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Tziouvara O, Petsana M, Kourounis D, Papadaki A, Basdra E, Braliou GG, Boleti H. Characterization of the First Secreted Sorting Nexin Identified in the Leishmania Protists. Int J Mol Sci 2024; 25:4095. [PMID: 38612903 PMCID: PMC11012638 DOI: 10.3390/ijms25074095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 04/14/2024] Open
Abstract
Proteins of the sorting nexin (SNX) family present a modular structural architecture with a phox homology (PX) phosphoinositide (PI)-binding domain and additional PX structural domains, conferring to them a wide variety of vital eukaryotic cell's functions, from signal transduction to membrane deformation and cargo binding. Although SNXs are well studied in human and yeasts, they are poorly investigated in protists. Herein, is presented the characterization of the first SNX identified in Leishmania protozoan parasites encoded by the LdBPK_352470 gene. In silico secondary and tertiary structure prediction revealed a PX domain on the N-terminal half and a Bin/amphiphysin/Rvs (BAR) domain on the C-terminal half of this protein, with these features classifying it in the SNX-BAR subfamily of SNXs. We named the LdBPK_352470.1 gene product LdSNXi, as it is the first SNX identified in Leishmania (L.) donovani. Its expression was confirmed in L. donovani promastigotes under different cell cycle phases, and it was shown to be secreted in the extracellular medium. Using an in vitro lipid binding assay, it was demonstrated that recombinant (r) LdSNXi (rGST-LdSNXi) tagged with glutathione-S-transferase (GST) binds to the PtdIns3P and PtdIns4P PIs. Using a specific a-LdSNXi antibody and immunofluorescence confocal microscopy, the intracellular localization of endogenous LdSNXi was analyzed in L. donovani promastigotes and axenic amastigotes. Additionally, rLdSNXi tagged with enhanced green fluorescent protein (rLdSNXi-EGFP) was heterologously expressed in transfected HeLa cells and its localization was examined. All observed localizations suggest functions compatible with the postulated SNX identity of LdSNXi. Sequence, structure, and evolutionary analysis revealed high homology between LdSNXi and the human SNX2, while the investigation of protein-protein interactions based on STRING (v.11.5) predicted putative molecular partners of LdSNXi in Leishmania.
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Affiliation(s)
- Olympia Tziouvara
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Marina Petsana
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2–4 Papasiopoulou Str., 35131 Lamia, Greece;
| | - Drosos Kourounis
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
| | - Amalia Papadaki
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
| | - Efthimia Basdra
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Georgia G. Braliou
- Department of Computer Science and Biomedical Informatics, University of Thessaly, 2–4 Papasiopoulou Str., 35131 Lamia, Greece;
| | - Haralabia Boleti
- Intracellular Parasitism Group, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece; (O.T.); (M.P.); (D.K.); (A.P.)
- Bioimaging Unit, Hellenic Pasteur Institute, 11521 Athens, Greece
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Clippinger AK, Naismith TV, Yoo W, Jansen S, Kast DJ, Hanson PI. IST1 regulates select recycling pathways. Traffic 2024; 25:e12921. [PMID: 37926552 PMCID: PMC11027954 DOI: 10.1111/tra.12921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 08/21/2023] [Accepted: 09/23/2023] [Indexed: 11/07/2023]
Abstract
ESCRTs (Endosomal Sorting Complex Required for Transports) are a modular set of protein complexes with membrane remodeling activities that include the formation and release of intraluminal vesicles (ILVs) to generate multivesicular endosomes. While most of the 12 ESCRT-III proteins are known to play roles in ILV formation, IST1 has been associated with a wider range of endosomal remodeling events. Here, we extend previous studies of IST1 function in endosomal trafficking and confirm that IST1, along with its binding partner CHMP1B, contributes to scission of early endosomal carriers. Functionally, depleting IST1 impaired delivery of transferrin receptor from early/sorting endosomes to the endocytic recycling compartment and instead increased its rapid recycling to the plasma membrane via peripheral endosomes enriched in the clathrin adaptor AP-1. IST1 is also important for export of mannose 6-phosphate receptor from early/sorting endosomes. Examination of IST1 binding partners on endosomes revealed that IST1 interacts with the MIT domain-containing sorting nexin SNX15, a protein previously reported to regulate endosomal recycling. Our kinetic and spatial analyses establish that SNX15 and IST1 occupy a clathrin-containing subdomain on the endosomal perimeter distinct from those previously implicated in cargo retrieval or degradation. Using live-cell microscopy, we see that SNX15 and CHMP1B alternately recruit IST1 to this subdomain or the base of endosomal tubules. These findings indicate that IST1 contributes to a subset of recycling pathways from the early/sorting endosome.
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Affiliation(s)
- Amy K Clippinger
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Teresa V Naismith
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Wonjin Yoo
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Silvia Jansen
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - David J Kast
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Phyllis I Hanson
- Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Arlt H, Raman B, Filali-Mouncef Y, Hu Y, Leytens A, Hardenberg R, Guimarães R, Kriegenburg F, Mari M, Smaczynska-de Rooij II, Ayscough KR, Dengjel J, Ungermann C, Reggiori F. The dynamin Vps1 mediates Atg9 transport to the sites of autophagosome formation. J Biol Chem 2023; 299:104712. [PMID: 37060997 DOI: 10.1016/j.jbc.2023.104712] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/14/2023] [Accepted: 04/06/2023] [Indexed: 04/17/2023] Open
Abstract
Autophagy is a key process in eukaryotes to maintain cellular homeostasis by delivering cellular components to lysosomes/vacuoles for degradation and reuse of the resulting metabolites. Membrane rearrangements and trafficking events are mediated by the core machinery of autophagy-related (Atg) proteins, which carry out a variety of functions. How Atg9, a lipid scramblase and the only conserved transmembrane protein within this core Atg machinery, is trafficked during autophagy remained largely unclear. Here, we addressed this question in yeast Saccharomyces cerevisiae and found that retromer complex and dynamin Vps1 mutants alter Atg9 subcellular distribution and severely impair the autophagic flux by affecting two separate autophagy steps. We provide evidence that Vps1 interacts with Atg9 at Atg9 reservoirs. In the absence of Vps1, Atg9 fails to reach the sites of autophagosome formation, and this results in an autophagy defect. The function of Vps1 in autophagy requires its GTPase activity. Moreover, Vps1 point mutants associated with human diseases such as microcytic anemia and Charcot-Marie-Tooth are unable to sustain autophagy and affect Atg9 trafficking. Together, our data provide novel insights on the role of dynamins in Atg9 trafficking and suggest that a defect in this autophagy step could contribute to severe human pathologies.
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Affiliation(s)
- Henning Arlt
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Babu Raman
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Yasmina Filali-Mouncef
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Yan Hu
- Department of Biomedicine, Aarhus University, Ole Worms Allé 4, 8000 Aarhus C, Denmark
| | - Alexandre Leytens
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Ralph Hardenberg
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Rodrigo Guimarães
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Franziska Kriegenburg
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Muriel Mari
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedicine, Aarhus University, Ole Worms Allé 4, 8000 Aarhus C, Denmark
| | | | - Kathryn R Ayscough
- Department of Biomedical Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Jörn Dengjel
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland
| | - Christian Ungermann
- University of Osnabrück, Department of Biology/Chemistry, Biochemistry section, Barbarastrasse 13, 49076 Osnabrück, Germany
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Biomedicine, Aarhus University, Ole Worms Allé 4, 8000 Aarhus C, Denmark; Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Høegh-Guldbergs Gade 6B, 8000 Aarhus C, Denmark.
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4
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Huang J, Tiu AC, Jose PA, Yang J. Sorting nexins: role in the regulation of blood pressure. FEBS J 2023; 290:600-619. [PMID: 34847291 PMCID: PMC9149145 DOI: 10.1111/febs.16305] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 10/13/2021] [Accepted: 11/29/2021] [Indexed: 02/06/2023]
Abstract
Sorting nexins (SNXs) are a family of proteins that regulate cellular cargo sorting and trafficking, maintain intracellular protein homeostasis, and participate in intracellular signaling. SNXs are also important in the regulation of blood pressure via several mechanisms. Aberrant expression and dysfunction of SNXs participate in the dysregulation of blood pressure. Genetic studies show a correlation between SNX gene variants and the response to antihypertensive drugs. In this review, we summarize the progress in SNX-mediated regulation of blood pressure, discuss the potential role of SNXs in the pathophysiology and treatment of hypertension, and propose novel strategies for the medical therapy of hypertension.
