1
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Zhao XY, Xu DE, Wu ML, Liu JC, Shi ZL, Ma QH. Regulation and function of endoplasmic reticulum autophagy in neurodegenerative diseases. Neural Regen Res 2025; 20:6-20. [PMID: 38767472 DOI: 10.4103/nrr.nrr-d-23-00995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 12/13/2023] [Indexed: 05/22/2024] Open
Abstract
The endoplasmic reticulum, a key cellular organelle, regulates a wide variety of cellular activities. Endoplasmic reticulum autophagy, one of the quality control systems of the endoplasmic reticulum, plays a pivotal role in maintaining endoplasmic reticulum homeostasis by controlling endoplasmic reticulum turnover, remodeling, and proteostasis. In this review, we briefly describe the endoplasmic reticulum quality control system, and subsequently focus on the role of endoplasmic reticulum autophagy, emphasizing the spatial and temporal mechanisms underlying the regulation of endoplasmic reticulum autophagy according to cellular requirements. We also summarize the evidence relating to how defective or abnormal endoplasmic reticulum autophagy contributes to the pathogenesis of neurodegenerative diseases. In summary, this review highlights the mechanisms associated with the regulation of endoplasmic reticulum autophagy and how they influence the pathophysiology of degenerative nerve disorders. This review would help researchers to understand the roles and regulatory mechanisms of endoplasmic reticulum-phagy in neurodegenerative disorders.
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Affiliation(s)
- Xiu-Yun Zhao
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - De-En Xu
- Department of Neurology, Jiangnan University Medical Center, Wuxi, Jiangsu Province, China
| | - Ming-Lei Wu
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Ji-Chuan Liu
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Zi-Ling Shi
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
| | - Quan-Hong Ma
- Department of Neurology and Clinical Research Center of Neurological Disease, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
- Institute of Neuroscience & Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Soochow University, Suzhou, Jiangsu Province, China
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2
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Zhang M, Wang Z, Zhao Q, Yang Q, Bai J, Yang C, Zhang ZR, Liu Y. USP20 deubiquitinates and stabilizes the reticulophagy receptor RETREG1/FAM134B to drive reticulophagy. Autophagy 2024:1-18. [PMID: 38705724 DOI: 10.1080/15548627.2024.2347103] [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: 07/31/2023] [Accepted: 04/19/2024] [Indexed: 05/07/2024] Open
Abstract
The endoplasmic reticulum (ER) serves as a hub for various cellular processes, and maintaining ER homeostasis is essential for cell function. Reticulophagy is a selective process that removes impaired ER subdomains through autophagy-mediatedlysosomal degradation. While the involvement of ubiquitination in autophagy regulation is well-established, its role in reticulophagy remains unclear. In this study, we screened deubiquitinating enzymes (DUBs) involved in reticulophagy and identified USP20 (ubiquitin specific peptidase 20) as a key regulator of reticulophagy under starvation conditions. USP20 specifically cleaves K48- and K63-linked ubiquitin chains on the reticulophagy receptor RETREG1/FAM134B (reticulophagy regulator 1), thereby stabilizing the substrate and promoting reticulophagy. Remarkably, despite lacking a transmembrane domain, USP20 is recruited to the ER through its interaction with VAPs (VAMP associated proteins). VAPs facilitate the recruitment of early autophagy proteins, including WIPI2 (WD repeat domain, phosphoinositide interacting 2), to specific ER subdomains, where USP20 and RETREG1 are enriched. The recruitment of WIPI2 and other proteins in