1
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Deretic V, Duque T, Trosdal E, Paddar M, Javed R, Akepati P. Membrane atg8ylation in Canonical and Noncanonical Autophagy. J Mol Biol 2024; 436:168532. [PMID: 38479594 PMCID: PMC11260254 DOI: 10.1016/j.jmb.2024.168532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/04/2024] [Accepted: 03/07/2024] [Indexed: 04/13/2024]
Abstract
Membrane atg8ylation is a homeostatic process responding to membrane remodeling and stress signals. Membranes are atg8ylated by mammalian ATG8 ubiquitin-like proteins through a ubiquitylation-like cascade. A model has recently been put forward which posits that atg8ylation of membranes is conceptually equivalent to ubiquitylation of proteins. Like ubiquitylation, membrane atg8ylation involves E1, E2 and E3 enzymes. The E3 ligases catalyze the final step of atg8ylation of aminophospholipids in membranes. Until recently, the only known E3 ligase for membrane atg8ylation was ATG16L1 in a noncovalent complex with the ATG12-ATG5 conjugate. ATG16L1 was first identified as a factor in canonical autophagy. During canonical autophagy, the ATG16L1-based E3 ligase complex includes WIPI2, which in turn recognizes phosphatidylinositiol 3-phosphate and directs atg8ylation of autophagic phagophores. As an alternative to WIPIs, binding of ATG16L1 to the proton pump V-ATPase guides atg8ylation of endolysosomal and phagosomal membranes in response to lumenal pH changes. Recently, a new E3 complex containing TECPR1 instead of ATG16L1, has been identified that responds to sphingomyelin's presence on the cytofacial side of perturbed endolysosomal membranes. In present review, we cover the principles of membrane atg8ylation, catalog its various presentations, and provide a perspective on the growing repertoire of E3 ligase complexes directing membrane atg8ylation at diverse locations.
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Affiliation(s)
- Vojo Deretic
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA.
| | - Thabata Duque
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Einar Trosdal
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Masroor Paddar
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Ruheena Javed
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Prithvi Akepati
- Gastroenterology Division, Department of Internal Medicine, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
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2
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Popelka H, Klionsky DJ. When an underdog becomes a major player: the role of protein structural disorder in the Atg8 conjugation system. Autophagy 2024:1-8. [PMID: 38808635 DOI: 10.1080/15548627.2024.2357496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 05/06/2024] [Indexed: 05/30/2024] Open
Abstract
The noncanonical ubiquitin-like conjugation cascade involving the E1 (Atg7), E2 (Atg3, Atg10), and E3 (Atg12-Atg5-Atg16 complex) enzymes is essential for incorporation of Atg8 into the growing phagophore via covalent linkage to PE. This process is an indispensable step in autophagy. Atg8 and E1-E3 enzymes are the first subset from the core autophagy protein machinery structures that were investigated in earlier studies by crystallographic analyses of globular domains. However, research over the past decade shows that many important functions in the conjugation machinery are mediated by intrinsically disordered protein regions (IDPRs) - parts of the protein that do not adopt a stable secondary or tertiary structure, which are inherently dynamic and well suited for protein-membrane interactions but are invisible in protein crystals. Here, we summarize earlier and recent findings on the autophagy conjugation machinery by focusing on the IDPRs. This summary reveals that IDPRs, originally considered dispensable, are in fact major players and a driving force in the function of the autophagy conjugation system. Abbreviation: AD, activation domain of Atg7; AH, amphipathic helix; AIM, Atg8-family interacting motif; CL, catalytic loop (of Atg7); CTD, C-terminal domain; FR, flexible region (of Atg3 or Atg10); GUV, giant unilammelar vesicles; HR, handle region (of Atg3); IDPR, intrinsically disordered protein region; IDPs: intrinsically disordered proteins; LIR, LC3-interacting region; NHD: N-terminal helical domain; NMR, nuclear magnetic resonance; PE, phosphatidylethanolamine; UBL, ubiquitin like.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
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3
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Ye Y, Liang X, Wang G, Bewley MC, Hamamoto K, Liu X, Flanagan JM, Wang HG, Takahashi Y, Tian F. Identification of membrane curvature sensing motifs essential for VPS37A phagophore recruitment and autophagosome closure. Commun Biol 2024; 7:334. [PMID: 38491121 PMCID: PMC10942982 DOI: 10.1038/s42003-024-06026-7] [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: 02/06/2024] [Accepted: 03/07/2024] [Indexed: 03/18/2024] Open
Abstract
VPS37A, an ESCRT-I complex component, is required for recruiting a subset of ESCRT proteins to the phagophore for autophagosome closure. However, the mechanism by which VPS37A is targeted to the phagophore remains obscure. Here, we demonstrate that the VPS37A N-terminal domain exhibits selective interactions with highly curved membranes, mediated by two membrane-interacting motifs within the disordered regions surrounding its Ubiquitin E2 variant-like (UEVL) domain. Site-directed mutations of residues in these motifs disrupt ESCRT-I localization to the phagophore and result in defective phagophore closure and compromised autophagic flux in vivo, highlighting their essential role during autophagy. In conjunction with the UEVL domain, we postulate that these motifs guide a functional assembly of the ESCRT machinery at the highly curved tip of the phagophore for autophagosome closure. These results advance the notion that the distinctive membrane architecture of the cup-shaped phagophore spatially regulates autophagosome biogenesis.
