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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 PMCID: PMC11246128 DOI: 10.4103/nrr.nrr-d-23-00995] [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: 06/13/2023] [Revised: 11/09/2023] [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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Kumar K, Chidambaram R, Parashar S, Ferro-Novick S. RTN3L and CALCOCO1 function in parallel to maintain proteostasis in the endoplasmic reticulum. Autophagy 2024; 20:2067-2075. [PMID: 38818751 PMCID: PMC11346533 DOI: 10.1080/15548627.2024.2353502] [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: 10/24/2023] [Revised: 04/22/2024] [Accepted: 05/06/2024] [Indexed: 06/01/2024] Open
Abstract
Reticulophagy is mediated by autophagy receptors that function in one of the two domains of the ER, tubules or flat sheets. Three different conserved mammalian receptors mediate autophagy in ER tubules: RTN3L, ATL3 and CALCOCO1. Previous studies have shown that RTN3L maintains proteostasis by targeting mutant aggregation-prone proteins for autophagy at distinct foci in ER tubules that we named ERPHS (ER-reticulophagy sites). The role for ATL3 and CALCOCO1 in proteostasis has not been addressed. Here we analyzed three different misfolded disease-causing RTN3L substrates and show that ATL3 and CALCOCO1 target the same cargoes for autophagy. Colocalization and knock down studies revealed that RTN3L and ATL3 are both required for the formation of RTN3L-containing ERPHS, while CALCOCO1 is not. We propose that RTN3L, ATL3 and CALCOCO1 work in parallel to maintain proteostasis within the ER network by targeting cargoes at different sites in the tubules.Abbreviation ATL3: atlastin GTPase 3; Baf: bafilomycin A1; CALCOCO1: calcium binding and coiled-coil domain 1; Epr1: ER-phagy receptor 1; ER: endoplasmic reticulum; ERAD: ER-associated protein degradation; ERPHS: ER-reticulophagy sites; LAMP1: lysosomal associated membrane protein 1; PGRMC1: progesterone receptor membrane component 1; POMC: proopiomelanocortin; Pro-AVP: pro-arginine vasopressin; RETREG1: reticulophagy regulator 1; reticulophagy: endoplasmic reticulum selective autophagy; RTN3L: reticulon 3 long isoform; VAPA: VAMP associated protein A.
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Affiliation(s)
- Kamal Kumar
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Ravi Chidambaram
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Smriti Parashar
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Susan Ferro-Novick
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
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3
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Mou W, Tang Y, Huang Y, Wu Z, Cui Y. Upregulation of neuronal ER-phagy improves organismal fitness and alleviates APP toxicity. Cell Rep 2024; 43:114255. [PMID: 38761376 DOI: 10.1016/j.celrep.2024.114255] [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: 12/05/2023] [Revised: 03/31/2024] [Accepted: 05/04/2024] [Indexed: 05/20/2024] Open
Abstract
ER-phagy, a selective autophagy targeting the endoplasmic reticulum (ER) for lysosomal degradation through cargo receptors, plays a critical role in ER quality control and is linked to various diseases. However, its physiological and pathological roles remain largely unclear due to a lack of animal model studies. This study establishes Drosophila as an in vivo ER-phagy model. Starvation triggers ER-phagy across multiple fly tissues. Disturbing ER-phagy by either globally upregulating or downregulating ER-phagy receptors, Atl or Rtnl1, harms the fly. Notably, moderate upregulation of ER-phagy in fly brains by overexpressing Atl or Rtnl1 significantly attenuates age-associated neurodegenerations. Furthermore, in a Drosophila model of Alzheimer's disease expressing human amyloid precursor protein (APP), impaired ER-phagy is observed. Enhancing ER-phagy in the APP-expressing fly brain facilitates APP degradation, significantly alleviating disease symptoms. Therefore, our findings suggest that modulating ER-phagy may offer a therapeutic strategy to treat aging and diseases associated with ER protein aggregation.
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Affiliation(s)
- Wenqing Mou
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China
| | - Yinglu Tang
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX 75275, USA
| | - Yunpeng Huang
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Zhihao Wu
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX 75275, USA.
| | - Yixian Cui
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and Metabolism, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430071, China.
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4
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Yang K, Yan Y, Yu A, Zhang R, Zhang Y, Qiu Z, Li Z, Zhang Q, Wu S, Li F. Mitophagy in neurodegenerative disease pathogenesis. Neural Regen Res 2024; 19:998-1005. [PMID: 37862201 PMCID: PMC10749592 DOI: 10.4103/1673-5374.385281] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/23/2023] [Accepted: 08/15/2023] [Indexed: 10/22/2023] Open
Abstract
Mitochondria are critical cellular energy resources and are central to the life of the neuron. Mitophagy selectively clears damaged or dysfunctional mitochondria through autophagic machinery to maintain mitochondrial quality control and homeostasis. Mature neurons are postmitotic and consume substantial energy, thus require highly efficient mitophagy pathways to turn over damaged or dysfunctional mitochondria. Recent evidence indicates that mitophagy is pivotal to the pathogenesis of neurological diseases. However, more work is needed to study mitophagy pathway components as potential therapeutic targets. In this review, we briefly discuss the characteristics of nonselective autophagy and selective autophagy, including ERphagy, aggrephagy, and mitophagy. We then introduce the mechanisms of Parkin-dependent and Parkin-independent mitophagy pathways under physiological conditions. Next, we summarize the diverse repertoire of mitochondrial membrane receptors and phospholipids that mediate mitophagy. Importantly, we review the critical role of mitophagy in the pathogenesis of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Last, we discuss recent studies considering mitophagy as a potential therapeutic target for treating neurodegenerative diseases. Together, our review may provide novel views to better understand the roles of mitophagy in neurodegenerative disease pathogenesis.
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Affiliation(s)
- Kan Yang
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children’s Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Key Laboratory of Primate Neurobiology, Chinese Academy of Sciences, Shanghai, China
- College of Materials and Chemical Engineering, Hunan Institute of Engineering, Xiangtan, Hunan Province, China
| | - Yuqing Yan
- School of Medicine, Yunnan University, Kunming, Yunnan Province, China
| | - Anni Yu
- College of Materials and Chemical Engineering, Hunan Institute of Engineering, Xiangtan, Hunan Province, China
| | - Ru Zhang
- College of Materials and Chemical Engineering, Hunan Institute of Engineering, Xiangtan, Hunan Province, China
| | - Yuefang Zhang
- Songjiang Research Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zilong Qiu
- Songjiang Research Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhengyi Li
- Neurosurgery Department, Kunming Yenan Hospital, Kunming, Yunnan Province, China
| | - Qianlong Zhang
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children’s Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shihao Wu
- School of Medicine, Yunnan University, Kunming, Yunnan Province, China
| | - Fei Li
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children’s Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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5
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Ahmed N, Preisinger C, Wilhelm T, Huber M. TurboID-Based IRE1 Interactome Reveals Participants of the Endoplasmic Reticulum-Associated Protein Degradation Machinery in the Human Mast Cell Leukemia Cell Line HMC-1.2. Cells 2024; 13:747. [PMID: 38727283 PMCID: PMC11082977 DOI: 10.3390/cells13090747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/02/2024] [Accepted: 04/17/2024] [Indexed: 05/13/2024] Open
Abstract
The unfolded protein response is an intricate system of sensor proteins in the endoplasmic reticulum (ER) that recognizes misfolded proteins and transmits information via transcription factors to either regain proteostasis or, depending on the severity, to induce apoptosis. The main transmembrane sensor is IRE1α, which contains cytoplasmic kinase and RNase domains relevant for its activation and the mRNA splicing of the transcription factor XBP1. Mast cell leukemia (MCL) is a severe form of systemic mastocytosis. The inhibition of IRE1α in the MCL cell line HMC-1.2 has anti-proliferative and pro-apoptotic effects, motivating us to elucidate the IRE1α interactors/regulators in HMC-1.2 cells. Therefore, the TurboID proximity labeling technique combined with MS analysis was applied. Gene Ontology and pathway enrichment analyses revealed that the majority of the enriched proteins are involved in vesicle-mediated transport, protein stabilization, and ubiquitin-dependent ER-associated protein degradation pathways. In particular, the AAA ATPase VCP and the oncoprotein MTDH as IRE1α-interacting proteins caught our interest for further analyses. The pharmacological inhibition of VCP activity resulted in the increased stability of IRE1α and MTDH as well as the activation of IRE1α. The interaction of VCP with both IRE1α and MTDH was dependent on ubiquitination. Moreover, MTDH stability was reduced in IRE1α-knockout cells. Hence, pharmacological manipulation of IRE1α-MTDH-VCP complex(es) might enable the treatment of MCL.
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Affiliation(s)
- Nabil Ahmed
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany (T.W.)
| | - Christian Preisinger
- Proteomics Facility, Interdisciplinary Centre for Clinical Research (IZKF), RWTH Aachen University, 52074 Aachen, Germany;
| | - Thomas Wilhelm
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany (T.W.)
| | - Michael Huber
- Institute of Biochemistry and Molecular Immunology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany (T.W.)