this process plays a crucial role in facilitating RETREG1-mediated reticulophagy in response to nutrient deprivation. These findings highlight the critical role of USP20 in maintaining ER homeostasis by deubiquitinating and stabilizing RETREG1 at distinct ER subdomains, where USP20 further recruits VAPs and promotes efficient reticulophagy.Abbreviations: ACTB actin beta; ADRB2 adrenoceptor beta 2; AMFR/gp78 autocrine motility factor receptor; ATG autophagy related; ATL3 atlastin GTPase 3; BafA1 bafilomycin A1; BECN1 beclin 1; CALCOCO1 calcium binding and coiled-coil domain 1; CCPG1 cell cycle progression 1; DAPI 4',6-diamidino-2-phenylindole; DTT dithiothreitol; DUB deubiquitinating enzyme; EBSS Earle's Balanced Salt Solution; FFAT two phenylalanines (FF) in an acidic tract; GABARAP GABA type A receptor-associated protein; GFP green fluorescent protein; HMGCR 3-hydroxy-3-methylglutaryl-CoA reductase; IL1B interleukin 1 beta; LIR LC3-interacting region; MAP1LC3/LC3 microtubule associated protein 1 light chain 3; PIK3C3/Vps34 phosphatidylinositol 3-kinase catalytic subunit type 3; RB1CC1/FIP200 RB1 inducible coiled-coil 1; RETREG1/FAM134B reticulophagy regulator 1; RFP red fluorescent protein; RHD reticulon homology domain; RIPK1 receptor interacting serine/threonine kinase 1; RTN3L reticulon 3 long isoform; SEC61B SEC61 translocon subunit beta; SEC62 SEC62 homolog, preprotein translocation factor; SIM super-resolution structured illumination microscopy; SNAI2 snail family transcriptional repressor 2; SQSTM1/p62 sequestosome 1; STING1/MITA stimulator of interferon response cGAMP interactor 1; STX17 syntaxin 17; TEX264 testis expressed 264, ER-phagy receptor; TNF tumor necrosis factor; UB ubiquitin; ULK1 unc-51 like autophagy activating kinase 1; USP20 ubiquitin specific peptidase 20; USP33 ubiquitin specific peptidase 33; VAMP8 vesicle associated membrane protein 8; VAPs VAMP associated proteins; VMP1 vacuole membrane protein 1; WIPI2 WD repeat domain, phosphoinositide interacting 2; ZFYVE1/DFCP1 zinc finger FYVE-type containing 1.
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Affiliation(s)
- Man Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Zhangshun Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Qing Zhao
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Qian Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jieyun Bai
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Cuiwei Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Zai-Rong Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, Beijing, China
| | - Yanfen Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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3
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Johnson DH, Kou OH, Bouzos N, Zeno WF. Protein-membrane interactions: sensing and generating curvature. Trends Biochem Sci 2024; 49:401-416. [PMID: 38508884 PMCID: PMC11069444 DOI: 10.1016/j.tibs.2024.02.005] [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: 09/23/2023] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/22/2024]
Abstract
Biological membranes are integral cellular structures that can be curved into various geometries. These curved structures are abundant in cells as they are essential for various physiological processes. However, curved membranes are inherently unstable, especially on nanometer length scales. To stabilize curved membranes, cells can utilize proteins that sense and generate membrane curvature. In this review, we summarize recent research that has advanced our understanding of interactions between proteins and curved membrane surfaces, as well as work that has expanded our ability to study curvature sensing and generation. Additionally, we look at specific examples of cellular processes that require membrane curvature, such as neurotransmission, clathrin-mediated endocytosis (CME), and organelle biogenesis.