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Affiliation(s)
- Yansheng Ye
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA.
| | - Xinwen Liang
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Guifang Wang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Maria C Bewley
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Kouta Hamamoto
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Xiaoming Liu
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - John M Flanagan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Hong-Gang Wang
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Yoshinori Takahashi
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Fang Tian
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA.
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4
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Rao S, Skulsuppaisarn M, Strong LM, Ren X, Lazarou M, Hurley JH, Hummer G. Three-step docking by WIPI2, ATG16L1, and ATG3 delivers LC3 to the phagophore. SCIENCE ADVANCES 2024; 10:eadj8027. [PMID: 38324698 PMCID: PMC10851258 DOI: 10.1126/sciadv.adj8027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 01/05/2024] [Indexed: 02/09/2024]
Abstract
The covalent attachment of ubiquitin-like LC3 proteins (microtubule-associated proteins 1A/1B light chain 3) prepares the autophagic membrane for cargo recruitment. We resolve key steps in LC3 lipidation by combining molecular dynamics simulations and experiments in vitro and in cellulo. We show how the E3-like ligaseautophagy-related 12 (ATG12)-ATG5-ATG16L1 in complex with the E2-like conjugase ATG3 docks LC3 onto the membrane in three steps by (i) the phosphatidylinositol 3-phosphate effector protein WD repeat domain phosphoinositide-interacting protein 2 (WIPI2), (ii) helix α2 of ATG16L1, and (iii) a membrane-interacting surface of ATG3. Phosphatidylethanolamine (PE) lipids concentrate in a region around the thioester bond between ATG3 and LC3, highlighting residues with a possible role in the catalytic transfer of LC3 to PE, including two conserved histidines. In a near-complete pathway from the initial membrane recruitment to the LC3 lipidation reaction, the three-step targeting of the ATG12-ATG5-ATG16L1 machinery establishes a high level of regulatory control.
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Affiliation(s)
- Shanlin Rao
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Marvin Skulsuppaisarn
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Lisa M. Strong
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xuefeng Ren
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michael Lazarou
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - James H. Hurley
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
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5
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Tooze SA, Zhang W, Lazzeri G, Gahlot D, Thukral L, Covino R, Nishimura T. Membrane association of the ATG8 conjugation machinery emerges as a key regulatory feature for autophagosome biogenesis. FEBS Lett 2024; 598:107-113. [PMID: 37259601 PMCID: PMC10952647 DOI: 10.1002/1873-3468.14676] [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: 04/22/2023] [Revised: 05/10/2023] [Accepted: 05/10/2023] [Indexed: 06/02/2023]
Abstract
Autophagy is a highly conserved intracellular pathway that is essential for survival in all eukaryotes. In healthy cells, autophagy is used to remove damaged intracellular components, which can be as simple as unfolded proteins or as complex as whole mitochondria. Once the damaged component is captured, the autophagosome engulfs it and closes, isolating the content from the cytoplasm. The autophagosome then fuses with the late endosome and/or lysosome to deliver its content to the lysosome for degradation. Formation of the autophagosome, sequestration or capture of content, and closure all require the ATG proteins, which constitute the essential core autophagy protein machinery. This brief 'nutshell' will highlight recent data revealing the importance of small membrane-associated domains in the ATG proteins. In particular, recent findings from two parallel studies reveal the unexpected key role of α-helical structures in the ATG8 conjugation machinery and ATG8s. These studies illustrate how unique membrane association modules can control the formation of autophagosomes.