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6
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Liu J, Wu Y, Meng S, Xu P, Li S, Li Y, Hu X, Ouyang L, Wang G. Selective autophagy in cancer: mechanisms, therapeutic implications, and future perspectives. Mol Cancer 2024; 23:22. [PMID: 38262996 PMCID: PMC10807193 DOI: 10.1186/s12943-024-01934-y] [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: 12/01/2023] [Accepted: 01/05/2024] [Indexed: 01/25/2024] Open
Abstract
Eukaryotic cells engage in autophagy, an internal process of self-degradation through lysosomes. Autophagy can be classified as selective or non-selective depending on the way it chooses to degrade substrates. During the process of selective autophagy, damaged and/or redundant organelles like mitochondria, peroxisomes, ribosomes, endoplasmic reticulum (ER), lysosomes, nuclei, proteasomes, and lipid droplets are selectively recycled. Specific cargo is delivered to autophagosomes by specific receptors, isolated and engulfed. Selective autophagy dysfunction is closely linked with cancers, neurodegenerative diseases, metabolic disorders, heart failure, etc. Through reviewing latest research, this review summarized molecular markers and important signaling pathways for selective autophagy, and its significant role in cancers. Moreover, we conducted a comprehensive analysis of small-molecule compounds targeting selective autophagy for their potential application in anti-tumor therapy, elucidating the underlying mechanisms involved. This review aims to supply important scientific references and development directions for the biological mechanisms and drug discovery of anti-tumor targeting selective autophagy in the future.
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Affiliation(s)
- Jiaxi Liu
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China
| | - Yongya Wu
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China
| | - Sha Meng
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China
| | - Ping Xu
- Emergency Department, Zigong Fourth People's Hospital, Zigong, 643000, China
| | - Shutong Li
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China
| | - Yong Li
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China
| | - Xiuying Hu
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China.
| | - Liang Ouyang
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China.
| | - Guan Wang
- Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China.
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7
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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: 6] [Impact Index Per Article: 6.0] [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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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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Ishiwata-Kimata Y, Kimata Y. Fundamental and Applicative Aspects of the Unfolded Protein Response in Yeasts. J Fungi (Basel) 2023; 9:989. [PMID: 37888245 PMCID: PMC10608004 DOI: 10.3390/jof9100989] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/28/2023] Open
Abstract
Upon the dysfunction or functional shortage of the endoplasmic reticulum (ER), namely, ER stress, eukaryotic cells commonly provoke a protective gene expression program called the unfolded protein response (UPR). The molecular mechanism of UPR has been uncovered through frontier genetic studies using Saccharomyces cerevisiae as a model organism. Ire1 is an ER-located transmembrane protein that directly senses ER stress and is activated as an RNase. During ER stress, Ire1 promotes the splicing of HAC1 mRNA, which is then translated into a transcription factor that induces the expression of various genes, including those encoding ER-located molecular chaperones and protein modification enzymes. While this mainstream intracellular UPR signaling pathway was elucidated in the 1990s, new intriguing insights have been gained up to now. For instance, various additional factors allow UPR evocation strictly in response to ER stress. The UPR machineries in other yeasts and fungi, including pathogenic species, are another important research topic. Moreover, industrially beneficial yeast strains carrying an enforced and enlarged ER have been produced through the artificial and constitutive induction of the UPR. In this article, we review canonical and up-to-date insights concerning the yeast UPR, mainly from the viewpoint of the functions and regulation of Ire1 and HAC1.
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Affiliation(s)
| | - Yukio Kimata
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara 630-0192, Japan
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10
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Fukuda T, Saigusa T, Furukawa K, Inoue K, Yamashita SI, Kanki T. Hva22, a REEP family protein in fission yeast, promotes reticulophagy in collaboration with a receptor protein. Autophagy 2023; 19:2657-2667. [PMID: 37191320 PMCID: PMC10472877 DOI: 10.1080/15548627.2023.2214029] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/28/2023] [Accepted: 05/10/2023] [Indexed: 05/17/2023] Open
Abstract
The endoplasmic reticulum (ER) undergoes selective autophagy called reticulophagy or ER-phagy. Multiple reticulon- and receptor expression enhancing protein (REEP)-like ER-shaping proteins, including budding yeast Atg40, serve as reticulophagy receptors that stabilize the phagophore on the ER by interacting with phagophore-conjugated Atg8. Additionally, they facilitate phagophore engulfment of the ER by remodeling ER morphology. We reveal that Hva22, a REEP family protein in fission yeast, promotes reticulophagy without Atg8-binding capacity. The role of Hva22 in reticulophagy can be replaced by expressing Atg40 independently of its Atg8-binding ability. Conversely, adding an Atg8-binding sequence to Hva22 enables it to substitute for Atg40 in budding yeast. Thus, the phagophore-stabilizing and ER-shaping activities, both of which Atg40 solely contains, are divided between two separate factors, receptors and Hva22, respectively, in fission yeast.Abbreviations: AIM: Atg8-family interacting motif; Atg: autophagy related; DTT: dithiothreitol; ER: endoplasmic reticulum GFP: green fluorescent protein; NAA: 1-naphthaleneacetic acid; REEP: receptor expression enhancing protein; RFP: red fluorescent protein; UPR: unfolded protein response.
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Affiliation(s)
- Tomoyuki Fukuda
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tetsu Saigusa
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kentaro Furukawa
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Keiichi Inoue
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Shun-ichi Yamashita
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomotake Kanki
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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11
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Zhang T, Li Y, Li C, Zang J, Gao E, Kroon JT, Qu X, Hussey PJ, Wang P. Exo84c interacts with VAP27 to regulate exocytotic compartment degradation and stigma senescence. Nat Commun 2023; 14:4888. [PMID: 37580356 PMCID: PMC10425460 DOI: 10.1038/s41467-023-40729-5] [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: 11/14/2022] [Accepted: 08/08/2023] [Indexed: 08/16/2023] Open
Abstract
In plants, exocyst subunit isoforms exhibit significant functional diversity in that they are involved in either protein secretion or autophagy, both of which are essential for plant development and survival. Although the molecular basis of autophagy is widely reported, its contribution to plant reproduction is not very clear. Here, we have identified Exo84c, a higher plant-specific Exo84 isoform, as having a unique function in modulating exocytotic compartment degradation during stigmatic tissue senescence. This process is achieved through its interaction with the ER localised VAP27 proteins, which regulate the turnover of Exo84c through the autophagy pathway. VAP27 recruits Exo84c onto the ER membrane as well as numerous ER-derived autophagosomes that are labelled with ATG8. These Exo84c/exocyst and VAP27 positive structures are accumulated in the vacuole for degradation, and this process is partially perturbed in the exo84c knock-out mutants. Interestingly, the exo84c mutant showed a prolonged effective pollination period with higher seed sets, possibly because of the delayed stigmatic senescence when Exo84c regulated autophagy is blocked. In conclusion, our studies reveal a link between the exocyst complex and the ER network in regulating the degradation of exocytosis vesicles, a process that is essential for normal papilla cell senescence and flower receptivity.
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Affiliation(s)
- Tong Zhang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Yifan Li
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Chengyang Li
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Jingze Zang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Erlin Gao
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Johan T Kroon
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Xiaolu Qu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Patrick J Hussey
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Pengwei Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China.
- Hubei Hongshan Laboratory, Wuhan, 430070, China.
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12
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Wang N, Shibata Y, Paulo JA, Gygi SP, Rapoport TA. A conserved membrane curvature-generating protein is crucial for autophagosome formation in fission yeast. Nat Commun 2023; 14:4765. [PMID: 37553386 PMCID: PMC10409813 DOI: 10.1038/s41467-023-40530-4] [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: 09/22/2022] [Accepted: 07/26/2023] [Indexed: 08/10/2023] Open
Abstract
Organelles are shaped by curvature-generating proteins, which include the reticulons and REEPs that are involved in forming the endoplasmic reticulum (ER). A conserved REEP subfamily differs from the ER-shaping REEPs in abundance and membrane topology and has unidentified functions. Here, we show that Rop1, the single member of this family in the fission yeast Schizosacharomyces pombe, is crucial for the macroautophagy of organelles and cytosolic proteins. Rop1 is needed for the formation of phagophores, cup-like structures consisting of two closely apposed membrane sheets that encapsulate cargo. It is recruited at early stages to phagophores and is required for their maturation into autophagosomes. Rop1 function relies on its ability to generate high membrane curvature and on its colocalization with the autophagy component Atg2 that is thought to reside at the phagophore rim. We propose that Rop1 facilitates the formation and growth of the double-membrane structure of the autophagosome.
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Affiliation(s)
- Ning Wang
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA
| | - Yoko Shibata
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA
| | - Tom A Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA.
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13
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Zhang Y, Lou H, Lu J, Tang X, Pang T, Lei S, Cong D, Wang Y, Sun L. Scalp acupuncture alleviates cerebral ischemic stroke-induced motor dysfunction in rats via regulating endoplasmic reticulum stress and ER-phagy. Sci Rep 2023; 13:10119. [PMID: 37344501 DOI: 10.1038/s41598-023-36147-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 05/30/2023] [Indexed: 06/23/2023] Open
Abstract
Cerebral ischemic stroke is a high-risk disease and imposes heavy burdens on patients in china. Acupuncture has been used for thousands of years to treat motor dysfunction, cognitive disorder and language barrier caused by cerebral ischemic stroke. Acupoint lines, vertex middle line and anterior oblique line of vertex temple, are always employed to treat cerebral ischemic stroke. However, the mechanism of the two acupoint lines in relieving cerebral ischemic stroke needs further exploration. In the present study, scalp acupuncture treatment alleviated the motor dysfunction, brain damage, and cell death induced by middle cerebral artery occlusion (MCAO) in rats. Proteomics analysis and ultrastructure observation indicated that endoplasmic reticulum and lysosomes might involve in the mechanism of the scalp acupuncture treatment in suppressing MCAO-triggered neural deficits. Effect of the scalp acupuncture treatment on ER stress was then investigated and found that the activation of ER stress mediators, including PERK, IRE1, and ATF6, was downregulated after the scalp acupuncture treatment. Co-localisation analysis of KDEL and CD63 showed that the engulfment of ER fragments by lysosomes was accelerated by the scalp acupuncture treatment. Moreover, expression of pro-apoptotic protein CHOP, phosphorylated-JNK, cleaved capases-3 and -9 also decreased after the scalp acupuncture. In conclusion, the present study showed that scalp acupuncture of vertex middle line and anterior oblique line of vertex temple may alleviate cerebral ischemic stroke by inhibiting ER stress-accelerated apoptosis.