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Affiliation(s)
- Juan Huang
- Department of Clinical Nutrition, The Third Affiliated Hospital of Chongqing Medical University, Chongqing 410020, P.R. China
| | - Andrew C. Tiu
- Department of Medicine, Einstein Medical Center Philadelphia, Philadelphia, PA 19141, USA
| | - Pedro A. Jose
- Division of Renal Diseases & Hypertension, Department of Medicine, and Department of Physiology and Pharmacology, The George Washington University School of Medicine & Health Sciences, Washington, DC 20052, USA
| | - Jian Yang
- Department of Clinical Nutrition, The Third Affiliated Hospital of Chongqing Medical University, Chongqing 410020, P.R. China
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5
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Deb S, Sun J. Endosomal Sorting Protein SNX27 and Its Emerging Roles in Human Cancers. Cancers (Basel) 2022; 15:cancers15010070. [PMID: 36612066 PMCID: PMC9818000 DOI: 10.3390/cancers15010070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/14/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
SNX27 belongs to the sorting nexin (SNX) family of proteins that play a critical role in protein sorting and trafficking in the endocytosis pathway. This protein family is characterized by the presence of a Phox (PX) domain; however, SNX27 is unique in containing an additional PDZ domain. Recently, SNX27 has gained popularity as an important sorting protein that is associated with the retromer complex and mediates the recycling of internalized proteins from endosomes to the plasma membrane in a PDZ domain-dependent manner. Over 100 cell surface proteins have been identified as binding partners of the SNX27-retromer complex. However, the roles and underlying mechanisms governed by SNX27 in tumorigenesis remains to be poorly understood. Many of its known binding partners include several G-protein coupled receptors, such as β2-andrenergic receptor and parathyroid hormone receptor, are associated with multiple pathways implicated in oncogenic signaling and tumorigenesis. Additionally, SNX27 mediates the recycling of GLUT1 and the activation of mTORC1, both of which can regulate intracellular energy balance and promote cell survival and proliferation under conditions of nutrient deprivation. In this review, we summarize the structure and fundamental roles of SNX proteins, with a focus on SNX27, and provide the current evidence indicating towards the role of SNX27 in human cancers. We also discuss the gap in the field and future direction of SNX27 research. Insights into the emerging roles and mechanism of SNX27 in cancers will provide better development strategies to prevent and treat tumorigenesis.
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Affiliation(s)
- Shreya Deb
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Jun Sun
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612, USA
- University of Illinois at Chicago (UIC) Cancer Center, University of Illinois at Chicago, Chicago, IL 60612, USA
- Jesse Brown VA Medical Center, Chicago, IL 60612, USA
- Correspondence: ; Tel.: +1-312-996-5020
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6
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Overduin M, Tran A, Eekels DM, Overduin F, Kervin TA. Transmembrane Membrane Readers form a Novel Class of Proteins That Include Peripheral Phosphoinositide Recognition Domains and Viral Spikes. Membranes (Basel) 2022; 12:1161. [PMID: 36422153 PMCID: PMC9692390 DOI: 10.3390/membranes12111161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/11/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Membrane proteins are broadly classified as transmembrane (TM) or peripheral, with functions that pertain to only a single bilayer at a given time. Here, we explicate a class of proteins that contain both transmembrane and peripheral domains, which we dub transmembrane membrane readers (TMMRs). Their transmembrane and peripheral elements anchor them to one bilayer and reversibly attach them to another section of bilayer, respectively, positioning them to tether and fuse membranes while recognizing signals such as phosphoinositides (PIs) and modifying lipid chemistries in proximity to their transmembrane domains. Here, we analyze full-length models from AlphaFold2 and Rosetta, as well as structures from nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, using the Membrane Optimal Docking Area (MODA) program to map their membrane-binding surfaces. Eukaryotic TMMRs include phospholipid-binding C1, C2, CRAL-TRIO, FYVE, GRAM, GTPase, MATH, PDZ, PH, PX, SMP, StART and WD domains within proteins including protrudin, sorting nexins and synaptotagmins. The spike proteins of SARS-CoV-2 as well as other viruses are also TMMRs, seeing as they are anchored into the viral membrane while mediating fusion with host cell membranes. As such, TMMRs have key roles in cell biology and membrane trafficking, and include drug targets for diseases such as COVID-19.
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Affiliation(s)
- Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Anh Tran
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | | | - Finn Overduin
- Institute of Nutritional Science, University of Potsdam, 14476 Potsdam, Germany
| | - Troy A. Kervin
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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7
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Simonetti B, Daly JL, Simón-Gracia L, Klein K, Weeratunga S, Antón-Plágaro C, Tobi A, Hodgson L, Lewis PA, Heesom KJ, Shoemark DK, Davidson AD, Collins BM, Teesalu T, Yamauchi Y, Cullen PJ. ESCPE-1 mediates retrograde endosomal sorting of the SARS-CoV-2 host factor Neuropilin-1. Proc Natl Acad Sci U S A 2022; 119:e2201980119. [PMID: 35696571 DOI: 10.1073/pnas.2201980119] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Endosomal sorting maintains cellular homeostasis by recycling transmembrane proteins and associated proteins and lipids (termed "cargoes") from the endosomal network to multiple subcellular destinations, including retrograde traffic to the trans-Golgi network (TGN). Viral and bacterial pathogens subvert retrograde trafficking machinery to facilitate infectivity. Here, we develop a proteomic screen to identify retrograde cargo proteins of the endosomal SNX-BAR sorting complex promoting exit 1 (ESCPE-1). Using this methodology, we identify Neuropilin-1 (NRP1), a recently characterized host factor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as a cargo directly bound and trafficked by ESCPE-1. ESCPE-1 mediates retrograde trafficking of engineered nanoparticles functionalized with the NRP1-interacting peptide of the SARS-CoV-2 spike (S) protein. CRISPR-Cas9 deletion of ESCPE-1 subunits reduces SARS-CoV-2 infection levels in cell culture. ESCPE-1 sorting of NRP1 may therefore play a role in the intracellular membrane trafficking of NRP1-interacting viruses such as SARS-CoV-2.
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8
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Liang C, Li C, Wu J, Zhao M, Chen D, Liu C, Chu J, Zhang W, Hwang I, Wang M. SORTING NEXIN2 proteins mediate stomatal movement and the response to drought stress by modulating trafficking and protein levels of the ABA exporter ABCG25. Plant J 2022; 110:1603-1618. [PMID: 35384109 DOI: 10.1111/tpj.15758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 03/23/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
The phytohormone abscisic acid (ABA) regulates ion channel activity and stomatal movement in response to drought stress. Cellular ABA levels change depending on cellular and environmental conditions via modulation of its biosynthesis, catabolism and transport. Although factors involved in ABA biosynthesis and degradation have been studied extensively, how ABA transporters are modulated to fine-tune ABA levels, especially under drought stress, remains elusive. Here, we show that Arabidopsis thaliana SORTING NEXIN 2 (SNX2) proteins play a critical role in endosomal trafficking of the ABA exporter ATP BINDING CASETTE G25 (ABCG25) via direct interaction at endosomes, leading to its degradation in the vacuole. In agreement, snx2a and snx2b mutant plants showed enhanced recycling of GFP-ABCG25 from early endosomes to the plasma membrane and higher accumulation of GFP-ABCG25. Phenotypically, snx2a and snx2b plants were highly sensitive to exogenous ABA and displayed enhanced ABA-mediated inhibition of inward K+ currents and ABA-mediated activation of slow anion currents in guard cells, resulting in an increased tolerance to drought stress. Based on these results, we propose that SNX2 proteins play a crucial role in stomatal movement and tolerance to drought stress by modulating the endosomal trafficking of ABCG25 and thus cellular ABA levels.
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Affiliation(s)
- Chaochao Liang
- Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China
| | - Chunlong Li
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, P.R. China
| | - Jing Wu
- Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China
| | - Min Zhao
- Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China
| | - Donghua Chen
- Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China
| | - Cuimei Liu
- National Centre for Plant Gene Research (Beijing), Innovation Academy for Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, P.R. China
| | - Jinfang Chu
- National Centre for Plant Gene Research (Beijing), Innovation Academy for Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, P.R. China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100039, P.R. China
| | - Wei Zhang
- Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 790-784, South Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, South Korea
| | - Mei Wang
- Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China
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Koyama-Honda I, Mizushima N. Transient visit of STX17 (syntaxin 17) to autophagosomes. Autophagy 2022; 18:1213-1215. [PMID: 35613317 DOI: 10.1080/15548627.2022.2079337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
STX17 (syntaxin 17) mediates autophagosome-lysosome fusion, and the translocation of STX17 to autophagosomes is characteristic of this process. STX17 arrives at autophagosomes when they are closed, stays there for approximately 10 min to promote fusion with lysosomes, and leaves when the autolysosomes are mature. However, the mechanism of this transient visit remains largely unknown. Here, we summarize the current knowledge about this phenomenon, including a recently discovered retrieval mechanism, and discuss remaining questions.Abbreviations: MAM: mitochondria-associated membrane; SNX: sorting nexin; STX17: syntaxin 17.
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Affiliation(s)
- Ikuko Koyama-Honda
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
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Podinovskaia M, Prescianotto-Baschong C, Buser DP, Spang A. A novel live-cell imaging assay reveals regulation of endosome maturation. eLife 2021; 10:e70982. [PMID: 34846303 PMCID: PMC8635980 DOI: 10.7554/elife.70982] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/09/2021] [Indexed: 12/12/2022] Open
Abstract
Cell-cell communication is an essential process in life, with endosomes acting as key organelles for regulating uptake and secretion of signaling molecules. Endocytosed material is accepted by the sorting endosome where it either is sorted for recycling or remains in the endosome as it matures to be degraded in the lysosome. Investigation of the endosome maturation process has been hampered by the small size and rapid movement of endosomes in most cellular systems. Here, we report an easy versatile live-cell imaging assay to monitor endosome maturation kinetics, which can be applied to a variety of mammalian cell types. Acute ionophore treatment led to enlarged early endosomal compartments that matured into late endosomes and fused with lysosomes to form endolysosomes. Rab5-to-Rab7 conversion and PI(3)P formation and turn over were recapitulated with this assay and could be observed with a standard widefield microscope. We used this approach to show that Snx1 and Rab11-positive recycling endosome recruitment occurred throughout endosome maturation and was uncoupled from Rab conversion. In contrast, efficient endosomal acidification was dependent on Rab conversion. The assay provides a powerful tool to further unravel various aspects of endosome maturation.