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Affiliation(s)
- Sharon A. Tooze
- Molecular Cell Biology of Autophagy LaboratoryThe Francis Crick InstituteLondonUK
| | - Wenxin Zhang
- Molecular Cell Biology of Autophagy LaboratoryThe Francis Crick InstituteLondonUK
| | | | - Deepanshi Gahlot
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative Research (AcSIR)GhaziabadIndia
| | - Lipi Thukral
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative Research (AcSIR)GhaziabadIndia
| | | | - Taki Nishimura
- PRESTO, Japan Science and Technology AgencyTokyoJapan
- Department of Biochemistry and Molecular Biology, Graduate School of MedicineThe University of TokyoJapan
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6
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Popelka H, Lahiri V, Hawkins WD, da Veiga Leprevost F, Nesvizhskii AI, Klionsky DJ. The Intrinsically Disordered N Terminus in Atg12 from Yeast Is Necessary for the Functional Structure of the Protein. Int J Mol Sci 2023; 24:15036. [PMID: 37894717 PMCID: PMC10606595 DOI: 10.3390/ijms242015036] [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: 08/16/2023] [Revised: 09/29/2023] [Accepted: 10/02/2023] [Indexed: 10/29/2023] Open
Abstract
The Atg12 protein in yeast is an indispensable polypeptide in the highly conserved ubiquitin-like conjugation system operating in the macroautophagy/autophagy pathway. Atg12 is covalently conjugated to Atg5 through the action of Atg7 and Atg10; the Atg12-Atg5 conjugate binds Atg16 to form an E3 ligase that functions in a separate conjugation pathway involving Atg8. Atg12 is comprised of a ubiquitin-like (UBL) domain preceded at the N terminus by an intrinsically disordered protein region (IDPR), a domain that comprises a major portion of the protein but remains elusive in its conformation and function. Here, we show that the IDPR in unconjugated Atg12 is positioned in proximity to the UBL domain, a configuration that is important for the functional structure of the protein. A major deletion in the IDPR disrupts intactness of the UBL domain at the unconjugated C terminus, and a mutation in the predicted α0 helix in the IDPR prevents Atg12 from binding to Atg7 and Atg10, which ultimately affects the protein function in the ubiquitin-like conjugation cascade. These findings provide evidence that the IDPR is an indispensable part of the Atg12 protein from yeast.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (V.L.); (W.D.H.); (D.J.K.)
| | - Vikramjit Lahiri
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (V.L.); (W.D.H.); (D.J.K.)
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wayne D. Hawkins
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (V.L.); (W.D.H.); (D.J.K.)
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Felipe da Veiga Leprevost
- Department of Pathology, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA; (F.d.V.L.); (A.I.N.)
| | - Alexey I. Nesvizhskii
- Department of Pathology, Michigan Medicine, University of Michigan, Ann Arbor, MI 48109, USA; (F.d.V.L.); (A.I.N.)
| | - Daniel J. Klionsky
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; (V.L.); (W.D.H.); (D.J.K.)
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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7
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Deretic V. Atg8ylation as a host-protective mechanism against Mycobacterium tuberculosis. FRONTIERS IN TUBERCULOSIS 2023; 1:1275882. [PMID: 37901138 PMCID: PMC10612523 DOI: 10.3389/ftubr.2023.1275882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Nearly two decades have passed since the first report on autophagy acting as a cell-autonomous defense against Mycobacterium tuberculosis. This helped usher a new area of research within the field of host-pathogen interactions and led to the recognition of autophagy as an immunological mechanism. Interest grew in the fundamental mechanisms of antimicrobial autophagy and in the prophylactic and therapeutic potential for tuberculosis. However, puzzling in vivo data have begun to emerge in murine models of M. tuberculosis infection. The control of infection in mice affirmed the effects of certain autophagy genes, specifically ATG5, but not of other ATGs. Recent studies with a more complete inactivation of ATG genes now show that multiple ATG genes are indeed necessary for protection against M. tuberculosis. These particular ATG genes are involved in the process of membrane atg8ylation. Atg8ylation in mammalian cells is a broad response to membrane stress, damage and remodeling of which canonical autophagy is one of the multiple downstream outputs. The current developments clarify the controversies and open new avenues for both fundamental and translational studies.
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Affiliation(s)
- Vojo Deretic
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
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8
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Ye Y, Tyndall ER, Bui V, Bewley MC, Wang G, Hong X, Shen Y, Flanagan JM, Wang HG, Tian F. Multifaceted membrane interactions of human Atg3 promote LC3-phosphatidylethanolamine conjugation during autophagy. Nat Commun 2023; 14:5503. [PMID: 37679347 PMCID: PMC10485044 DOI: 10.1038/s41467-023-41243-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
Autophagosome formation, a crucial step in macroautophagy (autophagy), requires the covalent conjugation of LC3 proteins to the amino headgroup of phosphatidylethanolamine (PE) lipids. Atg3, an E2-like enzyme, catalyzes the transfer of LC3 from LC3-Atg3 to PEs in targeted membranes. Here we show that the catalytically important C-terminal regions of human Atg3 (hAtg3) are conformationally dynamic and directly interact with the membrane, in collaboration with its N-terminal membrane curvature-sensitive helix. The functional relevance of these interactions was confirmed by in vitro conjugation and in vivo cellular assays. Therefore, highly curved phagophoric rims not only serve as a geometric cue for hAtg3 recruitment, but also their interaction with hAtg3 promotes LC3-PE conjugation by targeting its catalytic center to the membrane surface and bringing substrates into proximity. Our studies advance the notion that autophagosome biogenesis is directly guided by the spatial interactions of Atg3 with highly curved phagophoric rims.
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Affiliation(s)
- Yansheng Ye
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Erin R Tyndall
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Van Bui
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Maria C Bewley
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Guifang Wang
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Xupeng Hong
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, MD, USA
| | - John M Flanagan
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Hong-Gang Wang
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, USA.
| | - Fang Tian
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, USA.
