathrin-mediated endocytosis. PNAS NEXUS 2024; 3:pgae342. [PMID: 39253396 PMCID: PMC11382290 DOI: 10.1093/pnasnexus/pgae342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2024] [Accepted: 07/30/2024] [Indexed: 09/11/2024]
Abstract
Clathrin-mediated endocytosis is an essential cellular pathway that enables signaling and recycling of transmembrane proteins and lipids. During endocytosis, dozens of cytosolic proteins come together at the plasma membrane, assembling into a highly interconnected network that drives endocytic vesicle biogenesis. Recently, multiple groups have reported that early endocytic proteins form flexible condensates, which provide a platform for efficient assembly of endocytic vesicles. Given the importance of this network in the dynamics of endocytosis, how might cells regulate its stability? Many receptors and endocytic proteins are ubiquitylated, while early endocytic proteins such as Eps15 contain ubiquitin-interacting motifs. Therefore, we examined the influence of ubiquitin on the stability of the early endocytic protein network. In vitro, we found that recruitment of small amounts of polyubiquitin dramatically increased the stability of Eps15 condensates, suggesting that ubiquitylation could nucleate endocytic assemblies. In live-cell imaging experiments, a version of Eps15 that lacked the ubiquitin-interacting motif failed to rescue defects in endocytic initiation created by Eps15 knockout. Furthermore, fusion of Eps15 to a deubiquitylase enzyme destabilized nascent endocytic sites within minutes. In both in vitro and live-cell settings, dynamic exchange of Eps15 proteins, a measure of protein network stability, was decreased by Eps15-ubiquitin interactions and increased by loss of ubiquitin. These results collectively suggest that ubiquitylation drives assembly of the flexible protein network responsible for catalyzing endocytic events. More broadly, this work illustrates a biophysical mechanism by which ubiquitylated transmembrane proteins at the plasma membrane could regulate the efficiency of endocytic internalization.
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Affiliation(s)
- Feng Yuan
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sadhana Gollapudi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kasey J Day
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Grant Ashby
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Arjun Sangani
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Brandon T Malady
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Liping Wang
- Department of Biochemistry and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Eileen M Lafer
- Department of Biochemistry and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Jon M Huibregtse
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
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2
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Harders RH, Morthorst TH, Landgrebe LE, Lande AD, Fuglsang MS, Mortensen SB, Feteira-Montero V, Jensen HH, Wesseltoft JB, Olsen A. CED-6/GULP and components of the clathrin-mediated endocytosis machinery act redundantly to correctly display CED-1 on the cell membrane in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2024; 14:jkae088. [PMID: 38696649 PMCID: PMC11228867 DOI: 10.1093/g3journal/jkae088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/03/2024] [Accepted: 04/16/2024] [Indexed: 05/04/2024]
Abstract
CED-1 (cell death abnormal) is a transmembrane receptor involved in the recognition of "eat-me" signals displayed on the surface of apoptotic cells and thus central for the subsequent engulfment of the cell corpse in Caenorhabditis elegans. The roles of CED-1 in engulfment are well established, as are its downstream effectors. The latter include the adapter protein CED-6/GULP and the ATP-binding cassette family homolog CED-7. However, how CED-1 is maintained on the plasma membrane in the absence of engulfment is currently unknown. Here, we show that CED-6 and CED-7 have a novel role in maintaining CED-1 correctly on the plasma membrane. We propose that the underlying mechanism is via endocytosis as CED-6 and CED-7 act redundantly with clathrin and its adaptor, the Adaptor protein 2 complex, in ensuring correct CED-1 localization. In conclusion, CED-6 and CED-7 impact other cellular processes than engulfment of apoptotic cells.
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Affiliation(s)
- Rikke Hindsgaul Harders
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Tine H Morthorst
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Line E Landgrebe
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Anna D Lande
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Marie Sikjær Fuglsang
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Stine Bothilde Mortensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Verónica Feteira-Montero
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Helene Halkjær Jensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Jonas Bruhn Wesseltoft
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Anders Olsen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
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3
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Li W, Chen C, Zheng H, Lin Y, An M, Liu D, Zhang Y, Gao M, Lan T, He W. UBE2C-induced crosstalk between mono- and polyubiquitination of SNAT2 promotes lymphatic metastasis in bladder cancer. J Clin Invest 2024; 134:e179122. [PMID: 38949026 PMCID: PMC11213464 DOI: 10.1172/jci179122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 05/10/2024] [Indexed: 07/02/2024] Open
Abstract
Ubiquitination plays an essential role in protein stability, subcellular localization, and interactions. Crosstalk between different types of ubiquitination results in distinct biological outcomes for proteins. However, the role of ubiquitination-related crosstalk in lymph node (LN) metastasis and the key regulatory factors controlling this process have not been determined. Using high-throughput sequencing, we found that ubiquitin-conjugating enzyme E2 C (UBE2C) was overexpressed in bladder cancer (BCa) and was strongly associated with an unfavorable prognosis. Overexpression of UBE2C increased BCa lymphangiogenesis and promoted LN metastasis both in vitro and in vivo. Mechanistically, UBE2C mediated sodium-coupled neutral amino acid transporter 2 (SNAT2) monoubiquitination at lysine 59 to inhibit K63-linked polyubiquitination at lysine 33 of SNAT2. Crosstalk between monoubiquitination and K63-linked polyubiquitination increased SNAT2 membrane protein levels by suppressing epsin 1-mediated (EPN1-mediated) endocytosis. SNAT2 facilitated glutamine uptake and metabolism to promote VEGFC secretion, ultimately leading to lymphangiogenesis and LN metastasis in patients with BCa. Importantly, inhibition of UBE2C significantly attenuated BCa lymphangiogenesis in a patient-derived xenograft model. Our results reveal the mechanism by which UBE2C mediates crosstalk between the monoubiquitination and K63-linked polyubiquitination of SNAT2 to promote BCa metastasis and identify UBE2C as a promising target for treating LN-metastatic BCa.
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Affiliation(s)
- Wenjie Li
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Changhao Chen
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Hanhao Zheng
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Yan Lin
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Mingjie An
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Daiyin Liu
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Yonghai Zhang
- Department of Urology, Shantou Central Hospital, Shantou, Guangdong, China
| | - Mingchao Gao
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Tianhang Lan
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
| | - Wang He
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Guangdong-Hong Kong Joint Laboratory for RNA Medicinem, Guangdong, China
- Guangdong Provincial Clinical Research Center for Urological Diseases, Guangdong, China
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4
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Yuan F, Gollapudi S, Day K, Ashby G, Sangani A, Malady B, Wang L, Lafer EM, Huibregtse J, Stachowiak J. Ubiquitin-driven protein condensation initiates clathrin-mediated endocytosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.21.554139. [PMID: 37662320 PMCID: PMC10473642 DOI: 10.1101/2023.08.21.554139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Clathrin-mediated endocytosis is an essential cellular pathway that enables signaling and recycling of transmembrane proteins and lipids. During endocytosis, dozens of cytosolic proteins come together at the plasma membrane, assembling into a highly interconnected network that drives endocytic vesicle biogenesis. Recently, multiple groups have reported that early endocytic proteins form flexible condensates, which provide a platform for efficient assembly of endocytic vesicles. Given the importance of this network in the dynamics of endocytosis, how might cells regulate its stability? Many receptors and endocytic proteins are ubiquitylated, while early endocytic proteins such as Eps15 contain ubiquitin-interacting motifs. Therefore, we examined the influence of ubiquitin on the stability of the early endocytic protein network. In vitro, we found that recruitment of small amounts of polyubiquitin dramatically increased the stability of Eps15 condensates, suggesting that ubiquitylation could nucleate endocytic assemblies. In live cell imaging experiments, a version of Eps15 that lacked the ubiquitin-interacting motif failed to rescue defects in endocytic initiation created by Eps15 knockout. Furthermore, fusion of Eps15 to a deubiquitylase enzyme destabilized nascent endocytic sites within minutes. In both in vitro and live cell settings, dynamic exchange of Eps15 proteins, a hallmark of liquidlike systems, was modulated by Eps15-Ub interactions. These results collectively suggest that ubiquitylation drives assembly of the flexible protein network responsible for catalyzing endocytic events. More broadly, this work illustrates a biophysical mechanism by which ubiquitylated transmembrane proteins at the plasma membrane could regulate the efficiency of endocytic recycling.
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5
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Lin DW, Yang TM, Ho C, Shih YH, Lin CL, Hsu YC. Targeting Macrophages: Therapeutic Approaches in Diabetic Kidney Disease. Int J Mol Sci 2024; 25:4350. [PMID: 38673935 PMCID: PMC11050450 DOI: 10.3390/ijms25084350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Diabetes is not solely a metabolic disorder but also involves inflammatory processes. The immune response it incites is a primary contributor to damage in target organs. Research indicates that during the initial phases of diabetic nephropathy, macrophages infiltrate the kidneys alongside lymphocytes, initiating a cascade of inflammatory reactions. The interplay between macrophages and other renal cells is pivotal in the advancement of kidney disease within a hyperglycemic milieu. While M1 macrophages react to the inflammatory stimuli induced by elevated glucose levels early in the disease progression, their subsequent transition to M2 macrophages, which possess anti-inflammatory and tissue repair properties, also contributes to fibrosis in the later stages of nephropathy by transforming into myofibroblasts. Comprehending the diverse functions of macrophages in diabetic kidney disease and regulating their activity could offer therapeutic benefits for managing this condition.
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Affiliation(s)
- Da-Wei Lin
- Department of Internal Medicine, St. Martin De Porres Hospital, Chiayi City 60069, Taiwan;
| | - Tsung-Ming Yang
- Division of Pulmonary and Critical Care Medicine, Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
- School of Traditional Chinese Medicine, College of Medicine, Chang Gung University, Taoyuan 33303, Taiwan;
| | - Cheng Ho
- Division of Endocrinology and Metabolism, Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
| | - Ya-Hsueh Shih
- Departments of Nephrology, Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
- Kidney and Diabetic Complications Research Team (KDCRT), Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
| | - Chun-Liang Lin
- School of Traditional Chinese Medicine, College of Medicine, Chang Gung University, Taoyuan 33303, Taiwan;
- Departments of Nephrology, Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
- Kidney and Diabetic Complications Research Team (KDCRT), Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
- Kidney Research Center, Chang Gung Memorial Hospital, Taipei 10507, Taiwan
- Center for Shockwave Medicine and Tissue Engineering, Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan
| | - Yung-Chien Hsu
- Departments of Nephrology, Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
- Kidney and Diabetic Complications Research Team (KDCRT), Chang Gung Memorial Hospital, Chiayi County 61363, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan 33303, Taiwan
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6
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Cowan DB, Wu H, Chen H. Epsin Endocytic Adaptor Proteins in Angiogenic and Lymphangiogenic Signaling. Cold Spring Harb Perspect Med 2024; 14:a041165. [PMID: 37217282 PMCID: PMC10759987 DOI: 10.1101/cshperspect.a041165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Circulating vascular endothelial growth factor (VEGF) ligands and receptors are central regulators of vasculogenesis, angiogenesis, and lymphangiogenesis. In response to VEGF ligand binding, VEGF receptor tyrosine kinases initiate the chain of events that transduce extracellular signals into endothelial cell responses such as survival, proliferation, and migration. These events are controlled by intricate cellular processes that include the regulation of gene expression at multiple levels, interactions of numerous proteins, and intracellular trafficking of receptor-ligand complexes. Endocytic uptake and transport of macromolecular complexes through the endosome-lysosome system helps fine-tune endothelial cell responses to VEGF signals. Clathrin-dependent endocytosis remains the best understood means of macromolecular entry into cells, although the importance of non-clathrin-dependent pathways is increasingly recognized. Many of these endocytic events rely on adaptor proteins that coordinate internalization of activated cell-surface receptors. In the endothelium of both blood and lymphatic vessels, epsins 1 and 2 are functionally redundant adaptors involved in receptor endocytosis and intracellular sorting. These proteins are capable of binding both lipids and proteins and are important for promoting curvature of the plasma membrane as well as binding ubiquitinated cargo. Here, we discuss the role of epsin proteins and other endocytic adaptors in governing VEGF signaling in angiogenesis and lymphangiogenesis and discuss their therapeutic potential as molecular targets.