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Affiliation(s)
- David H Johnson
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Orianna H Kou
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
| | - Nicoletta Bouzos
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA
| | - Wade F Zeno
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
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4
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Pandey MP, Telles de Souza PC, Pezeshkian W, Khandelia H. Bending of a lipid membrane edge by annexin A5 trimers. Biophys J 2024; 123:1006-1014. [PMID: 38486451 PMCID: PMC11052700 DOI: 10.1016/j.bpj.2024.03.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 11/10/2023] [Accepted: 03/11/2024] [Indexed: 03/28/2024] Open
Abstract
Plasma membrane damage occurs in healthy cells and more frequently in cancer cells where high growth rates and metastasis result in frequent membrane damage. The annexin family of proteins plays a key role in membrane repair. Annexins are recruited at the membrane injury site by Ca+2 and repair the damaged membrane in concert with several other proteins. Annexin A4 (ANXA4) and ANXA5 form trimers at the bilayer surface, and previous simulations show that the trimers induce high local negative membrane curvature on a flat bilayer. The membrane-curvature-inducing property of ANXA5 is presumed to be vital to the membrane repair mechanism. A previously proposed descriptive model hypothesizes that ANXA5-mediated curvature force is utilized at the free edge of the membrane at a wound site to pull the wound edges together, resulting in the formation of a "neck"-shaped structure, which, when combined with a constriction force exerted by ANXA6, leads to membrane repair. The molecular details and mechanisms of repair remain unknown, in part because the membrane edge is a transient structure that is difficult to investigate both experimentally and computationally. For the first time, we investigate the impact of ANXA5 near a membrane edge, which is modeled by a bicelle under periodic boundary conditions. ANXA5 trimers induce local curvature on the membrane leading to global bending of the bicelle. The global curvature depends on the density of annexins on the bicelle, and the curvature increases with the ANXA5 concentration until it reaches a plateau. The simulations suggest that not only do annexins induce local membrane curvature, but they can change the overall shape of a free-standing membrane. We also demonstrate that ANXA5 trimers reduce the rate of phosphatidylserine lipid diffusion from the cytoplasmic to the exoplasmic leaflet along the edge of the bicelle. In this way, membrane-bound annexins can potentially delay the apoptotic signal triggered by the presence of phosphatidylserine lipids in the outer leaflet, thus biding time for repair of the membrane hole. Our findings provide new insights into the role of ANXA5 at the edges of the membrane (the injury site) and support the curvature-constriction model of membrane repair.
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Affiliation(s)
- Mayank Prakash Pandey
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark
| | - Paulo Cesar Telles de Souza
- Laboratoire de Biologie et Modélisation de la Cellule, CNRS, UMR 5239, INSERM, U1293, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, Lyon, France; Centre Blaise Pascal de Simulation et de Modélisation Numérique, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Weria Pezeshkian
- Niels Bohr International Academy, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Himanshu Khandelia
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark.
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5
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Fábián B, Javanainen M. Diffusion Analyses along Mean and Gaussian-Curved Membranes with CurD. J Phys Chem Lett 2024; 15:3214-3220. [PMID: 38483514 DOI: 10.1021/acs.jpclett.4c00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Curved cellular membranes are both abundant and functionally relevant. While novel tomography approaches reveal the structural details of curved membranes, their dynamics pose an experimental challenge. Curvature especially affects the diffusion of lipids and macromolecules, yet neither experiments nor continuum models distinguish geometric effects from those caused by curvature-induced changes in membrane properties. Molecular simulations could excel here, yet despite community interest toward curved membranes, tools for their analysis are still lacking. Here, we satisfy this demand by introducing CurD, our novel and openly available implementation of the Vertex-oriented Triangle Propagation algorithm to the study of lipid diffusion along membranes with mean and/or Gaussian curvature. This approach, aided by our highly optimized implementation, computes geodetic distances significantly faster than conventional implementations of path-finding algorithms. Our tool, applied to coarse-grained simulations, allows for the first time the analysis of curvature effects on diffusion at size scales relevant to physiological processes such as endocytosis. Our analyses with different membrane geometries reveal that Gaussian curvature plays a surprisingly small role on lipid motion, whereas mean curvature; i.e., the packing of lipid headgroups largely dictates their mobility.
