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Abstract
Obligate intracellular malaria parasites reside within a vacuolar compartment generated during invasion which is the principal interface between pathogen and host. To subvert their host cell and support their metabolism, these parasites coordinate a range of transport activities at this membrane interface that are critically important to parasite survival and virulence, including nutrient import, waste efflux, effector protein export, and uptake of host cell cytosol. Here, we review our current understanding of the transport mechanisms acting at the malaria parasite vacuole during the blood and liver-stages of development with a particular focus on recent advances in our understanding of effector protein translocation into the host cell by the Plasmodium Translocon of EXported proteins (PTEX) and small molecule transport by the PTEX membrane-spanning pore EXP2. Comparison to Toxoplasma gondii and other related apicomplexans is provided to highlight how similar and divergent mechanisms are employed to fulfill analogous transport activities.
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Affiliation(s)
- Josh R. Beck
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Chi-Min Ho
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
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2
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Garten M, Beck JR, Roth R, Tenkova-Heuser T, Heuser J, Istvan ES, Bleck CKE, Goldberg DE, Zimmerberg J. Contacting domains segregate a lipid transporter from a solute transporter in the malarial host-parasite interface. Nat Commun 2020; 11:3825. [PMID: 32732874 PMCID: PMC7393353 DOI: 10.1038/s41467-020-17506-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 06/30/2020] [Indexed: 12/18/2022] Open
Abstract
The malaria parasite interfaces with its host erythrocyte (RBC) using a unique organelle, the parasitophorous vacuole (PV). The mechanism(s) are obscure by which its limiting membrane, the parasitophorous vacuolar membrane (PVM), collaborates with the parasite plasma membrane (PPM) to support the transport of proteins, lipids, nutrients, and metabolites between the cytoplasm of the parasite and the cytoplasm of the RBC. Here, we demonstrate that the PV has structure characterized by micrometer-sized regions of especially close apposition between the PVM and the PPM. To determine if these contact sites are involved in any sort of transport, we localize the PVM nutrient-permeable and protein export channel EXP2, as well as the PPM lipid transporter PfNCR1. We find that EXP2 is excluded from, but PfNCR1 is included within these regions of close apposition. We conclude that the host-parasite interface is structured to segregate those transporters of hydrophilic and hydrophobic substrates.
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Affiliation(s)
- Matthias Garten
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Josh R Beck
- Department of Biomedical Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Robyn Roth
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Tatyana Tenkova-Heuser
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - John Heuser
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Eva S Istvan
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Christopher K E Bleck
- Electron Microscopy Core Facility, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Daniel E Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
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3
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Crossing the Vacuolar Rubicon: Structural Insights into Effector Protein Trafficking in Apicomplexan Parasites. Microorganisms 2020; 8:microorganisms8060865. [PMID: 32521667 PMCID: PMC7355975 DOI: 10.3390/microorganisms8060865] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022] Open
Abstract
Apicomplexans form a large phylum of parasitic protozoa, including the genera Plasmodium, Toxoplasma, and Cryptosporidium, the causative agents of malaria, toxoplasmosis, and cryptosporidiosis, respectively. They cause diseases not only in humans but also in animals, with dramatic consequences in agriculture. Most apicomplexans are vacuole-dwelling and obligate intracellular parasites; as they invade the host cell, they become encased in a parasitophorous vacuole (PV) derived from the host cellular membrane. This creates a parasite-host interface that acts as a protective barrier but also constitutes an obstacle through which the pathogen must import nutrients, eliminate wastes, and eventually break free upon egress. Completion of the parasitic life cycle requires intense remodeling of the infected host cell. Host cell subversion is mediated by a subset of essential effector parasitic proteins and virulence factors actively trafficked across the PV membrane. In the malaria parasite Plasmodium, a unique and highly specialized ATP-driven vacuolar secretion system, the Plasmodium translocon of exported proteins (PTEX), transports effector proteins across the vacuolar membrane. Its core is composed of the three essential proteins EXP2, PTEX150, and HSP101, and is supplemented by the two auxiliary proteins TRX2 and PTEX88. Many but not all secreted malarial effector proteins contain a vacuolar trafficking signal or Plasmodium export element (PEXEL) that requires processing by an endoplasmic reticulum protease, plasmepsin V, for proper export. Because vacuolar parasitic protein export is essential to parasite survival and virulence, this pathway is a promising target for the development of novel antimalarial therapeutics. This review summarizes the current state of structural and mechanistic knowledge on the Plasmodium parasitic vacuolar secretion and effector trafficking pathway, describing its most salient features and discussing the existing differences and commonalities with the vacuolar effector translocation MYR machinery recently described in Toxoplasma and other apicomplexans of significance to medical and veterinary sciences.