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Affiliation(s)
- Yuxin Zhang
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
- Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Changchun, Jilin, People's Republic of China
| | - Huijuan Lou
- Massage Department, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
| | - Jing Lu
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
- Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Changchun, Jilin, People's Republic of China
| | - Xiaolei Tang
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
- Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Changchun, Jilin, People's Republic of China
| | - Tingting Pang
- Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
| | - Siyuan Lei
- Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
| | - Deyu Cong
- Massage Department, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China
| | - Yufeng Wang
- Massage Department, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China.
| | - Liwei Sun
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, Jilin, People's Republic of China.
- Key Laboratory of Active Substances and Biological Mechanisms of Ginseng Efficacy, Ministry of Education, Changchun, Jilin, People's Republic of China.
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14
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Wangsanut T, Amsri A, Pongpom M. Antibody screening reveals antigenic proteins involved in Talaromyces marneffei and human interaction. Front Cell Infect Microbiol 2023; 13:1118979. [PMID: 37404721 PMCID: PMC10315666 DOI: 10.3389/fcimb.2023.1118979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 05/30/2023] [Indexed: 07/06/2023] Open
Abstract
Talaromycosis is a fungal infection that generally affects immunocompromised hosts and is one of the most frequent systemic mycoses in HIV patients, especially in endemic areas such as Southeast Asia. Talaromyces marneffei, the causative agent of talaromycosis, grows as a mold in the environment but adapts to the human body and host niches by transitioning from conidia to yeast-like cells. Knowledge of the human host and T. marneffei interaction has a direct impact on the diagnosis, yet studies are still lacking. The morbidity and mortality rates are high in taloromycosis patients if the diagnosis and treatments are delayed. Immunogenic proteins are excellent candidates for developing detection tools. Previously, we identified antigenic proteins that were recognized by antibodies from talaromycosis sera. Three of these identified proteins have been previously characterized in detail, while the others have not been explored. To expedite the progress of antigen discovery, the complete list of antigenic proteins and their features was fully reported in this study. Functional annotation and Gene Ontology examination revealed that these proteins showed a high association with membrane trafficking. Further bioinformatics analyses were performed to search for antigenic protein characteristics, including functional domains, critical residues, subcellular localization, secretory signals, and epitope peptide sequences. Expression profiling of these antigenic encoding genes was investigated using quantitative real-time PCR. The results demonstrated that most genes were expressed at low levels in the mold form, but were highly upregulated in the pathogenic yeast phase, consistent with the antigenic role of these genes during the human-host interaction. Most transcripts accumulated in the conidia, suggesting a role during phase transition. The collection of all antigen-encoding DNA sequences described here is freely accessible at GenBank, which could be useful for the research community to develop into biomarkers, diagnostic tests, research detection tools, and even vaccines.
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15
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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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16
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Ishii S, Chino H, Ode KL, Kurikawa Y, Ueda HR, Matsuura A, Mizushima N, Itakura E. CCPG1 recognizes endoplasmic reticulum luminal proteins for selective ER-phagy. Mol Biol Cell 2023; 34:ar29. [PMID: 36735498 PMCID: PMC10092646 DOI: 10.1091/mbc.e22-09-0432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The endoplasmic reticulum (ER) is a major cell compartment where protein synthesis, folding, and posttranslational modifications occur with assistance from a wide variety of chaperones and enzymes. Quality control systems selectively eliminate abnormal proteins that accumulate inside the ER due to cellular stresses. ER-phagy, that is, selective autophagy of the ER, is a mechanism that maintains or reestablishes cellular and ER-specific homeostasis through removal of abnormal proteins. However, how ER luminal proteins are recognized by the ER-phagy machinery remains unclear. Here, we applied the aggregation-prone protein, six-repeated islet amyloid polypeptide (6xIAPP), as a model ER-phagy substrate and found that cell cycle progression 1 (CCPG1), which is an ER-phagy receptor, efficiently mediates its degradation via ER-phagy. We also identified prolyl 3-hydroxylase family member 4 (P3H4) as an endogenous cargo of CCPG1-dependent ER-phagy. The ER luminal region of CCPG1 contains several highly conserved regions that we refer to as cargo-interacting regions (CIRs); these interact directly with specific luminal cargos for ER-phagy. Notably, 6xIAPP and P3H4 interact directly with different CIRs. These findings indicate that CCPG1 is a bispecific ER-phagy receptor for ER luminal proteins and the autophagosomal membrane that contributes to the efficient removal of aberrant ER-resident proteins through ER-phagy.
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Affiliation(s)
- Shunsuke Ishii
- Department of Biology, Graduate School of Science and Engineering, Chiba University, Chiba 263-8522, Japan
| | - Haruka Chino
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Koji L Ode
- Department of Systems Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan
| | - Yoshitaka Kurikawa
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Hiroki R Ueda
- Department of Systems Pharmacology, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan.,Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka 565-0871, Japan
| | - Akira Matsuura
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Eisuke Itakura
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan
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17
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Wang P, Duckney P, Gao E, Hussey PJ, Kriechbaumer V, Li C, Zang J, Zhang T. Keep in contact: multiple roles of endoplasmic reticulum-membrane contact sites and the organelle interaction network in plants. THE NEW PHYTOLOGIST 2023; 238:482-499. [PMID: 36651025 DOI: 10.1111/nph.18745] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Functional regulation and structural maintenance of the different organelles in plants contribute directly to plant development, reproduction and stress responses. To ensure these activities take place effectively, cells have evolved an interconnected network amongst various subcellular compartments, regulating rapid signal transduction and the exchange of biomaterial. Many proteins that regulate membrane connections have recently been identified in plants, and this is the first step in elucidating both the mechanism and function of these connections. Amongst all organelles, the endoplasmic reticulum is the key structure, which likely links most of the different subcellular compartments through membrane contact sites (MCS) and the ER-PM contact sites (EPCS) have been the most intensely studied in plants. However, the molecular composition and function of plant MCS are being found to be different from other eukaryotic systems. In this article, we will summarise the most recent advances in this field and discuss the mechanism and biological relevance of these essential links in plants.
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Affiliation(s)
- Pengwei Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Patrick Duckney
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Erlin Gao
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Patrick J Hussey
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Verena Kriechbaumer
- Endomembrane Structure and Function Research Group, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Chengyang Li
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Jingze Zang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
| | - Tong Zhang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Hongshan Laboratory, Wuhan, 430070, China
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18
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Yao S, Yu Y, Xu L, Pan X. Genomic and clinical features of endoplasmic reticulum stress factor in digestive system pan-cancer studies. Front Oncol 2023; 12:1072576. [PMID: 36698399 PMCID: PMC9868864 DOI: 10.3389/fonc.2022.1072576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/29/2022] [Indexed: 01/11/2023] Open
Abstract
Introduction Digestive system pan-cancer is one of the lethal malignant tumors, which have the propensity for poor prognosis and difficult treatment. Endoplasmic reticulum (ER) stress has served as a pivotal role in the progression of the tumor, while the implication of ER stress on digestive system pan-cancers still needs elucidation, especially from the perspective of clinical outcome and that of genomic features. Methods First, Among the ER STRESS factors from the REACTOME_UNFOLDED_PROTEIN_RESPONSE_UPR (113 genes) and HALLMARK_UNFOLDED_PROTEIN_RESPONSE (92 genes) terms, 153 ER STRESS regulators were identified after removing replicates. The somatic mutation data and copy number variation data of gastrointestinal pan-cancer were downloaded from The Cancer Genome Atlas (TCGA) database. Then, we explored the clinical outcome and genetic mutation of ER stress-related differentially expressed genes (DEGs) by multiple bioinformatics analysis. Subsequently, we analyzed the Spearman correlation between the drug sensitivity of 179 gastrointestinal anticancer drugs and the transcriptional expression of 153 ER stress factors in 769 cancer cell lines of the GDSC2 cohort. Next, ssGSEA method was used to quantify the immune cell infiltration scores in the tumor microenvironment, and Spearman correlation was used to calculate the correlation between ER stress scores and immune cell infiltration. Finally, we analyzed the cellular origin of ER stress factor dysregulation. Results We analyzed the genomic changes and clinical outcomes of ER stress factors in different tumors of gastrointestinal pan-cancer. Endoplasmic reticulum stress factor (ER) in digestive tract tumors showed high SNV mutation frequency, less methylation dysregulation and was associated with multiple oncogenic pathways. Endoplasmic reticulum stress factor (ER) is a risk factor for many cancers, but the effect on overall survival in rectal adenocarcinoma is opposite to that in other gastrointestinal tumors. And ER stress factors are highly correlated with drugs that target important pathways. Discussion Based on the clinical prognosis and genomic analysis of ER stress-related factors in patients with gastrointestinal pan-cancer, this study provides a new direction for further research on gastrointestinal pan-cancer.
