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Isola D, Elazar Z. Phospholipid Supply for Autophagosome Biogenesis. J Mol Biol 2024; 436:168691. [PMID: 38944336 DOI: 10.1016/j.jmb.2024.168691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/10/2024] [Accepted: 06/24/2024] [Indexed: 07/01/2024]
Abstract
Autophagy is a cellular degradation pathway where double-membrane autophagosomes form de novo to engulf cytoplasmic material destined for lysosomal degradation. This process requires regulated membrane remodeling, beginning with the initial autophagosomal precursor and progressing to its elongation and maturation into a fully enclosed, fusion-capable vesicle. While the core protein machinery involved in autophagosome formation has been extensively studied over the past two decades, the role of phospholipids in this process has only recently been studied. This review focuses on the phospholipid composition of the phagophore membrane and the mechanisms that supply lipids to expand this unique organelle.
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Affiliation(s)
- Damilola Isola
- Departments of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Zvulun Elazar
- Departments of Biomolecular Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel.
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2
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Shinoda S, Sakai Y, Matsui T, Uematsu M, Koyama-Honda I, Sakamaki JI, Yamamoto H, Mizushima N. Syntaxin 17 recruitment to mature autophagosomes is temporally regulated by PI4P accumulation. eLife 2024; 12:RP92189. [PMID: 38831696 PMCID: PMC11152571 DOI: 10.7554/elife.92189] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024] Open
Abstract
During macroautophagy, cytoplasmic constituents are engulfed by autophagosomes. Lysosomes fuse with closed autophagosomes but not with unclosed intermediate structures. This is achieved in part by the late recruitment of the autophagosomal SNARE syntaxin 17 (STX17) to mature autophagosomes. However, how STX17 recognizes autophagosome maturation is not known. Here, we show that this temporally regulated recruitment of STX17 depends on the positively charged C-terminal region of STX17. Consistent with this finding, mature autophagosomes are more negatively charged compared with unclosed intermediate structures. This electrostatic maturation of autophagosomes is likely driven by the accumulation of phosphatidylinositol 4-phosphate (PI4P) in the autophagosomal membrane. Accordingly, dephosphorylation of autophagosomal PI4P prevents the association of STX17 to autophagosomes. Furthermore, molecular dynamics simulations support PI4P-dependent membrane insertion of the transmembrane helices of STX17. Based on these findings, we propose a model in which STX17 recruitment to mature autophagosomes is temporally regulated by a PI4P-driven change in the surface charge of autophagosomes.
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Affiliation(s)
- Saori Shinoda
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
| | - Yuji Sakai
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
- Department of Biosystems Science, Institute for Life and Medical Sciences, Kyoto UniversityKyotoJapan
| | - Takahide Matsui
- Department of Molecular Oncology, Institute for Advanced Medical Sciences, Nippon Medical SchoolTokyoJapan
| | - Masaaki Uematsu
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
| | - Ikuko Koyama-Honda
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
| | - Jun-ichi Sakamaki
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
| | - Hayashi Yamamoto
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
- Department of Molecular Oncology, Institute for Advanced Medical Sciences, Nippon Medical SchoolTokyoJapan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduated School of Medicine, The University of TokyoTokyoJapan
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3
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Körschgen H, Behl C. Aggresome-aggrephagy transition process: getting closer to the functional roles of HDAC6 and BAG3. Neural Regen Res 2024; 19:1181-1182. [PMID: 37905854 PMCID: PMC11467942 DOI: 10.4103/1673-5374.386407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/24/2023] [Accepted: 08/21/2023] [Indexed: 11/02/2023] Open
Affiliation(s)
- Hagen Körschgen
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christian Behl
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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4