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Affiliation(s)
| | | | | | - Anne Spang
- Biozentrum, University of BaselBaselSwitzerland
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11
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Yang Z, Li Z, Teasdale RD. Retromer dependent changes in cellular homeostasis and Parkinson's disease. Essays Biochem 2021:EBC20210023. [PMID: 34528672 DOI: 10.1042/EBC20210023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 12/18/2022]
Abstract
To date, mechanistic treatments targeting the initial cause of Parkinson's disease (PD) are limited due to the underlying biological cause(s) been unclear. Endosomes and their associated cellular homeostasis processes have emerged to have a significant role in the pathophysiology associated with PD. Several variants within retromer complex have been identified and characterised within familial PD patients. The retromer complex represents a key sorting platform within the endosomal system that regulates cargo sorting that maintains cellular homeostasis. In this review, we summarise the current understandings of how PD-associated retromer variants disrupt cellular trafficking and how the retromer complex can interact with other PD-associated genes to contribute to the disease progression.
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12
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Yong X, Zhao L, Hu W, Sun Q, Ham H, Liu Z, Ren J, Zhang Z, Zhou Y, Yang Q, Mo X, Hu J, Billadeau DD, Jia D. SNX27-FERM-SNX1 complex structure rationalizes divergent trafficking pathways by SNX17 and SNX27. Proc Natl Acad Sci U S A 2021; 118:e2105510118. [PMID: 34462354 DOI: 10.1073/pnas.2105510118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The molecular events that determine the recycling versus degradation fates of internalized membrane proteins remain poorly understood. Two of the three members of the SNX-FERM family, SNX17 and SNX31, utilize their FERM domain to mediate endocytic trafficking of cargo proteins harboring the NPxY/NxxY motif. In contrast, SNX27 does not recycle NPxY/NxxY-containing cargo but instead recycles cargo containing PDZ-binding motifs via its PDZ domain. The underlying mechanism governing this divergence in FERM domain binding is poorly understood. Here, we report that the FERM domain of SNX27 is functionally distinct from SNX17 and interacts with a novel DLF motif localized within the N terminus of SNX1/2 instead of the NPxY/NxxY motif in cargo proteins. The SNX27-FERM-SNX1 complex structure reveals that the DLF motif of SNX1 binds to a hydrophobic cave surrounded by positively charged residues on the surface of SNX27. The interaction between SNX27 and SNX1/2 is critical for efficient SNX27 recruitment to endosomes and endocytic recycling of multiple cargoes. Finally, we show that the interaction between SNX27 and SNX1/2 is critical for brain development in zebrafish. Altogether, our study solves a long-standing puzzle in the field and suggests that SNX27 and SNX17 mediate endocytic recycling through fundamentally distinct mechanisms.
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13
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Yong XLH, Zhang L, Yang L, Chen X, Tan JZA, Yu X, Chandra M, Livingstone E, Widagdo J, Vieira MM, Roche KW, Lynch JW, Keramidas A, Collins BM, Anggono V. Regulation of NMDA receptor trafficking and gating by activity-dependent CaMKIIα phosphorylation of the GluN2A subunit. Cell Rep 2021; 36:109338. [PMID: 34233182 PMCID: PMC8313361 DOI: 10.1016/j.celrep.2021.109338] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/19/2021] [Accepted: 06/11/2021] [Indexed: 01/23/2023] Open
Abstract
NMDA receptor (NMDAR)-dependent Ca2+ influx underpins multiple forms of synaptic plasticity. Most synaptic NMDAR currents in the adult forebrain are mediated by GluN2A-containing receptors, which are rapidly inserted into synapses during long-term potentiation (LTP); however, the underlying molecular mechanisms remain poorly understood. In this study, we show that GluN2A is phosphorylated at Ser-1459 by Ca2+/calmodulin-dependent kinase IIα (CaMKIIα) in response to glycine stimulation that mimics LTP in primary neurons. Phosphorylation of Ser-1459 promotes GluN2A interaction with the sorting nexin 27 (SNX27)-retromer complex, thereby enhancing the endosomal recycling of NMDARs. Loss of SNX27 or CaMKIIα function blocks the glycine-induced increase in GluN2A-NMDARs on the neuronal membrane. Interestingly, mutations of Ser-1459, including the rare S1459G human epilepsy variant, prolong the decay times of NMDAR-mediated synaptic currents in heterosynapses by increasing the duration of channel opening. These findings not only identify a critical role of Ser-1459 phosphorylation in regulating the function of NMDARs, but they also explain how the S1459G variant dysregulates NMDAR function.
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Affiliation(s)
- Xuan Ling Hilary Yong
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Lingrui Zhang
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Liming Yang
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xiumin Chen
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jing Zhi Anson Tan
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Xiaojun Yu
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Mintu Chandra
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Emma Livingstone
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Marta M Vieira
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joseph W Lynch
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Angelo Keramidas
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, QLD 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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14
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Abstract
The retromer complex was first identified more than 20 years ago through studies conducted in the yeast Saccharomyces cerevisiae. Data obtained using many different model systems have revealed that retromer is a key component of the endosomal protein sorting machinery being necessary for recognition of membrane “cargo” proteins and formation of tubular carriers that function as transport intermediates. Naturally, over the course of time and with literally hundreds of papers published on retromer, there have arisen disparities, conflicting observations and some controversies as to how retromer functions in endosomal protein sorting – the most note-worthy being associated with the two activities that define a vesicle coat: cargo selection and vesicle/tubule formation. In this review, we will attempt to chart a course through some of the more fundamental controversies to arrive at a clearer understanding of retromer.
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Affiliation(s)
- Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Matthew N J Seaman
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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15
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Elson A, Stein M, Rabie G, Barnea-Zohar M, Winograd-Katz S, Reuven N, Shalev M, Sekeres J, Kanaan M, Tuckermann J, Geiger B. Sorting Nexin 10 as a Key Regulator of Membrane Trafficking in Bone-Resorbing Osteoclasts: Lessons Learned From Osteopetrosis. Front Cell Dev Biol 2021; 9:671210. [PMID: 34095139 PMCID: PMC8173195 DOI: 10.3389/fcell.2021.671210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/23/2021] [Indexed: 12/30/2022] Open
Abstract
Bone homeostasis is a complex, multi-step process, which is based primarily on a tightly orchestrated interplay between bone formation and bone resorption that is executed by osteoblasts and osteoclasts (OCLs), respectively. The essential physiological balance between these cells is maintained and controlled at multiple levels, ranging from regulated gene expression to endocrine signals, yet the underlying cellular and molecular mechanisms are still poorly understood. One approach for deciphering the mechanisms that regulate bone homeostasis is the characterization of relevant pathological states in which this balance is disturbed. In this article we describe one such “error of nature,” namely the development of acute recessive osteopetrosis (ARO) in humans that is caused by mutations in sorting nexin 10 (SNX10) that affect OCL functioning. We hypothesize here that, by virtue of its specific roles in vesicular trafficking, SNX10 serves as a key selective regulator of the composition of diverse membrane compartments in OCLs, thereby affecting critical processes in the sequence of events that link the plasma membrane with formation of the ruffled border and with extracellular acidification. As a result, SNX10 determines multiple features of these cells either directly or, as in regulation of cell-cell fusion, indirectly. This hypothesis is further supported by the similarities between the cellular defects observed in OCLs form various models of ARO, induced by mutations in SNX10 and in other genes, which suggest that mutations in the known ARO-associated genes act by disrupting the same plasma membrane-to-ruffled border axis, albeit to different degrees. In this article, we describe the population genetics and spread of the original arginine-to-glutamine mutation at position 51 (R51Q) in SNX10 in the Palestinian community. We further review recent studies, conducted in animal and cellular model systems, that highlight the essential roles of SNX10 in critical membrane functions in OCLs, and discuss possible future research directions that are needed for challenging or substantiating our hypothesis.
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Affiliation(s)
- Ari Elson
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
| | - Merle Stein
- Institute of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Grace Rabie
- Hereditary Research Laboratory and Department of Life Sciences, Bethlehem University, Bethlehem, Palestine
| | - Maayan Barnea-Zohar
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
| | | | - Nina Reuven
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
| | - Moran Shalev
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
| | - Juraj Sekeres
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
| | - Moien Kanaan
- Hereditary Research Laboratory and Department of Life Sciences, Bethlehem University, Bethlehem, Palestine
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany
| | - Benjamin Geiger
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
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16
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Seaman MNJ. The Retromer Complex: From Genesis to Revelations. Trends Biochem Sci 2021; 46:608-620. [PMID: 33526371 DOI: 10.1016/j.tibs.2020.12.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/13/2022]
Abstract
The retromer complex has a well-established role in endosomal protein sorting, being necessary for maintaining the dynamic localisation of hundreds of membrane proteins that traverse the endocytic system. Retromer function and dysfunction is linked with neurodegenerative diseases, including Alzheimer's and Parkinson's disease, and many pathogens, both viral and bacterial, exploit or interfere in retromer function for their own ends. In this review, the history of retromer is distilled into a concentrated form that spans the identification of retromer to recent discoveries that have shed new light on how retromer functions in endosomal protein sorting and why retromer is increasingly being viewed as a potential therapeutic target in neurodegenerative disease.