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Affiliation(s)
- Douglas B Cowan
- Vascular Biology Program, Boston Children's Hospital, and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Hao Wu
- Vascular Biology Program, Boston Children's Hospital, and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Hong Chen
- Vascular Biology Program, Boston Children's Hospital, and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA
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7
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Grones P, De Meyer A, Pleskot R, Mylle E, Kraus M, Vandorpe M, Yperman K, Eeckhout D, Dragwidge JM, Jiang Q, Nolf J, Pavie B, De Jaeger G, De Rybel B, Van Damme D. The endocytic TPLATE complex internalizes ubiquitinated plasma membrane cargo. NATURE PLANTS 2022; 8:1467-1483. [PMID: 36456802 PMCID: PMC7613989 DOI: 10.1038/s41477-022-01280-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/19/2022] [Indexed: 05/12/2023]
Abstract
Endocytosis controls the perception of stimuli by modulating protein abundance at the plasma membrane. In plants, clathrin-mediated endocytosis is the most prominent internalization pathway and relies on two multimeric adaptor complexes, the AP-2 and the TPLATE complex (TPC). Ubiquitination is a well-established modification triggering endocytosis of cargo proteins, but how this modification is recognized to initiate the endocytic event remains elusive. Here we show that TASH3, one of the large subunits of TPC, recognizes ubiquitinated cargo at the plasma membrane via its SH3 domain-containing appendage. TASH3 lacking this evolutionary specific appendage modification allows TPC formation but the plants show severely reduced endocytic densities, which correlates with reduced endocytic flux. Moreover, comparative plasma membrane proteomics identified differential accumulation of multiple ubiquitinated cargo proteins for which we confirm altered trafficking. Our findings position TPC as a key player for ubiquitinated cargo internalization, allowing future identification of target proteins under specific stress conditions.
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Affiliation(s)
- Peter Grones
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- Center for Plant Systems Biology, VIB, Ghent, Belgium.
| | - Andreas De Meyer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Roman Pleskot
- Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Evelien Mylle
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Michael Kraus
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Michael Vandorpe
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Klaas Yperman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Jonathan Michael Dragwidge
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Qihang Jiang
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Jonah Nolf
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Benjamin Pavie
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- BioImaging Core, VIB, 9052 Ghent, Belgium
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Bert De Rybel
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Daniël Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.
- Center for Plant Systems Biology, VIB, Ghent, Belgium.
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8
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Yang C, Colosi P, Hugelier S, Zabezhinsky D, Lakadamyali M, Svitkina T. Actin polymerization promotes invagination of flat clathrin-coated lattices in mammalian cells by pushing at lattice edges. Nat Commun 2022; 13:6127. [PMID: 36253374 PMCID: PMC9576739 DOI: 10.1038/s41467-022-33852-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 10/05/2022] [Indexed: 12/24/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) requires energy input from actin polymerization in mechanically challenging conditions. The roles of actin in CME are poorly understood due to inadequate knowledge of actin organization at clathrin-coated structures (CCSs). Using platinum replica electron microscopy of mammalian cells, we show that Arp2/3 complex-dependent branched actin networks, which often emerge from microtubule tips, assemble along the CCS perimeter, lack interaction with the apical clathrin lattice, and have barbed ends oriented toward the CCS. This structure is hardly compatible with the widely held "apical pulling" model describing actin functions in CME. Arp2/3 complex inhibition or epsin knockout produce large flat non-dynamic CCSs, which split into invaginating subdomains upon recovery from Arp2/3 inhibition. Moreover, epsin localization to CCSs depends on Arp2/3 activity. We propose an "edge pushing" model for CME, wherein branched actin polymerization promotes severing and invagination of flat CCSs in an epsin-dependent manner by pushing at the CCS boundary, thus releasing forces opposing the intrinsic curvature of clathrin lattices.
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Affiliation(s)
- Changsong Yang
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Patricia Colosi
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Siewert Hugelier
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Daniel Zabezhinsky
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
| | - Melike Lakadamyali
- grid.25879.310000 0004 1936 8972Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Tatyana Svitkina
- grid.25879.310000 0004 1936 8972Department of Biology, University of Pennsylvania, Philadelphia, PA USA
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9
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Tsunoda T, Riku M, Yamada N, Tsuchiya H, Tomita T, Suzuki M, Kizuki M, Inoko A, Ito H, Murotani K, Murakami H, Saeki Y, Kasai K. ENTREP/FAM189A2 encodes a new ITCH ubiquitin ligase activator that is downregulated in breast cancer. EMBO Rep 2022; 23:e51182. [PMID: 34927784 PMCID: PMC8811627 DOI: 10.15252/embr.202051182] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/13/2021] [Accepted: 11/29/2021] [Indexed: 11/09/2022] Open
Abstract
The HECT-type ubiquitin E3 ligases including ITCH regulate many aspects of cellular function through ubiquitinating various substrates. These ligases are known to be allosterically autoinhibited and to require an activator protein to fully achieve the ubiquitination of their substrates. Here we demonstrate that FAM189A2, a downregulated gene in breast cancer, encodes a new type of ITCH activator. FAM189A2 is a transmembrane protein harboring PPxY motifs, and the motifs mediate its association with and ubiquitination by ITCH. FAM189A2 also associates with Epsin and accumulates in early and late endosomes along with ITCH. Intriguingly, FAM189A2 facilitates the association of a chemokine receptor CXCR4 with ITCH and enhances ITCH-mediated ubiquitination of CXCR4. FAM189A2-knockout prohibits CXCL12-induced endocytosis of CXCR4, thereby enhancing the effects of CXCL12 on the chemotaxis and mammosphere formation of breast cancer cells. In comparison to other activators or adaptors known in the previous studies, FAM189A2 is a unique activator for ITCH to desensitize CXCR4 activity, and we here propose that FAM189A2 be renamed as ENdosomal TRansmembrane binding with EPsin (ENTREP).
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Affiliation(s)
- Takumi Tsunoda
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | - Miho Riku
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | - Norika Yamada
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | - Hikaru Tsuchiya
- Protein Metabolism ProjectTokyo Metropolitan Institute of Medical ScienceTokyoJapan
| | - Takuya Tomita
- Protein Metabolism ProjectTokyo Metropolitan Institute of Medical ScienceTokyoJapan
| | - Minako Suzuki
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | - Mari Kizuki
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | - Akihito Inoko
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
- Division of Cancer Epidemiology and PreventionAichi Cancer Center Research InstituteNagoyaJapan
| | - Hideaki Ito
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | | | - Hideki Murakami
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
| | - Yasushi Saeki
- Protein Metabolism ProjectTokyo Metropolitan Institute of Medical ScienceTokyoJapan
| | - Kenji Kasai
- Department of PathologyAichi Medical University School of MedicineNagakuteJapan
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10
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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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11
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Seib E, Klein T. The role of ligand endocytosis in notch signalling. Biol Cell 2021; 113:401-418. [PMID: 34038572 DOI: 10.1111/boc.202100009] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 05/05/2021] [Accepted: 05/17/2021] [Indexed: 12/12/2022]
Abstract
The Notch signalling receptor is a mechanoreceptor that is activated by force. This force elicits a conformational change in Notch that results in the release of its intracellular domain into the cytosol by two consecutive proteolytic cleavages. In most cases, the force is generated by pulling of the ligands on the receptor upon their endocytosis. In this review, we summarise recent work that shed a more detailed light on the role of endocytosis during ligand-dependent Notch activation and discuss the role of ubiquitylation of the ligands during this process.
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Affiliation(s)
- Ekaterina Seib
- Institute of Genetics, Heinrich-Heine-Universitaet Duesseldorf, Universitaetsstr. 1, Duesseldorf, 40225, Germany
| | - Thomas Klein
- Institute of Genetics, Heinrich-Heine-Universitaet Duesseldorf, Universitaetsstr. 1, Duesseldorf, 40225, Germany
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12
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Mishra R, Sengül GF, Candiello E, Schu P. Synaptic AP2 CCV life cycle regulation by the Eps15, ITSN1, Sgip1/AP2, synaptojanin1 interactome. Sci Rep 2021; 11:8007. [PMID: 33850201 PMCID: PMC8044098 DOI: 10.1038/s41598-021-87591-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/30/2021] [Indexed: 11/18/2022] Open
Abstract
The AP1/σ1B knockout causes impaired synaptic vesicle recycling and enhanced protein sorting into endosomes, leading to severe intellectual disability. These disturbances in synaptic protein sorting induce as a secondary phenotype the upregulation of AP2 CCV mediated endocytosis. Synapses contain canonical AP2 CCV and AP2 CCV with a more stable coat and thus extended life time. In AP1/σ1B knockout synapses, pool sizes of both CCV classes are doubled. Additionally, stable CCV of the knockout are more stabilised than stable wt CCV. One mechanism responsible for enhanced CCV stabilisation is the reduction of synaptojanin1 CCV levels, the PI-4,5-P2 phosphatase essential for AP2 membrane dissociation. To identify mechanisms regulating synaptojanin1 recruitment, we compared synaptojanin1 CCV protein interactome levels and CCV protein interactions between both CCV classes from wt and knockout mice. We show that ITSN1 determines synaptojanin1 CCV levels. Sgip1/AP2 excess hinders synaptojanin1 binding to ITSN1, further lowering its levels. ITSN1 levels are determined by Eps15, not Eps15L1. In addition, the data reveal that reduced amounts of pacsin1 can be counter balanced by its enhanced activation. These data exemplify the complexity of CCV life cycle regulation and indicate how cargo proteins determine the life cycle of their CCV.