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Körschgen H, Baeken M, Schmitt D, Nagel H, Behl C. Co-chaperone BAG3 enters autophagic pathway via its interaction with microtubule associated protein 1 light chain 3 beta. Traffic 2023; 24:564-575. [PMID: 37654251 DOI: 10.1111/tra.12916] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 07/20/2023] [Accepted: 08/18/2023] [Indexed: 09/02/2023]
Abstract
The co-chaperone BAG3 is a hub for a variety of cellular pathways via its multiple domains and its interaction with chaperones of the HSP70 family or small HSPs. During aging and under cellular stress conditions in particular, BAG3, together with molecular chaperones, ensures the sequestration of aggregated or aggregation-prone ubiquitinated proteins to the autophagic-lysosomal system via ubiquitin receptors. Accumulating evidence for BAG3-mediated selective autophagy independent of cargo ubiquitination led to analyses predicting a direct interaction of BAG3 with LC3 proteins. Phylogenetically, BAG3 comprises several highly conserved potential LIRs, LC3-interacting regions, which might allow for the direct targeting of BAG3 including its cargo to autophagosomes and drive their autophagic degradation. Based on pull-down experiments, peptide arrays and proximity ligation assays, our results provide evidence of an interaction of BAG3 with LC3B. In addition, we could demonstrate that disabling all predicted LIRs abolished the inducibility of a colocalization of BAG3 with LC3B-positive structures and resulted in a substantial decrease of BAG3 levels within purified native autophagic vesicles compared with wild-type BAG3. These results suggest an autophagic targeting of BAG3 via interaction with LC3B. Therefore, we conclude that, in addition to being a key co-chaperone to HSP70, BAG3 may also act as a cargo receptor for client proteins, which would significantly extend the role of BAG3 in selective macroautophagy and protein quality control.
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Affiliation(s)
- Hagen Körschgen
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Marius Baeken
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Daniel Schmitt
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Heike Nagel
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Christian Behl
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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5
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Lambert M, Gebel J, Trejtnar C, Wesch N, Bozkurt S, Adrian-Allgood M, Löhr F, Münch C, Dötsch V. Fuzzy interactions between the auto-phosphorylated C-terminus and the kinase domain of CK1δ inhibits activation of TAp63α. Sci Rep 2023; 13:16423. [PMID: 37777570 PMCID: PMC10542812 DOI: 10.1038/s41598-023-43515-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 09/25/2023] [Indexed: 10/02/2023] Open
Abstract
The p53 family member TAp63α plays an important role in maintaining the genetic integrity in oocytes. DNA damage, in particular DNA double strand breaks, lead to the transformation of the inhibited, only dimeric conformation into the active tetrameric one that results in the initiation of an apoptotic program. Activation requires phosphorylation by the kinase CK1 which phosphorylates TAp63α at four positions. The third phosphorylation event is the decisive step that transforms TAp63α into the active state. This third phosphorylation, however, is ~ 20 times slower than the first two phosphorylation events. This difference in the phosphorylation kinetics constitutes a safety mechanism that allows oocytes with a low degree of DNA damage to survive. So far these kinetic investigations of the phosphorylation steps have been performed with the isolated CK1 kinase domain. However, all CK1 enzymes contain C-terminal extensions that become auto-phosphorylated and inhibit the activity of the kinase. Here we have investigated the effect of auto-phosphorylation of the C-terminus in the kinase CK1δ and show that it slows down phosphorylation of the first two sites in TAp63α but basically inhibits the phosphorylation of the third site. We have identified up to ten auto-phosphorylation sites in the CK1δ C-terminal domain and show that all of them interact with the kinase domain in a "fuzzy" way in which not a single site is particularly important. Through mutation analysis we further show that hydrophobic amino acids following the phosphorylation site are important for a substrate to be able to successfully compete with the auto-inhibitory effect of the C-terminal domain. This auto-phosphorylation adds a new layer to the regulation of apoptosis in oocytes.
