1
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Zhao XY, Xu DE, Wu ML, Liu JC, Shi ZL, Ma QH. Regulation and function of endoplasmic reticulum autophagy in neurodegenerative diseases. Neural Regen Res 2025; 20:6-20. [PMID: 38767472 DOI: 10.4103/nrr.nrr-d-23-00995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 12/13/2023] [Indexed: 05/22/2024] Open
Abstract
The endoplasmic reticulum, a key cellular organelle, regulates a wide variety of cellular activities. Endoplasmic reticulum autophagy, one of the quality control systems of the endoplasmic reticulum, plays a pivotal role in maintaining endoplasmic reticulum homeostasis by controlling endoplasmic reticulum turnover, remodeling, and proteostasis. In this review, we briefly describe the endoplasmic reticulum quality control system, and subsequently focus on the role of endoplasmic reticulum autophagy, emphasizing the spatial and temporal mechanisms underlying the regulation of endoplasmic reticulum autophagy according to cellular requirements. We also summarize the evidence relating to how defective or abnormal endoplasmic reticulum autophagy contributes to the pathogenesis of neurodegenerative diseases. In summary, this review highlights the mechanisms associated with the regulation of endoplasmic reticulum autophagy and how they influence the pathophysiology of degenerative nerve disorders. This review would help researchers to understand the roles and regulatory mechanisms of endoplasmic reticulum-phagy in neurodegenerative disorders.
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Affiliation(s)
- Xiu-Yun Zhao
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - De-En Xu
- Department of Neurology, Jiangnan University Medical Center, Wuxi, Jiangsu Province, China
| | - Ming-Lei Wu
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Ji-Chuan Liu
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Zi-Ling Shi
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Quan-Hong Ma
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
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2
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Hoyer MJ, Capitanio C, Smith IR, Paoli JC, Bieber A, Jiang Y, Paulo JA, Gonzalez-Lozano MA, Baumeister W, Wilfling F, Schulman BA, Harper JW. Combinatorial selective ER-phagy remodels the ER during neurogenesis. Nat Cell Biol 2024; 26:378-392. [PMID: 38429475 PMCID: PMC10940164 DOI: 10.1038/s41556-024-01356-4] [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: 04/24/2023] [Accepted: 01/11/2024] [Indexed: 03/03/2024]
Abstract
The endoplasmic reticulum (ER) employs a diverse proteome landscape to orchestrate many cellular functions, ranging from protein and lipid synthesis to calcium ion flux and inter-organelle communication. A case in point concerns the process of neurogenesis, where a refined tubular ER network is assembled via ER shaping proteins into the newly formed neuronal projections to create highly polarized dendrites and axons. Previous studies have suggested a role for autophagy in ER remodelling, as autophagy-deficient neurons in vivo display axonal ER accumulation within synaptic boutons, and the membrane-embedded ER-phagy receptor FAM134B has been genetically linked with human sensory and autonomic neuropathy. However, our understanding of the mechanisms underlying selective removal of the ER and the role of individual ER-phagy receptors is limited. Here we combine a genetically tractable induced neuron (iNeuron) system for monitoring ER remodelling during in vitro differentiation with proteomic and computational tools to create a quantitative landscape of ER proteome remodelling via selective autophagy. Through analysis of single and combinatorial ER-phagy receptor mutants, we delineate the extent to which each receptor contributes to both the magnitude and selectivity of ER protein clearance. We define specific subsets of ER membrane or lumenal proteins as preferred clients for distinct receptors. Using spatial sensors and flux reporters, we demonstrate receptor-specific autophagic capture of ER in axons, and directly visualize tubular ER membranes within autophagosomes in neuronal projections by cryo-electron tomography. This molecular inventory of ER proteome remodelling and versatile genetic toolkit provide a quantitative framework for understanding the contributions of individual ER-phagy receptors for reshaping ER during cell state transitions.