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Affiliation(s)
- R Mishra
- Department of Cellular Biochemistry, University Medical Center, Georg-August University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Cambridge, England, UK
| | - G F Sengül
- Department of Cellular Biochemistry, University Medical Center, Georg-August University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - E Candiello
- Department of Cellular Biochemistry, University Medical Center, Georg-August University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
- Institute for Cancer Research and Treatment (IRCC), Turin, Italy
| | - P Schu
- Department of Cellular Biochemistry, University Medical Center, Georg-August University Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
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13
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Tarasenko D, Meinecke M. Protein-dependent membrane remodeling in mitochondrial morphology and clathrin-mediated endocytosis. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:295-306. [PMID: 33527201 PMCID: PMC8071792 DOI: 10.1007/s00249-021-01501-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022]
Abstract
Cellular membranes can adopt a plethora of complex and beautiful shapes, most of which are believed to have evolved for a particular physiological reason. The closely entangled relationship between membrane morphology and cellular physiology is strikingly seen in membrane trafficking pathways. During clathrin-mediated endocytosis, for example, over the course of a minute, a patch of the more or less flat plasma membrane is remodeled into a highly curved clathrin-coated vesicle. Such vesicles are internalized by the cell to degrade or recycle plasma membrane receptors or to take up extracellular ligands. Other, steadier, membrane morphologies can be observed in organellar membranes like the endoplasmic reticulum or mitochondria. In the case of mitochondria, which are double membrane-bound, ubiquitous organelles of eukaryotic cells, especially the mitochondrial inner membrane displays an intricated ultrastructure. It is highly folded and consequently has a much larger surface than the mitochondrial outer membrane. It can adopt different shapes in response to cellular demands and changes of the inner membrane morphology often accompany severe diseases, including neurodegenerative- and metabolic diseases and cancer. In recent years, progress was made in the identification of molecules that are important for the aforementioned membrane remodeling events. In this review, we will sum up recent results and discuss the main players of membrane remodeling processes that lead to the mitochondrial inner membrane ultrastructure and in clathrin-mediated endocytosis. We will compare differences and similarities between the molecular mechanisms that peripheral and integral membrane proteins use to deform membranes.
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Affiliation(s)
- Daryna Tarasenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
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14
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Giangreco G, Malabarba MG, Sigismund S. Specialised endocytic proteins regulate diverse internalisation mechanisms and signalling outputs in physiology and cancer. Biol Cell 2020; 113:165-182. [PMID: 33617023 DOI: 10.1111/boc.202000129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/20/2022]
Abstract
Although endocytosis was first described as the process mediating macromolecule or nutrient uptake through the plasma membrane, it is now recognised as a critical component of the cellular infrastructure involved in numerous processes, ranging from receptor signalling, proliferation and migration to polarity and stem cell regulation. To realise these varying roles, endocytosis needs to be finely regulated. Accordingly, multiple endocytic mechanisms exist that require specialised molecular machineries and an array of endocytic adaptor proteins with cell-specific functions. This review provides some examples of specialised functions of endocytic adaptors and other components of the endocytic machinery in different cell physiological processes, and how the alteration of these functions is linked to cancer. In particular, we focus on: (i) cargo selection and endocytic mechanisms linked to different adaptors; (ii) specialised functions in clathrin-mediated versus non-clathrin endocytosis; (iii) differential regulation of endocytic mechanisms by post-translational modification of endocytic proteins; (iv) cell context-dependent expression and function of endocytic proteins. As cases in point, we describe two endocytic protein families, dynamins and epsins. Finally, we discuss how dysregulation of the physiological role of these specialised endocytic proteins is exploited by cancer cells to increase cell proliferation, migration and invasion, leading to anti-apoptotic or pro-metastatic behaviours.
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Affiliation(s)
| | - Maria Grazia Malabarba
- IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy.,Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, , Milan, Italy
| | - Sara Sigismund
- IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy.,Università degli Studi di Milano, Dipartimento di Oncologia ed Emato-oncologia, , Milan, Italy
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15
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Bhave M, Mino RE, Wang X, Lee J, Grossman HM, Lakoduk AM, Danuser G, Schmid SL, Mettlen M. Functional characterization of 67 endocytic accessory proteins using multiparametric quantitative analysis of CCP dynamics. Proc Natl Acad Sci U S A 2020; 117:31591-31602. [PMID: 33257546 PMCID: PMC7749282 DOI: 10.1073/pnas.2020346117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) begins with the nucleation of clathrin assembly on the plasma membrane, followed by stabilization and growth/maturation of clathrin-coated pits (CCPs) that eventually pinch off and internalize as clathrin-coated vesicles. This highly regulated process involves a myriad of endocytic accessory proteins (EAPs), many of which are multidomain proteins that encode a wide range of biochemical activities. Although domain-specific activities of EAPs have been extensively studied, their precise stage-specific functions have been identified in only a few cases. Using single-guide RNA (sgRNA)/dCas9 and small interfering RNA (siRNA)-mediated protein knockdown, combined with an image-based analysis pipeline, we have determined the phenotypic signature of 67 EAPs throughout the maturation process of CCPs. Based on these data, we show that EAPs can be partitioned into phenotypic clusters, which differentially affect CCP maturation and dynamics. Importantly, these clusters do not correlate with functional modules based on biochemical activities. Furthermore, we discover a critical role for SNARE proteins and their adaptors during early stages of CCP nucleation and stabilization and highlight the importance of GAK throughout CCP maturation that is consistent with GAK's multifunctional domain architecture. Together, these findings provide systematic, mechanistic insights into the plasticity and robustness of CME.
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Affiliation(s)
- Madhura Bhave
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Rosa E Mino
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Xinxin Wang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jeon Lee
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Heather M Grossman
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ashley M Lakoduk
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Gaudenz Danuser
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Lyda Hill Department of Bioinformatics, 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;
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390;
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16
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Sen A, Hsieh WC, Hanna CB, Hsu CC, Pearson M, Tao WA, Aguilar RC. The Na + pump Ena1 is a yeast epsin-specific cargo requiring its ubiquitylation and phosphorylation sites for internalization. J Cell Sci 2020; 133:jcs245415. [PMID: 32694166 DOI: 10.1242/jcs.245415] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 07/14/2020] [Indexed: 12/16/2022] Open
Abstract
It is well known that in addition to its classical role in protein turnover, ubiquitylation is required for a variety of membrane protein sorting events. However, and despite substantial progress in the field, a long-standing question remains: given that all ubiquitin units are identical, how do different elements of the sorting machinery recognize their specific cargoes? Our results indicate that the yeast Na+ pump Ena1 is an epsin (Ent1 and Ent2 in yeast)-specific cargo and that its internalization requires K1090, which likely undergoes Art3-dependent ubiquitylation. In addition, an Ena1 serine and threonine (ST)-rich patch, proposed to be targeted for phosphorylation by casein kinases, was also required for its uptake. Interestingly, our data suggest that this phosphorylation was not needed for cargo ubiquitylation. Furthermore, epsin-mediated internalization of Ena1 required a specific spatial organization of the ST patch with respect to K1090 within the cytoplasmic tail of the pump. We hypothesize that ubiquitylation and phosphorylation of Ena1 are required for epsin-mediated internalization.
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Affiliation(s)
- Arpita Sen
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Wen-Chieh Hsieh
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Claudia B Hanna
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Chuan-Chih Hsu
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - McKeith Pearson
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - W Andy Tao
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - R Claudio Aguilar
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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17
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Wang X, Chen Z, Mettlen M, Noh J, Schmid SL, Danuser G. DASC, a sensitive classifier for measuring discrete early stages in clathrin-mediated endocytosis. eLife 2020; 9:53686. [PMID: 32352376 PMCID: PMC7192580 DOI: 10.7554/elife.53686] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) in mammalian cells is driven by resilient machinery that includes >70 endocytic accessory proteins (EAP). Accordingly, perturbation of individual EAPs often results in minor effects on biochemical measurements of CME, thus providing inconclusive/misleading information regarding EAP function. Live-cell imaging can detect earlier roles of EAPs preceding cargo internalization; however, this approach has been limited because unambiguously distinguishing abortive coats (ACs) from bona fide clathrin-coated pits (CCPs) is required but unaccomplished. Here, we develop a thermodynamics-inspired method, “disassembly asymmetry score classification (DASC)”, that resolves ACs from CCPs based on single channel fluorescent movies. After extensive verification, we use DASC-resolved ACs and CCPs to quantify CME progression in 11 EAP knockdown conditions. We show that DASC is a sensitive detector of phenotypic variation in CCP dynamics that is uncorrelated to the variation in biochemical measurements of CME. Thus, DASC is an essential tool for uncovering EAP function.
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Affiliation(s)
- Xinxin Wang
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Zhiming Chen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jungsik Noh
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Sandra L Schmid
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
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18
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Schwihla M, Korbei B. The Beginning of the End: Initial Steps in the Degradation of Plasma Membrane Proteins. FRONTIERS IN PLANT SCIENCE 2020; 11:680. [PMID: 32528512 PMCID: PMC7253699 DOI: 10.3389/fpls.2020.00680] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/30/2020] [Indexed: 05/05/2023]
Abstract
The plasma membrane (PM), as border between the inside and the outside of a cell, is densely packed with proteins involved in the sensing and transmission of internal and external stimuli, as well as transport processes and is therefore vital for plant development as well as quick and accurate responses to the environment. It is consequently not surprising that several regulatory pathways participate in the tight regulation of the spatiotemporal control of PM proteins. Ubiquitination of PM proteins plays a key role in directing their entry into the endo-lysosomal system, serving as a signal for triggering endocytosis and further sorting for degradation. Nevertheless, a uniting picture of the different roles of the respective types of ubiquitination in the consecutive steps of down-regulation of membrane proteins is still missing. The trans-Golgi network (TGN), which acts as an early endosome (EE) in plants receives the endocytosed cargo, and here the decision is made to either recycled back to the PM or further delivered to the vacuole for degradation. A multi-complex machinery, the endosomal sorting complex required for transport (ESCRT), concentrates ubiquitinated proteins and ushers them into the intraluminal vesicles of multi-vesicular bodies (MVBs). Several ESCRTs have ubiquitin binding subunits, which anchor and guide the cargos through the endocytic degradation route. Basic enzymes and the mode of action in the early degradation steps of PM proteins are conserved in eukaryotes, yet many plant unique components exist, which are often essential in this pathway. Thus, deciphering the initial steps in the degradation of ubiquitinated PM proteins, which is the major focus of this review, will greatly contribute to the larger question of how plants mange to fine-tune their responses to their environment.
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19
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Mutation-specific peripheral and ER quality control of hERG channel cell-surface expression. Sci Rep 2019; 9:6066. [PMID: 30988392 PMCID: PMC6465299 DOI: 10.1038/s41598-019-42331-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 03/28/2019] [Indexed: 12/11/2022] Open
Abstract
Impaired functional plasma membrane (PM) expression of the hERG K+-channel is associated with Long-QT syndrome type-2 (LQT2) and increased risk of cardiac arrhythmia. Reduced PM-expression is primarily attributed to retention and degradation of misfolded channels by endoplasmic reticulum (ER) protein quality control (QC) systems. However, as the molecular pathogenesis of LQT2 was defined using severely-misfolded hERG variants with limited PM-expression, the potential contribution of post-ER (peripheral) QC pathways to the disease phenotype remains poorly established. Here, we investigate the cellular processing of mildly-misfolded Per-Arnt-Sim (PAS)-domain mutant hERGs, which display incomplete ER-retention and PM-expression defects at physiological temperature. We show that the attenuated PM-expression of hERG is dictated by mutation-specific contributions from both the ER and peripheral QC systems. At the ER, PAS-mutants experience inefficient conformational maturation coupled with rapid ubiquitin-dependent proteasomal degradation. In post-ER compartments, they are rapidly endocytosed from the PM via a ubiquitin-independent mechanism and rapidly targeted for lysosomal degradation. Conformational destabilization underlies aberrant cellular processing at both ER- and post-ER compartments, since conformational correction by a hERG-specific pharmacochaperone or low-temperatures can restore WT-like trafficking. Our results demonstrate that the post-ER QC alone or jointly with the ER QC determines the loss-of-PM-expression phenotype of a subset of LQT2 mutations.