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Affiliation(s)
- Mahil Lambert
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt/Main, Germany
| | - Jakob Gebel
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt/Main, Germany
| | - Charlotte Trejtnar
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt/Main, Germany
| | - Nicole Wesch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt/Main, Germany
| | - Süleyman Bozkurt
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt/Main, Germany
| | - Martin Adrian-Allgood
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt/Main, Germany
| | - Frank Löhr
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt/Main, Germany
| | - Christian Münch
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt/Main, Germany
- Frankfurt Cancer Institute, Frankfurt/Main, Germany
- Cardio-Pulmonary Institute, Frankfurt/Main, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt/Main, Germany.
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Piletic K, Alsaleh G, Simon AK. Autophagy orchestrates the crosstalk between cells and organs. EMBO Rep 2023; 24:e57289. [PMID: 37465980 PMCID: PMC10481659 DOI: 10.15252/embr.202357289] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/24/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
Over the recent years, it has become apparent that a deeper understanding of cell-to-cell and organ-to-organ communication is necessary to fully comprehend both homeostatic and pathological states. Autophagy is indispensable for cellular development, function, and homeostasis. A crucial aspect is that autophagy can also mediate these processes through its secretory role. The autophagy-derived secretome relays its extracellular signals in the form of nutrients, proteins, mitochondria, and extracellular vesicles. These crosstalk mediators functionally shape cell fate decisions, tissue microenvironment and systemic physiology. The diversity of the secreted cargo elicits an equally diverse type of responses, which span over metabolic, inflammatory, and structural adaptations in disease and homeostasis. We review here the emerging role of the autophagy-derived secretome in the communication between different cell types and organs and discuss the mechanisms involved.
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Affiliation(s)
- Klara Piletic
- Kennedy Institute of RheumatologyUniversity of OxfordOxfordUK
| | - Ghada Alsaleh
- Kennedy Institute of RheumatologyUniversity of OxfordOxfordUK
- Botnar Institute for Musculoskeletal Sciences, NDORMSUniversity of OxfordOxfordUK
| | - Anna Katharina Simon
- Kennedy Institute of RheumatologyUniversity of OxfordOxfordUK
- Max Delbrück CenterBerlinGermany
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7
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Schmitt D, Bozkurt S, Henning-Domres P, Huesmann H, Eimer S, Bindila L, Behrends C, Boyle E, Wilfling F, Tascher G, Münch C, Behl C, Kern A. FACS-mediated isolation of native autophagic vesicles. Autophagy 2023; 19:2146-2147. [PMID: 36416088 PMCID: PMC10283435 DOI: 10.1080/15548627.2022.2151188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/24/2022] Open
Abstract
Autophagosome isolation enables the thorough investigation of structural components and engulfed materials. Recently, we introduced a novel antibody-based FACS-mediated method for isolation of native macroautophagic/autophagic vesicles and confirmed the quality of the preparations. We performed phospholipidomic and proteomic analyses to characterize autophagic vesicle-associated phospholipids and protein cargoes under different autophagy conditions. Lipidomic analyses identified phosphoglycerides and sphingomyelins within autophagic vesicles and revealed that the lipid composition was unaffected by different rates of autophagosome formation. Proteomic analyses identified more than 4500 potential autophagy substrates and showed that in comparison to autophagic vesicles isolated under basal autophagy conditions, starvation only marginally affected the cargo profile. Proteasome inhibition, however, resulted in the enhanced degradation of ubiquitin-proteasome system components. Taken together, the novel isolation method enriched large quantities of autophagic vesicles and enabled detailed analyses of their lipid and cargo composition.