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Affiliation(s)
- Matthew N J Seaman
- University of Cambridge, Cambridge Institute for Medical Research, The Keith Peters Building, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK.
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17
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Abstract
Eukaryotic cells employ diverse uptake mechanisms depending on their specialized functions. While such mechanisms vary widely in their defining criteria: scale, molecular machinery utilized, cargo selection, and cargo destination, to name a few, they all result in the internalization of extracellular solutes and fluid into membrane-bound endosomes. Upon scission from the plasma membrane, this compartment is immediately subjected to extensive remodeling which involves tubulation and vesiculation/budding of the limiting endomembrane. This is followed by a maturation process involving concomitant retrograde transport by microtubule-based motors and graded fusion with late endosomes and lysosomes, organelles that support the degradation of the internalized content. Here we review an important determinant for sorting and trafficking in early endosomes and in lysosomes; the control of tension on the endomembrane. Remodeling of endomembranes is opposed by high tension (caused by high hydrostatic pressure) and supported by the relief of tension. We describe how the timely and coordinated efflux of major solutes along the endocytic pathway affords the cell control over such tension. The channels and transporters that expel the smallest components of the ingested medium from the early endocytic fluid are described in detail as these systems are thought to enable endomembrane deformation by curvature-sensing/generating coat proteins. We also review similar considerations for the lysosome where resident hydrolases liberate building blocks from luminal macromolecules and transporters flux these organic solutes to orchestrate trafficking events. How the cell directs organellar trafficking based on the luminal contents of organelles of the endocytic pathway is not well-understood, however, we propose that the control over membrane tension by solute transport constitutes one means for this to ensue.
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Affiliation(s)
- Amra Saric
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Spencer A Freeman
- Program in Cell Biology, Peter Gilgan Center for Research and Learning, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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18
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DuChez BJ, Hueschen CL, Zimmerman SP, Baumer Y, Wincovitch S, Playford MP. Characterization of the interaction between β-catenin and sorting nexin 27: contribution of the type I PDZ-binding motif to Wnt signaling. Biosci Rep 2019; 39:BSR20191692. [PMID: 31696214 DOI: 10.1042/BSR20191692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/05/2019] [Accepted: 10/16/2019] [Indexed: 12/31/2022] Open
Abstract
Background: Sorting Nexin 27 (SNX27) is a 62-kDa protein localized to early endosomes and known to regulate the intracellular trafficking of ion channels and receptors. In addition to a PX domain common among all of the sorting nexin family, SNX27 is the only sorting family member that contains a PDZ domain. To identify novel SNX27–PDZ binding partners, we performed a proteomic screen in mouse principal kidney cortical collecting duct cells (mpkCCD) using a GST-SNX27 fusion construct as bait. We found that the C-terminal type I PDZ binding motif (DTDL) of β-catenin, an adherens junction scaffolding protein and transcriptional co-activator, interacts directly with SNX27. Using biochemical and immunofluorescent techniques, β-catenin was identified in endosomal compartments where co-localization with SNX27 was observed. Furthermore, E-cadherin, but not Axin, GSK3 or Lef-1 was located in SNX27 protein complexes. While overexpression of wild-type β-catenin protein increased TCF-LEF dependent transcriptional activity, an enhanced transcriptional activity was not observed in cells expressing β-Catenin ΔFDTDL or diminished SNX27 expression. These results imply importance of the C-terminal PDZ binding motif for the transcriptional activity of β-catenin and propose that SNX27 might be involved in the assembly of β-catenin complexes in the endosome.
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19
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You Y, Bao WL, Zhang SL, Li HD, Li H, Dang WZ, Zou SL, Cao XY, Wang X, Liu LX, Jiang H, Qu LF, Zheng M, Shen X. Sorting Nexin 10 Mediates Metabolic Reprogramming of Macrophages in Atherosclerosis Through the Lyn-Dependent TFEB Signaling Pathway. Circ Res 2020; 127:534-549. [PMID: 32316875 DOI: 10.1161/circresaha.119.315516] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
RATIONALE SNX10 (sorting nexin 10) has been reported to play a critical role in regulating macrophage function and lipid metabolism. OBJECTIVE To investigate the precise role of SNX10 in atherosclerotic diseases and the underlying mechanisms. METHODS AND RESULTS SNX10 expression was compared between human healthy vessels and carotid atherosclerotic plaques. Myeloid cell-specific SNX10 knockdown mice were crossed onto the APOE-/- (apolipoprotein E) background and atherogenesis (high-cholesterol diet-induced) was monitored for 16 weeks. We found that SNX10 expression was increased in atherosclerotic lesions of aortic specimens from humans and APOE-/- mice. Myeloid cell-specific SNX10 deficiency (Δ knockout [KO]) attenuated atherosclerosis progression in APOE-/- mice. The population of anti-inflammatory monocytes/macrophages was increased in the peripheral blood and atherosclerotic lesions of ΔKO mice. In vitro experiments showed that SNX10 deficiency-inhibited foam cell formation through interrupting the internalization of CD36, which requires the interaction of SNX10 and Lyn-AKT (protein kinase B). The reduced Lyn-AKT activation by SNX10 deficiency promoted the nuclear translocation of TFEB (transcription factor EB), thereby enhanced lysosomal biogenesis and LAL (lysosomal acid lipase) activity, resulting in an increase of free fatty acids to fuel mitochondrial fatty acid oxidation. This further promoted the reprogramming of macrophages and shifted toward the anti-inflammatory phenotype. CONCLUSIONS Our data demonstrate for the first time that SNX10 plays a crucial role in diet-induced atherogenesis via the previously unknown link between the Lyn-Akt-TFEB signaling pathway and macrophage reprogramming, suggest that SNX10 may be a potentially promising therapeutic target for atherosclerosis treatment.
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Affiliation(s)
- Yan You
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.).,National Institute of Allergy and Infectious, National Institute of Health, Rockville, MD (Y. You)
| | - Wei-Lian Bao
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Su-Lin Zhang
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Hai-Dong Li
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Hui Li
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Wen-Zhen Dang
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Si-Li Zou
- Department of Vascular and Endovascular Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China (S.-L. Zou, L.-F.Q.)
| | - Xin-Yue Cao
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Xu Wang
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Li-Xin Liu
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
| | - Hualiang Jiang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China (H.J., M.Z.)
| | - Le-Feng Qu
- Department of Vascular and Endovascular Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China (S.-L. Zou, L.-F.Q.)
| | - Mingyue Zheng
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China (H.J., M.Z.)
| | - Xiaoyan Shen
- From the Department of Pharmacology & the Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai, China (Y.Y., W.-L.B., S.-l. Zhang, H.-D.L., H.L., W.-Z.D., X.-Y.C., X.W., L.-X.L., X.S.)
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20
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Geng L, Wang S, Zhang F, Xiong K, Huang J, Zhao T, Shi D, Lv F, Li L, Liang D, Cui Y, Liu Y, Xie D, Chen YH. SNX17 ( Sorting Nexin 17) Mediates Atrial Fibrillation Onset Through Endocytic Trafficking of the Kv1.5 (Potassium Voltage-Gated Channel Subfamily A Member 5) Channel. Circ Arrhythm Electrophysiol 2020; 12:e007097. [PMID: 30939909 DOI: 10.1161/circep.118.007097] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Kv1.5 (Potassium voltage-gated channel subfamily A member 5) has been regarded as a promising target of interventions for atrial fibrillation (AF). SNX17 (sorting nexin 17), a member of the SNXs (sorting nexin family), regulates the intracellular trafficking of membrane proteins through its FERM (four-point-one, ezrin, radixin, moesin) domain. However, whether SNX17 regulates the trafficking process of Kv1.5 remains unknown. METHODS A SNX17 knockout rat line was generated to test the role of SNX17 in atrial electrophysiology. The protein expression of SNX17 and membrane ion channels was detected by Western blotting. Electrophysiology changes in the atrial tissue and myocytes were analyzed by optical mapping and patch clamp, respectively. Acetylcholine and electrical stimulation were used to induce AF, and ECG recording was adopted to assess the influence of SNX17 deficiency on AF susceptibility. The spatial relationship between Kv1.5 and SNX17 was evaluated by immunostaining and confocal scanning, and the functional region of SNX17 regulating Kv1.5 trafficking was identified using plasmids with truncated SNX17 domains. RESULTS Embryonic death occurred in homozygous SNX17 knockout rats. SNX17 heterozygous rats survived, and the level of the SNX17 protein in the atrium was decreased by ≈50%. SNX17 deficiency increased the membrane expression of Kv1.5 and atria-specific ultrarapid delayed rectifier outward potassium current ( IKur) density, resulting in a shortened action potential duration, and eventually contributing to AF susceptibility. Mechanistically, SNX17 facilitated the endocytic sorting of Kv1.5 from the plasma membrane to early endosomes via the FERM domain. CONCLUSIONS SNX17 mediates susceptibility to AF by regulating endocytic sorting of the Kv1.5 channel through the FERM domain. SNX17 could be a potential target for the development of new drugs for AF.