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Affiliation(s)
- Melissa J Hoyer
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Cristina Capitanio
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Ian R Smith
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Velia Therapeutics, San Diego, CA, USA
| | - Julia C Paoli
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Anna Bieber
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Yizhi Jiang
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Miguel A Gonzalez-Lozano
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Wolfgang Baumeister
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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3
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Maruyama T, Hama Y, Noda NN. Mechanisms of mitochondrial reorganization. J Biochem 2024; 175:167-178. [PMID: 38016932 DOI: 10.1093/jb/mvad098] [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: 08/30/2023] [Revised: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 11/30/2023] Open
Abstract
The cytoplasm of eukaryotes is dynamically zoned by membrane-bound and membraneless organelles. Cytoplasmic zoning allows various biochemical reactions to take place at the right time and place. Mitochondrion is a membrane-bound organelle that provides a zone for intracellular energy production and metabolism of lipids and iron. A key feature of mitochondria is their high dynamics: mitochondria constantly undergo fusion and fission, and excess or damaged mitochondria are selectively eliminated by mitophagy. Therefore, mitochondria are appropriate model systems to understand dynamic cytoplasmic zoning by membrane organelles. In this review, we summarize the molecular mechanisms of mitochondrial fusion and fission as well as mitophagy unveiled through studies using yeast and mammalian models.
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Affiliation(s)
- Tatsuro Maruyama
- Institute of Microbial Chemistry (BIKAKEN), 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
| | - Yutaro Hama
- Institute of Microbial Chemistry (BIKAKEN), 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
- Institute for Genetic Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo 060-0815, Japan
| | - Nobuo N Noda
- Institute of Microbial Chemistry (BIKAKEN), 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan
- Institute for Genetic Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo 060-0815, Japan
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4
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Rogov VV, Nezis IP, Tsapras P, Zhang H, Dagdas Y, Noda NN, Nakatogawa H, Wirth M, Mouilleron S, McEwan DG, Behrends C, Deretic V, Elazar Z, Tooze SA, Dikic I, Lamark T, Johansen T. Atg8 family proteins, LIR/AIM motifs and other interaction modes. AUTOPHAGY REPORTS 2023; 2:27694127.2023.2188523. [PMID: 38214012 PMCID: PMC7615515 DOI: 10.1080/27694127.2023.2188523] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
The Atg8 family of ubiquitin-like proteins play pivotal roles in autophagy and other processes involving vesicle fusion and transport where the lysosome/vacuole is the end station. Nuclear roles of Atg8 proteins are also emerging. Here, we review the structural and functional features of Atg8 family proteins and their protein-protein interaction modes in model organisms such as yeast, Arabidopsis, C. elegans and Drosophila to humans. Although varying in number of homologs, from one in yeast to seven in humans, and more than ten in some plants, there is a strong evolutionary conservation of structural features and interaction modes. The most prominent interaction mode is between the LC3 interacting region (LIR), also called Atg8 interacting motif (AIM), binding to the LIR docking site (LDS) in Atg8 homologs. There are variants of these motifs like "half-LIRs" and helical LIRs. We discuss details of the binding modes and how selectivity is achieved as well as the role of multivalent LIR-LDS interactions in selective autophagy. A number of LIR-LDS interactions are known to be regulated by phosphorylation. New methods to predict LIR motifs in proteins have emerged that will aid in discovery and analyses. There are also other interaction surfaces than the LDS becoming known where we presently lack detailed structural information, like the N-terminal arm region and the UIM-docking site (UDS). More interaction modes are likely to be discovered in future studies.