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Nessel T, Beck JM, Rayatpisheh S, Jami-Alahmadi Y, Wohlschlegel JA, Goldberg DE, Beck JR. EXP1 is required for organisation of EXP2 in the intraerythrocytic malaria parasite vacuole. Cell Microbiol 2020; 22:e13168. [PMID: 31990132 DOI: 10.1111/cmi.13168] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/04/2019] [Accepted: 01/07/2020] [Indexed: 12/17/2022]
Abstract
Intraerythrocytic malaria parasites reside within a parasitophorous vacuole membrane (PVM) that closely overlays the parasite plasma membrane. Although the PVM is the site of several transport activities essential to parasite survival, the basis for organisation of this membrane system is unknown. Here, we performed proximity labeling at the PVM with BioID2, which highlighted a group of single-pass integral membrane proteins that constitute a major component of the PVM proteome but whose function remains unclear. We investigated EXP1, the longest known member of this group, by adapting a CRISPR/Cpf1 genome editing system to install the TetR-DOZI-aptamers system for conditional translational control. Importantly, although EXP1 was required for intraerythrocytic development, a previously reported in vitro glutathione S-transferase activity could not account for this essential EXP1 function in vivo. EXP1 knockdown was accompanied by profound changes in vacuole ultrastructure, including apparent increased separation of the PVM from the parasite plasma membrane and formation of abnormal membrane structures. Furthermore, although activity of the Plasmodium translocon of exported proteins was not impacted by depletion of EXP1, the distribution of the translocon pore-forming protein EXP2 but not the HSP101 unfoldase was substantially altered. Collectively, our results reveal a novel PVM defect that indicates a critical role for EXP1 in maintaining proper organisation of EXP2 within the PVM.
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Affiliation(s)
- Timothy Nessel
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa
| | - John M Beck
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa
| | - Shima Rayatpisheh
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California
| | - James A Wohlschlegel
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California
| | - Daniel E Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University, St. Louis, Missouri
| | - Josh R Beck
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa.,Departments of Medicine and Molecular Microbiology, Washington University, St. Louis, Missouri
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The parasitophorous vacuole of the blood-stage malaria parasite. Nat Rev Microbiol 2020; 18:379-391. [PMID: 31980807 DOI: 10.1038/s41579-019-0321-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2019] [Indexed: 12/31/2022]
Abstract
The pathology of malaria is caused by infection of red blood cells with unicellular Plasmodium parasites. During blood-stage development, the parasite replicates within a membrane-bound parasitophorous vacuole. A central nexus for host-parasite interactions, this unique parasite shelter functions in nutrient acquisition, subcompartmentalization and the export of virulence factors, making its functional molecules attractive targets for the development of novel intervention strategies to combat the devastating impact of malaria. In this Review, we explore the origin, development, molecular composition and functions of the parasitophorous vacuole of Plasmodium blood stages. We also discuss the relevance of the malaria parasite's intravacuolar lifestyle for successful erythrocyte infection and provide perspectives for future research directions in parasitophorous vacuole biology.