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20
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DeGroot ACM, Busch DJ, Hayden CC, Mihelic SA, Alpar AT, Behar M, Stachowiak JC. Entropic Control of Receptor Recycling Using Engineered Ligands. Biophys J 2019; 114:1377-1388. [PMID: 29590595 DOI: 10.1016/j.bpj.2018.01.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/16/2018] [Accepted: 01/23/2018] [Indexed: 01/04/2023] Open
Abstract
Receptor internalization by endocytosis regulates diverse cellular processes, from the rate of nutrient uptake to the timescale of essential signaling events. The established view is that internalization is tightly controlled by specific protein-binding interactions. However, recent work suggests that physical aspects of receptors influence the process in ways that cannot be explained by biochemistry alone. Specifically, work from several groups suggests that increasing the steric bulk of receptors may inhibit their uptake by multiple types of trafficking vesicles. How do biochemical and biophysical factors work together to control internalization? Here, we show that receptor uptake is well described by a thermodynamic trade-off between receptor-vesicle binding energy and the entropic cost of confining receptors within endocytic vesicles. Specifically, using large ligands to acutely increase the size of engineered variants of the transferrin receptor, we demonstrate that an increase in the steric bulk of a receptor dramatically decreases its probability of uptake by clathrin-coated structures. Further, in agreement with a simple thermodynamic analysis, all data collapse onto a single trend relating fractional occupancy of the endocytic structure to fractional occupancy of the surrounding plasma membrane, independent of receptor size. This fundamental scaling law provides a simple tool for predicting the impact of receptor expression level, steric bulk, and the size of endocytic structures on receptor uptake. More broadly, this work suggests that bulky ligands could be used to drive the accumulation of specific receptors at the plasma membrane surface, providing a biophysical tool for targeted modulation of signaling and metabolism from outside the cell.
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Affiliation(s)
- Andre C M DeGroot
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - David J Busch
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Carl C Hayden
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Samuel A Mihelic
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Aaron T Alpar
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Marcelo Behar
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas; Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas.
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21
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Takatori S, Tomita T. AP180 N-Terminal Homology (ANTH) and Epsin N-Terminal Homology (ENTH) Domains: Physiological Functions and Involvement in Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1111:55-76. [DOI: 10.1007/5584_2018_218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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22
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Ma T, Li B, Wang R, Lau PK, Huang Y, Jiang L, Schekman R, Guo Y. A mechanism for differential sorting of the planar cell polarity proteins Frizzled6 and Vangl2 at the trans-Golgi network. J Biol Chem 2018; 293:8410-8427. [PMID: 29666182 DOI: 10.1074/jbc.ra118.001906] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/12/2018] [Indexed: 01/14/2023] Open
Abstract
In planar cell polarity (PCP), the epithelial cells are polarized along the plane of the cell surface perpendicular to the classical apical-basal axis, a process mediated by several conserved signaling receptors. Two PCP-signaling proteins, VANGL planar cell polarity protein 2 (Vangl2) and Frizzled6 (Fzd6), are located asymmetrically on opposite boundaries of the cell. Examining sorting of these two proteins at the trans-Golgi network (TGN), we demonstrated previously that the GTP-binding protein ADP-ribosylation factor-related protein 1 (Arfrp1) and the clathrin-associated adaptor protein complex 1 (AP-1) are required for Vangl2 transport from the TGN. In contrast, TGN export of Frizzled6 does not depend on Arfrp1 or AP-1. Here, to further investigate the TGN sorting process in mammalian cells, we reconstituted release of Vangl2 and Frizzled6 from the TGN into vesicles in vitro Immunoblotting of released vesicles indicated that Vangl2 and Frizzled6 exit the TGN in separate compartments. Knockdown analysis revealed that a clathrin adaptor, epsinR, regulates TGN export of Frizzled6 but not of Vangl2. Protein interaction analysis suggested that epsinR forms a stable complex with clathrin and that this complex interacts with a conserved polybasic motif in the Frizzled6 cytosolic domain to package Frizzled6 into transport vesicles. Moreover, we found that Frizzled6-epsinR binding dissociates epsinR from AP-1, which may separate these two cargo adaptors from each other to perform distinct cargo-sorting functions. Our results suggest that Vangl2 and Frizzled6 are packaged into separate vesicles that are regulated by different clathrin adaptors at the TGN, which may contribute to their asymmetric localizations.
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Affiliation(s)
- Tianji Ma
- From the Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Baiying Li
- the Centre for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Ryan Wang
- the Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, and
| | - Pik Ki Lau
- From the Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yan Huang
- From the Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Liwen Jiang
- the Centre for Cell and Developmental Biology, State Key Laboratory of Agrobiotechnology, School of Life Sciences, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Randy Schekman
- the Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, and
| | - Yusong Guo
- From the Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China,
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23
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Takahashi TS, Hirade Y, Toma A, Sato Y, Yamagata A, Goto-Ito S, Tomita A, Nakada S, Fukai S. Structural insights into two distinct binding modules for Lys63-linked polyubiquitin chains in RNF168. Nat Commun 2018; 9:170. [PMID: 29330428 PMCID: PMC5766498 DOI: 10.1038/s41467-017-02345-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 11/22/2017] [Indexed: 12/18/2022] Open
Abstract
The E3 ubiquitin (Ub) ligase RNF168 plays a critical role in the initiation of the DNA damage response to double-strand breaks (DSBs). The recruitment of RNF168 by ubiquitylated targets involves two distinct regions, Ub-dependent DSB recruitment module (UDM) 1 and UDM2. Here we report the crystal structures of the complex between UDM1 and Lys63-linked diUb (K63-Ub2) and that between the C-terminally truncated UDM2 (UDM2ΔC) and K63-Ub2. In both structures, UDM1 and UDM2ΔC fold as a single α-helix. Their simultaneous bindings to the distal and proximal Ub moieties provide specificity for Lys63-linked Ub chains. Structural and biochemical analyses of UDM1 elucidate an Ub-binding mechanism between UDM1 and polyubiquitylated targets. Mutations of Ub-interacting residues in UDM2 prevent the accumulation of RNF168 to DSB sites in U2OS cells, whereas those in UDM1 have little effect, suggesting that the interaction of UDM2 with ubiquitylated and polyubiquitylated targets mainly contributes to the RNF168 recruitment. E3 ubiquitin ligase RNF168 is important for the repair of DNA double-strand breaks and recognizes ubiquitylated targets through two Ub-dependent DSB recruitment modules UDM1 and UDM2. Here the authors combine crystallography, cell biology and biochemical experiments to reveal how UDM1 and UDM2 interact with polyubiquitin chains.
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Affiliation(s)
- Tomio S Takahashi
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Yoshihiro Hirade
- Department of Bioregulation and Cellular Response, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Aya Toma
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8501, Japan
| | - Yusuke Sato
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8501, Japan
| | - Atsushi Yamagata
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan.,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8501, Japan
| | - Sakurako Goto-Ito
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Akiko Tomita
- Department of Bioregulation and Cellular Response, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Shinichiro Nakada
- Department of Bioregulation and Cellular Response, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan. .,Institute for Advanced Co-Creation Studies, Osaka University, Osaka, 565-0871, Japan.
| | - Shuya Fukai
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan. .,Synchrotron Radiation Research Organization, The University of Tokyo, Tokyo, 113-0032, Japan. .,Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8501, Japan.
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24
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Ettelaie C, Collier MEW, Featherby S, Greenman J, Maraveyas A. Peptidyl-prolyl isomerase 1 (Pin1) preserves the phosphorylation state of tissue factor and prolongs its release within microvesicles. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1865:12-24. [PMID: 28962834 DOI: 10.1016/j.bbamcr.2017.09.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/07/2017] [Accepted: 09/24/2017] [Indexed: 01/23/2023]
Abstract
The exposure and release of TF is regulated by post-translational modifications of its cytoplasmic domain. Here, the potential of Pin1 to interact with the cytoplasmic domain of TF, and the outcome on TF function was examined. MDA-MB-231 and transfected-primary endothelial cells were incubated with either Pin1 deactivator Juglone, or its control Plumbagin, as well as transfected with Pin1-specific or control siRNA. TF release into microvesicles following activation, and also phosphorylation and ubiquitination states of cellular-TF were then assessed. Furthermore, the ability of Pin1 to bind wild-type and mutant forms of overexpressed TF-tGFP was investigated by co-immunoprecipitation. Additionally, the ability of recombinant or cellular Pin1 to bind to peptides of the C-terminus of TF, synthesised in different phosphorylation states was examined by binding assays and spectroscopically. Finally, the influence of recombinant Pin1 on the ubiquitination and dephosphorylation of the TF-peptides was examined. Pre-incubation of Pin1 with Juglone but not Plumbagin, reduced TF release as microvesicles and was also achievable following transfection with Pin1-siRNA. This was concurrent with early ubiquitination and dephosphorylation of cellular TF at Ser253. Pin1 co-immunoprecipitated with overexpressed wild-type TF-tGFP but not Ser258→Ala or Pro259→Ala substituted mutants. Pin1 did interact with Ser258-phosphorylated and double-phosphorylated TF-peptides, with the former having higher affinity. Finally, recombinant Pin1 was capable of interfering with the ubiquitination and dephosphorylation of TF-derived peptides. In conclusion, Pin1 is a fast-acting enzyme which may be utilised by cells to protect the phosphorylation state of TF in activated cells prolonging TF activity and release, and therefore ensuring adequate haemostasis.