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Affiliation(s)
- Sheng Yao
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yuanquan Yu
- Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Laboratory of Gastroenterology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Liyi Xu
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China,*Correspondence: Liyi Xu, ; Xiang Pan,
| | - Xiang Pan
- Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,Laboratory of Gastroenterology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China,*Correspondence: Liyi Xu, ; Xiang Pan,
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19
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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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20
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Luo Y, Jiao Q, Chen Y. Targeting endoplasmic reticulum stress-the responder to lipotoxicity and modulator of non-alcoholic fatty liver diseases. Expert Opin Ther Targets 2022; 26:1073-1085. [PMID: 36657744 DOI: 10.1080/14728222.2022.2170780] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Endoplasmic reticulum (ER) stress occurs with aberrant lipid accumulation and resultant adverse effects and widely exists in nonalcoholic fatty liver disease (NAFLD). It triggers the unfolded protein response (UPR) to restore ER homeostasis and actively participates in NAFLD pathological processes, including hepatic steatosis, inflammation, hepatocyte death, and fibrosis. Such acknowledges drive the discovery of novel NAFLD biomarker and therapeutic targets and the development of ER-stress targeted NAFLD drugs. AREAS COVERED This article discusses and updates the role of ER stress and UPR in NAFLD, the underlying action mechanism, and especially their full participation in NAFLD pathophysiology. It characterizes key molecular targets useful for the prevention and treatment of NAFLD and highlights the recent ER stress-targeted therapeutic strategies for NAFLD. EXPERT OPINION Targeting ER Stress is a valuable and promising strategy for NAFLD treatment, but its smooth translation into clinical application still requires better clarification of the different UPR patterns in diverse NAFLD physiological states. Further understanding of the distinct effects of these various patterns on NAFLD, the thresholds deciding their final impacts, and their actions via non-liver tissues and cells would be of great help to develop a precise and effective therapy for NAFLD. [Figure: see text].
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Affiliation(s)
- Yu Luo
- School of Pharmaceutical Science, University of South China, Hengyang, Hunan, China
| | - Qiangqiang Jiao
- School of Pharmaceutical Science, University of South China, Hengyang, Hunan, China
| | - Yuping Chen
- School of Pharmaceutical Science, University of South China, Hengyang, Hunan, China.,Institute of Pharmacy & Pharmacology, University of South China, Hengyang, Hunan, China
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21
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Zhao Y, Kim HS, Zou X, Huang L, Liang X, Li Z, Kim JS, Lin W. Harnessing Dual-Fluorescence Lifetime Probes to Validate Regulatory Mechanisms of Organelle Interactions. J Am Chem Soc 2022; 144:20854-20865. [DOI: 10.1021/jacs.2c08966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Yuping Zhao
- Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China
| | - Hyeong Seok Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Xiang Zou
- Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China
| | - Ling Huang
- Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China
| | - Xing Liang
- Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China
| | - Zihong Li
- Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China
| | - Jong Seung Kim
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Weiying Lin
- Guangxi Key Laboratory of Electrochemical Energy Materials, Institute of Optical Materials and Chemical Biology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, P. R. China
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22
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Gasdermin D mediates endoplasmic reticulum stress via FAM134B to regulate cardiomyocyte autophagy and apoptosis in doxorubicin-induced cardiotoxicity. Cell Death Dis 2022; 13:901. [PMID: 36289195 PMCID: PMC9606128 DOI: 10.1038/s41419-022-05333-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 01/23/2023]
Abstract
Cardiomyocyte pyroptosis and apoptosis play a vital role in the pathophysiology of several cardiovascular diseases. Our recent study revealed that gasdermin D (GSDMD) can promote myocardial I/R injury via the caspase-11/GSDMD pathway. We also found that GSDMD deletion attenuated myocardial I/R and MI injury by reducing cardiomyocyte apoptosis and pyroptosis. However, how GSDMD mediates cardiomyocyte apoptosis and protects myocardial function remains unclear. Here, we found that doxorubicin (DOX) treatment resulted in increased apoptosis and pyroptosis in cardiomyocytes and that caspase-11/GSDMD could mediate DOX-induced cardiotoxicity (DIC) injury. Interestingly, GSDMD overexpression promoted cardiomyocyte apoptosis, which was attenuated by GSDMD knockdown. Notably, GSDMD overexpression exacerbated DIC injury, impaired cardiac function in vitro and in vivo, and enhanced DOX-induced cardiomyocyte autophagy. Mechanistically, GSDMD regulated the activity of FAM134B, an endoplasmic reticulum autophagy receptor, by pore formation on the endoplasmic reticulum membrane via its N-terminus, thus activating endoplasmic reticulum stress. In turn, FAM134B interacted with autophagic protein LC3, thus inducing cardiac autophagy, promoting cardiomyocyte apoptosis, and aggravating DIC. These results suggest that GSDMD promotes autophagy and induces cardiomyocyte apoptosis by modulating the reaction of FAM134B and LC3, thereby promoting DIC injury. Targeted regulation of GSDMD may be a new target for the prevention and treatment of DIC.
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23
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Navarro-Betancourt JR, Cybulsky AV. The IRE1α pathway in glomerular diseases: The unfolded protein response and beyond. FRONTIERS IN MOLECULAR MEDICINE 2022; 2:971247. [PMID: 39086958 PMCID: PMC11285563 DOI: 10.3389/fmmed.2022.971247] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/07/2022] [Indexed: 08/02/2024]
Abstract
Endoplasmic reticulum (ER) function is vital for protein homeostasis ("proteostasis"). Protein misfolding in the ER of podocytes (glomerular visceral epithelial cells) is an important contributor to the pathogenesis of human glomerular diseases. ER protein misfolding causes ER stress and activates a compensatory signaling network called the unfolded protein response (UPR). Disruption of the UPR, in particular deletion of the UPR transducer, inositol-requiring enzyme 1α (IRE1α) in mouse podocytes leads to podocyte injury and albuminuria in aging, and exacerbates injury in glomerulonephritis. The UPR may interact in a coordinated manner with autophagy to relieve protein misfolding and its consequences. Recent studies have identified novel downstream targets of IRE1α, which provide new mechanistic insights into proteostatic pathways. Novel pathways of IRE1α signaling involve reticulophagy, mitochondria, metabolism, vesicular trafficking, microRNAs, and others. Mechanism-based therapies for glomerulopathies are limited, and development of non-invasive ER stress biomarkers, as well as targeting ER stress with pharmacological compounds may represent a therapeutic opportunity for preventing or attenuating progression of chronic kidney disease.
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Affiliation(s)
| | - Andrey V. Cybulsky
- Department of Medicine, McGill University Health Centre Research Institute, McGill University, Montreal, QC, Canada
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24
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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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25
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Gentile D, Esposito M, Grumati P. Metabolic adaption of cancer cells toward autophagy: Is there a role for ER-phagy? Front Mol Biosci 2022; 9:930223. [PMID: 35992272 PMCID: PMC9382244 DOI: 10.3389/fmolb.2022.930223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Autophagy is an evolutionary conserved catabolic pathway that uses a unique double-membrane vesicle, called autophagosome, to sequester cytosolic components, deliver them to lysosomes and recycle amino-acids. Essentially, autophagy acts as a cellular cleaning system that maintains metabolic balance under basal conditions and helps to ensure nutrient viability under stress conditions. It is also an important quality control mechanism that removes misfolded or aggregated proteins and mediates the turnover of damaged and obsolete organelles. In this regard, the idea that autophagy is a non-selective bulk process is outdated. It is now widely accepted that forms of selective autophagy are responsible for metabolic rewiring in response to cellular demand. Given its importance, autophagy plays an essential role during tumorigenesis as it sustains malignant cellular growth by acting as a coping-mechanisms for intracellular and environmental stress that occurs during malignant transformation. Cancer development is accompanied by the formation of a peculiar tumor microenvironment that is mainly characterized by hypoxia (oxygen < 2%) and low nutrient availability. Such conditions challenge cancer cells that must adapt their metabolism to survive. Here we review the regulation of autophagy and selective autophagy by hypoxia and the crosstalk with other stress response mechanisms, such as UPR. Finally, we discuss the emerging role of ER-phagy in sustaining cellular remodeling and quality control during stress conditions that drive tumorigenesis.
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Affiliation(s)
- Debora Gentile
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
| | - Marianna Esposito
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Scuola Superiore Meridionale, Naples, Italy
| | - Paolo Grumati
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
- *Correspondence: Paolo Grumati,
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26
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Zhang J, Wang YY, Pan ZQ, Li Y, Sui J, Du LL, Ye K. Structural mechanism of protein recognition by the FW domain of autophagy receptor Nbr1. Nat Commun 2022; 13:3650. [PMID: 35752625 PMCID: PMC9233695 DOI: 10.1038/s41467-022-31439-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 06/16/2022] [Indexed: 12/21/2022] Open
Abstract
Neighbor of BRCA1 (Nbr1) is a conserved autophagy receptor that provides cargo selectivity to autophagy. The four-tryptophan (FW) domain is a signature domain of Nbr1, but its exact function remains unclear. Here, we show that Nbr1 from the filamentous fungus Chaetomium thermophilum uses its FW domain to bind the α-mannosidase Ams1, a cargo of selective autophagy in both budding yeast and fission yeast, and delivers Ams1 to the vacuole by conventional autophagy in heterologous fission yeast. The structure of the Ams1-FW complex was determined at 2.2 Å resolution by cryo-electron microscopy. The FW domain adopts an immunoglobulin-like β-sandwich structure and recognizes the quaternary structure of the Ams1 tetramer. Notably, the N-terminal di-glycine of Ams1 is specifically recognized by a conserved pocket of the FW domain. The FW domain becomes degenerated in fission yeast Nbr1, which binds Ams1 with a ZZ domain instead. Our findings illustrate the protein binding mode of the FW domain and reveal the versatility of Nbr1-mediated cargo recognition. Nbr1 recognizes cargos in selective autophagy. Here, authors show filamentous yeast Nbr1 binds Ams1 via an FW domain, and the cryo-EM structure reveals that Nbr1 recognizes the N-terminal di-glycine and tetrameric assembly of Ams1.