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Andersson A, Kudva R, Magoulopoulou A, Lejarre Q, Lara P, Xu P, Goel S, Pissi J, Ru X, Hessa T, Wahlgren M, von Heijne G, Nilsson I, Tellgren-Roth Å. Membrane integration and topology of RIFIN and STEVOR proteins of the Plasmodium falciparum parasite. FEBS J 2019; 287:2744-2762. [PMID: 31821735 DOI: 10.1111/febs.15171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/20/2019] [Accepted: 12/06/2019] [Indexed: 01/18/2023]
Abstract
The malarial parasite Plasmodium exports its own proteins to the cell surfaces of red blood cells (RBCs) during infection. Examples of exported proteins include members of the repetitive interspersed family (RIFIN) and subtelomeric variable open reading frame (STEVOR) family of proteins from Plasmodium falciparum. The presence of these parasite-derived proteins on surfaces of infected RBCs triggers the adhesion of infected cells to uninfected cells (rosetting) and to the vascular endothelium potentially obstructing blood flow. While there is a fair amount of information on the localization of these proteins on the cell surfaces of RBCs, less is known about how they can be exported to the membrane and the topologies they can adopt during the process. The first step of export is plausibly the cotranslational insertion of proteins into the endoplasmic reticulum (ER) of the parasite, and here, we investigate the insertion of three RIFIN and two STEVOR proteins into the ER membrane. We employ a well-established experimental system that uses N-linked glycosylation of sites within the protein as a measure to assess the extent of membrane insertion and the topology it assumes when inserted into the ER membrane. Our results indicate that for all the proteins tested, transmembranes (TMs) 1 and 3 integrate into the membrane, so that the protein assumes an overall topology of Ncyt-Ccyt. We also show that the segment predicted to be TM2 for each of the proteins likely does not reside in the membrane, but is translocated to the lumen.
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Affiliation(s)
- Annika Andersson
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Renuka Kudva
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Anastasia Magoulopoulou
- Department of Biochemistry and Biophysics, Stockholm University, Sweden.,Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Quentin Lejarre
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Patricia Lara
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Peibo Xu
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Suchi Goel
- Center for Infectious Disease Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jennifer Pissi
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Xing Ru
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Tara Hessa
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Mats Wahlgren
- Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Gunnar von Heijne
- Department of Biochemistry and Biophysics, Stockholm University, Sweden.,Center for Infectious Disease Research, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - IngMarie Nilsson
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Åsa Tellgren-Roth
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
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Wolanin K, Fontinha D, Sanches-Vaz M, Nyboer B, Heiss K, Mueller AK, Prudêncio M. A crucial role for the C-terminal domain of exported protein 1 during the mosquito and hepatic stages of the Plasmodium berghei life cycle. Cell Microbiol 2019; 21:e13088. [PMID: 31364224 PMCID: PMC6771729 DOI: 10.1111/cmi.13088] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/25/2019] [Accepted: 07/28/2019] [Indexed: 12/19/2022]
Abstract
Intracellular Plasmodium parasites develop inside a parasitophorous vacuole (PV), a specialised compartment enclosed by a membrane (PVM) that contains proteins of both host and parasite origin. Although exported protein 1 (EXP1) is one of the earliest described parasitic PVM proteins, its function throughout the Plasmodium life cycle remains insufficiently understood. Here, we show that whereas the N-terminus of Plasmodium berghei EXP1 (PbEXP1) is essential for parasite survival in the blood, parasites lacking PbEXP1's entire C-terminal (CT) domain replicate normally in the blood but cause less severe pathology than their wild-type counterparts. Moreover, truncation of PbEXP1's CT domain not only impairs parasite development in the mosquito but also abrogates PbEXP1 localization to the PVM of intrahepatic parasites, severely limiting their replication and preventing their egress into the blood. Our findings highlight the importance of EXP1 during the Plasmodium life cycle and identify this protein as a promising target for antiplasmodial intervention.