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Affiliation(s)
- Vladimir V. Rogov
- Institute for Pharmaceutical Chemistry, Department of Biochemistry, Chemistry and Pharmacy, Goethe University, 60438 Frankfurt, am Main, and Structural Genomics Consortium, Buchmann Institute for Molecular Life Sciences, Goethe University, 60438 Frankfurt am Main, Germany
| | - Ioannis P. Nezis
- School of Life Sciences, University of Warwick, CV4 7AL Coventry, UK
| | | | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China and College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yasin Dagdas
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Nobuo N. Noda
- Institute for Genetic Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo 060-0815, Japan
| | - Hitoshi Nakatogawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Martina Wirth
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Stephane Mouilleron
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | | | - Christian Behrends
- Munich Cluster of Systems Neurology, Ludwig-Maximilians-Universität München, München, Germany
| | - Vojo Deretic
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence, Albuquerque, NM and Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM
| | - Zvulun Elazar
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Sharon A. Tooze
- Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Ivan Dikic
- Institute of Biochemistry II, Medical Faculty, Goethe-University, Frankfurt am Main, and Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
| | - Trond Lamark
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
| | - Terje Johansen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
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5
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Berkane R, Ho-Xuan H, Glogger M, Sanz-Martinez P, Brunello L, Glaesner T, Kuncha SK, Holzhüter K, Cano-Franco S, Buonomo V, Cabrerizo-Poveda P, Balakrishnan A, Tascher G, Husnjak K, Juretschke T, Misra M, González A, Dötsch V, Grumati P, Heilemann M, Stolz A. The function of ER-phagy receptors is regulated through phosphorylation-dependent ubiquitination pathways. Nat Commun 2023; 14:8364. [PMID: 38102139 PMCID: PMC10724265 DOI: 10.1038/s41467-023-44101-5] [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: 07/18/2022] [Accepted: 11/30/2023] [Indexed: 12/17/2023] Open
Abstract
Selective autophagy of the endoplasmic reticulum (ER), known as ER-phagy, is an important regulator of ER remodeling and essential to maintain cellular homeostasis during environmental changes. We recently showed that members of the FAM134 family play a critical role during stress-induced ER-phagy. However, the mechanisms on how they are activated remain largely unknown. In this study, we analyze phosphorylation of FAM134 as a trigger of FAM134-driven ER-phagy upon mTOR (mechanistic target of rapamycin) inhibition. An unbiased screen of kinase inhibitors reveals CK2 to be essential for FAM134B- and FAM134C-driven ER-phagy after mTOR inhibition. Furthermore, we provide evidence that ER-phagy receptors are regulated by ubiquitination events and that treatment with E1 inhibitor suppresses Torin1-induced ER-phagy flux. Using super-resolution microscopy, we show that CK2 activity is essential for the formation of high-density FAM134B and FAM134C clusters. In addition, dense clustering of FAM134B and FAM134C requires phosphorylation-dependent ubiquitination of FAM134B and FAM134C. Treatment with the CK2 inhibitor SGC-CK2-1 or mutation of FAM134B and FAM134C phosphosites prevents ubiquitination of FAM134 proteins, formation of high-density clusters, as well as Torin1-induced ER-phagy flux. Therefore, we propose that CK2-dependent phosphorylation of ER-phagy receptors precedes ubiquitin-dependent activation of ER-phagy flux.
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Affiliation(s)
- Rayene Berkane
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Hung Ho-Xuan
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Marius Glogger
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Pablo Sanz-Martinez
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Lorène Brunello
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Tristan Glaesner
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Santosh Kumar Kuncha
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Katharina Holzhüter
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Sara Cano-Franco
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Viviana Buonomo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Paloma Cabrerizo-Poveda
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Ashwin Balakrishnan
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Georg Tascher
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Koraljka Husnjak
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | | | - Mohit Misra
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Alexis González
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Paolo Grumati
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Alexandra Stolz
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany.
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6
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Knupp J, Pletan ML, Arvan P, Tsai B. Autophagy of the ER: the secretome finds the lysosome. FEBS J 2023; 290:5656-5673. [PMID: 37920925 PMCID: PMC11044768 DOI: 10.1111/febs.16986] [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: 08/03/2023] [Revised: 09/20/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023]
Abstract
Lysosomal degradation of the endoplasmic reticulum (ER) and its components through the autophagy pathway has emerged as a major regulator of ER proteostasis. Commonly referred to as ER-phagy and ER-to-lysosome-associated degradation (ERLAD), how the ER is targeted to the lysosome has been recently clarified by a growing number of studies. Here, we summarize the discoveries of the molecular components required for lysosomal degradation of the ER and their proposed mechanisms of action. Additionally, we discuss how cells employ these machineries to create the different routes of ER-lysosome-associated degradation. Further, we review the role of ER-phagy in viral infection pathways, as well as the implication of ER-phagy in human disease. In sum, we provide a comprehensive overview of the current field of ER-phagy.