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Affiliation(s)
- Jianxiu Zhang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying-Ying Wang
- College of Life Sciences, Beijing Normal University, 100875, Beijing, China.,National Institute of Biological Sciences, 102206, Beijing, China.,School of Basic Medical Sciences, Henan University of Science and Technology, Luoyang, 471023, Henan, China
| | - Zhao-Qian Pan
- National Institute of Biological Sciences, 102206, Beijing, China
| | - Yulu Li
- National Institute of Biological Sciences, 102206, Beijing, China
| | - Jianhua Sui
- National Institute of Biological Sciences, 102206, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206, Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, 102206, Beijing, China. .,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206, Beijing, China.
| | - Keqiong Ye
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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27
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Aroca A, Gotor C. Hydrogen sulfide action in the regulation of plant autophagy. FEBS Lett 2022; 596:2186-2197. [PMID: 35735749 DOI: 10.1002/1873-3468.14433] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/30/2022] [Accepted: 06/13/2022] [Indexed: 11/09/2022]
Abstract
Hydrogen sulfide is a signaling molecule with a well-established impact on both plant and animal physiology. Intense investigation into the regulation of autophagy by sulfide in Arabidopsis thaliana has revealed that the post-translational modification of persulfidation/S-sulfhydration plays a key role. In this review focused on plants, we discuss the nature of the sulfide molecule involved in the regulation of autophagy, the final outcome of this modification, and the persulfidated autophagy proteins identified so far. A detailed outline of the actual knowledge of the regulation mechanism of the autophagy-related proteins ATG4a and ATG18a from Arabidopsis by sulfide is also included. This information will be instrumental for furthering research on the regulation of autophagy by sulfide.
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Affiliation(s)
- Angeles Aroca
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Seville, Spain
| | - Cecilia Gotor
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC-Universidad de Sevilla, Seville, Spain
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28
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Luong AM, Koestel J, Bhati KK, Batoko H. Cargo receptors and adaptors for selective autophagy in plant cells. FEBS Lett 2022; 596:2104-2132. [PMID: 35638898 DOI: 10.1002/1873-3468.14412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/08/2022] [Accepted: 05/23/2022] [Indexed: 11/06/2022]
Abstract
Plant selective (macro)autophagy is a highly regulated process whereby eukaryotic cells spatiotemporally degrade some of their constituents that have become superfluous or harmful. The identification and characterization of the factors determining this selectivity make it possible to integrate selective (macro)autophagy into plant cell physiology and homeostasis. The specific cargo receptors and/or scaffold proteins involved in this pathway are generally not structurally conserved, as are the biochemical mechanisms underlying recognition and integration of a given cargo into the autophagosome in different cell types. This review discusses the few specific cargo receptors described in plant cells to highlight key features of selective autophagy in the plant kingdom and its integration with plant physiology, so as to identify evolutionary convergence and knowledge gaps to be filled by future research.
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Affiliation(s)
- Ai My Luong
- Louvain Institute of Biomolecular Science and Technology, University of Louvain Croix du Sud 4, L7.07.14, 1348, Louvain-la-Neuve, Belgium
| | - Jérôme Koestel
- Louvain Institute of Biomolecular Science and Technology, University of Louvain Croix du Sud 4, L7.07.14, 1348, Louvain-la-Neuve, Belgium
| | - Kaushal Kumar Bhati
- Louvain Institute of Biomolecular Science and Technology, University of Louvain Croix du Sud 4, L7.07.14, 1348, Louvain-la-Neuve, Belgium
| | - Henri Batoko
- Louvain Institute of Biomolecular Science and Technology, University of Louvain Croix du Sud 4, L7.07.14, 1348, Louvain-la-Neuve, Belgium
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29
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Guo Y, Song S, DU X, Tian L, Zhang M, Zhou H, Chen ZK, Chang S. Romidepsin (FK228) improves the survival of allogeneic skin grafts through downregulating the production of donor-specific antibody via suppressing the IRE1α-XBP1 pathway. J Zhejiang Univ Sci B 2022; 23:392-406. [PMID: 35557040 DOI: 10.1631/jzus.b2100780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antibody-mediated rejection (AMR) is one of the major causes of graft loss after transplantation. Recently, the regulation of B cell differentiation and the prevention of donor-specific antibody (DSA) production have gained increased attention in transplant research. Herein, we established a secondary allogeneic in vivo skin transplant model to study the effects of romidepsin (FK228) on DSA. The survival of grafted skins was monitored daily. The serum levels of DSA and the number of relevant immunocytes in the recipient spleens were evaluated by flow cytometry. Then, we isolated and purified B cells from B6 mouse spleens in vitro by magnetic bead sorting. The B cells were cultured with interleukin-4 (IL-4) and anti-clusters of differentiation 40 (CD40) antibody with or without FK228 treatment. The immunoglobulin G1 (IgG1) and IgM levels in the supernatant were evaluated by enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blotting were conducted to determine the corresponding levels of messenger RNA (mRNA) and protein expression in cultured cells and the recipient spleens. The results showed that FK228 significantly improved the survival of allogeneic skin grafts. Moreover, FK228 inhibited DSA production in the serum along with the suppression of histone deacetylase 1 (HADC1) and HDAC2 and the upregulation of the acetylation of histones H2A and H3. It also inhibited the differentiation of B cells to plasma cells, decreased the transcription of positive regulatory domain-containing 1 (Prdm1) and X-box-binding protein 1 (Xbp1), and decreased the expression of phosphorylated inositol-requiring enzyme 1 α (p-IRE1α), XBP1, and B lymphocyte-induced maturation protein-1 (Blimp-1). In conclusion, FK228 could decrease the production of antibodies by B cells via inhibition of the IRE1α-XBP1 signaling pathway. Thus, FK228 is considered as a promising therapeutic agent for the clinical treatment of AMR.
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Affiliation(s)
- Yuliang Guo
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan 430030, China
| | - Siyu Song
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan 430030, China
| | - Xiaoxiao DU
- Henan Key Laboratory of Digestive Organ Transplantation, Open and Key Laboratory of Hepatobiliary & Pancreatic Surgery and Digestive Organ Transplantation at Henan Universities, Zhengzhou Key Laboratory of Hepatobiliary & Pancreatic Diseases and Organ Transplantation, Department of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Li Tian
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan 430030, China
| | - Man Zhang
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan 430030, China
| | - Hongmin Zhou
- Department of Cardiothoracic and Vascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhonghua Klaus Chen
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan 430030, China
| | - Sheng Chang
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. .,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan 430030, China.
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30
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Gubas A, Dikic I. ER remodeling via ER-phagy. Mol Cell 2022; 82:1492-1500. [PMID: 35452617 PMCID: PMC9098120 DOI: 10.1016/j.molcel.2022.02.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/24/2022] [Accepted: 02/09/2022] [Indexed: 01/01/2023]
Abstract
The endoplasmic reticulum (ER) is a hotspot for many essential cellular functions. The ER membrane is highly dynamic, which affects many cellular processes that take place within the ER. One such process is ER-phagy, a selective degradation of ER fragments (including membranes and luminal content), which serves to preserve the size of ER while adapting its morphology under basal and stress conditions. In order to be degraded, the ER undergoes selective fragmentation facilitated by specialized ER-shaping proteins that also act as ER-phagy receptors. Their ability to sense and induce membrane curvature, as well as to bridge the ER with autophagy machinery, allows for a successful ER fragmentation and delivery of these fragments to the lysosome for degradation and recycling. In this review, we provide insights into ER-phagy from the perspective of membrane remodeling. We highlight the importance of ER membrane dynamics during ER-phagy and emphasize how its dysregulation reflects on human physiology and pathology.
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Affiliation(s)
- Andrea Gubas
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany.
| | - Ivan Dikic
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany; Max Planck Institute of Biophysics, Frankfurt, Germany.
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31
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Fission Yeast Autophagy Machinery. Cells 2022; 11:cells11071086. [PMID: 35406650 PMCID: PMC8997447 DOI: 10.3390/cells11071086] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/19/2022] [Accepted: 03/22/2022] [Indexed: 01/27/2023] Open
Abstract
Autophagy is a conserved process that delivers cytoplasmic components to the vacuole/lysosome. It plays important roles in maintaining cellular homeostasis and conferring stress resistance. In the fission yeast Schizosaccharomyces pombe, autophagy is important for cell survival under nutrient depletion and ER stress conditions. Experimental analyses of fission yeast autophagy machinery in the last 10 years have unveiled both similarities and differences in autophagosome biogenesis mechanisms between fission yeast and other model eukaryotes for autophagy research, in particular, the budding yeast Saccharomyces cerevisiae. More recently, selective autophagy pathways that deliver hydrolytic enzymes, the ER, and mitochondria to the vacuole have been discovered in fission yeast, yielding novel insights into how cargo selectivity can be achieved in autophagy. Here, we review the progress made in understanding the autophagy machinery in fission yeast.
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32
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Chen Y, Cao B, Zheng W, Sun Y, Xu T. eIF3k inhibits NF-κB signaling by targeting MyD88 for ATG5-mediated autophagic degradation in teleost fish. J Biol Chem 2022; 298:101730. [PMID: 35176284 PMCID: PMC8914388 DOI: 10.1016/j.jbc.2022.101730] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 12/18/2022] Open
Abstract
Optimal activation of NF-κB signaling is crucial for the initiation of inflammatory responses and eliminating invading bacteria. Bacteria have likewise evolved the ability to evade immunity; however, mechanisms by which bacteria dysregulate host NF-κB signaling are unclear. In this study, we identify eukaryotic translation initiation factor eIF3k, a nonessential member of the eIF3 translation initiation complex, as a suppressor of the NF-κB pathway. Mechanistically, we show that eIF3k expression induced by Vibrio harveyi enhances E3 ligase Nrdp1-mediated K27-linked ubiquitination of MyD88, an upstream regulator of NF-κB pathway activation. Furthermore, we show that eIF3k acts as a bridge linking ubiquitin-tagged MyD88 and ATG5, an important mediator of autophagy. We demonstrate that the MyD88-eIF3k-ATG5 complex is transported to the autophagosome for degradation, and that innate immune signaling is subsequently terminated and does not attack invading V. harveyi. Therefore, our study identifies eIF3k as a specific inhibitor of the MyD88-dependent NF-κB pathway and suggests that eIF3k may act as a selective autophagic receptor that synergizes with ATG5 to promote the autophagic degradation of MyD88, which helps V. harveyi to evade innate immunity. We conclude that V. harveyi can manipulate a host's autophagy process to evade immunity in fish and also provide a new perspective on mammalian resistance to bacterial invasion.