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Affiliation(s)
- Balázs Fábián
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16000 Prague 6, Czech Republic
| | - Matti Javanainen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 542/2, CZ-16000 Prague 6, Czech Republic
- Institute of Biotechnology, University of Helsinki, FI-00790 Helsinki, Finland
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6
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Li S, Wu B, Luo YL, Han W. Simulations of Functional Motions of Super Large Biomolecules with a Mixed-Resolution Model. J Chem Theory Comput 2024; 20:2228-2245. [PMID: 38374639 PMCID: PMC10938502 DOI: 10.1021/acs.jctc.3c01046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 01/18/2024] [Accepted: 01/29/2024] [Indexed: 02/21/2024]
Abstract
Many large protein machines function through an interplay between large-scale movements and intricate conformational changes. Understanding functional motions of these proteins through simulations becomes challenging for both all-atom and coarse-grained (CG) modeling techniques because neither approach alone can readily capture the full details of these motions. In this study, we develop a multiscale model by employing the popular MARTINI CG model to represent a heterogeneous environment and structurally stable proteins and using the united-atom (UA) model PACE to describe proteins undergoing subtle conformational changes. PACE was previously developed to be compatible with the MARTINI solvent and membrane. Here, we couple the protein descriptions of the two models by directly mixing UA and CG interaction parameters to greatly simplify parameter determination. Through extensive validations with diverse protein systems in solution or membrane, we demonstrate that only additional parameter rescaling is needed to enable the resulting model to recover the stability of native structures of proteins under mixed representation. Moreover, we identify the optimal scaling factors that can be applied to various protein systems, rendering the model potentially transferable. To further demonstrate its applicability for realistic systems, we apply the model to a mechanosensitive ion channel Piezo1 that has peripheral arms for sensing membrane tension and a central pore for ion conductance. The model can reproduce the coupling between Piezo1's large-scale arm movement and subtle pore opening in response to membrane stress while consuming much less computational costs than all-atom models. Therefore, our model shows promise for studying functional motions of large protein machines.
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Affiliation(s)
- Shu Li
- Centre
for Artificial Intelligence Driven Drug Discovery, Faculty of Applied
Sciences, Macao Polytechnic University, Macao 999078, China
- State
Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key
Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Bohua Wu
- State
Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key
Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Yun Lyna Luo
- Department
of Biotechnology and Pharmaceutical Sciences, Western University of Health Sciences, Pomona, California 91766, United States
| | - Wei Han
- State
Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key
Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Department
of Chemistry, Faculty of Science, Hong Kong
Baptist University, Hong Kong SAR 999077, China
- Shenzhen
Bay Laboratory, Institute of Chemical Biology, Shenzhen 518132, China
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7
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Liao Z, Si T, Kai JJ, Fan J. Mechanism of Membrane Curvature Induced by SNX1: Insights from Molecular Dynamics Simulations. J Phys Chem B 2024; 128:2144-2153. [PMID: 38408890 DOI: 10.1021/acs.jpcb.3c07009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
SNX proteins have been found to induce membrane remodeling to facilitate the generation of transport carriers in endosomal pathways. However, the molecular mechanism of membrane bending and the role of lipids in the bending process remain elusive. Here, we conducted coarse-grained molecular dynamics simulations to investigate the role of the three structural modules (PX, BAR, and AH) of SNX1 and the PI3P lipids in membrane deformation. We observed that the presence of all three domains is essential for SNX1 to achieve a stable membrane deformation. BAR is capable of remodeling the membrane through the charged residues on its concave surface, but it requires PX and AH to establish stable membrane binding. AH penetrates into the lipid membrane, thereby promoting the induction of membrane curvature; however, it is inadequate on its own to maintain membrane bending. PI3P lipids are also indispensable for membrane remodeling, as they play a dominant role in the interactions of lipids with the BAR domain. Our results enhance the comprehension of the molecular mechanism underlying SNX1-induced membrane curvature and help future studies of curvature-inducing proteins.