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9
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Nishimura T, Lazzeri G, Mizushima N, Covino R, Tooze SA. Unique amphipathic α helix drives membrane insertion and enzymatic activity of ATG3. SCIENCE ADVANCES 2023; 9:eadh1281. [PMID: 37352354 PMCID: PMC10289646 DOI: 10.1126/sciadv.adh1281] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/22/2023] [Indexed: 06/25/2023]
Abstract
Autophagosome biogenesis requires a localized perturbation of lipid membrane dynamics and a unique protein-lipid conjugate. Autophagy-related (ATG) proteins catalyze this biogenesis on cellular membranes, but the underlying molecular mechanism remains unclear. Focusing on the final step of the protein-lipid conjugation reaction, the ATG8/LC3 lipidation, we show how the membrane association of the conjugation machinery is organized and fine-tuned at the atomistic level. Amphipathic α helices in ATG3 proteins (AHATG3) have low hydrophobicity and contain less bulky residues. Molecular dynamics simulations reveal that AHATG3 regulates the dynamics and accessibility of the thioester bond of the ATG3~LC3 conjugate to lipids, enabling the covalent lipidation of LC3. Live-cell imaging shows that the transient membrane association of ATG3 with autophagic membranes is governed by the less bulky-hydrophobic feature of AHATG3. The unique properties of AHATG3 facilitate protein-lipid bilayer association, leading to the remodeling of the lipid bilayer required for the formation of autophagosomes.
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Affiliation(s)
- Taki Nishimura
- PRESTO, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0076, Japan
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Molecular Cell Biology of Autophagy Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Gianmarco Lazzeri
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, Frankfurt am Main 60438, Germany
- Goethe University, Frankfurt am Main 60438, Germany
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Roberto Covino
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, Frankfurt am Main 60438, Germany
- Goethe University, Frankfurt am Main 60438, Germany
| | - Sharon A. Tooze
- Molecular Cell Biology of Autophagy Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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10
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Koehler Leman J, Künze G. Recent Advances in NMR Protein Structure Prediction with ROSETTA. Int J Mol Sci 2023; 24:ijms24097835. [PMID: 37175539 PMCID: PMC10178863 DOI: 10.3390/ijms24097835] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/15/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a powerful method for studying the structure and dynamics of proteins in their native state. For high-resolution NMR structure determination, the collection of a rich restraint dataset is necessary. This can be difficult to achieve for proteins with high molecular weight or a complex architecture. Computational modeling techniques can complement sparse NMR datasets (<1 restraint per residue) with additional structural information to elucidate protein structures in these difficult cases. The Rosetta software for protein structure modeling and design is used by structural biologists for structure determination tasks in which limited experimental data is available. This review gives an overview of the computational protocols available in the Rosetta framework for modeling protein structures from NMR data. We explain the computational algorithms used for the integration of different NMR data types in Rosetta. We also highlight new developments, including modeling tools for data from paramagnetic NMR and hydrogen-deuterium exchange, as well as chemical shifts in CS-Rosetta. Furthermore, strategies are discussed to complement and improve structure predictions made by the current state-of-the-art AlphaFold2 program using NMR-guided Rosetta modeling.
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Affiliation(s)
- Julia Koehler Leman
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, NY 10010, USA
| | - Georg Künze
- Institute for Drug Discovery, Medical Faculty, University of Leipzig, Brüderstr. 34, D-04103 Leipzig, Germany
- Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstr. 16-18, D-04107 Leipzig, Germany
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11
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Liu L, Tang Y, Zhou Z, Huang Y, Zhang R, Lyu H, Xiao S, Guo D, Ali DW, Michalak M, Chen XZ, Zhou C, Tang J. Membrane Curvature: The Inseparable Companion of Autophagy. Cells 2023; 12:1132. [PMID: 37190041 PMCID: PMC10136490 DOI: 10.3390/cells12081132] [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: 12/07/2022] [Revised: 04/06/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Autophagy is a highly conserved recycling process of eukaryotic cells that degrades protein aggregates or damaged organelles with the participation of autophagy-related proteins. Membrane bending is a key step in autophagosome membrane formation and nucleation. A variety of autophagy-related proteins (ATGs) are needed to sense and generate membrane curvature, which then complete the membrane remodeling process. The Atg1 complex, Atg2-Atg18 complex, Vps34 complex, Atg12-Atg5 conjugation system, Atg8-phosphatidylethanolamine conjugation system, and transmembrane protein Atg9 promote the production of autophagosomal membranes directly or indirectly through their specific structures to alter membrane curvature. There are three common mechanisms to explain the change in membrane curvature. For example, the BAR domain of Bif-1 senses and tethers Atg9 vesicles to change the membrane curvature of the isolation membrane (IM), and the Atg9 vesicles are reported as a source of the IM in the autophagy process. The amphiphilic helix of Bif-1 inserts directly into the phospholipid bilayer, causing membrane asymmetry, and thus changing the membrane curvature of the IM. Atg2 forms a pathway for lipid transport from the endoplasmic reticulum to the IM, and this pathway also contributes to the formation of the IM. In this review, we introduce the phenomena and causes of membrane curvature changes in the process of macroautophagy, and the mechanisms of ATGs in membrane curvature and autophagosome membrane formation.