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Affiliation(s)
- Camille Ettelaie
- Biomedical Section, Department of Biological Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK.
| | - Mary E W Collier
- Department of Cardiovascular Sciences, University of Leicester, Clinical Sciences Wing, Glenfield General Hospital, Leicester LE3 9QP, UK
| | - Sophie Featherby
- Biomedical Section, Department of Biological Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK
| | - John Greenman
- Biomedical Section, Department of Biological Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK
| | - Anthony Maraveyas
- Division of Cancer, Hull York Medical School University of Hull, Cottingham Road, Hull HU6 7RX, UK
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25
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Arnold N, Girke T, Sureshchandra S, Messaoudi I. Acute Simian Varicella Virus Infection Causes Robust and Sustained Changes in Gene Expression in the Sensory Ganglia. J Virol 2016; 90:10823-10843. [PMID: 27681124 PMCID: PMC5110160 DOI: 10.1128/jvi.01272-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/19/2016] [Indexed: 12/13/2022] Open
Abstract
Primary infection with varicella-zoster virus (VZV), a neurotropic alphaherpesvirus, results in varicella. VZV establishes latency in the sensory ganglia and can reactivate later in life to cause herpes zoster. The relationship between VZV and its host during acute infection in the sensory ganglia is not well understood due to limited access to clinical specimens. Intrabronchial inoculation of rhesus macaques with simian varicella virus (SVV) recapitulates the hallmarks of VZV infection in humans. We leveraged this animal model to characterize the host-pathogen interactions in the ganglia during both acute and latent infection by measuring both viral and host transcriptomes on days postinfection (dpi) 3, 7, 10, 14, and 100. SVV DNA and transcripts were detected in sensory ganglia 3 dpi, before the appearance of rash. CD4 and CD8 T cells were also detected in the sensory ganglia 3 dpi. Moreover, lung-resident T cells isolated from the same animals 3 dpi also harbored SVV DNA and transcripts, suggesting that T cells may be responsible for trafficking SVV to the ganglia. Transcriptome sequencing (RNA-Seq) analysis showed that cessation of viral transcription 7 dpi coincides with a robust antiviral innate immune response in the ganglia. Interestingly, a significant number of genes that play a critical role in nervous system development and function remained downregulated into latency. These studies provide novel insights into host-pathogen interactions in the sensory ganglia during acute varicella and demonstrate that SVV infection results in profound and sustained changes in neuronal gene expression. IMPORTANCE Many aspects of VZV infection of sensory ganglia remain poorly understood, due to limited access to human specimens and the fact that VZV is strictly a human virus. Infection of rhesus macaques with simian varicella virus (SVV), a homolog of VZV, provides a robust model of the human disease. Using this model, we show that SVV reaches the ganglia early after infection, most likely by T cells, and that the induction of a robust innate immune response correlates with cessation of virus transcription. We also report significant changes in the expression of genes that play an important role in neuronal function. Importantly, these changes persist long after viral replication ceases. Given the homology between SVV and VZV, and the genetic and physiological similarities between rhesus macaques and humans, our results provide novel insight into the interactions between VZV and its human host and explain some of the neurological consequences of VZV infection.
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Affiliation(s)
- Nicole Arnold
- Graduate Program in Microbiology, University of California-Riverside, Riverside, California, USA
| | - Thomas Girke
- Department of Botany and Plant Sciences, University of California-Riverside, Riverside, California, USA
| | - Suhas Sureshchandra
- Graduate Program in Genetics, Genomics and Bioinformatics, University of California-Riverside, Riverside, California, USA
| | - Ilhem Messaoudi
- Graduate Program in Microbiology, University of California-Riverside, Riverside, California, USA
- Graduate Program in Genetics, Genomics and Bioinformatics, University of California-Riverside, Riverside, California, USA
- Division of Biomedical Sciences, School of Medicine, University of California-Riverside, Riverside, California, USA
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26
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Oligoubiquitination of tissue factor on Lys255 promotes Ser253-dephosphorylation and terminates TF release. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2846-2857. [PMID: 27599717 DOI: 10.1016/j.bbamcr.2016.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 08/25/2016] [Accepted: 09/02/2016] [Indexed: 11/24/2022]
Abstract
Restriction of tissue factor (TF) activity at the cell surface and TF release are critical for prevention of excessive coagulation. This study examined the regulation of TF dephosphorylation and its release through ubiquitination. A plasmid containing the sequence to express the tandem protein TF-tGFP was mutated to include an arginine-substitution at Lys255 within TF. MDA-MB-231 cell line, and HCAEC endothelial cells were transfected and subsequently activated with PAR2-agonist peptide. The wild-type and mutant TF-tGFP were immunoprecipitated from the cell lysates and the ubiquitination and phosphorylation state of TF examined. Analysis of the proteins showed that arginine-substitution of Lys255 within TF prevented its ubiquitination while the wild-type TF-tGFP was oligoubiquitinated. The TF-associated oligoubiquitin chain was estimated to contain up to 4 ubiquitin units, with the linkage formed between Lys63 of one ubiquitin unit, and the C-terminus of the next unit. The Lys255→Arg substitution of TF-tGFP prolonged the phosphorylation of Ser253 within TF, compared to the wild-type TF-tGFP, lengthened the presence of TF-tGFP at the cell surface and extended the duration of TF-tGFP release from cells following PAR2 activation. A biotinylated 19-mer peptide corresponding to the C-terminus of TF (TFc) was used as substrate to show that the ubiquitination of TF was mediated by the Ube2D family of E2-enzymes and involved Mdm2. Moreover, double-phosphorylation of TFc was prerequisite for ubiquitination, with subsequent dephosphorylation of Ser253 by phosphatase PP2A. In conclusion, oligoubiquitination of Lys255 within TF permits PP2A to bind and dephosphorylate Ser253 and occurs to terminate TF release and contain its activity.
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27
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Falk MM, Bell CL, Kells Andrews RM, Murray SA. Molecular mechanisms regulating formation, trafficking and processing of annular gap junctions. BMC Cell Biol 2016; 17 Suppl 1:22. [PMID: 27230503 PMCID: PMC4896261 DOI: 10.1186/s12860-016-0087-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Internalization of gap junction plaques results in the formation of annular gap junction vesicles. The factors that regulate the coordinated internalization of the gap junction plaques to form annular gap junction vesicles, and the subsequent events involved in annular gap junction processing have only relatively recently been investigated in detail. However it is becoming clear that while annular gap junction vesicles have been demonstrated to be degraded by autophagosomal and endo-lysosomal pathways, they undergo a number of additional processing events. Here, we characterize the morphology of the annular gap junction vesicle and review the current knowledge of the processes involved in their formation, fission, fusion, and degradation. In addition, we address the possibility for connexin protein recycling back to the plasma membrane to contribute to gap junction formation and intercellular communication. Information on gap junction plaque removal from the plasma membrane and the subsequent processing of annular gap junction vesicles is critical to our understanding of cell-cell communication as it relates to events regulating development, cell homeostasis, unstable proliferation of cancer cells, wound healing, changes in the ischemic heart, and many other physiological and pathological cellular phenomena.
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Affiliation(s)
- Matthias M Falk
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, 18049, USA.
| | - Cheryl L Bell
- Department of Cell Biology and Physiology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, l5261, USA
| | | | - Sandra A Murray
- Department of Cell Biology and Physiology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, l5261, USA.
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28
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Paez Valencia J, Goodman K, Otegui MS. Endocytosis and Endosomal Trafficking in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2016; 67:309-35. [PMID: 27128466 DOI: 10.1146/annurev-arplant-043015-112242] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Endocytosis and endosomal trafficking are essential processes in cells that control the dynamics and turnover of plasma membrane proteins, such as receptors, transporters, and cell wall biosynthetic enzymes. Plasma membrane proteins (cargo) are internalized by endocytosis through clathrin-dependent or clathrin-independent mechanism and delivered to early endosomes. From the endosomes, cargo proteins are recycled back to the plasma membrane via different pathways, which rely on small GTPases and the retromer complex. Proteins that are targeted for degradation through ubiquitination are sorted into endosomal vesicles by the ESCRT (endosomal sorting complex required for transport) machinery for degradation in the vacuole. Endocytic and endosomal trafficking regulates many cellular, developmental, and physiological processes, including cellular polarization, hormone transport, metal ion homeostasis, cytokinesis, pathogen responses, and development. In this review, we discuss the mechanisms that mediate the recognition and sorting of endocytic and endosomal cargos, the vesiculation processes that mediate their trafficking, and their connection to cellular and physiological responses in plants.
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Affiliation(s)
- Julio Paez Valencia
- Department of Botany
- R.M. Bock Laboratories of Cell and Molecular Biology, and
| | - Kaija Goodman
- Department of Botany
- R.M. Bock Laboratories of Cell and Molecular Biology, and
| | - Marisa S Otegui
- Department of Botany
- R.M. Bock Laboratories of Cell and Molecular Biology, and
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin 53706; , ,
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29
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Frazier MN, Davies AK, Voehler M, Kendall AK, Borner GHH, Chazin WJ, Robinson MS, Jackson LP. Molecular Basis for the Interaction Between AP4 β4 and its Accessory Protein, Tepsin. Traffic 2016; 17:400-15. [PMID: 26756312 PMCID: PMC4805503 DOI: 10.1111/tra.12375] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/07/2016] [Accepted: 01/07/2016] [Indexed: 01/08/2023]
Abstract
The adaptor protein 4 (AP4) complex (ϵ/β4/μ4/σ4 subunits) forms a non-clathrin coat on vesicles departing the trans-Golgi network. AP4 biology remains poorly understood, in stark contrast to the wealth of molecular data available for the related clathrin adaptors AP1 and AP2. AP4 is important for human health because mutations in any AP4 subunit cause severe neurological problems, including intellectual disability and progressive spastic para- or tetraplegias. We have used a range of structural, biochemical and biophysical approaches to determine the molecular basis for how the AP4 β4 C-terminal appendage domain interacts with tepsin, the only known AP4 accessory protein. We show that tepsin harbors a hydrophobic sequence, LFxG[M/L]x[L/V], in its unstructured C-terminus, which binds directly and specifically to the C-terminal β4 appendage domain. Using nuclear magnetic resonance chemical shift mapping, we define the binding site on the β4 appendage by identifying residues on the surface whose signals are perturbed upon titration with tepsin. Point mutations in either the tepsin LFxG[M/L]x[L/V] sequence or in its cognate binding site on β4 abolish in vitro binding. In cells, the same point mutations greatly reduce the amount of tepsin that interacts with AP4. However, they do not abolish the binding between tepsin and AP4 completely, suggesting the existence of additional interaction sites between AP4 and tepsin. These data provide one of the first detailed mechanistic glimpses at AP4 coat assembly and should provide an entry point for probing the role of AP4-coated vesicles in cell biology, and especially in neuronal function.
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Affiliation(s)
- Meredith N Frazier
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Alexandra K Davies
- Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, UK
| | - Markus Voehler
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Department of Biochemistry and Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Amy K Kendall
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Georg H H Borner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Walter J Chazin
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
- Department of Biochemistry and Chemistry, Vanderbilt University, Nashville, TN, USA
| | - Margaret S Robinson
- Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge, UK
| | - Lauren P Jackson
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
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30
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Szymanska M, Fosdahl AM, Raiborg C, Dietrich M, Liestøl K, Stang E, Bertelsen V. Interaction with epsin 1 regulates the constitutive clathrin-dependent internalization of ErbB3. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1179-88. [PMID: 26975582 DOI: 10.1016/j.bbamcr.2016.03.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/24/2016] [Accepted: 03/10/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND In contrast to other members of the EGF receptor family, ErbB3 is constitutively internalized in a clathrin-dependent manner. Previous studies have shown that ErbB3 does not interact with the coated pit localized adaptor complex 2 (AP-2), and that ErbB3 lacks two AP-2 interacting internalization signals identified in the EGF receptor. Several other clathrin-associated sorting proteins which may recruit cargo into coated pits have, however, been identified, and the study was performed to identify adaptors needed for constitutive internalization of ErbB3. METHODS A high-throughput siRNA screen was used to identify adaptor proteins needed for internalization of ErbB3. Upon knock-down of candidate proteins internalization of ErbB3 was identified using an antibody-based internalization assay combined with automatic fluorescence microscopy. RESULTS Among 29 candidates only knock-down of epsin 1 turned out to inhibit ErbB3. Epsin 1 has ubiquitin interacting motifs (UIMs) and we show that ErbB3 interacts with an epsin 1 deletion mutant containing these UIMs. In support of an ErbB3-epsin 1 UIM dependent interaction, we show that ErbB3 is constitutively ubiquitinated, but that both ubiquitination and the ErbB3-epsin 1 interaction increase upon ligand binding. CONCLUSION Altogether the results are consistent with a model whereby both constitutive and ligand-induced internalization of ErbB3 are regulated through interaction with epsin 1. GENERAL SIGNIFICANCE Internalization is an important regulator of growth factor receptor mediated signaling and the current study identify mechanisms regulating plasma membrane turnover of ErbB3.