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Affiliation(s)
- Ya Chen
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Baolan Cao
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Weiwei Zheng
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Yuena Sun
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai, China
| | - Tianjun Xu
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, Shanghai, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, Shanghai, China.
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33
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Reggiori F, Molinari M. ER-phagy: mechanisms, regulation and diseases connected to the lysosomal clearance of the endoplasmic reticulum. Physiol Rev 2022; 102:1393-1448. [PMID: 35188422 PMCID: PMC9126229 DOI: 10.1152/physrev.00038.2021] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
ER-phagy (reticulo-phagy) defines the degradation of portions of the endoplasmic reticulum (ER) within lysosomes or vacuoles. It is part of the self-digestion (i.e., auto-phagic) programs recycling cytoplasmic material and organelles, which rapidly mobilize metabolites in cells confronted with nutrient shortage. Moreover, selective clearance of ER subdomains participates to the control of ER size and activity during ER stress, the re-establishment of ER homeostasis after ER stress resolution and the removal of ER parts, in which aberrant and potentially cytotoxic material has been segregated. ER-phagy relies on the individual and/or concerted activation of the ER-phagy receptors, ER peripheral or integral membrane proteins that share the presence of LC3/Atg8-binding motifs in their cytosolic domains. ER-phagy involves the physical separation of portions of the ER from the bulk ER network, and their delivery to the endolysosomal/vacuolar catabolic district. This last step is accomplished by a variety of mechanisms including macro-ER-phagy (in which ER fragments are sequestered by double-membrane autophagosomes that eventually fuse with lysosomes/vacuoles), micro-ER-phagy (in which ER fragments are directly engulfed by endosomes/lysosomes/vacuoles), or direct fusion of ER-derived vesicles with lysosomes/vacuoles. ER-phagy is dysfunctional in specific human diseases and its regulators are subverted by pathogens, highlighting its crucial role for cell and organism life.
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Affiliation(s)
- Fulvio Reggiori
- Department of Biomedical Sciences of Cells & Systems, grid.4830.fUniversity of Groningen, Netherlands
| | - Maurizio Molinari
- Protein Folding and Quality Control, grid.7722.0Institute for Research in Biomedicine, Bellinzona, Switzerland
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B B, Zeng Z, Zhou C, Lian G, Guo F, Wang J, Han N, Zhu M, Bian H. Identification of New ATG8s-Binding Proteins with Canonical LC3-Interacting Region in Autophagosomes of Barley Callus. PLANT & CELL PHYSIOLOGY 2022:pcac015. [PMID: 35134996 DOI: 10.1093/pcp/pcac015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Autophagy is essential to maintain cellular homeostasis for normal cell growth and development. In selective autophagy, ATG8 plays a crucial role in cargo target recognition by binding to various adaptors and receptors with the ATG8-interacting motif, also known as the LC3-interacting region (LIR). However, the process of autophagy in the callus, as a proliferating cell type, is largely unknown. In this study, we overexpressed green fluorescent protein (GFP)-ATG8a and GFP-ATG8b transgenic barley callus and checked their autophagic activities. We identified five new ATG8 candidate interactors containing the canonical LIR motif by using immunoprecipitation coupled with mass spectrometry: RPP3, COPE, NCLN, RAE1, and CTSL. The binding activities between these candidate interactors and ATG8 were further demonstrated in the punctate structure. Notably, RPP3 was colocalized in ATG8-labeled autophagosomes under tunicamycin-induced ER stress. GST pull-down assays showed that the interaction between RPP3 and ATG8 could be prevented by mutating the LIRs region of RPP3 or the LIR docking site (LDS) of ATG8, suggesting that RPP3 directly interacted with ATG8 in an LIR-dependent manner via the LDS. Our findings would provide the basis for further investigations on novel receptors and functions of autophagy in plants, especially in the physiological state of cell de-differentiation.
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35
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ER-phagy requires the assembly of actin at sites of contact between the cortical ER and endocytic pits. Proc Natl Acad Sci U S A 2022; 119:2117554119. [PMID: 35101986 PMCID: PMC8833162 DOI: 10.1073/pnas.2117554119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/24/2021] [Indexed: 01/03/2023] Open
Abstract
Portions of the endoplasmic reticulum (ER) are degraded by autophagy (ER-phagy) in response to starvation or the accumulation of misfolded proteins. We show that ER-phagy requires assembly of actin at sites of contact between the edges of ER sheets and endocytic pits on the plasma membrane. Actin assembly may help to bring an element of the ER carrying the selective autophagy receptor Atg40 into the cell interior, where it associates with Atg11, a scaffold needed to recruit components for autophagosome assembly. Understanding the mechanism by which regions of the ER are selected for degradation and sequestered within autophagosomes may help in the development of novel approaches to treat diseases that result from the accumulation of misfolded proteins within the ER. Fragments of the endoplasmic reticulum (ER) are selectively delivered to the lysosome (mammals) or vacuole (yeast) in response to starvation or the accumulation of misfolded proteins through an autophagic process known as ER-phagy. A screen of the Saccharomyces cerevisiae deletion library identified end3Δ as a candidate knockout strain that is defective in ER-phagy during starvation conditions, but not bulk autophagy. We find that loss of End3 and its stable binding partner Pan1, or inhibition of the Arp2/3 complex that is coupled by the End3-Pan1 complex to endocytic pits, blocks the association of the cortical ER autophagy receptor, Atg40, with the autophagosomal assembly scaffold protein Atg11. The membrane contact site module linking the rim of cortical ER sheets and endocytic pits, consisting of Scs2 or Scs22, Osh2 or Osh3, and Myo3 or Myo5, is also needed for ER-phagy. Both Atg40 and Scs2 are concentrated at the edges of ER sheets and can be cross-linked to each other. Our results are consistent with a model in which actin assembly at sites of contact between the cortical ER and endocytic pits contributes to ER sequestration into autophagosomes.
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Novick P, Liu D, Ferro-Novick S. Autophagy of the ER requires actin assembly driven by the interaction of ER with endocytic pits. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2022; 5:25152564221093215. [PMID: 37102157 PMCID: PMC10129067 DOI: 10.1177/25152564221093215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 04/28/2023]
Abstract
Autophagy of the cortical ER in budding yeast was unexpectedly found to require End3, a component of the endocytic machinery that promotes the assembly of actin at endocytic pits on the plasma membrane. The cortical ER transiently interacts with invaginating endocytic pits through a linkage consisting of VAP proteins, oxysterol binding proteins and type I myosins. These proteins are required for actin assembly and for autophagy of the ER. Assembly of actin at these contact sites may direct the movement of ER away from the cortex towards sites of autophagosome assembly.
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Affiliation(s)
- Peter Novick
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, USA
| | - Dongmei Liu
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, USA
| | - Susan Ferro-Novick
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, USA
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37
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Emami P, Ueno M. 3,3'-Diindolylmethane induces apoptosis and autophagy in fission yeast. PLoS One 2021; 16:e0255758. [PMID: 34890395 PMCID: PMC8664220 DOI: 10.1371/journal.pone.0255758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/25/2021] [Indexed: 01/26/2023] Open
Abstract
3,3'-Diindolylmethane (DIM) is a compound derived from the digestion of indole-3-carbinol, found in the broccoli family. It induces apoptosis and autophagy in some types of human cancer. DIM extends lifespan in the fission yeast Schizosaccharomyces pombe. The mechanisms by which DIM induces apoptosis and autophagy in humans and expands lifespan in fission yeasts are not fully understood. Here, we show that DIM induces apoptosis and autophagy in log-phase cells, which is dose-dependent in fission yeast. A high concentration of DIM disrupted the nuclear envelope (NE) structure and induced chromosome condensation at an early time point. In contrast, a low concentration of DIM induced autophagy but did not disrupt NE structure. The mutant defective in autophagy was more sensitive to a low concentration of DIM, demonstrating that the autophagic pathway contributes to the survival of cells against DIM. Moreover, our results showed that the lem2 mutant is more sensitive to DIM. NE in the lem2 mutant was disrupted even at the low concentration of DIM. Our results demonstrate that the autophagic pathway and NE integrity are important to maintain viability in the presence of a low concentration of DIM. The mechanism of apoptosis and autophagy induction by DIM might be conserved in fission yeast and humans. Further studies will contribute to the understanding of the mechanism of apoptosis and autophagy by DIM in fission yeast and humans.