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Affiliation(s)
- Lei Liu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Yu Tang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Zijuan Zhou
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Yuan Huang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Rui Zhang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Hao Lyu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Shuai Xiao
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Dong Guo
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Declan William Ali
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Xing-Zhen Chen
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Cefan Zhou
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Jingfeng Tang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
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12
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Mallén-Ponce MJ, Gámez-Arcas S, Pérez-Pérez ME. Redox partner interactions in the ATG8 lipidation system in microalgae. Free Radic Biol Med 2023; 203:58-68. [PMID: 37028463 DOI: 10.1016/j.freeradbiomed.2023.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/29/2023] [Accepted: 04/05/2023] [Indexed: 04/09/2023]
Abstract
Autophagy is a catabolic pathway that functions as a degradative and recycling process to maintain cellular homeostasis in most eukaryotic cells, including photosynthetic organisms such as microalgae. This process involves the formation of double-membrane vesicles called autophagosomes, which engulf the material to be degraded and recycled in lytic compartments. Autophagy is mediated by a set of highly conserved autophagy-related (ATG) proteins that play a fundamental role in the formation of the autophagosome. The ATG8 ubiquitin-like system catalyzes the conjugation of ATG8 to the lipid phosphatidylethanolamine, an essential reaction in the autophagy process. Several studies identified the ATG8 system and other core ATG proteins in photosynthetic eukaryotes. However, how ATG8 lipidation is driven and regulated in these organisms is not fully understood yet. A detailed analysis of representative genomes from the entire microalgal lineage revealed a high conservation of ATG proteins in these organisms with the remarkable exception of red algae, which likely lost ATG genes before diversification. Here, we examine in silico the mechanisms and dynamic interactions between different components of the ATG8 lipidation system in plants and algae. Moreover, we also discuss the role of redox post-translational modifications in the regulation of ATG proteins and the activation of autophagy in these organisms by reactive oxygen species.
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Affiliation(s)
- Manuel J Mallén-Ponce
- Institut de Biologie Paris-Seine, UMR 7238, CNRS, Sorbonne Université, 75005, Paris, France
| | - Samuel Gámez-Arcas
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092, Sevilla, Spain
| | - María Esther Pérez-Pérez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092, Sevilla, Spain.
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13
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Ran L, Xiang J, Zeng X, He W, Dong Y, Yu W, Qi X, Xiao Y, Cao K, Zou J, Guan Z. The influence of NQO2 on the dysfunctional autophagy and oxidative stress induced in the hippocampus of rats and in SH-SY5Y cells by fluoride. CNS Neurosci Ther 2023; 29:1129-1141. [PMID: 36650666 PMCID: PMC10018107 DOI: 10.1111/cns.14090] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/24/2022] [Accepted: 12/29/2022] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION For investigating the mechanism of brain injury caused by chronic fluorosis, this study was designed to determine whether NRH:quinone oxidoreductase 2 (NQO2) can influence autophagic disruption and oxidative stress induced in the central nervous system exposed to a high level of fluoride. METHODS Sprague-Dawley rats drank tap water containing different concentrations of fluoride for 3 or 6 months. SH-SY5Y cells were either transfected with NQO2 RNA interference or treated with NQO2 inhibitor or activator and at the same time exposed to fluoride. The enrichment of gene signaling pathways related to autophagy was evaluated by Gene Set Enrichment Analysis; expressions of NQO2 and autophagy-related protein 5 (ATG5), LC3-II and p62, and mammalian target of rapamycin (mTOR) were quantified by Western-blotting or fluorescent staining; and the levels of malondialdehyde (MDA) and superoxide dismutase (SOD) assayed biochemically and reactive oxygen species (ROS) detected by flow cytometry. RESULTS In the hippocampal CA3 region of rats exposed to high fluoride, the morphological characteristics of neurons were altered; the numbers of autophagosomes in the cytoplasm and the levels of NQO2 increased; the level of p-mTOR was decreased, and the levels of ATG5, LC3-II and p62 were elevated; and genes related to autophagy enriched. In vitro, in addition to similar changes in NQO2, p-mTOR, ATG5, LC3 II, and p62, exposure of SH-SY5Y cells to fluoride enhanced MDA and ROS contents and reduced SOD activity. Inhibition of NQO2 with RNAi or an inhibitor attenuated the disturbance of the autophagic flux and enhanced oxidative stress in these cells exposed to high fluoride. CONCLUSION Our findings indicate that NQO2 may be involved in regulating autophagy and oxidative stress and thereby exerts an impact on brain injury caused by chronic fluorosis.