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Affiliation(s)
- Li Geng
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Shuo Wang
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Fulei Zhang
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Ke Xiong
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Jian Huang
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Tingting Zhao
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Dan Shi
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Fei Lv
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Li Li
- Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Dandan Liang
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Yingyu Cui
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Yi Liu
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
| | - Duanyang Xie
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,School of Life Science and Technology (D.X.), Tongji University, Shanghai, China
| | - Yi-Han Chen
- Key Laboratory of Arrhythmias of the Ministry of Education of East Hospital (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China.,Institute of Medical Genetics (L.G., S.W., F.Z., K.X., J.H., T.Z., D.S., F.L., L.L., D.L., Y.C., Y.L., D.X., Y.-H.C.), Tongji University, Shanghai, China
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Parente DJ, Morris SM, McKinstry RC, Brandt T, Gabau E, Ruiz A, Shinawi M. Sorting nexin 27 (SNX27) variants associated with seizures, developmental delay, behavioral disturbance, and subcortical brain abnormalities. Clin Genet 2019; 97:437-446. [PMID: 31721175 DOI: 10.1111/cge.13675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 11/27/2022]
Abstract
Sorting nexin 27 (SNX27) influences the composition of the cellular membrane via regulation of selective endosomal recycling. Molecular analysis indicates that SNX27 regulates numerous cellular processes through promiscuous interactions with its receptor cargos. SNX27 deficient (Snx27 -/- ) mice exhibit reduced embryonic survival, marked postnatal growth restriction and lethality. Haploinsufficient mice (Snx27 +/- ) show a less severe phenotype, with deficits in learning, memory, synaptic transmission and neuronal plasticity. One family previously reported with a homozygous SNX27 frameshift variant (c.515_516del;p.His172Argfs*6), exhibited infantile intractable myoclonic epilepsy, axial hypotonia, startle-like movements, cardiac septal defects, global developmental delay, failure to thrive, recurrent chest infections, persistent hypoxemia and early death secondary to respiratory failure. Here, we report two additional patients with compound heterozygous SNX27 variants, that are predicted to be damaging: (a) c.510C>G;p.Tyr170* and c.1295G>A;p.Cys432Tyr, and (b) c.782dupT;p.Leu262Profs*6 and c.989G>A;p.Arg330His. They exhibit global developmental delay, behavioral disturbance, epilepsy, some dysmorphic features and subcortical white matter abnormalities. In addition, possible connective tissue involvement was noted. Epilepsy, developmental delays and subcortical white matter abnormalities appear to be core features of SNX27-related disorders. We correlate the observed phenotype with available in vitro, in vivo and proteomic data and suggest additional possible molecular mediators of SNX27-related pathology.
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Affiliation(s)
- Daniel J Parente
- Department of Family Medicine, University of Kansas Medical Center, Kansas City, Kansas
| | - Stephanie M Morris
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | - Robert C McKinstry
- Pediatric Radiology and Pediatric Neuroradiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | | | - Elisabeth Gabau
- Paediatric Unit, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Anna Ruiz
- Genetics Laboratory, UDIAT-Centre Diagnòstic, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
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22
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Kovtun O, Leneva N, Bykov YS, Ariotti N, Teasdale RD, Schaffer M, Engel BD, Owen DJ, Briggs JAG, Collins BM. Structure of the membrane-assembled retromer coat determined by cryo-electron tomography. Nature 2018; 561:561-4. [PMID: 30224749 DOI: 10.1038/s41586-018-0526-z] [Citation(s) in RCA: 133] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 08/08/2018] [Indexed: 02/02/2023]
Abstract
Eukaryotic cells traffic proteins and lipids between different compartments using protein-coated vesicles and tubules. The retromer complex is required to generate cargo-selective tubulovesicular carriers from endosomal membranes1-3. Conserved in eukaryotes, retromer controls the cellular localization and homeostasis of hundreds of transmembrane proteins, and its disruption is associated with major neurodegenerative disorders4-7. How retromer is assembled and how it is recruited to form coated tubules is not known. Here we describe the structure of the retromer complex (Vps26-Vps29-Vps35) assembled on membrane tubules with the bin/amphiphysin/rvs-domain-containing sorting nexin protein Vps5, using cryo-electron tomography and subtomogram averaging. This reveals a membrane-associated Vps5 array, from which arches of retromer extend away from the membrane surface. Vps35 forms the 'legs' of these arches, and Vps29 resides at the apex where it is free to interact with regulatory factors. The bases of the arches connect to each other and to Vps5 through Vps26, and the presence of the same arches on coated tubules within cells confirms their functional importance. Vps5 binds to Vps26 at a position analogous to the previously described cargo- and Snx3-binding site, which suggests the existence of distinct retromer-sorting nexin assemblies. The structure provides insight into the architecture of the coat and its mechanism of assembly, and suggests that retromer promotes tubule formation by directing the distribution of sorting nexin proteins on the membrane surface while providing a scaffold for regulatory-protein interactions.
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23
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Abstract
Membrane protein recycling is a fundamental process from yeast to humans. The lysosome (or vacuole in yeast) receives membrane proteins from the secretory, endocytic, and macroautophagy/autophagy pathways. Although some of these membrane proteins appear to be recycled, the molecular mechanisms underlying this retrograde trafficking are poorly understood. Our recent study revealed that the transmembrane autophagy protein Atg27 is recycled from the vacuole membrane using a 2-step recycling process. First, the Snx4 complex recycles Atg27 from the vacuole to the endosome. Then, the retromer complex mediates endosome-to-Golgi retrograde transport. Thus, 2 distinct protein complexes facilitate the sequential retrograde trafficking for Atg27. As far as we know, Atg27 is the first physiological substrate for the vacuole-to-endosome retrograde trafficking pathway.
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Affiliation(s)
- Sho W Suzuki
- a Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics , Cornell University , Ithaca, New York , USA
| | - Scott D Emr
- a Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics , Cornell University , Ithaca, New York , USA
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24
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Wang J, Fedoseienko A, Chen B, Burstein E, Jia D, Billadeau DD. Endosomal receptor trafficking: Retromer and beyond. Traffic 2018; 19:578-590. [PMID: 29667289 PMCID: PMC6043395 DOI: 10.1111/tra.12574] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 12/17/2022]
Abstract
The tubular endolysosomal network is a quality control system that ensures the proper delivery of internalized receptors to specific subcellular destinations in order to maintain cellular homeostasis. Although retromer was originally described in yeast as a regulator of endosome-to-Golgi receptor recycling, mammalian retromer has emerged as a central player in endosome-to-plasma membrane recycling of a variety of receptors. Over the past decade, information regarding the mechanism by which retromer facilitates receptor trafficking has emerged, as has the identification of numerous retromer-associated molecules including the WASH complex, sorting nexins (SNXs) and TBC1d5. Moreover, the recent demonstration that several SNXs can directly interact with retromer cargo to facilitate endosome-to-Golgi retrieval has provided new insight into how these receptors are trafficked in cells. The mechanism by which SNX17 cargoes are recycled out of the endosomal system was demonstrated to involve a retromer-like complex termed the retriever, which is recruited to WASH positive endosomes through an interaction with the COMMD/CCDC22/CCDC93 (CCC) complex. Lastly, the mechanisms by which bacterial and viral pathogens highjack this complex sorting machinery in order to escape the endolysosomal system or remain hidden within the cells are beginning to emerge. In this review, we will highlight recent studies that have begun to unravel the intricacies by which the retromer and associated molecules contribute to receptor trafficking and how deregulation at this sorting domain can contribute to disease or facilitate pathogen infection.
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Affiliation(s)
- Jing Wang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, Division of Neurology, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Alina Fedoseienko
- Division of Oncology Research, Department of Biochemistry and Molecular Biology, and Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Bayou Chen
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | - Ezra Burstein
- Department of Internal Medicine, and Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, Division of Neurology, West China Second University Hospital, State Key Laboratory of Biotherapy and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Daniel D. Billadeau
- Division of Oncology Research, Department of Biochemistry and Molecular Biology, and Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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Welin A, Weber S, Hilbi H. Quantitative Imaging Flow Cytometry of Legionella-Infected Dictyostelium Amoebae Reveals the Impact of Retrograde Trafficking on Pathogen Vacuole Composition. Appl Environ Microbiol 2018; 84:e00158-18. [PMID: 29602783 DOI: 10.1128/AEM.00158-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/27/2018] [Indexed: 01/15/2023] Open
Abstract
The ubiquitous environmental bacterium Legionella pneumophila survives and replicates within amoebae and human macrophages by forming a Legionella-containing vacuole (LCV). In an intricate process governed by the bacterial Icm/Dot type IV secretion system and a plethora of effector proteins, the nascent LCV interferes with a number of intracellular trafficking pathways, including retrograde transport from endosomes to the Golgi apparatus. Conserved retrograde trafficking components, such as the retromer coat complex or the phosphoinositide (PI) 5-phosphatase D. discoideum 5-phosphatase 4 (Dd5P4)/oculocerebrorenal syndrome of Lowe (OCRL), restrict intracellular replication of L. pneumophila by an unknown mechanism. Here, we established an imaging flow cytometry (IFC) approach to assess in a rapid, unbiased, and large-scale quantitative manner the role of retrograde-linked PI metabolism and actin dynamics in the LCV composition. Exploiting Dictyostelium discoideum genetics, we found that Dd5P4 modulates the acquisition of fluorescently labeled LCV markers, such as calnexin, the small GTPase Rab1 (but not Rab7 and Rab8), and retrograde trafficking components (Vps5, Vps26, Vps35). The actin-nucleating protein and retromer interactor WASH (Wiskott-Aldrich syndrome protein [WASP] and suppressor of cAMP receptor [SCAR] homologue) promotes the accumulation of Rab1 and Rab8 on LCVs. Collectively, our findings validate IFC for the quantitative and unbiased analysis of the pathogen vacuole composition and reveal the impact of retrograde-linked PI metabolism and actin dynamics on the LCV composition. The IFC approach employed here can be adapted for a molecular analysis of the pathogen vacuole composition of other amoeba-resistant pathogens.IMPORTANCELegionella pneumophila is an amoeba-resistant environmental bacterium which can cause a life-threatening pneumonia termed Legionnaires' disease. In order to replicate intracellularly, the opportunistic pathogen forms a protective compartment, the Legionella-containing vacuole (LCV). An in-depth analysis of the LCV composition and the complex process of pathogen vacuole formation is crucial for understanding the virulence of L. pneumophila Here, we established an imaging flow cytometry (IFC) approach to assess in a rapid, unbiased, and quantitative manner the accumulation of fluorescently labeled markers and probes on LCVs. Using IFC and L. pneumophila-infected Dictyostelium discoideum or defined mutant amoebae, a role for phosphoinositide (PI) metabolism, retrograde trafficking, and the actin cytoskeleton in the LCV composition was revealed. In principle, the powerful IFC approach can be used to analyze the molecular composition of any cellular compartment harboring bacterial pathogens.