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Affiliation(s)
- Jeffrey Knupp
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Madison L Pletan
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
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7
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Hoyer MJ, Capitanio C, Smith IR, Paoli JC, Bieber A, Jiang Y, Paulo JA, Gonzalez-Lozano MA, Baumeister W, Wilfling F, Schulman BA, Harper JW. Combinatorial selective ER-phagy remodels the ER during neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546565. [PMID: 37425907 PMCID: PMC10326971 DOI: 10.1101/2023.06.26.546565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The endoplasmic reticulum (ER) employs a diverse proteome landscape to orchestrate many cellular functions ranging from protein and lipid synthesis to calcium ion flux and inter-organelle communication. A case in point concerns the process of neurogenesis: a refined tubular ER network is assembled via ER shaping proteins into the newly formed neuronal projections to create highly polarized dendrites and axons. Previous studies have suggested a role for autophagy in ER remodeling, as autophagy-deficient neurons in vivo display axonal ER accumulation within synaptic boutons, and the membrane-embedded ER-phagy receptor FAM134B has been genetically linked with human sensory and autonomic neuropathy. However, our understanding of the mechanisms underlying selective removal of ER and the role of individual ER-phagy receptors is limited. Here, we combine a genetically tractable induced neuron (iNeuron) system for monitoring ER remodeling during in vitro differentiation with proteomic and computational tools to create a quantitative landscape of ER proteome remodeling via selective autophagy. Through analysis of single and combinatorial ER-phagy receptor mutants, we delineate the extent to which each receptor contributes to both magnitude and selectivity of ER protein clearance. We define specific subsets of ER membrane or lumenal proteins as preferred clients for distinct receptors. Using spatial sensors and flux reporters, we demonstrate receptor-specific autophagic capture of ER in axons, and directly visualize tubular ER membranes within autophagosomes in neuronal projections by cryo-electron tomography. This molecular inventory of ER proteome remodeling and versatile genetic toolkit provides a quantitative framework for understanding contributions of individual ER-phagy receptors for reshaping ER during cell state transitions.
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8
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Zou CX, Ma ZH, Jiang ZD, Pan ZQ, Xu DD, Suo F, Shao GC, Dong MQ, Du LL. The ortholog of human REEP1-4 is required for autophagosomal enclosure of ER-phagy/nucleophagy cargos in fission yeast. PLoS Biol 2023; 21:e3002372. [PMID: 37939137 PMCID: PMC10659188 DOI: 10.1371/journal.pbio.3002372] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 11/20/2023] [Accepted: 10/10/2023] [Indexed: 11/10/2023] Open
Abstract
Selective macroautophagy of the endoplasmic reticulum (ER) and the nucleus, known as ER-phagy and nucleophagy, respectively, are processes whose mechanisms remain inadequately understood. Through an imaging-based screen, we find that in the fission yeast Schizosaccharomyces pombe, Yep1 (also known as Hva22 or Rop1), the ortholog of human REEP1-4, is essential for ER-phagy and nucleophagy but not for bulk autophagy. In the absence of Yep1, the initial phase of ER-phagy and nucleophagy proceeds normally, with the ER-phagy/nucleophagy receptor Epr1 coassembling with Atg8. However, ER-phagy/nucleophagy cargos fail to reach the vacuole. Instead, nucleus- and cortical-ER-derived membrane structures not enclosed within autophagosomes accumulate in the cytoplasm. Intriguingly, the outer membranes of nucleus-derived structures remain continuous with the nuclear envelope-ER network, suggesting a possible outer membrane fission defect during cargo separation from source compartments. We find that the ER-phagy role of Yep1 relies on its abilities to self-interact and shape membranes and requires its C-terminal amphipathic helices. Moreover, we show that human REEP1-4 and budding yeast Atg40 can functionally substitute for Yep1 in ER-phagy, and Atg40 is a divergent ortholog of Yep1 and REEP1-4. Our findings uncover an unexpected mechanism governing the autophagosomal enclosure of ER-phagy/nucleophagy cargos and shed new light on the functions and evolution of REEP family proteins.