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Affiliation(s)
- Long‐Yan Ran
- Department of Pathology at the Affiliated Hospital of Guizhou Medical UniversityKey Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of EducationGuiyangChina
- Department of Medical Science and TechnologyGuiyang Healthcare Vocational UniversityGuiyangChina
| | - Jie Xiang
- Department of Pathology at the Affiliated Hospital of Guizhou Medical UniversityKey Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of EducationGuiyangChina
| | - Xiao‐Xiao Zeng
- Department of Pathology at the Affiliated Hospital of Guizhou Medical UniversityKey Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of EducationGuiyangChina
| | - Wen‐Wen He
- Department of Pathology at the Affiliated Hospital of Guizhou Medical UniversityKey Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of EducationGuiyangChina
| | - Yang‐Ting Dong
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of Education and Provincial Key Laboratory of Medical Molecular BiologyGuiyangChina
| | - Wen‐Feng Yu
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of Education and Provincial Key Laboratory of Medical Molecular BiologyGuiyangChina
| | - Xiao‐Lan Qi
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of Education and Provincial Key Laboratory of Medical Molecular BiologyGuiyangChina
| | - Yan Xiao
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of Education and Provincial Key Laboratory of Medical Molecular BiologyGuiyangChina
| | - Kun Cao
- Department of Hepatobiliary SurgeryAffiliated Hospital to Guizhou Medical UniversityGuiyangChina
| | - Jian Zou
- Department of Pathology at the Affiliated Hospital of Guizhou Medical UniversityKey Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of EducationGuiyangChina
| | - Zhi‐Zhong Guan
- Department of Pathology at the Affiliated Hospital of Guizhou Medical UniversityKey Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of EducationGuiyangChina
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University) of the Ministry of Education and Provincial Key Laboratory of Medical Molecular BiologyGuiyangChina
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14
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Iriondo MN, Etxaniz A, Varela YR, Ballesteros U, Lázaro M, Valle M, Fracchiolla D, Martens S, Montes LR, Goñi FM, Alonso A. Effect of ATG12-ATG5-ATG16L1 autophagy E3-like complex on the ability of LC3/GABARAP proteins to induce vesicle tethering and fusion. Cell Mol Life Sci 2023; 80:56. [PMID: 36729310 PMCID: PMC9894987 DOI: 10.1007/s00018-023-04704-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 02/03/2023]
Abstract
In macroautophagy, the autophagosome (AP) engulfs portions of cytoplasm to allow their lysosomal degradation. AP formation in humans requires the concerted action of the ATG12 and LC3/GABARAP conjugation systems. The ATG12-ATG5-ATG16L1 or E3-like complex (E3 for short) acts as a ubiquitin-like E3 enzyme, promoting LC3/GABARAP proteins anchoring to the AP membrane. Their role in the AP expansion process is still unclear, in part because there are no studies comparing six LC3/GABARAP family member roles under the same conditions, and also because the full human E3 was only recently available. In the present study, the lipidation of six members of the LC3/GABARAP family has been reconstituted in the presence and absence of E3, and the mechanisms by which E3 and LC3/GABARAP proteins participate in vesicle tethering and fusion have been investigated. In the absence of E3, GABARAP and GABARAPL1 showed the highest activities. Differences found within LC3/GABARAP proteins suggest the existence of a lipidation threshold, lower for the GABARAP subfamily, as a requisite for tethering and inter-vesicular lipid mixing. E3 increases and speeds up lipidation and LC3/GABARAP-promoted tethering. However, E3 hampers LC3/GABARAP capacity to induce inter-vesicular lipid mixing or subsequent fusion, presumably through the formation of a rigid scaffold on the vesicle surface. Our results suggest a model of AP expansion in which the growing regions would be areas where the LC3/GABARAP proteins involved should be susceptible to lipidation in the absence of E3, or else a regulatory mechanism would allow vesicle incorporation and phagophore growth when E3 is present.
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Affiliation(s)
- Marina N Iriondo
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain
| | - Asier Etxaniz
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain
| | - Yaiza R Varela
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain
| | - Uxue Ballesteros
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain
| | - Melisa Lázaro
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 800, 48160, Derio, Bizkaia, Spain
| | - Mikel Valle
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 800, 48160, Derio, Bizkaia, Spain
| | - Dorotea Fracchiolla
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9, 1030, Vienna, Austria
| | - Sascha Martens
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr. Bohr-Gasse 9, 1030, Vienna, Austria
| | - L Ruth Montes
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain
| | - Félix M Goñi
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain
| | - Alicia Alonso
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, 48940, Leioa, Spain.
- Department of Biochemistry and Molecular Biology, University of the Basque Country, 48940, Leioa, Spain.