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Affiliation(s)
- Zhenyu Liao
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077 Hong Kong, China
| | - Ting Si
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077 Hong Kong, China
- Department of Physics, City University of Hong Kong, Kowloon 999077 Hong Kong, China
| | - Ji-Jung Kai
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon 999077 Hong Kong, China
- Centre for Advanced Nuclear Safety and Sustainable Development, City University of Hong Kong, Kowloon 999077 Hong Kong, China
| | - Jun Fan
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077 Hong Kong, China
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon 999077 Hong Kong, China
- Centre for Advanced Nuclear Safety and Sustainable Development, City University of Hong Kong, Kowloon 999077 Hong Kong, China
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8
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Hoyer MJ, Capitanio C, Smith IR, Paoli JC, Bieber A, Jiang Y, Paulo JA, Gonzalez-Lozano MA, Baumeister W, Wilfling F, Schulman BA, Harper JW. Combinatorial selective ER-phagy remodels the ER during neurogenesis. Nat Cell Biol 2024; 26:378-392. [PMID: 38429475 PMCID: PMC10940164 DOI: 10.1038/s41556-024-01356-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 01/11/2024] [Indexed: 03/03/2024]
Abstract
The endoplasmic reticulum (ER) employs a diverse proteome landscape to orchestrate many cellular functions, ranging from protein and lipid synthesis to calcium ion flux and inter-organelle communication. A case in point concerns the process of neurogenesis, where a refined tubular ER network is assembled via ER shaping proteins into the newly formed neuronal projections to create highly polarized dendrites and axons. Previous studies have suggested a role for autophagy in ER remodelling, as autophagy-deficient neurons in vivo display axonal ER accumulation within synaptic boutons, and the membrane-embedded ER-phagy receptor FAM134B has been genetically linked with human sensory and autonomic neuropathy. However, our understanding of the mechanisms underlying selective removal of the ER and the role of individual ER-phagy receptors is limited. Here we combine a genetically tractable induced neuron (iNeuron) system for monitoring ER remodelling during in vitro differentiation with proteomic and computational tools to create a quantitative landscape of ER proteome remodelling via selective autophagy. Through analysis of single and combinatorial ER-phagy receptor mutants, we delineate the extent to which each receptor contributes to both the magnitude and selectivity of ER protein clearance. We define specific subsets of ER membrane or lumenal proteins as preferred clients for distinct receptors. Using spatial sensors and flux reporters, we demonstrate receptor-specific autophagic capture of ER in axons, and directly visualize tubular ER membranes within autophagosomes in neuronal projections by cryo-electron tomography. This molecular inventory of ER proteome remodelling and versatile genetic toolkit provide a quantitative framework for understanding the contributions of individual ER-phagy receptors for reshaping ER during cell state transitions.
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Affiliation(s)
- Melissa J Hoyer
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Cristina Capitanio
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Ian R Smith
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Velia Therapeutics, San Diego, CA, USA
| | - Julia C Paoli
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Anna Bieber
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Yizhi Jiang
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Miguel A Gonzalez-Lozano
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Wolfgang Baumeister
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Florian Wilfling
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Brenda A Schulman
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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9
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Roberts BS, Mitra D, Abishek S, Beher R, Satpute-Krishnan P. The p24-family and COPII subunit SEC24C facilitate the clearance of alpha1-antitrypsin Z from the endoplasmic reticulum to lysosomes. Mol Biol Cell 2024; 35:ar45. [PMID: 38294851 PMCID: PMC10916869 DOI: 10.1091/mbc.e23-06-0257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 01/16/2024] [Accepted: 01/24/2024] [Indexed: 02/01/2024] Open
Abstract
A subpopulation of the alpha-1-antitrypsin misfolding Z mutant (ATZ) is cleared from the endoplasmic reticulum (ER) via an ER-to-lysosome-associated degradation (ERLAD) pathway. Here, we report that the COPII subunit SEC24C and the p24-family of proteins facilitate the clearance of ATZ via ERLAD. In addition to the previously reported ERLAD components calnexin and FAM134B, we discovered that ATZ coimmunoprecipitates with the p24-family members TMP21 and TMED9. This contrasts with wild type alpha1-antitrypsin, which did not coimmunoprecipitate with FAM134B, calnexin or the p24-family members. Live-cell imaging revealed that ATZ and the p24-family members traffic together from the ER to lysosomes. Using chemical inhibitors to block ER exit or autophagy, we demonstrated that p24-family members and ATZ co-accumulate at SEC24C marked ER-exit sites or in ER-derived compartments, respectively. Furthermore, depletion of SEC24C, TMP21, or TMED9 inhibited lysosomal trafficking of ATZ and resulted in the increase of intracellular ATZ levels. Conversely, overexpression of these p24-family members resulted in the reduction of ATZ levels. Intriguingly, the p24-family members coimmunoprecipitate with ATZ, FAM134B, and SEC24C. Thus, we propose a model in which the p24-family functions in an adaptor complex linking SEC24C with the ERLAD machinery for the clearance of ATZ.