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Affiliation(s)
- Chen-Xi Zou
- National Institute of Biological Sciences, Beijing, China
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Zhu-Hui Ma
- National Institute of Biological Sciences, Beijing, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, Beijing, China
| | - Zhao-Qian Pan
- National Institute of Biological Sciences, Beijing, China
| | - Dan-Dan Xu
- National Institute of Biological Sciences, Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, China
| | - Guang-Can Shao
- National Institute of Biological Sciences, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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9
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Liu S, Yao S, Yang H, Liu S, Wang Y. Autophagy: Regulator of cell death. Cell Death Dis 2023; 14:648. [PMID: 37794028 PMCID: PMC10551038 DOI: 10.1038/s41419-023-06154-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 09/05/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
Autophagy is the process by which cells degrade and recycle proteins and organelles to maintain intracellular homeostasis. Generally, autophagy plays a protective role in cells, but disruption of autophagy mechanisms or excessive autophagic flux usually leads to cell death. Despite recent progress in the study of the regulation and underlying molecular mechanisms of autophagy, numerous questions remain to be answered. How does autophagy regulate cell death? What are the fine-tuned regulatory mechanisms underlying autophagy-dependent cell death (ADCD) and autophagy-mediated cell death (AMCD)? In this article, we highlight the different roles of autophagy in cell death and discuss six of the main autophagy-related cell death modalities, with a focus on the metabolic changes caused by excessive endoplasmic reticulum-phagy (ER-phagy)-induced cell death and the role of mitophagy in autophagy-mediated ferroptosis. Finally, we discuss autophagy enhancement in the treatment of diseases and offer a new perspective based on the use of autophagy for different functional conversions (including the conversion of autophagy and that of different autophagy-mediated cell death modalities) for the clinical treatment of tumors.
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Affiliation(s)
- ShiZuo Liu
- School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
| | - ShuaiJie Yao
- School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
| | - Huan Yang
- The Second School of Clinical Medicine, Xinjiang Medical University, Urumqi, China
| | - ShuaiJie Liu
- School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
| | - YanJiao Wang
- Xinjiang Key Laboratory of Molecular Biology for Endemic Diseases, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China.
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10
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Hill MA, Sykes AM, Mellick GD. ER-phagy in neurodegeneration. J Neurosci Res 2023; 101:1611-1623. [PMID: 37334842 DOI: 10.1002/jnr.25225] [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: 02/20/2023] [Revised: 05/11/2023] [Accepted: 05/31/2023] [Indexed: 06/21/2023]
Abstract
There are many cellular mechanisms implicated in the initiation and progression of neurodegenerative disorders. However, age and the accumulation of unwanted cellular products are a common theme underlying many neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and Niemann-Pick type C. Autophagy has been studied extensively in these diseases and various genetic risk factors have implicated disruption in autophagy homoeostasis as a major pathogenic mechanism. Autophagy is essential in the maintenance of neuronal homeostasis, as their postmitotic nature makes them particularly susceptible to the damage caused by accumulation of defective or misfolded proteins, disease-prone aggregates, and damaged organelles. Recently, autophagy of the endoplasmic reticulum (ER-phagy) has been identified as a novel cellular mechanism for regulating ER morphology and response to cellular stress. As neurodegenerative diseases are generally precipitated by cellular stressors such as protein accumulation and environmental toxin exposure the role of ER-phagy has begun to be investigated. In this review we discuss the current research in ER-phagy and its involvement in neurodegenerative diseases.
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Affiliation(s)
- Melissa A Hill
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Alex M Sykes
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - George D Mellick
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
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11
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Chino H, Mizushima N. ER-Phagy: Quality and Quantity Control of the Endoplasmic Reticulum by Autophagy. Cold Spring Harb Perspect Biol 2023; 15:cshperspect.a041256. [PMID: 35940904 PMCID: PMC9808580 DOI: 10.1101/cshperspect.a041256] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The endoplasmic reticulum (ER) is the largest organelle and has multiple roles in various cellular processes such as protein secretion, lipid synthesis, calcium storage, and organelle biogenesis. The quantity and quality of this organelle are controlled by the ubiquitin-proteasome system and autophagy (termed "ER-phagy"). ER-phagy is defined as the degradation of part of the ER by the vacuole or lysosomes, and there are at least two types of ER-phagy: macro-ER-phagy and micro-ER-phagy. In macro-ER-phagy, ER fragments are enclosed by autophagosomes, which is mediated by ER-phagy receptors. In micro-ER-phagy, a portion of the ER is engulfed directly by the vacuole or lysosomes. In these two pathways, some proteins in the ER lumen can be recognized selectively and subjected to ER-phagy. This review summarizes our current knowledge of ER-phagy, focusing on its membrane dynamics, molecular mechanisms, substrate specificity, and physiological significance.