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Elwell C, Engel J. Emerging Role of Retromer in Modulating Pathogen Growth. Trends Microbiol 2018; 26:769-780. [PMID: 29703496 DOI: 10.1016/j.tim.2018.04.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/21/2018] [Accepted: 04/02/2018] [Indexed: 12/20/2022]
Abstract
Intracellular pathogens have developed elegant mechanisms to modulate host endosomal trafficking. The highly conserved retromer pathway has emerged as an important target of viruses and intravacuolar bacteria. Some pathogens require retromer function to survive. For others, retromer activity restricts intracellular growth; these pathogens must disrupt retromer function to survive. In this review, we discuss recent paradigm changes to the current model for retromer assembly and cargo selection. We highlight how the study of pathogen effectors has contributed to these fundamental insights, with a special focus on the biology and structure of two recently described bacterial effectors, Chlamydia trachomatis IncE and Legionella pneumophila RidL. These two pathogens employ distinct strategies to target retromer components and overcome restriction of intracellular growth imposed by retromer.
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Affiliation(s)
- Cherilyn Elwell
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joanne Engel
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA.
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27
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Zhang H, Huang T, Hong Y, Yang W, Zhang X, Luo H, Xu H, Wang X. The Retromer Complex and Sorting Nexins in Neurodegenerative Diseases. Front Aging Neurosci 2018; 10:79. [PMID: 29632483 PMCID: PMC5879135 DOI: 10.3389/fnagi.2018.00079] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/12/2018] [Indexed: 02/04/2023] Open
Abstract
The retromer complex and associated sorting nexins (SNXs) comprise a critical trafficking machinery which mediates endosomal protein sorting. Retromer and/or SNX dysfunction has been linked to several neurodegenerative diseases including Alzheimer’s disease (AD), Parkinson’s disease (PD), and Down’s syndrome (DS). In AD, deficiency of the retromer complex or its cargo proteins impairs endosomal trafficking of amyloid precursor protein (APP), resulting in the overproduction of β-amyloid (Aβ). Several SNX components directly interact with APP or APP-cleaving enzymes (β- and γ-secretases) to regulate amyloidogenic APP processing and Aβ generation. In addition, PD-linked mutations in retromer components cause mistrafficking of retromer cargo proteins and mitochondrial dysfunction, and dysregulation retromer-mediated trafficking has been considered as an important cause of hereditary spastic paraplegia (HSP) and neuronal ceroid lipofuscinoses (NCLs). Moreover, SNX27 deficiency is an important contributor for synaptic and cognitive impairment in DS. Here we review recent findings describing the retromer complex and/or SNXs-mediated endosomal sorting in neurodegenerative disorders.
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Affiliation(s)
- Hongfeng Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China
| | - Timothy Huang
- Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, United States
| | - Yujuan Hong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China
| | - Weijie Yang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China
| | - Xian Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China
| | - Hong Luo
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China.,Neuroscience Initiative, Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA, United States
| | - Xin Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Collaborative Innovation Center for Brain Science, Xiamen University, Xiamen, China
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28
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Bärlocher K, Welin A, Hilbi H. Formation of the Legionella Replicative Compartment at the Crossroads of Retrograde Trafficking. Front Cell Infect Microbiol 2017; 7:482. [PMID: 29226112 PMCID: PMC5706426 DOI: 10.3389/fcimb.2017.00482] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/06/2017] [Indexed: 12/13/2022] Open
Abstract
Retrograde trafficking from the endosomal system through the Golgi apparatus back to the endoplasmic reticulum is an essential pathway in eukaryotic cells, serving to maintain organelle identity and to recycle empty cargo receptors delivered by the secretory pathway. Intracellular replication of several bacterial pathogens, including Legionella pneumophila, is restricted by the retrograde trafficking pathway. L. pneumophila employs the Icm/Dot type IV secretion system (T4SS) to form the replication-permissive Legionella-containing vacuole (LCV), which is decorated with multiple components of the retrograde trafficking machinery as well as retrograde cargo receptors. The L. pneumophila effector protein RidL is secreted by the T4SS and interferes with retrograde trafficking. Here, we review recent evidence that the LCV interacts with the retrograde trafficking pathway, discuss the possible sites of action and function of RidL in the retrograde route, and put forth the hypothesis that the LCV is an acceptor compartment of retrograde transport vesicles.
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Affiliation(s)
- Kevin Bärlocher
- Institute of Medical Microbiology, University of Zürich, Zurich, Switzerland
| | - Amanda Welin
- Institute of Medical Microbiology, University of Zürich, Zurich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Zurich, Switzerland
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29
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Follett J, Bugarcic A, Collins BM, Teasdale RD. Retromer's Role in Endosomal Trafficking and Impaired Function in Neurodegenerative Diseases. Curr Protein Pept Sci 2017; 18:687-701. [PMID: 26965691 DOI: 10.2174/1389203717666160311121246] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 06/15/2016] [Accepted: 06/30/2016] [Indexed: 11/22/2022]
Abstract
The retromer complex is a highly conserved membrane trafficking assembly composed of three proteins - Vps26, Vps29 and Vps35 - that were identified over a decade ago in Saccharomyces cerevisiae (S. cerevisiae). Initially, mammalian retromer was shown to sort transmembrane proteins from the endosome to the trans-Golgi network (TGN), though recent work has identified a critical role for retromer in multiple trafficking pathways, including recycling to the plasma membrane and regulation of cell polarity. In recent years, genetic, cellular, pharmacological and animal model studies have identified retromer and its interacting proteins as being linked to familial forms of neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's (PD). Here, this commentary will summarize recently identified point mutations in retromer linked to PD, and explore the molecular functions of retromer that may be relevant to disease progression.
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Affiliation(s)
- Jordan Follett
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland. Australia
| | - Andrea Bugarcic
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland. Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland. Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072. Australia
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Xu J, Zhang L, Ye Y, Shan Y, Wan C, Wang J, Pei D, Shu X, Liu J. SNX16 Regulates the Recycling of E-Cadherin through a Unique Mechanism of Coordinated Membrane and Cargo Binding. Structure 2017; 25:1251-1263.e5. [PMID: 28712807 DOI: 10.1016/j.str.2017.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 04/28/2017] [Accepted: 06/15/2017] [Indexed: 10/19/2022]
Abstract
E-Cadherin is a major component of adherens junctions on cell surfaces. SNX16 is a unique member of sorting nexins that contains a coiled-coil (CC) domain downstream of the PX domain. We report here that SNX16 regulates the recycling trafficking of E-cadherin. We solved the crystal structure of PX-CC unit of SNX16 and revealed a unique shear shaped homodimer. We identified a novel PI3P binding pocket in SNX16 that consists of both the PX and the CC domains. Surprisingly, we showed that the PPII/α2 loop, which is generally regarded as a membrane insertion loop in PX family proteins, is involved in the E-cadherin binding with SNX16. We then proposed a multivalent membrane binding model for SNX16. Our study postulates a new mechanism for coordinated membrane binding and cargo binding for SNX family proteins in general, and provide novel insights into recycling trafficking of E-cadherin.
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Affiliation(s)
- Jinxin Xu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Leilei Zhang
- CAS Key Laboratory of Regenerative Biology, Guangdong Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Medical University Joint School of Biological Sciences, South China Institute of Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Yinghua Ye
- CAS Key Laboratory of Regenerative Biology, Guangdong Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Medical University Joint School of Biological Sciences, South China Institute of Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Yongli Shan
- CAS Key Laboratory of Regenerative Biology, Guangdong Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Medical University Joint School of Biological Sciences, South China Institute of Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Chanjuan Wan
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Junfeng Wang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Duanqing Pei
- CAS Key Laboratory of Regenerative Biology, Guangdong Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Medical University Joint School of Biological Sciences, South China Institute of Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Xiaodong Shu
- CAS Key Laboratory of Regenerative Biology, Guangdong Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Medical University Joint School of Biological Sciences, South China Institute of Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.
| | - Jinsong Liu
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China.