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15
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Cail RC, Drubin DG. Membrane curvature as a signal to ensure robustness of diverse cellular processes. Trends Cell Biol 2022; 33:427-441. [PMID: 36244874 DOI: 10.1016/j.tcb.2022.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/05/2022]
Abstract
An increasing corpus of research has demonstrated that membrane shape, generated either by the external environment of the cell or by intrinsic mechanisms such as cytokinesis and vesicle or organelle formation, is an important parameter in the control of diverse cellular processes. In this review we discuss recent findings that demonstrate how membrane curvature (from nanometer to micron length-scales) alters protein function. We describe an expanding toolkit for experimentally modulating membrane curvature to reveal effects on protein function, and discuss how membrane curvature - far from being a passive consequence of the physical environment and the internal protein activity of a cell - is an important signal that controls protein affinity and enzymatic activity to ensure robust forward progression of key processes within the cell.
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16
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Theater in the Self-Cleaning Cell: Intrinsically Disordered Proteins or Protein Regions Acting with Membranes in Autophagy. MEMBRANES 2022; 12:membranes12050457. [PMID: 35629783 PMCID: PMC9143426 DOI: 10.3390/membranes12050457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 12/30/2022]
Abstract
Intrinsically disordered proteins and protein regions (IDPs/IDPRs) are mainly involved in signaling pathways, where fast regulation, temporal interactions, promiscuous interactions, and assemblies of structurally diverse components including membranes are essential. The autophagy pathway builds, de novo, a membrane organelle, the autophagosome, using carefully orchestrated interactions between proteins and lipid bilayers. Here, we discuss molecular mechanisms related to the protein disorder-based interactions of the autophagy machinery with membranes. We describe not only membrane binding phenomenon, but also examples of membrane remodeling processes including membrane tethering, bending, curvature sensing, and/or fragmentation of membrane organelles such as the endoplasmic reticulum, which is an important membrane source as well as cargo for autophagy. Summary of the current state of knowledge presented here will hopefully inspire new studies. A profound understanding of the autophagic protein–membrane interface is essential for advancements in therapeutic interventions against major human diseases, in which autophagy is involved including neurodegeneration, cancer as well as cardiovascular, metabolic, infectious, musculoskeletal, and other disorders.
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17
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Iriondo MN, Etxaniz A, Antón Z, Montes LR, Alonso A. Molecular and mesoscopic geometries in autophagosome generation. A review. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183731. [PMID: 34419487 DOI: 10.1016/j.bbamem.2021.183731] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/12/2021] [Accepted: 08/15/2021] [Indexed: 01/18/2023]
Abstract
Autophagy is an essential process in cell self-repair and survival. The centre of the autophagic event is the generation of the so-called autophagosome (AP), a vesicle surrounded by a double membrane (two bilayers). The AP delivers its cargo to a lysosome, for degradation and re-use of the hydrolysis products as new building blocks. AP formation is a very complex event, requiring dozens of specific proteins, and involving numerous instances of membrane biogenesis and architecture, including membrane fusion and fission. Many stages of AP generation can be rationalised in terms of curvature, both the molecular geometry of lipids interpreted in terms of 'intrinsic curvature', and the overall mesoscopic curvature of the whole membrane, as observed with microscopy techniques. The present contribution intends to bring together the worlds of biophysics and cell biology of autophagy, in the hope that the resulting cross-pollination will generate abundant fruit.
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Affiliation(s)
- Marina N Iriondo
- Instituto Biofisika (CSIC, UPV/EHU) and Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, 48940 Leioa, Spain
| | - Asier Etxaniz
- Instituto Biofisika (CSIC, UPV/EHU) and Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, 48940 Leioa, Spain
| | - Zuriñe Antón
- Instituto Biofisika (CSIC, UPV/EHU) and Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, 48940 Leioa, Spain
| | - L Ruth Montes
- Instituto Biofisika (CSIC, UPV/EHU) and Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, 48940 Leioa, Spain
| | - Alicia Alonso
- Instituto Biofisika (CSIC, UPV/EHU) and Departamento de Bioquímica y Biología Molecular, Universidad del País Vasco, 48940 Leioa, Spain.
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18
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Xie S, Jiang X, Qin R, Song S, Lu Y, Wang L, Chen Y, Lu D. miR-1307 promotes hepatocarcinogenesis by CALR-OSTC-endoplasmic reticulum protein folding pathway. iScience 2021; 24:103271. [PMID: 34761190 PMCID: PMC8567365 DOI: 10.1016/j.isci.2021.103271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/27/2021] [Accepted: 10/12/2021] [Indexed: 12/20/2022] Open
Abstract
miR-1307 is highly expressed in liver cancer and inhibits methyltransferase protein8. Thereby, miR-1307 inhibits the expression of KDM3A and KDM3B and increases the methylation modification of histone H3 lysine 9, which enhances the expression of endoplasmic-reticulum-related gene CALR. Of note, miR-1307 weakens the binding ability of OSTC to CDK2, CDK4, CyclinD1, and cyclinE and enhances the binding ability of CALR to CDK2, CDK4, CyclinD1, and cyclinE, decreasing of p21WAF1/CIP1, GADD45, pRB, and p18, and decreasing of ppRB. Furthermore, miR-1307 increases the activity of H-Ras, PKM2, and PLK1. Strikingly, miR-1307 reduces the binding ability of OSTC to ATG4 and enhances the binding ability of CALR to ATG4. Therefore, miR-1307 reduces the occurrence of autophagy based on ATG4-LC3-ATG3-ATG7-ATG5-ATG16L1-ATG12-ATG9- Beclin1. In particular, miR-1307 enhances the expression of PAK2, PLK1, PRKAR2A, MYBL1, and Trim44 and inhibits the expression of Sash1 and Smad5 via autophagy. Our observations suggest that miR-1307 promotes hepatocarcinogenesis by CALR-OSTC-endoplasmic reticulum protein folding pathway.