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Affiliation(s)
| | - Debashree Mitra
- Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Sudhanshu Abishek
- Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Richa Beher
- Uniformed Services University of the Health Sciences, Bethesda, MD 20814
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10
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Beck M, Covino R, Hänelt I, Müller-McNicoll M. Understanding the cell: Future views of structural biology. Cell 2024; 187:545-562. [PMID: 38306981 DOI: 10.1016/j.cell.2023.12.017] [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: 10/04/2023] [Revised: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 02/04/2024]
Abstract
Determining the structure and mechanisms of all individual functional modules of cells at high molecular detail has often been seen as equal to understanding how cells work. Recent technical advances have led to a flush of high-resolution structures of various macromolecular machines, but despite this wealth of detailed information, our understanding of cellular function remains incomplete. Here, we discuss present-day limitations of structural biology and highlight novel technologies that may enable us to analyze molecular functions directly inside cells. We predict that the progression toward structural cell biology will involve a shift toward conceptualizing a 4D virtual reality of cells using digital twins. These will capture cellular segments in a highly enriched molecular detail, include dynamic changes, and facilitate simulations of molecular processes, leading to novel and experimentally testable predictions. Transferring biological questions into algorithms that learn from the existing wealth of data and explore novel solutions may ultimately unveil how cells work.
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Affiliation(s)
- Martin Beck
- Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; Goethe University Frankfurt, Frankfurt, Germany.
| | - Roberto Covino
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, 60438 Frankfurt am Main, Germany.
| | - Inga Hänelt
- Goethe University Frankfurt, Frankfurt, Germany.
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11
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Pajtinka P, Vácha R. Amphipathic Helices Can Sense Both Positive and Negative Curvatures of Lipid Membranes. J Phys Chem Lett 2024; 15:175-179. [PMID: 38153203 PMCID: PMC10788957 DOI: 10.1021/acs.jpclett.3c02785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/09/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023]
Abstract
Curvature sensing is an essential ability of biomolecules to preferentially localize to membrane regions of a specific curvature. It has been shown that amphipathic helices (AHs), helical peptides with both hydrophilic and hydrophobic regions, could sense a positive membrane curvature. The origin of this AH sensing has been attributed to their ability to exploit lipid-packing defects that are enhanced in regions of positive curvature. In this study, we revisit an alternative framework where AHs act as sensors of local internal stress within the membrane, suggesting the possibility of an AH sensing a negative membrane curvature. Using molecular dynamics simulations, we gradually tuned the hydrophobicity of AHs, thereby adjusting their insertion depth so that the curvature preference of AHs is switched from positive to negative. This study suggests that highly hydrophobic AHs could preferentially localize proteins to regions of a negative membrane curvature.