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Affiliation(s)
- Haruka Chino
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
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12
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Popelka H, Klionsky DJ. When acidic residues do not mimic phosphorylation: high-affinity binding of the reticulophagy receptor TEX264 to LC3/GABARAP. Autophagy 2022; 18:2515-2518. [PMID: 36041015 PMCID: PMC9629098 DOI: 10.1080/15548627.2022.2119350] [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] [Indexed: 12/15/2022] Open
Abstract
Substrates that are selected for degradation by autophagy interact in more complex eukaryotes with Atg8-family proteins via the LC3-interacting region (LIR) that is often preceded by either acidic residues or phosphorylated serine or threonine. These upstream amino acid residues increase the binding affinity of the LIR motif to its binding site on the surface of LC3/GABARAP. It is not fully understood whether or how phosphorylation functionally replaces acidic residues in the LIR-Atg8-family protein interactions. A recent study by Chino et al. discussed in this article analyzed the phosphorylation of two serine residues upstream of the LIR motif in TEX264, a reticulophagy receptor that exhibits a high binding affinity to LC3/GABARAP proteins. The authors found a structural basis for the high-affinity interaction yielded by phosphorylation but not by an acidic residue in place of phosphoserine. Furthermore, finding that phosphorylation of TEX264 generates its high binding affinity to Atg8-family proteins uncovers a mechanistic alternative to that utilized by other reticulophagy receptors when they interact with LC3/GABARAP.Abbreviations: CSNK2: casein kinase 2; ER: endoplasmic reticulum; IDPR: intrinsically disordered protein region; LIR: LC3-interacting region; p-S: phosphorylated serine.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Daniel J Klionsky
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
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13
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Trembley JH, Kren BT, Afzal M, Scaria GA, Klein MA, Ahmed K. Protein kinase CK2 – diverse roles in cancer cell biology and therapeutic promise. Mol Cell Biochem 2022; 478:899-926. [PMID: 36114992 PMCID: PMC9483426 DOI: 10.1007/s11010-022-04558-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/01/2022] [Indexed: 11/29/2022]
Abstract
The association of protein kinase CK2 (formerly casein kinase II or 2) with cell growth and proliferation in cells was apparent at early stages of its investigation. A cancer-specific role for CK2 remained unclear until it was determined that CK2 was also a potent suppressor of cell death (apoptosis); the latter characteristic differentiated its function in normal versus malignant cells because dysregulation of both cell growth and cell death is a universal feature of cancer cells. Over time, it became evident that CK2 exerts its influence on a diverse range of cell functions in normal as well as in transformed cells. As such, CK2 and its substrates are localized in various compartments of the cell. The dysregulation of CK2 is documented in a wide range of malignancies; notably, by increased CK2 protein and activity levels with relatively moderate change in its RNA abundance. High levels of CK2 are associated with poor prognosis in multiple cancer types, and CK2 is a target for active research and testing for cancer therapy. Aspects of CK2 cellular roles and targeting in cancer are discussed in the present review, with focus on nuclear and mitochondrial functions and prostate, breast and head and neck malignancies.
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Affiliation(s)
- Janeen H Trembley
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA.
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA.
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA.
| | - Betsy T Kren
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA
| | - Muhammad Afzal
- Department of Biochemistry, Riphah International University, Islamabad, Pakistan
| | - George A Scaria
- Hematology/Oncology Section, Primary Care Service Line, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA
| | - Mark A Klein
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA
- Hematology/Oncology Section, Primary Care Service Line, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA
- Department of Medicine, Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Khalil Ahmed
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, 55417, USA.
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, 55455, USA.
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, 55455, USA.
- Department of Urology, University of Minnesota, Minneapolis, MN, 55455, USA.