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Affiliation(s)
- Parvaneh Emami
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Masaru Ueno
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
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38
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Redox Control of the Dormant Cancer Cell Life Cycle. Cells 2021; 10:cells10102707. [PMID: 34685686 PMCID: PMC8535080 DOI: 10.3390/cells10102707] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/11/2021] [Accepted: 09/28/2021] [Indexed: 02/05/2023] Open
Abstract
Following efficient tumor therapy, some cancer cells may survive through a dormancy process, contributing to tumor recurrence and worse outcomes. Dormancy is considered a process where most cancer cells in a tumor cell population are quiescent with no, or only slow, proliferation. Recent advances indicate that redox mechanisms control the dormant cancer cell life cycle, including dormancy entrance, long-term dormancy, and metastatic relapse. This regulatory network is orchestrated mainly through redox modification on key regulators or global change of reactive oxygen species (ROS) levels in dormant cancer cells. Encouragingly, several strategies targeting redox signaling, including sleeping, awaking, or killing dormant cancer cells are currently under early clinical evaluation. However, the molecular mechanisms underlying redox control of the dormant cancer cell cycle are poorly understood and need further exploration. In this review, we discuss the underlying molecular basis of redox signaling in the cell life cycle of dormant cancer and the potential redox-based targeting strategies for eliminating dormant cancer cells.
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Yu ZQ, Liu XM, Zhao D, Xu DD, Du LL. Visual detection of binary, ternary and quaternary protein interactions in fission yeast using a Pil1 co-tethering assay. J Cell Sci 2021; 134:272452. [PMID: 34499173 DOI: 10.1242/jcs.258774] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 09/03/2021] [Indexed: 01/28/2023] Open
Abstract
Protein-protein interactions are vital for executing nearly all cellular processes. To facilitate the detection of protein-protein interactions in living cells of the fission yeast Schizosaccharomyces pombe, here we present an efficient and convenient method termed the Pil1 co-tethering assay. In its basic form, we tether a bait protein to mCherry-tagged Pil1, which forms cortical filamentary structures, and examine whether a GFP-tagged prey protein colocalizes with the bait. We demonstrate that this assay is capable of detecting pairwise protein-protein interactions of cytosolic proteins and nuclear proteins. Furthermore, we show that this assay can be used for detecting not only binary protein-protein interactions, but also ternary and quaternary protein-protein interactions. Using this assay, we systematically characterized the protein-protein interactions in the Atg1 complex and in the phosphatidylinositol 3-kinase (PtdIns3K) complexes and found that Atg38 is incorporated into the PtdIns3K complex I via an Atg38-Vps34 interaction. Our data show that this assay is a useful and versatile tool and should be added to the routine toolbox of fission yeast researchers. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Zhong-Qiu Yu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Dan Zhao
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Dan-Dan Xu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, 102206 Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
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40
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He L, Qian X, Cui Y. Advances in ER-Phagy and Its Diseases Relevance. Cells 2021; 10:cells10092328. [PMID: 34571977 PMCID: PMC8465915 DOI: 10.3390/cells10092328] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/27/2021] [Accepted: 09/01/2021] [Indexed: 01/18/2023] Open
Abstract
As an important form of selective autophagy in cells, ER-phagy (endoplasmic reticulum-selective autophagy), the autophagic degradation of endoplasmic reticulum (ER), degrades ER membranes and proteins to maintain cellular homeostasis. The relationship between ER-phagy and human diseases, including neurodegenerative disorders, cancer, and other metabolic diseases has been unveiled by extensive research in recent years. Starting with the catabolic process of ER-phagy and key mediators in this pathway, this paper reviews the advances in the mechanism of ER-phagy and its diseases relevance. We hope to provide some enlightenment for further study on ER-phagy and the development of novel therapeutic strategies for related diseases.
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Affiliation(s)
- Lingang He
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan 430071, China; (L.H.); (X.Q.)
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Xuehong Qian
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan 430071, China; (L.H.); (X.Q.)
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
| | - Yixian Cui
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University, Wuhan 430071, China; (L.H.); (X.Q.)
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan 430071, China
- Correspondence: ; Tel.: +86-27-87267099
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41
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Yang M, Luo S, Wang X, Li C, Yang J, Zhu X, Xiao L, Sun L. ER-Phagy: A New Regulator of ER Homeostasis. Front Cell Dev Biol 2021; 9:684526. [PMID: 34307364 PMCID: PMC8299523 DOI: 10.3389/fcell.2021.684526] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/04/2021] [Indexed: 12/17/2022] Open
Abstract
The endoplasmic reticulum (ER) is one of the most important cellular organelles and is essential for cell homeostasis. Upon external stimulation, ER stress induces the unfolded protein response (UPR) and ER-associated degradation (ERAD) to maintain ER homeostasis. However, persistent ER stress can lead to cell damage. ER-phagy is a selective form of autophagy that ensures the timely removal of damaged ER, thereby protecting cells from damage caused by excessive ER stress. As ER-phagy is a newly identified form of autophagy, many receptor-mediated ER-phagy pathways have been discovered in recent years. In this review, we summarize our understanding of the maintenance of ER homeostasis and describe the receptors identified to date. Finally, the relationships between ER-phagy and diseases are also discussed.
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Affiliation(s)
- Ming Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Shilu Luo
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
| | - Xi Wang
- Department of Nutrition, Xiangya Hospital, Central South University, Changsha, China
| | - Chenrui Li
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jinfei Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xuejing Zhu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Li Xiao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Lin Sun
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Kidney Disease and Blood Purification, Changsha, China
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42
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Wang YY, Zhang J, Liu XM, Li Y, Sui J, Dong MQ, Ye K, Du LL. Molecular and structural mechanisms of ZZ domain-mediated cargo selection by Nbr1. EMBO J 2021; 40:e107497. [PMID: 34169534 DOI: 10.15252/embj.2020107497] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 05/17/2021] [Accepted: 05/25/2021] [Indexed: 12/14/2022] Open
Abstract
In selective autophagy, cargo selectivity is determined by autophagy receptors. However, it remains scarcely understood how autophagy receptors recognize specific protein cargos. In the fission yeast Schizosaccharomyces pombe, a selective autophagy pathway termed Nbr1-mediated vacuolar targeting (NVT) employs Nbr1, an autophagy receptor conserved across eukaryotes including humans, to target cytosolic hydrolases into the vacuole. Here, we identify two new NVT cargos, the mannosidase Ams1 and the aminopeptidase Ape4, that bind competitively to the first ZZ domain of Nbr1 (Nbr1-ZZ1). High-resolution cryo-EM analyses reveal how a single ZZ domain recognizes two distinct protein cargos. Nbr1-ZZ1 not only recognizes the N-termini of cargos via a conserved acidic pocket, similar to other characterized ZZ domains, but also engages additional parts of cargos in a cargo-specific manner. Our findings unveil a single-domain bispecific mechanism of autophagy cargo recognition, elucidate its underlying structural basis, and expand the understanding of ZZ domain-mediated protein-protein interactions.
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Affiliation(s)
- Ying-Ying Wang
- College of Life Sciences, Beijing Normal University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Jianxiu Zhang
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, Beijing, China
| | - Yulu Li
- National Institute of Biological Sciences, Beijing, China
| | - Jianhua Sui
- National Institute of Biological Sciences, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Keqiong Ye
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, 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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Abstract
Selective autophagy is the lysosomal degradation of specific intracellular components sequestered into autophagosomes, late endosomes, or lysosomes through the activity of selective autophagy receptors (SARs). SARs interact with autophagy-related (ATG)8 family proteins via sequence motifs called LC3-interacting region (LIR) motifs in vertebrates and Atg8-interacting motifs (AIMs) in yeast and plants. SARs can be divided into two broad groups: soluble or membrane bound. Cargo or substrate selection may be independent or dependent of ubiquitin labeling of the cargo. In this review, we discuss mechanisms of mammalian selective autophagy with a focus on the unifying principles employed in substrate recognition, interaction with the forming autophagosome via LIR-ATG8 interactions, and the recruitment of core autophagy components for efficient autophagosome formation on the substrate. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Trond Lamark
- Molecular Cancer Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, 9037 Tromsø, Norway; ,
| | - Terje Johansen
- Molecular Cancer Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, 9037 Tromsø, Norway; ,
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44
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Neefjes J, Cabukusta B. What the VAP: The Expanded VAP Family of Proteins Interacting With FFAT and FFAT-Related Motifs for Interorganellar Contact. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211012246. [PMID: 34036242 PMCID: PMC7610837 DOI: 10.1177/25152564211012246] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Membrane contact sites are formed by tether proteins that have the ability to bring two organellar membranes together. VAP proteins are a family of endoplasmic reticulum (ER)-resident tether proteins specialized in interacting with FFAT (two phenylalanines in an acidic tract) peptide motifs in other proteins. If the FFAT-motif-containing proteins reside on other organelles, VAP proteins form contact sites between these organelles and the ER. The role of VAPA and VAPB, the two founding members of the VAP family in recruiting proteins to the ER and forming membrane contact sites is well appreciated as numerous interaction partners of VAPA and VAPB at different intracellular contact sites have been characterized. Recently, three new proteins -MOSPD1, MOSPD2 and MOSPD3-have been added to the VAP family. While MOSPD2 has a motif preference similar to VAPA and VAPB, MOSPD1 and MOSPD3 prefer to interact with proteins containing FFNT (two phenylalanines in a neutral tract) motifs. In this review, we discuss the recent advances in motif binding by VAP proteins along with the other biological processes VAP proteins are involved in.