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Affiliation(s)
- Daniel Schmitt
- Institute of Pathobiochemistry, The Autophagy Lab, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Süleyman Bozkurt
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Pascale Henning-Domres
- Institute of Pathobiochemistry, The Autophagy Lab, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Heike Huesmann
- Institute of Pathobiochemistry, The Autophagy Lab, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Stefan Eimer
- Department of Structural Cell Biology, Institute for Cell Biology and Neuroscience, Goethe University, Frankfurt am Main, Germany
| | - Laura Bindila
- Institute of Physiological Chemistry, Clinical Lipidomics Unit, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Christian Behrends
- Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians- University, Munich, Germany
| | - Emily Boyle
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Georg Tascher
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Christian Münch
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Christian Behl
- Institute of Pathobiochemistry, The Autophagy Lab, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Andreas Kern
- Institute of Pathobiochemistry, The Autophagy Lab, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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8
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Gestal-Mato U, Herhaus L. Autophagy-dependent regulation of MHC-I molecule presentation. J Cell Biochem 2023. [PMID: 37126231 DOI: 10.1002/jcb.30416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/03/2023] [Accepted: 04/18/2023] [Indexed: 05/02/2023]
Abstract
The major histocompatibility complex (MHC) class I molecules present peptide antigens to MHC class I-restricted CD8+ T lymphocytes to elicit an effective immune response. The conventional antigen-processing pathway for MHC-I presentation depends on proteasome-mediated peptide generation and peptide loading in the endoplasmic reticulum by members of the peptide loading complex. Recent discoveries in this field highlight the role of alternative MHC-I peptide loading and presentation pathways, one of them being autophagy. Autophagy is a cell-intrinsic degradative pathway that ensures cellular homoeostasis and plays critical roles in cellular immunity. In this review article, we discuss the role of autophagy in MHC class I-restricted antigen presentation, elucidating new findings on the crosstalk of autophagy and ER-mediated MHC-I peptide presentation, dendritic cell-mediated cross-presentation and also mechanisms governing immune evasion. A detailed molecular understanding of the key drivers of autophagy-mediated MHC-I modulation holds promising targets to devise effective measures to improve T cell immunotherapies.
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Affiliation(s)
- Uxia Gestal-Mato
- Goethe University School of Medicine, Institute of Biochemistry II, Frankfurt am Main, Germany
| | - Lina Herhaus
- Goethe University School of Medicine, Institute of Biochemistry II, Frankfurt am Main, Germany
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9
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Fuller DM, Melia TJ. Closing the autophagosome is easy-PC. EMBO J 2023; 42:e113046. [PMID: 36478568 PMCID: PMC9841321 DOI: 10.15252/embj.2022113046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
In their recent article, Polyansky et al identify phosphatidylcholine (PC) as the most abundant lipid in the autophagosome membrane and demonstrate that eliminating de novo PC synthesis sharply impairs autophagic processing. In the absence of PC synthesis, open cup-like structures accumulate, implicating PC as a key component in the closure of autophagosomes.
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Affiliation(s)
- Devin M Fuller
- Department of Cell BiologyYale University School of MedicineNew HavenCTUSA
| | - Thomas J Melia
- Department of Cell BiologyYale University School of MedicineNew HavenCTUSA
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Capitanio C, Bieber A, Wilfling F. How Membrane Contact Sites Shape the Phagophore. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231162495. [PMID: 37366413 PMCID: PMC10243513 DOI: 10.1177/25152564231162495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/15/2023] [Accepted: 02/18/2023] [Indexed: 06/28/2023]
Abstract
During macroautophagy, phagophores establish multiple membrane contact sites (MCSs) with other organelles that are pivotal for proper phagophore assembly and growth. In S. cerevisiae, phagophore contacts have been observed with the vacuole, the ER, and lipid droplets. In situ imaging studies have greatly advanced our understanding of the structure and function of these sites. Here, we discuss how in situ structural methods like cryo-CLEM can give unprecedented insights into MCSs, and how they help to elucidate the structural arrangements of MCSs within cells. We further summarize the current knowledge of the contact sites in autophagy, focusing on autophagosome biogenesis in the model organism S. cerevisiae.
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Affiliation(s)
- Cristina Capitanio
- Department of Molecular Machines and
Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Aligning Science Across Parkinson's (ASAP)
Collaborative Research Network, Chevy Chase, MD, USA
| | - Anna Bieber
- Department of Molecular Machines and
Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Aligning Science Across Parkinson's (ASAP)
Collaborative Research Network, Chevy Chase, MD, USA
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt a. M., Germany
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