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31
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Liebl D, Qi X, Zhe Y, Barnett TC, Teasdale RD. SopB-Mediated Recruitment of SNX18 Facilitates Salmonella Typhimurium Internalization by the Host Cell. Front Cell Infect Microbiol 2017; 7:257. [PMID: 28664153 PMCID: PMC5471308 DOI: 10.3389/fcimb.2017.00257] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/31/2017] [Indexed: 11/16/2022] Open
Abstract
To invade epithelial cells, Salmonella enterica serovar Typhimurium (S. Typhimurium) induces macropinocytosis through the action of virulence proteins delivered across the host cell membrane via a type III secretion system. We show that after docking at the plasma membrane S. Typhimurium triggers rapid recruitment of cytosolic SNX18, a SH3-PX-BAR domain sorting nexin protein, to the bacteria-induced membrane ruffles and to the nascent Salmonella-containing vacuole. SNX18 recruitment required the inositol-phosphatase activity of the Salmonella effector SopB and an intact phosphoinositide-binding site within the PX domain of SNX18, but occurred independently of Rho-GTPases Rac1 and Cdc42 activation. SNX18 promotes formation of the SCV from the plasma membrane by acting as a scaffold to recruit Dynamin-2 and N-WASP in a process dependent on the SH3 domain of SNX18. Quantification of bacteria uptake revealed that overexpression of SNX18 increased bacteria internalization, whereas a decrease was detected in cells overexpressing the phosphoinositide-binding mutant R303Q, the ΔSH3 mutant, and in cells where endogenous levels of SNX18 were knocked-down. This study identifies SNX18 as a novel target of SopB and suggests a mechanism where S. Typhimurium engages host factors via local manipulation of phosphoinositide composition at the site of invasion to orchestrate the internalization process.
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Affiliation(s)
- David Liebl
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Xiaying Qi
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Yang Zhe
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia
| | - Timothy C Barnett
- Australian Infectious Diseases Research Centre, The University of QueenslandBrisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of QueenslandBrisbane, QLD, Australia
| | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of QueenslandBrisbane, QLD, Australia.,Australian Infectious Diseases Research Centre, The University of QueenslandBrisbane, QLD, Australia.,School of Biomedical Sciences, The University of QueenslandBrisbane, QLD, Australia
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Elwell CA, Czudnochowski N, von Dollen J, Johnson JR, Nakagawa R, Mirrashidi K, Krogan NJ, Engel JN, Rosenberg OS. Chlamydia interfere with an interaction between the mannose-6-phosphate receptor and sorting nexins to counteract host restriction. eLife 2017; 6. [PMID: 28252385 PMCID: PMC5364026 DOI: 10.7554/elife.22709] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/26/2017] [Indexed: 02/02/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogen that resides in a membrane-bound compartment, the inclusion. The bacteria secrete a unique class of proteins, Incs, which insert into the inclusion membrane and modulate the host-bacterium interface. We previously reported that IncE binds specifically to the Sorting Nexin 5 Phox domain (SNX5-PX) and disrupts retromer trafficking. Here, we present the crystal structure of the SNX5-PX:IncE complex, showing IncE bound to a unique and highly conserved hydrophobic groove on SNX5. Mutagenesis of the SNX5-PX:IncE binding surface disrupts a previously unsuspected interaction between SNX5 and the cation-independent mannose-6-phosphate receptor (CI-MPR). Addition of IncE peptide inhibits the interaction of CI-MPR with SNX5. Finally, C. trachomatis infection interferes with the SNX5:CI-MPR interaction, suggesting that IncE and CI-MPR are dependent on the same binding surface on SNX5. Our results provide new insights into retromer assembly and underscore the power of using pathogens to discover disease-related cell biology.
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Affiliation(s)
- Cherilyn A Elwell
- Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Nadine Czudnochowski
- Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - John von Dollen
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Jeffrey R Johnson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Rachel Nakagawa
- Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Kathleen Mirrashidi
- Department of Medicine, University of California, San Francisco, San Francisco, United States
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,QB3, California Institute for Quantitative Biosciences, San Francisco, United States.,Gladstone Institutes, San Francisco, United States
| | - Joanne N Engel
- Department of Medicine, University of California, San Francisco, San Francisco, United States.,Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Oren S Rosenberg
- Department of Medicine, University of California, San Francisco, San Francisco, United States
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Paul B, Kim HS, Kerr MC, Huston WM, Teasdale RD, Collins BM. Structural basis for the hijacking of endosomal sorting nexin proteins by Chlamydia trachomatis. eLife 2017; 6. [PMID: 28226239 PMCID: PMC5348129 DOI: 10.7554/elife.22311] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/19/2017] [Indexed: 12/17/2022] Open
Abstract
During infection chlamydial pathogens form an intracellular membrane-bound replicative niche termed the inclusion, which is enriched with bacterial transmembrane proteins called Incs. Incs bind and manipulate host cell proteins to promote inclusion expansion and provide camouflage against innate immune responses. Sorting nexin (SNX) proteins that normally function in endosomal membrane trafficking are a major class of inclusion-associated host proteins, and are recruited by IncE/CT116. Crystal structures of the SNX5 phox-homology (PX) domain in complex with IncE define the precise molecular basis for these interactions. The binding site is unique to SNX5 and related family members SNX6 and SNX32. Intriguingly the site is also conserved in SNX5 homologues throughout evolution, suggesting that IncE captures SNX5-related proteins by mimicking a native host protein interaction. These findings thus provide the first mechanistic insights both into how chlamydial Incs hijack host proteins, and how SNX5-related PX domains function as scaffolds in protein complex assembly.
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Affiliation(s)
- Blessy Paul
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Hyun Sung Kim
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Markus C Kerr
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | | | - Rohan D Teasdale
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Australia
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Clairfeuille T, Norwood SJ, Qi X, Teasdale RD, Collins BM. Structure and Membrane Binding Properties of the Endosomal Tetratricopeptide Repeat (TPR) Domain-containing Sorting Nexins SNX20 and SNX21. J Biol Chem 2015; 290:14504-17. [PMID: 25882846 DOI: 10.1074/jbc.m115.650598] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Indexed: 01/08/2023] Open
Abstract
Sorting nexins (SNX) orchestrate membrane trafficking and signaling events required for the proper distribution of proteins within the endosomal network. Their phox homology (PX) domain acts as a phosphoinositide (PI) recognition module that targets them to specific endocytic membrane domains. The modularity of SNX proteins confers a wide variety of functions from signaling to membrane deformation and cargo binding, and many SNXs are crucial modulators of endosome dynamics and are involved in a myriad of physiological and pathological processes such as neurodegenerative diseases, cancer, and inflammation. Here, we have studied the poorly characterized SNX20 and its paralogue SNX21, which contain an N-terminal PX domain and a C-terminal PX-associated B (PXB) domain of unknown function. The two proteins share similar PI-binding properties and are recruited to early endosomal compartments by their PX domain. The crystal structure of the SNX21 PXB domain reveals a tetratricopeptide repeat (TPR)-fold, a module that typically binds short peptide motifs, with three TPR α-helical repeats. However, the C-terminal capping helix adopts a highly unusual and potentially self-inhibitory topology. SAXS solution structures of SNX20 and SNX21 show that these proteins adopt a compact globular architecture, and membrane interaction analyses indicate the presence of overlapping PI-binding sites that may regulate their intracellular localization. This study provides the first structural analysis of this poorly characterized subfamily of SNX proteins, highlighting a likely role as endosome-associated scaffolds.
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Affiliation(s)
- Thomas Clairfeuille
- From the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Suzanne J Norwood
- From the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Xiaying Qi
- From the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Rohan D Teasdale
- From the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Brett M Collins
- From the Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland 4072, Australia
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35
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Blum A, Brumbarova T, Bauer P, Ivanov R. Hormone influence on the spatial regulation of IRT1 expression in iron-deficient Arabidopsis thaliana roots. Plant Signal Behav 2014; 9:e28787. [PMID: 24721759 PMCID: PMC4091473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 04/03/2014] [Accepted: 04/04/2014] [Indexed: 02/28/2024]
Abstract
The IRON-REGULATED TRANSPORTER1 (IRT1) is the principal importer of soil iron in Arabidopsis thaliana. It has a complex intracellular trafficking behavior, including continuous cycling between plasma membrane and endosomes. SORTING NEXIN1 is required for the recycling of endosome-localized IRT1. In its absence, IRT1 is mistargeted for degradation, resulting in reduced plant iron-uptake efficiency. Consequently, IRT1 promoter activity gets limited to a specific portion of the root. We tested the influence of two hormones known to positively affect iron uptake on IRT1 spatial regulation. We found that ethylene treatment in wild-type background mimics the effects of the SNX-loss-of-function situation. Conversely, auxin splits the IRT1 expression zone and forces it toward the two extremities of the root. This shows that IRT1 expression along the root is modulated by ethylene-auxin interplay.