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Affiliation(s)
- Kamil Wolanin
- Parasitology Unit, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Diana Fontinha
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Margarida Sanches-Vaz
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Britta Nyboer
- Parasitology Unit, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Kirsten Heiss
- Parasitology Unit, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.,German Centre for Infection Research, Heidelberg Division, Heidelberg, Germany.,PEPperPRINT GmbH, Research & Development Division, Heidelberg, Germany
| | - Ann-Kristin Mueller
- Parasitology Unit, Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.,German Centre for Infection Research, Heidelberg Division, Heidelberg, Germany
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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Deligianni E, Andreadaki M, Koutsouris K, Siden-Kiamos I. Sequence and functional divergence of gametocyte-specific parasitophorous vacuole membrane proteins in Plasmodium parasites. Mol Biochem Parasitol 2018; 220:15-18. [PMID: 29307698 DOI: 10.1016/j.molbiopara.2018.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/08/2017] [Accepted: 01/03/2018] [Indexed: 10/18/2022]
Abstract
Plasmodium parasites develop within red blood cells in a Parasitophorous Vacuole enclosed by a Membrane, the PVM. The protein family ETRAMP (Early Transcribed Membrane Protein) comprises small proteins inserted in the PVM via a single transmembrane domain. Among those, Pfs16 is specifically found in P. falciparum gametocyte PVM. The P. berghei gene PBANKA_1003900 is syntenic with pfs16. The encoded proteins have a similar domain structure but the overall protein similarity is low. A transcript of the P. berghei gene is only found in gametocytes and ookinetes and a C-terminal mCherry fusion of the protein revealed its presence only in gametocytes. A knock-out mutant of the PBANKA_1003900 gene was not affected in sexual development and ookinete formation was similar to WT. The mutation had no adverse effect on transmission through the mosquito although there was a reduction of the number of oocysts formed by the mutant parasites.
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Affiliation(s)
- Elena Deligianni
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Maria Andreadaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Konstantinos Koutsouris
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece; Department of Biology, University of Crete, Heraklion, Greece
| | - Inga Siden-Kiamos
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece.
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Khosh-Naucke M, Becker J, Mesén-Ramírez P, Kiani P, Birnbaum J, Fröhlke U, Jonscher E, Schlüter H, Spielmann T. Identification of novel parasitophorous vacuole proteins in P. falciparum parasites using BioID. Int J Med Microbiol 2017; 308:13-24. [PMID: 28784333 DOI: 10.1016/j.ijmm.2017.07.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 07/14/2017] [Accepted: 07/17/2017] [Indexed: 10/19/2022] Open
Abstract
Malaria blood stage parasites develop within red blood cells where they are contained in a vacuolar compartment known as the parasitophorous vacuole (PV). This compartment holds a key role in the interaction of the parasite with its host cell. However, the proteome of this compartment has so far not been comprehensively analysed. Here we used BioID in asexual blood stages of the most virulent human malaria parasite Plasmodium falciparum to identify new proteins of the PV. The resulting proteome contained many of the already known PV proteins and validation by GFP-knock-in of 10 previously in P. falciparum uncharacterised hits revealed 5 new PV proteins and two with a partial PV localisation. This included proteins peripherally attached to the inner face of the PV membrane as well as proteins anchored in the parasite plasma membrane that protrude into the PV. Using selectable targeted gene disruption we generated mutants for 2 of the 10 candidates. In contrast we could not select parasites with disruptions for another 3 candidates, strongly suggesting that they are important for parasite growth. Interestingly, one of these included the orthologue of UIS2, a protein previously proposed to regulate protein translation in the parasite cytoplasm but here shown to be an essential PV protein. This work extends the number of known PV proteins and provides a starting point for further functional analyses of this compartment.
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Affiliation(s)
- Melissa Khosh-Naucke
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Johanna Becker
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Paolo Mesén-Ramírez
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Parnian Kiani
- Core Facility Mass Spectrometric Proteomics, Institute of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Jakob Birnbaum
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Ulrike Fröhlke
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Ernst Jonscher
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany
| | - Hartmut Schlüter
- Core Facility Mass Spectrometric Proteomics, Institute of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany.
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