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Affiliation(s)
- Sijie Xie
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Xiaoxue Jiang
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Rushi Qin
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Shuting Song
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Yanan Lu
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Liyan Wang
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Yingjie Chen
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
| | - Dongdong Lu
- Shanghai Putuo People's Hospital, School of Life Science and Technology, Tongji University, 200092 Shanghai, China
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Ye Y, Wang G, Bewley MC, Wang HG, Tian F. NMR resonance assignments of human Atg3 in aqueous solution and bicelles. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:421-425. [PMID: 34296398 PMCID: PMC8484069 DOI: 10.1007/s12104-021-10040-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
Human Atg3 (hAtg3) is an E2-like enzyme that catalyzes the conjugation of LC3 family proteins to phosphatidylethanolamine (PE) lipids in the autophagosomal membrane during autophagy. The reaction product, LC3-PE, acts as a marker for autophagic cargo and is required for the effective construction of functional autophagosomes. However, the structural and molecular basis of this conjugation reaction remains elusive, at least in part, because of the absence of lipid bilayers in structural studies conducted to date. Here, we report a sequential resonance assignment for an hAtg3 construct both in aqueous solution and in bicelles. hAtg3 has 314 residues, and our construct lacks the unstructured region from residues 90 to 190. Our results demonstrate a structural rearrangement of hAtg3 N-terminus when it interacts with membranes.
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Affiliation(s)
- Yansheng Ye
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Guifang Wang
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Maria C Bewley
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA
| | - Hong-Gang Wang
- Department of Pediatrics, Penn State College of Medicine, Hershey, PA, USA
| | - Fang Tian
- Department of Biochemistry and Molecular Biology, Penn State College of Medicine, Hershey, PA, USA.
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20
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Popelka H, Klionsky DJ. Multiple structural rearrangements mediated by high-plasticity regions in Atg3 are key for efficient conjugation of Atg8 to PE during autophagy. Autophagy 2021; 17:1805-1808. [PMID: 34338142 DOI: 10.1080/15548627.2021.1954457] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The Atg3 protein is highly homologous from yeast to human. Atg3 functions as an E2-like enzyme promoting conjugation of Atg8-family proteins to phosphatidylethanolamine (PE), a lipid molecule embedded in the growing phagophore membrane during stress-induced autophagy. Over the last decade, Atg3 became one of the most explored autophagy proteins, resulting in observations that provided specific insights into the structural mechanisms of its function. In this article, we describe a recent study by Ye et al. that reveals, using the human ATG3, how the membrane binding capability of the enzyme is tightly linked to its conjugation activity. We summarize the current knowledge on important mechanisms that involve protein-protein or protein-membrane interactions of Atg3 and that ultimately lead to efficient Atg8-PE conjugation.Abbreviations: AH: amphipathic helix; FR: flexible region; HR: handle region; NMR: nuclear magnetic resonance.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
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21
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Fang D, Xie H, Hu T, Shan H, Li M. Binding Features and Functions of ATG3. Front Cell Dev Biol 2021; 9:685625. [PMID: 34235149 PMCID: PMC8255673 DOI: 10.3389/fcell.2021.685625] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/24/2021] [Indexed: 12/31/2022] Open
Abstract
Autophagy is an evolutionarily conserved catabolic process that is essential for maintaining cellular, tissue, and organismal homeostasis. Autophagy-related (ATG) genes are indispensable for autophagosome formation. ATG3 is one of the key genes involved in autophagy, and its homologs are common in eukaryotes. During autophagy, ATG3 acts as an E2 ubiquitin-like conjugating enzyme in the ATG8 conjugation system, contributing to phagophore elongation. ATG3 has also been found to participate in many physiological and pathological processes in an autophagy-dependent manner, such as tumor occurrence and progression, ischemia-reperfusion injury, clearance of pathogens, and maintenance of organelle homeostasis. Intriguingly, a few studies have recently discovered the autophagy-independent functions of ATG3, including cell differentiation and mitosis. Here, we summarize the current knowledge of ATG3 in autophagosome formation, highlight its binding partners and binding sites, review its autophagy-dependent functions, and provide a brief introduction into its autophagy-independent functions.
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Affiliation(s)
- Dongmei Fang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Huazhong Xie
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Tao Hu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Hao Shan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Min Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
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