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Affiliation(s)
- Monika Szymanska
- Department of Pathology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Anne Marthe Fosdahl
- Department of Pathology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Camilla Raiborg
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway; Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Markus Dietrich
- Department of Pathology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Knut Liestøl
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway; Department of Informatics, University of Oslo, Oslo, Norway
| | - Espen Stang
- Department of Pathology, Oslo University Hospital, Oslo, Norway.
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31
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Cell Adhesion Molecules and Ubiquitination-Functions and Significance. BIOLOGY 2015; 5:biology5010001. [PMID: 26703751 PMCID: PMC4810158 DOI: 10.3390/biology5010001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/02/2015] [Accepted: 12/15/2015] [Indexed: 12/11/2022]
Abstract
Cell adhesion molecules of the immunoglobulin (Ig) superfamily represent the biggest group of cell adhesion molecules. They have been analyzed since approximately 40 years ago and most of them have been shown to play a role in tumor progression and in the nervous system. All members of the Ig superfamily are intensively posttranslationally modified. However, many aspects of their cellular functions are not yet known. Since a few years ago it is known that some of the Ig superfamily members are modified by ubiquitin. Ubiquitination has classically been described as a proteasomal degradation signal but during the last years it became obvious that it can regulate many other processes including internalization of cell surface molecules and lysosomal sorting. The purpose of this review is to summarize the current knowledge about the ubiquitination of cell adhesion molecules of the Ig superfamily and to discuss its potential physiological roles in tumorigenesis and in the nervous system.
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32
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Abstract
The plasma membrane (PM) and endocytic protein quality control (QC) in conjunction with the endosomal sorting machinery either repairs or targets conformationally damaged membrane proteins for lysosomal/vacuolar degradation. Here, we provide an overview of emerging aspects of the underlying mechanisms of PM QC that fulfill a critical role in preserving cellular protein homeostasis in health and diseases.
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Affiliation(s)
- Pirjo M Apaja
- Department of Physiology and Research Group Focused on Protein Structure (GRASP), McGill University, Montreal, Quebec, Canada; and
| | - Gergely L Lukacs
- Department of Physiology and Research Group Focused on Protein Structure (GRASP), McGill University, Montreal, Quebec, Canada; and Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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33
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Holkar SS, Kamerkar SC, Pucadyil TJ. Spatial Control of Epsin-induced Clathrin Assembly by Membrane Curvature. J Biol Chem 2015; 290:14267-76. [PMID: 25837255 PMCID: PMC4505496 DOI: 10.1074/jbc.m115.653394] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Indexed: 11/21/2022] Open
Abstract
Epsins belong to the family of highly conserved clathrin-associated sorting proteins that are indispensable for clathrin-mediated endocytosis, but their precise functions remain unclear. We have developed an assay system of budded supported membrane tubes displaying planar and highly curved membrane surfaces to analyze intrinsic membrane curvature preference shown by clathrin-associated sorting proteins. Using real-time fluorescence microscopy, we find that epsin preferentially partitions to and assembles clathrin on highly curved membrane surfaces. Sorting of epsin to regions of high curvature strictly depends on binding to phosphatidylinositol 4,5-bisphosphate. Fluorescently labeled clathrins rapidly assemble as foci, which in turn cluster epsin, while maintaining tube integrity. Clathrin foci grow in intensity with a typical time constant of ∼75 s, similar to the time scales for coated pit formation seen in cells. Epsin therefore effectively senses membrane curvature to spatially control clathrin assembly. Our results highlight the potential role of membrane curvature in orchestrating the myriad molecular interactions necessary for the success of clathrin-mediated membrane budding.
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Affiliation(s)
- Sachin S Holkar
- From the Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, India
| | - Sukrut C Kamerkar
- From the Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, India
| | - Thomas J Pucadyil
- From the Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pashan, Pune 411 008, India
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34
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Chang B, Tessneer KL, McManus J, Liu X, Hahn S, Pasula S, Wu H, Song H, Chen Y, Cai X, Dong Y, Brophy ML, Rahman R, Ma JX, Xia L, Chen H. Epsin is required for Dishevelled stability and Wnt signalling activation in colon cancer development. Nat Commun 2015; 6:6380. [PMID: 25871009 PMCID: PMC4397653 DOI: 10.1038/ncomms7380] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/26/2015] [Indexed: 02/08/2023] Open
Abstract
Uncontrolled canonical Wnt signalling supports colon epithelial tumour expansion and malignant transformation. Understanding the regulatory mechanisms involved is crucial for elucidating the pathogenesis of and will provide new therapeutic targets for colon cancer. Epsins are ubiquitin-binding adaptor proteins upregulated in several human cancers; however, the involvement of epsins in colon cancer is unknown. Here we show that loss of intestinal epithelial epsins protects against colon cancer by significantly reducing the stability of the crucial Wnt signalling effector, dishevelled (Dvl2), and impairing Wnt signalling. Consistently, epsins and Dvl2 are correspondingly upregulated in colon cancer. Mechanistically, epsin binds Dvl2 via its epsin N-terminal homology domain and ubiquitin-interacting motifs and prohibits Dvl2 polyubiquitination and degradation. Our findings reveal an unconventional role for epsins in stabilizing Dvl2 and potentiating Wnt signalling in colon cancer cells to ensure robust colon cancer progression. The pro-carcinogenic role of Epsins suggests that they are potential therapeutic targets to combat colon cancer.
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Affiliation(s)
- Baojun Chang
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Kandice L Tessneer
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - John McManus
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Xiaolei Liu
- 1] Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA [2] Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Scott Hahn
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Satish Pasula
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Hao Wu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Hoogeun Song
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Yiyuan Chen
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Xiaofeng Cai
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Yunzhou Dong
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Megan L Brophy
- 1] Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA [2] Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Ruby Rahman
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA
| | - Jian-Xing Ma
- Department of Endocrinology and Diabetes, Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Lijun Xia
- 1] Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA [2] Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Hong Chen
- 1] Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104, USA [2] Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Erpapazoglou Z, Walker O, Haguenauer-Tsapis R. Versatile roles of k63-linked ubiquitin chains in trafficking. Cells 2014; 3:1027-88. [PMID: 25396681 PMCID: PMC4276913 DOI: 10.3390/cells3041027] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/14/2014] [Accepted: 10/21/2014] [Indexed: 12/11/2022] Open
Abstract
Modification by Lys63-linked ubiquitin (UbK63) chains is the second most abundant form of ubiquitylation. In addition to their role in DNA repair or kinase activation, UbK63 chains interfere with multiple steps of intracellular trafficking. UbK63 chains decorate many plasma membrane proteins, providing a signal that is often, but not always, required for their internalization. In yeast, plants, worms and mammals, this same modification appears to be critical for efficient sorting to multivesicular bodies and subsequent lysosomal degradation. UbK63 chains are also one of the modifications involved in various forms of autophagy (mitophagy, xenophagy, or aggrephagy). Here, in the context of trafficking, we report recent structural studies investigating UbK63 chains assembly by various E2/E3 pairs, disassembly by deubiquitylases, and specifically recognition as sorting signals by receptors carrying Ub-binding domains, often acting in tandem. In addition, we address emerging and unanticipated roles of UbK63 chains in various recycling pathways that function by activating nucleators required for actin polymerization, as well as in the transient recruitment of signaling molecules at the plasma or ER membrane. In this review, we describe recent advances that converge to elucidate the mechanisms underlying the wealth of trafficking functions of UbK63 chains.
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Affiliation(s)
- Zoi Erpapazoglou
- Institut Jacques Monod-CNRS, UMR 7592, Université-Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France.
| | - Olivier Walker
- Institut des Sciences Analytiques, UMR5280, Université de Lyon/Université Lyon 1, 69100 Villeurbanne, France.
| | - Rosine Haguenauer-Tsapis
- Institut Jacques Monod-CNRS, UMR 7592, Université-Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France.
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Gucwa AL, Brown DA. UIM domain-dependent recruitment of the endocytic adaptor protein Eps15 to ubiquitin-enriched endosomes. BMC Cell Biol 2014; 15:34. [PMID: 25260758 PMCID: PMC4181756 DOI: 10.1186/1471-2121-15-34] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 09/22/2014] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Eps15 is an endocytic adaptor protein that stimulates clathrin-mediated endocytosis. Among other interactions, Eps15 binds ubiquitin via UIM domains, recruiting ubiquitinated cargo into clathrin-coated vesicles. In EGF-treated cells, Eps15 also localizes to endosomes. The basis of this localization is not known. RESULTS We show that accumulation of ubiquitinated cargo can recruit Eps15 to endosomes via UIM domain interactions. First, treatment of SK-Br-3 breast cancer cells, which overexpress the EGFR family member ErbB2, with geldanamycin to promote receptor ubiquitination and endosomal transport, recruited FLAG-Eps15 to endosomes. Two in-frame ubiquitin constructs, PM-GFP-Ub (retained in endosomes after endocytosis), and GFP-FYVE-UbΔGG (targeted directly to endosomes) also recruited Eps15 to endosomes, as did slowing endosome maturation with constitutively-active Rab5-Q79L. Endosomal recruitment required the UIM domains, but not the N-terminal EH domains or central coiled-coil domains, of Eps15. Silencing of the endosomal Eps15 binding partner Hrs did not affect recruitment of Eps15 to ubiquitin-enriched endosomes. In fact, Hrs silencing itself modestly recruited Eps15 to endosomes, probably by accumulating endogenous ubiquitinated cargo. Eps15 silencing did not affect lysosomal degradation of ubiquitinated ErbB2; however, GFP-FYVE-UbΔGG overexpression inhibited internalization of EGFR and transferrin receptor. CONCLUSIONS We show for the first time that ubiquitin is sufficient for Eps15 recruitment to endosomes. We speculate that Eps15 recruitment to ubiquitin-rich endosomes may reduce the level of Eps15 at the plasma membrane, slowing endocytosis to allow time for processing of ubiquitinated cargo in endosomes.
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Affiliation(s)
- Azad L Gucwa
- Department of Biomedical Sciences, Long Island University at Post, Brookville, NY 11548-1300, USA.