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Affiliation(s)
- Ailisa Blum
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
| | - Tzvetina Brumbarova
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
- Institute of Botany; Heinrich-Heine University; Düsseldorf, Germany
| | - Petra Bauer
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
- Institute of Botany; Heinrich-Heine University; Düsseldorf, Germany
| | - Rumen Ivanov
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
- Institute of Botany; Heinrich-Heine University; Düsseldorf, Germany
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36
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Blum A, Brumbarova T, Bauer P, Ivanov R. Hormone influence on the spatial regulation of IRT1 expression in iron-deficient Arabidopsis thaliana roots. Plant Signal Behav 2014; 9:28787. [PMID: 24721759 PMCID: PMC4091473 DOI: 10.4161/psb.28787] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 04/03/2014] [Accepted: 04/04/2014] [Indexed: 05/21/2023]
Abstract
The IRON-REGULATED TRANSPORTER1 (IRT1) is the principal importer of soil iron in Arabidopsis thaliana. It has a complex intracellular trafficking behavior, including continuous cycling between plasma membrane and endosomes. SORTING NEXIN1 is required for the recycling of endosome-localized IRT1. In its absence, IRT1 is mistargeted for degradation, resulting in reduced plant iron-uptake efficiency. Consequently, IRT1 promoter activity gets limited to a specific portion of the root. We tested the influence of two hormones known to positively affect iron uptake on IRT1 spatial regulation. We found that ethylene treatment in wild-type background mimics the effects of the SNX-loss-of-function situation. Conversely, auxin splits the IRT1 expression zone and forces it toward the two extremities of the root. This shows that IRT1 expression along the root is modulated by ethylene-auxin interplay.
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Affiliation(s)
- Ailisa Blum
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
| | - Tzvetina Brumbarova
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
- Institute of Botany; Heinrich-Heine University; Düsseldorf, Germany
| | - Petra Bauer
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
- Institute of Botany; Heinrich-Heine University; Düsseldorf, Germany
| | - Rumen Ivanov
- Department of Biosciences-Plant Biology; Saarland University; Saarbrücken, Germany
- Institute of Botany; Heinrich-Heine University; Düsseldorf, Germany
- Correspondence to: Rumen Ivanov,
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37
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Harrison MS, Hung CS, Liu TT, Christiano R, Walther TC, Burd CG. A mechanism for retromer endosomal coat complex assembly with cargo. Proc Natl Acad Sci U S A 2014; 111:267-72. [PMID: 24344282 DOI: 10.1073/pnas.1316482111] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Retromer is an evolutionarily conserved protein complex composed of the VPS26, VPS29, and VPS35 proteins that selects and packages cargo proteins into transport carriers that export cargo from the endosome. The mechanisms by which retromer is recruited to the endosome and captures cargo are unknown. We show that membrane recruitment of retromer is mediated by bivalent recognition of an effector of PI3K, SNX3, and the RAB7A GTPase, by the VPS35 retromer subunit. These bivalent interactions prime retromer to capture integral membrane cargo, which enhances membrane association of retromer and initiates cargo sorting. The role of RAB7A is severely impaired by a mutation, K157N, that causes Charcot-Marie-Tooth neuropathy 2B. The results elucidate minimal requirements for retromer assembly on the endosome membrane and reveal how PI3K and RAB signaling are coupled to initiate retromer-mediated cargo export.
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38
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Deng YZ, Qu Z, He Y, Naqvi NI. Sorting nexin Snx41 is essential for conidiation and mediates glutathione-based antioxidant defense during invasive growth in Magnaporthe oryzae. Autophagy 2012; 8:1058-70. [PMID: 22561104 DOI: 10.4161/auto.20217] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The sorting nexins Atg20/Snx42 and Snx41 regulate membrane traffic and endosomal protein sorting and are essential for Cvt and/or pexophagy in yeast. Previously, we showed that macroautophagy is necessary for conidiation in the rice-blast fungus Magnaporthe oryzae. Here, we analyzed the physiological function(s) of selective autophagy in Magnaporthe through targeted deletion of MGG_12832, an ortholog of yeast SNX41 and ATG20/SNX42. Loss of MGG_12832 (hereafter SNX41) abolished conidia formation and pathogenesis in M. oryzae. Snx41-GFP localized as dynamic puncta or short tubules that are partially associated with autophagosomes and/or autophagic vacuoles. PX domain, but not macroautophagy per se, was required for such localization of Snx41-GFP in Magnaporthe. Although not required for nonselective autophagy, Snx41 was essential for pexophagy in Magnaporthe. We identified Oxp1, an ATP-dependent oxoprolinase in the gamma-glutamyl cycle, as a binding partner and potential retrieval target of Snx41-dependent protein sorting. The substrate of Oxp1, 5-oxoproline, could partially restore conidiation in the snx41Δ. Exogenous glutathione, a product of the gamma-glutamyl cycle, significantly restored pathogenicity in the snx41Δ mutant, likely through counteracting the oxidative stress imposed by the host. We propose that the gamma-glutamyl cycle and glutathione biosynthesis are subject to regulation by Snx41-dependent vesicular trafficking, and mediate antioxidant defense crucial for in planta growth and pathogenic differentiation of Magnaporthe at the onset of blast disease in rice.
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Affiliation(s)
- Yi Zhen Deng
- Temasek Life Sciences Laboratory, and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
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Harbour ME, Seaman MNJ. Evolutionary variations of VPS29, and their implications for the heteropentameric model of retromer. Commun Integr Biol 2011; 4:619-22. [PMID: 22046480 DOI: 10.4161/cib.4.5.16855] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 06/09/2011] [Indexed: 11/19/2022] Open
Abstract
The retromer complex is conserved across all eukaryotic species and functions in physiologically important sorting processes at the endosomal membrane. A key component of retromer is the VPS29 protein that, although structurally similar to phospho-diesterases, has been convincingly shown in the recent study by Swarbrick et al. (PLoS One 6:e20420, 2011) to be a rigid scaffold that interacts with various proteins that function with retromer in endosomal protein sorting. A widely held view, based on initial observations in Saccharomyces cerevisiae, is that retromer functions as a stable heteropentamer. This is, however, contrary to experimental data presented in Swarbrick et al. (and in other studies) that indicate that retromer in higher eukaryotes is a looser association of two subcomplexes that respectively mediate cargo-selection and membrane tubulation. Here we present an analysis of evolutionary variation of the VPS29 protein and discuss why the retromer complex as first characterized in S. cerevisiae is not representative of retromer in other eukaryotic taxa.
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Affiliation(s)
- Michael E Harbour
- University of Cambridge; Cambridge Institue for Medical Research; Addenbrookes Hospital; Cambridge, UK
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Piek E, Van Dinther M, Parks WT, Sallee JM, Böttinger EP, Roberts AB, Ten Dijke P. RLP, a novel Ras-like protein, is an immediate-early transforming growth factor-beta (TGF-beta) target gene that negatively regulates transcriptional activity induced by TGF-beta. Biochem J 2004; 383:187-99. [PMID: 15239668 PMCID: PMC1134058 DOI: 10.1042/bj20040774] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Revised: 07/05/2004] [Accepted: 07/08/2004] [Indexed: 01/24/2023]
Abstract
We have described previously the use of microarray technology to identify novel target genes of TGF-beta (transforming growth factor-beta) signalling in mouse embryo fibroblasts deficient in Smad2 or Smad3 [Yang, Piek, Zavadil, Liang, Xie, Heyer, Pavlidis, Kucherlapati, Roberts and Böttinger (2003) Proc. Natl. Acad. Sci. U.S.A. 100, 10269-10274]. Among the TGF-beta target genes identified, a novel gene with sequence homology to members of the Ras superfamily was identified, which we have designated as RLP (Ras-like protein). RLP is a Smad3-dependent immediate-early TGF-beta target gene, its expression being induced within 45 min. Bone morphogenetic proteins also induce expression of RLP, whereas epidermal growth factor and phorbol ester PMA suppress TGF-beta-induced expression of RLP. Northern-blot analysis revealed that RLP was strongly expressed in heart, brain and kidney, and below the detection level in spleen and skeletal muscles. At the protein level, RLP is approx. 30% homologous with members of the Ras superfamily, particularly in domains characteristic for small GTPases. However, compared with prototypic Ras, RLP contains a modified P-loop, lacks the consensus G2 loop and the C-terminal prenylation site and harbours amino acid substitutions at positions that render prototypic Ras oncogenic. However, RLP does not have transforming activity, does not affect phosphorylation of mitogen-activated protein kinase and is unable to bind GTP or GDP. RLP was found to associate with certain subtypes of the TGF-beta receptor family, raising the possibility that RLP plays a role in TGF-beta signal transduction. Although RLP did not interact with Smads and did not affect TGF-beta receptor-induced Smad2 phosphorylation, it inhibited TGF-beta-induced transcriptional reporter activation, suggesting that it is a novel negative regulator of TGF-beta signalling.
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Key Words
- gtpase
- ras
- sorting nexin
- transcriptional regulation
- transforming growth factor-β
- bmp, bone morphogenetic protein
- chx, cycloheximide
- dmem, dulbecco's modified eagle's medium
- egf, epidermal growth factor
- egfr, egf receptor
- erk, extracellular-signal-regulated kinase
- fast-1, forkhead activin signal transducer-1
- fbs, fetal bovine serum
- gap, gtpase-activating protein
- gst, glutathione s-transferase
- ha, haemagglutinin
- jnk, c-jun n-terminal kinase
- mapk, mitogen-activated protein kinase
- mef, mouse embryo fibroblast
- moi, multiplicity of infection
- pdgfrβ, platelet-derived growth factor receptor β
- rlp, ras-like protein
- snx, sorting nexin
- tgf-β, transforming growth factor-β
- tβr, tgf-β receptor
- utr, untranslated region
- wt, wild-type
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Affiliation(s)
- Ester Piek
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands.
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