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Affiliation(s)
- Jacques Neefjes
- Cell and Chemical Biology, Oncode Institute, Leiden University Medical Center, Leiden, the Netherlands
| | - Birol Cabukusta
- Cell and Chemical Biology, Oncode Institute, Leiden University Medical Center, Leiden, the Netherlands
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45
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Kim J, Lee S, Kim H, Lee H, Seong KM, Youn H, Youn B. Autophagic Organelles in DNA Damage Response. Front Cell Dev Biol 2021; 9:668735. [PMID: 33912571 PMCID: PMC8072393 DOI: 10.3389/fcell.2021.668735] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/23/2021] [Indexed: 12/19/2022] Open
Abstract
Autophagy is an important subcellular event engaged in the maintenance of cellular homeostasis via the degradation of cargo proteins and malfunctioning organelles. In response to cellular stresses, like nutrient deprivation, infection, and DNA damaging agents, autophagy is activated to reduce the damage and restore cellular homeostasis. One of the responses to cellular stresses is the DNA damage response (DDR), the intracellular pathway that senses and repairs damaged DNA. Proper regulation of these pathways is crucial for preventing diseases. The involvement of autophagy in the repair and elimination of DNA aberrations is essential for cell survival and recovery to normal conditions, highlighting the importance of autophagy in the resolution of cell fate. In this review, we summarized the latest information about autophagic recycling of mitochondria, endoplasmic reticulum (ER), and ribosomes (called mitophagy, ER-phagy, and ribophagy, respectively) in response to DNA damage. In addition, we have described the key events necessary for a comprehensive understanding of autophagy signaling networks. Finally, we have highlighted the importance of the autophagy activated by DDR and appropriate regulation of autophagic organelles, suggesting insights for future studies. Especially, DDR from DNA damaging agents including ionizing radiation (IR) or anti-cancer drugs, induces damage to subcellular organelles and autophagy is the key mechanism for removing impaired organelles.
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Affiliation(s)
- Jeongha Kim
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Sungmin Lee
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Hyunwoo Kim
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Haksoo Lee
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea
| | - Ki Moon Seong
- Laboratory of Low Dose Risk Assessment, National Radiation Emergency Medical Center, Korea Institute of Radiological and Medical Sciences, Seoul, South Korea
| | - HyeSook Youn
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, South Korea
| | - BuHyun Youn
- Department of Integrated Biological Science, Pusan National University, Busan, South Korea.,Department of Biological Sciences, Pusan National University, Busan, South Korea
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46
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Molinari M. ER-phagy responses in yeast, plants, and mammalian cells and their crosstalk with UPR and ERAD. Dev Cell 2021; 56:949-966. [PMID: 33765438 DOI: 10.1016/j.devcel.2021.03.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 12/24/2022]
Abstract
ER-phagy, literally endoplasmic reticulum (ER)-eating, defines the constitutive or regulated clearance of ER portions within metazoan endolysosomes or yeast and plant vacuoles. The advent of electron microscopy led to the first observations of ER-phagy over 60 years ago, but only recently, with the discovery of a set of regulatory proteins named ER-phagy receptors, has it been dissected mechanistically. ER-phagy receptors are activated by a variety of pleiotropic and ER-centric stimuli. They promote ER fragmentation and engage luminal, membrane-bound, and cytosolic factors, eventually driving lysosomal clearance of select ER domains along with their content. After short historical notes, this review introduces the concept of ER-phagy responses (ERPRs). ERPRs ensure lysosomal clearance of ER portions expendable during nutrient shortage, nonfunctional, present in excess, or containing misfolded proteins. They cooperate with unfolded protein responses (UPRs) and with ER-associated degradation (ERAD) in determining ER size, function, and homeostasis.
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Affiliation(s)
- Maurizio Molinari
- Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Institute for Research in Biomedicine, CH-6500 Bellinzona, Switzerland; School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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47
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Maintaining the structural and functional homeostasis of the plant endoplasmic reticulum. Dev Cell 2021; 56:919-932. [PMID: 33662257 DOI: 10.1016/j.devcel.2021.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/21/2021] [Accepted: 02/08/2021] [Indexed: 12/14/2022]
Abstract
The endoplasmic reticulum (ER) is a ubiquitous organelle that is vital to the life of eukaryotic cells. It synthesizes essential lipids and proteins and initiates the glycosylation of intracellular and surface proteins. As such, the ER is necessary for cell growth and communication with the external environment. The ER is also a highly dynamic organelle, whose structure is continuously remodeled through an interaction with the cytoskeleton and the action of specialized ER shapers. Recent and significant advances in ER studies have brought to light conserved and unique features underlying the structure and function of this organelle in plant cells. In this review, exciting developments in the understanding of the mechanisms for plant ER structural and functional homeostasis, particularly those that underpin ER network architecture and ER degradation, are presented and discussed.
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48
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Ferro-Novick S, Reggiori F, Brodsky JL. ER-Phagy, ER Homeostasis, and ER Quality Control: Implications for Disease. Trends Biochem Sci 2021; 46:630-639. [PMID: 33509650 DOI: 10.1016/j.tibs.2020.12.013] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/14/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022]
Abstract
Lysosomal degradation of endoplasmic reticulum (ER) fragments by autophagy, termed ER-phagy or reticulophagy, occurs under normal as well as stress conditions. The recent discovery of multiple ER-phagy receptors has stimulated studies on the roles of ER-phagy. We discuss how the ER-phagy receptors and the cellular components that work with these receptors mediate two important functions: ER homeostasis and ER quality control. We highlight that ER-phagy plays an important role in alleviating ER expansion induced by ER stress, and acts as an alternative disposal pathway for misfolded proteins. We suggest that the latter function explains the emerging connection between ER-phagy and disease. Additional ER-phagy-associated functions and important unanswered questions are also discussed.
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Affiliation(s)
- Susan Ferro-Novick
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093-0668, USA.
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, The Netherlands.
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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Wu J, Michaeli S, Picchianti L, Dagdas Y, Galili G, Peled-Zehavi H. ATI1 (ATG8-interacting protein 1) and ATI2 define a plant starvation-induced reticulophagy pathway and serve as MSBP1/MAPR5 cargo receptors. Autophagy 2021; 17:3375-3388. [PMID: 33487099 DOI: 10.1080/15548627.2021.1872886] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Reticulophagy, the selective autophagy of endoplasmic reticulum (ER) components, is known to operate in eukaryotes from yeast and unicellular algae to animals and plants. Thus far, only ER-stress induced reticulophagy was reported and analyzed in plants. In this study we characterize a reticulophagy pathway in Arabidopsis thaliana that is triggered by dark-induced starvation but not by ER stress. This pathway is defined by the previously reported ATG8-interacting proteins, ATI1 and ATI2. We further identified the ER-localized MSBP1 (Membrane Steroid Binding Protein 1) as an ATI1- and ATI2-interacting protein and an autophagy cargo, and show that ATI1 and ATI2 serve as its cargo receptors. Together, these findings expand our knowledge on plant responses during energy deprivation and highlight the role of this special type of reticulophagy in this process.Abbreviations: AGO1: ARGONAUTE 1; ATI: ATG8-Interacting Protein; BiFC: Bimolecular Fluorescence Complementation; BR: brassinosteroid; conA: concanamycin A; DMSO: dimethyl sulfoxid; DTT: dithiothreitol; ER: endoplasmic reticulum; GFP: green fluorescent protein; MAPR: Membrane-Associated Progesterone Binding Protein; MSBP: Membrane Steroid Binding Protein; SD: standard deviation; SE: standard error; TM: tunicamycin; TOR: target of rapamycin; Y2H: yeast two-hybrid.
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Affiliation(s)
- Jian Wu
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Simon Michaeli
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Lorenzo Picchianti
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Yasin Dagdas
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Gad Galili
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Hadas Peled-Zehavi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
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Wu L, Liang C, Huang X, Deng X, Jiang J, Luo Z. Salubrinal Regulates the Apoptosis of Adrenocortical Carcinoma Cells via the PERK/eIF2 α/ATF4 Signaling Pathway. Int J Endocrinol 2021; 2021:5038130. [PMID: 34567111 PMCID: PMC8461226 DOI: 10.1155/2021/5038130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/15/2021] [Accepted: 08/19/2021] [Indexed: 01/22/2023] Open
Abstract
The protein-kinase-R- (PKR-) like endoplasmic reticulum kinase (PERK) signaling pathway is a well-known promoter of cell apoptosis. In this study, we aimed to determine whether salubrinal (Sal), a selective activator of eukaryotic translation initiation factor 2 (eIF2α), can induce apoptosis of human adrenocortical carcinoma (ACC) cell via activating the PERK/eIF2α/ATF4 signaling pathway, and the potential mechanisms of this action were explored. The ACC cell lines, including SW-13 and NCI-H295 R, were used. 3-(4,5)-Dimethylthiazol(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, cell scratch experiments, flow cytometry, and JC-1 staining assays were performed to detect the cell viability, cell migration, and cell apoptosis. The expression of PERK/eIF2α/ATF4 signaling-pathway-related proteins and apoptosis-related proteins was detected by western blot (WB). Intracellular Ca2+ ion concentration was determined by a confocal laser scanning microscope. The results showed that Sal inhibited the migration and proliferation of ACC cells. Sal remarkably increased the influx of Ca2+ ion and the apoptosis rate of ACC cells in vitro. Furthermore, the expression levels of PERK/eIF2α/ATF4 signaling-related proteins and apoptosis-related proteins were upregulated in the treatment of Sal. The research demonstrated that Sal reduces the cell viability, increases the intracellular calcium concentration, and promotes the apoptosis of ACC cells in vitro through increasing the phosphorylation level of eIF2α and activating the PERK/eIF2α/ATF4 signaling. PERK/eIF2α/ATF4 is expected to act as a potential therapeutic target for the treatment of adrenocortical carcinoma.
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Affiliation(s)
- Lili Wu
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
- Department of Integrated Medicine, Guangxi Medical University Cancer Hospital, Nanning, Guangxi 530021, China
| | - Chunfeng Liang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Xuemei Huang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Xiujun Deng
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Jiming Jiang
- Department of Analysis for Cosmetics (Dietary Supplements), Guangxi Institute for Food and Drug Control, Nanning, Guangxi 530021, China
| | - Zuojie Luo
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
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