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Molfetta R, Quatrini L, Gasparrini F, Zitti B, Santoni A, Paolini R. Regulation of fc receptor endocytic trafficking by ubiquitination. Front Immunol 2014; 5:449. [PMID: 25278942 PMCID: PMC4166898 DOI: 10.3389/fimmu.2014.00449] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 09/03/2014] [Indexed: 12/29/2022] Open
Abstract
Most immune cells, particularly phagocytes, express various receptors for the Fc portion of the different immunoglobulin isotypes (Fc receptors, FcRs). By binding to the antibody, they provide a link between the adaptive immune system and the powerful effector functions triggered by innate immune cells such as mast cells, neutrophils, macrophages, and NK cells. Upon ligation of the immune complexes, the downstream signaling pathways initiated by the different receptors are quite similar for different FcR classes leading to the secretion of preformed and de novo synthesized pro-inflammatory mediators. FcR engagement also promotes negative signals through the combined action of several molecules that limit the extent and duration of positive signaling. To this regard, ligand-induced ubiquitination of FcRs for IgE (FcεR) and IgG (FcγR) has become recognized as a key modification that generates signals for the internalization and/or delivery of engaged receptor complexes to lysosomes or cytoplasmic proteasomes for degradation, providing negative-feedback regulation of Fc receptor activity. In this review, we discuss recent advances in our understanding of the molecular mechanisms that ensure the clearance of engaged Fcε and Fcγ receptor complexes from the cell surface with an emphasis given to the cooperation between the ubiquitin pathway and endosomal adaptors including the endosomal sorting complex required for transport (ESCRT) in controlling receptor internalization and sorting along the endocytic compartments.
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Affiliation(s)
- Rosa Molfetta
- Department of Molecular Medicine, "Sapienza" University of Rome , Rome , Italy
| | - Linda Quatrini
- Department of Molecular Medicine, "Sapienza" University of Rome , Rome , Italy
| | - Francesca Gasparrini
- Lymphocyte Interaction Laboratory, London Research Institute, Cancer Research UK , London , UK
| | - Beatrice Zitti
- Department of Molecular Medicine, "Sapienza" University of Rome , Rome , Italy
| | - Angela Santoni
- Department of Molecular Medicine, "Sapienza" University of Rome , Rome , Italy ; Institute Pasteur-Fondazione Cenci Bolognetti, "Sapienza" University of Rome , Rome , Italy
| | - Rossella Paolini
- Department of Molecular Medicine, "Sapienza" University of Rome , Rome , Italy ; Institute Pasteur-Fondazione Cenci Bolognetti, "Sapienza" University of Rome , Rome , Italy
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38
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Abstract
Plants are permanently situated in a fixed location and thus are well adapted to sense and respond to environmental stimuli and developmental cues. At the cellular level, several of these responses require delicate adjustments that affect the activity and steady-state levels of plasma membrane proteins. These adjustments involve both vesicular transport to the plasma membrane and protein internalization via endocytic sorting. A substantial part of our current knowledge of plant plasma membrane protein sorting is based on studies of PIN-FORMED (PIN) auxin transport proteins, which are found at distinct plasma membrane domains and have been implicated in directional efflux of the plant hormone auxin. Here, we discuss the mechanisms involved in establishing such polar protein distributions, focusing on PINs and other key plant plasma membrane proteins, and we highlight the pathways that allow for dynamic adjustments in protein distribution and turnover, which together constitute a versatile framework that underlies the remarkable capabilities of plants to adjust growth and development in their ever-changing environment.
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Affiliation(s)
- Christian Luschnig
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, Vienna 1190, Austria
| | - Grégory Vert
- Institut des Sciences du Végétal, CNRS UPR 2355, 1 Avenue de la Terrasse, Bâtiment 23A, Gif-sur-Yvette 91190, France
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39
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Grove J, Metcalf DJ, Knight AE, Wavre-Shapton ST, Sun T, Protonotarios ED, Griffin LD, Lippincott-Schwartz J, Marsh M. Flat clathrin lattices: stable features of the plasma membrane. Mol Biol Cell 2014; 25:3581-94. [PMID: 25165141 PMCID: PMC4230618 DOI: 10.1091/mbc.e14-06-1154] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) is a fundamental property of eukaryotic cells. Classical CME proceeds via the formation of clathrin-coated pits (CCPs) at the plasma membrane, which invaginate to form clathrin-coated vesicles, a process that is well understood. However, clathrin also assembles into flat clathrin lattices (FCLs); these structures remain poorly described, and their contribution to cell biology is unclear. We used quantitative imaging to provide the first comprehensive description of FCLs and explore their influence on plasma membrane organization. Ultrastructural analysis by electron and superresolution microscopy revealed two discrete populations of clathrin structures. CCPs were typified by their sphericity, small size, and homogeneity. FCLs were planar, large, and heterogeneous and present on both the dorsal and ventral surfaces of cells. Live microscopy demonstrated that CCPs are short lived and culminate in a peak of dynamin recruitment, consistent with classical CME. In contrast, FCLs were long lived, with sustained association with dynamin. We investigated the biological relevance of FCLs using the chemokine receptor CCR5 as a model system. Agonist activation leads to sustained recruitment of CCR5 to FCLs. Quantitative molecular imaging indicated that FCLs partitioned receptors at the cell surface. Our observations suggest that FCLs provide stable platforms for the recruitment of endocytic cargo.
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Affiliation(s)
- Joe Grove
- MRC Laboratory for Molecular Cell Biology, London WC1E 6BT, United Kingdom Institute of Immunity and Transplantation, University College London, London NW3 2PF, United Kingdom
| | - Daniel J Metcalf
- Biophysics and Diagnostics, National Physical Laboratory, Teddington TW11 0LW, United Kingdom
| | - Alex E Knight
- Biophysics and Diagnostics, National Physical Laboratory, Teddington TW11 0LW, United Kingdom
| | | | - Tony Sun
- MRC Laboratory for Molecular Cell Biology, London WC1E 6BT, United Kingdom
| | | | - Lewis D Griffin
- CoMPLEX, University College London, London WC1E 6BT, United Kingdom
| | - Jennifer Lippincott-Schwartz
- Cell Biology and Metabolism Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Mark Marsh
- MRC Laboratory for Molecular Cell Biology, London WC1E 6BT, United Kingdom
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Messa M, Fernández-Busnadiego R, Sun EW, Chen H, Czapla H, Wrasman K, Wu Y, Ko G, Ross T, Wendland B, De Camilli P. Epsin deficiency impairs endocytosis by stalling the actin-dependent invagination of endocytic clathrin-coated pits. eLife 2014; 3:e03311. [PMID: 25122462 PMCID: PMC4161027 DOI: 10.7554/elife.03311] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Epsin is an evolutionarily conserved endocytic clathrin adaptor whose most critical function(s) in clathrin coat dynamics remain(s) elusive. To elucidate such function(s), we generated embryonic fibroblasts from conditional epsin triple KO mice. Triple KO cells displayed a dramatic cell division defect. Additionally, a robust impairment in clathrin-mediated endocytosis was observed, with an accumulation of early and U-shaped pits. This defect correlated with a perturbation of the coupling between the clathrin coat and the actin cytoskeleton, which we confirmed in a cell-free assay of endocytosis. Our results indicate that a key evolutionary conserved function of epsin, in addition to other roles that include, as we show here, a low affinity interaction with SNAREs, is to help generate the force that leads to invagination and then fission of clathrin-coated pits.
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Affiliation(s)
- Mirko Messa
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Rubén Fernández-Busnadiego
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Elizabeth Wen Sun
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Hong Chen
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Heather Czapla
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Kristie Wrasman
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Yumei Wu
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Genevieve Ko
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
| | - Theodora Ross
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, United States
| | - Beverly Wendland
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Pietro De Camilli
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, United States
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41
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Lin A, Man HY. Endocytic adaptor epidermal growth factor receptor substrate 15 (Eps15) is involved in the trafficking of ubiquitinated α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors. J Biol Chem 2014; 289:24652-64. [PMID: 25023288 DOI: 10.1074/jbc.m114.582114] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
AMPA-type glutamate receptors (AMPARs) play a critical role in mediating fast excitatory synaptic transmission in the brain. Alterations in receptor expression, distribution, and trafficking have been shown to underlie synaptic plasticity and higher brain functions, including learning and memory, as well as brain dysfunctions such as drug addiction and psychological disorders. Therefore, it is essential to elucidate the molecular mechanisms that regulate AMPAR dynamics. We have shown previously that mammalian AMPARs are subject to posttranslational modification by ubiquitin, with AMPAR ubiquitination enhancing receptor internalization and reducing AMPAR cell surface expression. Here we report a crucial role for epidermal growth factor receptor substrate 15 (Eps15), an endocytic adaptor, in ubiquitination-dependent AMPAR internalization. We find that suppression or overexpression of Eps15 results in changes in AMPAR surface expression. Eps15 interacts with AMPARs, which requires Nedd4-mediated GluA1 ubiquitination and the ubiquitin-interacting motif of Eps15. Importantly, we find that Eps15 plays an important role in AMPAR internalization. Knockdown of Eps15 suppresses the internalization of GluA1 but not the mutant GluA1 that lacks ubiquitination sites, indicating a role of Eps15 for the internalization of ubiquitinated AMPARs. These results reveal a novel molecular mechanism employed specifically for the trafficking of the ubiquitin-modified AMPARs.
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Affiliation(s)
- Amy Lin
- From the Department of Biology, Boston University, Boston, Massachusetts 02215
| | - Heng-Ye Man
- From the Department of Biology, Boston University, Boston, Massachusetts 02215
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42
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Chakraborty S, Umasankar PK, Preston GM, Khandelwal P, Apodaca G, Watkins SC, Traub LM. A phosphotyrosine switch for cargo sequestration at clathrin-coated buds. J Biol Chem 2014; 289:17497-514. [PMID: 24798335 DOI: 10.1074/jbc.m114.556589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The AP-2 clathrin adaptor complex oversees endocytic cargo selection in two parallel but independent manners. First, by physically engaging peptide-based endocytic sorting signals, a subset of clathrin-dependent transmembrane cargo is directly collected into assembling buds. Synchronously, by interacting with an assortment of clathrin-associated sorting proteins (CLASPs) that independently select different integral membrane cargo for inclusion within the incipient bud, AP-2 handles additional cargo capture indirectly. The distal platform subdomain of the AP-2 β2 subunit appendage is a privileged CLASP-binding surface that recognizes a cognate, short α-helical interaction motif. This signal, found in the CLASPs β-arrestin and the autosomal recessive hypercholesterolemia (ARH) protein, docks into an elongated groove on the β2 appendage platform. Tyr-888 is a critical constituent of this spatially confined β2 appendage contact interface and is phosphorylated in numerous high-throughput proteomic studies. We find that a phosphomimetic Y888E substitution does not interfere with incorporation of expressed β2-YFP subunit into AP-2 or alter AP-2 deposition at surface clathrin-coated structures. The Y888E mutation does not affect interactions involving the sandwich subdomain of the β2 appendage, indicating that the mutated appendage is folded and operational. However, the Y888E, but not Y888F, switch selectively uncouples interactions with ARH and β-arrestin. Phyogenetic conservation of Tyr-888 suggests that this residue can reversibly control occupancy of the β2 platform-binding site and, hence, cargo sorting.