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14
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Di Lorenzo G, Iavarone F, Maddaluno M, Plata-Gómez AB, Aureli S, Quezada Meza CP, Cinque L, Palma A, Reggio A, Cirillo C, Sacco F, Stolz A, Napolitano G, Marin O, Pinna LA, Ruzzene M, Limongelli V, Efeyan A, Grumati P, Settembre C. Phosphorylation of FAM134C by CK2 controls starvation-induced ER-phagy. SCIENCE ADVANCES 2022; 8:eabo1215. [PMID: 36044577 PMCID: PMC9432840 DOI: 10.1126/sciadv.abo1215] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 07/20/2022] [Indexed: 05/28/2023]
Abstract
Selective degradation of the endoplasmic reticulum (ER) via autophagy (ER-phagy) is initiated by ER-phagy receptors, which facilitate the incorporation of ER fragments into autophagosomes. FAM134 reticulon family proteins (FAM134A, FAM134B, and FAM134C) are ER-phagy receptors with structural similarities and nonredundant functions. Whether they respond differentially to the stimulation of ER-phagy is unknown. Here, we describe an activation mechanism unique to FAM134C during starvation. In fed conditions, FAM134C is phosphorylated by casein kinase 2 (CK2) at critical residues flanking the LIR domain. Phosphorylation of these residues negatively affects binding affinity to the autophagy proteins LC3. During starvation, mTORC1 inhibition limits FAM134C phosphorylation by CK2, hence promoting receptor activation and ER-phagy. Using a novel tool to study ER-phagy in vivo and FAM134C knockout mice, we demonstrated the physiological relevance of FAM134C phosphorylation during starvation-induced ER-phagy in liver lipid metabolism. These data provide a mechanistic insight into ER-phagy regulation and an example of autophagy selectivity during starvation.
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Affiliation(s)
| | | | | | - Ana Belén Plata-Gómez
- Metabolism and Cell Signaling Laboratory, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Simone Aureli
- Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Euler Institute, Lugano, Switzerland
| | | | - Laura Cinque
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Alessandro Palma
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Alessio Reggio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Carmine Cirillo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Francesca Sacco
- Department of Biology, University of Rome “Tor Vergata”, Rome, Italy
| | - Alexandra Stolz
- Institute of Biochemistry II, Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Gennaro Napolitano
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Translational Medicine, Federico II University, Naples, Italy
| | - Oriano Marin
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lorenzo A. Pinna
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- CNR Neuroscience Institute, Padova, Italy
| | - Maria Ruzzene
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- CNR Neuroscience Institute, Padova, Italy
| | - Vittorio Limongelli
- Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Euler Institute, Lugano, Switzerland
- Department of Pharmacy, Federico II University, Naples, Italy
| | - Alejo Efeyan
- Metabolism and Cell Signaling Laboratory, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Paolo Grumati
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Carmine Settembre
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
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15
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Mochida K, Nakatogawa H. ER
‐phagy: selective autophagy of the endoplasmic reticulum. EMBO Rep 2022; 23:e55192. [PMID: 35758175 PMCID: PMC9346472 DOI: 10.15252/embr.202255192] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/24/2022] [Accepted: 06/08/2022] [Indexed: 12/22/2022] Open
Abstract
Eukaryotic cells adequately control the mass and functions of organelles in various situations. Autophagy, an intracellular degradation system, largely contributes to this organelle control by degrading the excess or defective portions of organelles. The endoplasmic reticulum (ER) is an organelle with distinct structural domains associated with specific functions. The ER dynamically changes its mass, components, and shape in response to metabolic, developmental, or proteotoxic cues to maintain or regulate its functions. Therefore, elaborate mechanisms are required for proper degradation of the ER. Here, we review our current knowledge on diverse mechanisms underlying selective autophagy of the ER, which enable efficient degradation of specific ER subdomains according to different demands of cells.
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Affiliation(s)
- Keisuke Mochida
- School of Life Science and Technology Tokyo Institute of Technology Yokohama Japan
| | - Hitoshi Nakatogawa
- School of Life Science and Technology Tokyo Institute of Technology Yokohama Japan
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