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Affiliation(s)
| | | | | | - Puneet Khandelwal
- the Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Gerard Apodaca
- the Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
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43
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Kirchhausen T, Owen D, Harrison SC. Molecular structure, function, and dynamics of clathrin-mediated membrane traffic. Cold Spring Harb Perspect Biol 2014; 6:a016725. [PMID: 24789820 DOI: 10.1101/cshperspect.a016725] [Citation(s) in RCA: 321] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Clathrin is a molecular scaffold for vesicular uptake of cargo at the plasma membrane, where its assembly into cage-like lattices underlies the clathrin-coated pits of classical endocytosis. This review describes the structures of clathrin, major cargo adaptors, and other proteins that participate in forming a clathrin-coated pit, loading its contents, pinching off the membrane as a lattice-enclosed vesicle, and recycling the components. It integrates as much of the structural information as possible at the time of writing into a sketch of the principal steps in coated-pit and coated-vesicle formation.
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Affiliation(s)
- Tom Kirchhausen
- Department of Cell Biology, Harvard Medical School/PCMM, Boston, Massachusetts 02115
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44
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Sochacki KA, Shtengel G, van Engelenburg SB, Hess HF, Taraska JW. Correlative super-resolution fluorescence and metal-replica transmission electron microscopy. Nat Methods 2014; 11:305-8. [PMID: 24464288 PMCID: PMC3943662 DOI: 10.1038/nmeth.2816] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 12/16/2013] [Indexed: 01/14/2023]
Abstract
We combine super-resolution localization fluorescence microscopy with transmission electron microscopy of metal replicas to locate proteins on the landscape of the cellular plasma membrane at the nanoscale. We validate robust correlation on the scale of 20 nm by imaging endogenous clathrin (in two and three dimensions) and apply the method to find the previously unknown three-dimensional position of the endocytic protein epsin on clathrin-coated structures at the plasma membrane.
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Affiliation(s)
- Kem A Sochacki
- 1] National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, Maryland, USA. [2]
| | - Gleb Shtengel
- 1] Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, Virginia, USA. [2]
| | - Schuyler B van Engelenburg
- National Institute of Child Health and Human Development, US National Institutes of Health, Bethesda, Maryland, USA
| | - Harald F Hess
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, Virginia, USA
| | - Justin W Taraska
- National Heart, Lung, and Blood Institute, US National Institutes of Health, Bethesda, Maryland, USA
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45
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Thévenin AF, Kowal TJ, Fong JT, Kells RM, Fisher CG, Falk MM. Proteins and mechanisms regulating gap-junction assembly, internalization, and degradation. Physiology (Bethesda) 2014; 28:93-116. [PMID: 23455769 DOI: 10.1152/physiol.00038.2012] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Gap junctions (GJs) are the only known cellular structures that allow a direct cell-to-cell transfer of signaling molecules by forming densely packed arrays or "plaques" of hydrophilic channels that bridge the apposing membranes of neighboring cells. The crucial role of GJ-mediated intercellular communication (GJIC) for all aspects of multicellular life, including coordination of development, tissue function, and cell homeostasis, has been well documented. Assembly and degradation of these membrane channels is a complex process that includes biosynthesis of the connexin (Cx) subunit proteins (innexins in invertebrates) on endoplasmic reticulum (ER) membranes, oligomerization of compatible subunits into hexameric hemichannels (connexons), delivery of the connexons to the plasma membrane (PM), head-on docking of compatible connexons in the extracellular space at distinct locations, arrangement of channels into dynamic spatially and temporally organized GJ channel plaques, as well as internalization of GJs into the cytoplasm followed by their degradation. Clearly, precise modulation of GJIC, biosynthesis, and degradation are crucial for accurate function, and much research currently addresses how these fundamental processes are regulated. Here, we review posttranslational protein modifications (e.g., phosphorylation and ubiquitination) and the binding of protein partners (e.g., the scaffolding protein ZO-1) known to regulate GJ biosynthesis, internalization, and degradation. We also look closely at the atomic resolution structure of a GJ channel, since the structure harbors vital cues relevant to GJ biosynthesis and turnover.
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Affiliation(s)
- Anastasia F Thévenin
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, USA
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46
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Piper RC, Dikic I, Lukacs GL. Ubiquitin-dependent sorting in endocytosis. Cold Spring Harb Perspect Biol 2014; 6:6/1/a016808. [PMID: 24384571 DOI: 10.1101/cshperspect.a016808] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
When ubiquitin (Ub) is attached to membrane proteins on the plasma membrane, it directs them through a series of sorting steps that culminate in their delivery to the lumen of the lysosome where they undergo complete proteolysis. Ubiquitin is recognized by a series of complexes that operate at a number of vesicle transport steps. Ubiquitin serves as a sorting signal for internalization at the plasma membrane and is the major signal for incorporation into intraluminal vesicles of multivesicular late endosomes. The sorting machineries that catalyze these steps can bind Ub via a variety of Ub-binding domains. At the same time, many of these complexes are themselves ubiquitinated, thus providing a plethora of potential mechanisms to regulate their activity. Here we provide an overview of how membrane proteins are selected for ubiquitination and deubiquitination within the endocytic pathway and how that ubiquitin signal is interpreted by endocytic sorting machineries.
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Affiliation(s)
- Robert C Piper
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242
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47
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Spatiotemporal intracellular dynamics of neurotrophin and its receptors. Implications for neurotrophin signaling and neuronal function. Handb Exp Pharmacol 2014; 220:33-65. [PMID: 24668469 DOI: 10.1007/978-3-642-45106-5_3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Neurons possess a polarized morphology specialized to contribute to neuronal networks, and this morphology imposes an important challenge for neuronal signaling and communication. The physiology of the network is regulated by neurotrophic factors that are secreted in an activity-dependent manner modulating neuronal connectivity. Neurotrophins are a well-known family of neurotrophic factors that, together with their cognate receptors, the Trks and the p75 neurotrophin receptor, regulate neuronal plasticity and survival and determine the neuronal phenotype in healthy and regenerating neurons. Is it now becoming clear that neurotrophin signaling and vesicular transport are coordinated to modify neuronal function because disturbances of vesicular transport mechanisms lead to disturbed neurotrophin signaling and to diseases of the nervous system. This chapter summarizes our current understanding of how the regulated secretion of neurotrophin, the distribution of neurotrophin receptors in different locations of neurons, and the intracellular transport of neurotrophin-induced signaling in distal processes are achieved to allow coordinated neurotrophin signaling in the cell body and axons.
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48
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Baisa GA, Mayers JR, Bednarek SY. Budding and braking news about clathrin-mediated endocytosis. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:718-25. [PMID: 24139529 DOI: 10.1016/j.pbi.2013.09.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/20/2013] [Accepted: 09/23/2013] [Indexed: 05/07/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the predominate mechanism of endocytosis in eukaryotes, but an understanding of this mechanism in plants has lagged behind yeast and mammalian systems. The generation of Arabidopsis mutant libraries, and the development of the molecular tools and equipment necessary to characterize these plant lines has led to an astonishing number of new insights into the mechanisms of membrane trafficking in plants. Over the past few years progress has been made on identifying, and in some instances confirming, the core components of CME in plants. This review focuses on the recent progress made in the understanding of the mechanism and regulation of CME in plants.
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Affiliation(s)
- Gary A Baisa
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
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49
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Apaja PM, Foo B, Okiyoneda T, Valinsky WC, Barriere H, Atanasiu R, Ficker E, Lukacs GL, Shrier A. Ubiquitination-dependent quality control of hERG K+ channel with acquired and inherited conformational defect at the plasma membrane. Mol Biol Cell 2013; 24:3787-804. [PMID: 24152733 PMCID: PMC3861077 DOI: 10.1091/mbc.e13-07-0417] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Membrane trafficking in concert with the peripheral quality control machinery plays a critical role in preserving plasma membrane (PM) protein homeostasis. Unfortunately, the peripheral quality control may also dispose of partially or transiently unfolded polypeptides and thereby contribute to the loss-of-expression phenotype of conformational diseases. Defective functional PM expression of the human ether-a-go-go-related gene (hERG) K(+) channel leads to the prolongation of the ventricular action potential that causes long QT syndrome 2 (LQT2), with increased propensity for arrhythmia and sudden cardiac arrest. LQT2 syndrome is attributed to channel biosynthetic processing defects due to mutation, drug-induced misfolding, or direct channel blockade. Here we provide evidence that a peripheral quality control mechanism can contribute to development of the LQT2 syndrome. We show that PM hERG structural and metabolic stability is compromised by the reduction of extracellular or intracellular K(+) concentration. Cardiac glycoside-induced intracellular K(+) depletion conformationally impairs the complex-glycosylated channel, which provokes chaperone- and C-terminal Hsp70-interacting protein-dependent polyubiquitination, accelerated internalization, and endosomal sorting complex required for transport-dependent lysosomal degradation. A similar mechanism contributes to the down-regulation of PM hERG harboring LQT2 missense mutations, with incomplete secretion defect. These results suggest that PM quality control plays a determining role in the loss-of-expression phenotype of hERG in certain hereditary and acquired LTQ2 syndromes.
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Affiliation(s)
- Pirjo M Apaja
- Department of Physiology and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montréal, QC H3E 1Y6, Canada
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Lysine 63-linked polyubiquitination is required for EGF receptor degradation. Proc Natl Acad Sci U S A 2013; 110:15722-7. [PMID: 24019463 DOI: 10.1073/pnas.1308014110] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ubiquitination mediates endocytosis and endosomal sorting of various signaling receptors, transporters, and channels. However, the relative importance of mono- versus polyubiquitination and the role of specific types of polyubiquitin linkages in endocytic trafficking remain controversial. We used mass spectrometry-based targeted proteomics to show that activated epidermal growth factor receptor (EGFR) is ubiquitinated by one to two short (two to three ubiquitins) polyubiquitin chains mainly linked via lysine 63 (K63) or conjugated with a single monoubiquitin. Multimonoubiquitinated EGFR species were not found. To directly test whether K63 polyubiquitination is necessary for endocytosis and post-endocytic sorting of EGFR, a chimeric protein, in which the K63 linkage-specific deubiquitination enzyme AMSH [associated molecule with the Src homology 3 domain of signal transducing adaptor molecule (STAM)] was fused to the carboxyl terminus of EGFR, was generated. MS analysis of EGFR-AMSH ubiquitination demonstrated that the fraction of K63 linkages was substantially reduced, whereas relative amounts of monoubiquitin and K48 linkages increased, compared with that of wild-type EGFR. EGFR-AMSH was efficiently internalized into early endosomes, but, importantly, the rates of ligand-induced sorting to late endosomes and degradation of EGFR-AMSH were dramatically decreased. The slow degradation of EGFR-AMSH resulted in the sustained signaling activity of this chimeric receptor. Ubiquitination patterns, rate of endosomal sorting, and signaling kinetics of EGFR fused with the catalytically inactive mutant of AMSH were reversed to normal. Altogether, the data are consistent with the model whereby short K63-linked polyubiquitin chains but not multimonoubiquitin provide an increased avidity for EGFR interactions with ubiquitin adaptors, thus allowing rapid sorting of activated EGFR to the lysosomal degradation pathway.
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