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Affiliation(s)
- Peter Pajtinka
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- National
Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Robert Vácha
- CEITEC
− Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- National
Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
- Department
of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech
Republic
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12
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Berkane R, Ho-Xuan H, Glogger M, Sanz-Martinez P, Brunello L, Glaesner T, Kuncha SK, Holzhüter K, Cano-Franco S, Buonomo V, Cabrerizo-Poveda P, Balakrishnan A, Tascher G, Husnjak K, Juretschke T, Misra M, González A, Dötsch V, Grumati P, Heilemann M, Stolz A. The function of ER-phagy receptors is regulated through phosphorylation-dependent ubiquitination pathways. Nat Commun 2023; 14:8364. [PMID: 38102139 PMCID: PMC10724265 DOI: 10.1038/s41467-023-44101-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/30/2023] [Indexed: 12/17/2023] Open
Abstract
Selective autophagy of the endoplasmic reticulum (ER), known as ER-phagy, is an important regulator of ER remodeling and essential to maintain cellular homeostasis during environmental changes. We recently showed that members of the FAM134 family play a critical role during stress-induced ER-phagy. However, the mechanisms on how they are activated remain largely unknown. In this study, we analyze phosphorylation of FAM134 as a trigger of FAM134-driven ER-phagy upon mTOR (mechanistic target of rapamycin) inhibition. An unbiased screen of kinase inhibitors reveals CK2 to be essential for FAM134B- and FAM134C-driven ER-phagy after mTOR inhibition. Furthermore, we provide evidence that ER-phagy receptors are regulated by ubiquitination events and that treatment with E1 inhibitor suppresses Torin1-induced ER-phagy flux. Using super-resolution microscopy, we show that CK2 activity is essential for the formation of high-density FAM134B and FAM134C clusters. In addition, dense clustering of FAM134B and FAM134C requires phosphorylation-dependent ubiquitination of FAM134B and FAM134C. Treatment with the CK2 inhibitor SGC-CK2-1 or mutation of FAM134B and FAM134C phosphosites prevents ubiquitination of FAM134 proteins, formation of high-density clusters, as well as Torin1-induced ER-phagy flux. Therefore, we propose that CK2-dependent phosphorylation of ER-phagy receptors precedes ubiquitin-dependent activation of ER-phagy flux.
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Affiliation(s)
- Rayene Berkane
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Hung Ho-Xuan
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Marius Glogger
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Pablo Sanz-Martinez
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Lorène Brunello
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Tristan Glaesner
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Santosh Kumar Kuncha
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Katharina Holzhüter
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Sara Cano-Franco
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Viviana Buonomo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Paloma Cabrerizo-Poveda
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Ashwin Balakrishnan
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Georg Tascher
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Koraljka Husnjak
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | | | - Mohit Misra
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany
| | - Alexis González
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, Germany
| | - Paolo Grumati
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Alexandra Stolz
- Institute of Biochemistry II (IBC2), Faculty of Medicine, Goethe University, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Frankfurt am Main, Germany.
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13
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Kim H, Fábián B, Hummer G. Neighbor List Artifacts in Molecular Dynamics Simulations. J Chem Theory Comput 2023; 19:8919-8929. [PMID: 38035387 PMCID: PMC10720336 DOI: 10.1021/acs.jctc.3c00777] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023]
Abstract
Molecular dynamics (MD) simulations are widely used in biophysical research. To aid nonexpert users, most simulation packages provide default values for key input parameters. In MD simulations using the GROMACS package with default parameters, we found large membranes to deform under the action of a semi-isotropically coupled barostat. As the primary cause, we identified overly short outer cutoffs and infrequent neighbor list updates that resulted in missed nonbonded interactions. Small but systematic imbalances in the apparent pressure tensor then induce unphysical asymmetric box deformations that crumple the membrane. We also observed rapid oscillations in averages of the instantaneous pressure tensor components and traced these to the use of a dual pair list with dynamic pruning. We confirmed that similar effects are present in MD simulations of neat water in atomistic and coarse-grained representations. Whereas the slight pressure imbalances likely have minimal impact in most current atomistic MD simulations, we expect their impact to grow in studies of ever-larger systems with coarse-grained representation, in particular, in combination with anisotropic pressure coupling. We present measures to diagnose problems with missed interactions and guidelines for practitioners to avoid them, including estimates for appropriate values for the outer cutoff rl and the number of time steps nstlist between neighbor list updates.
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Affiliation(s)
- Hyuntae Kim
- Department
of Theoretical Biophysics, Max Planck Institute
of Biophysics, Max-von-Laue Straße 3, 60438 Frankfurt am Main, Germany
- International
Max Planck Research School on Cellular Biophysics, Max-von-Laue Straße 3, 60438 Frankfurt am Main, Germany
| | - Balázs Fábián
- Department
of Theoretical Biophysics, Max Planck Institute
of Biophysics, Max-von-Laue Straße 3, 60438 Frankfurt am Main, Germany
| | - Gerhard Hummer
- Department
of Theoretical Biophysics, Max Planck Institute
of Biophysics, Max-von-Laue Straße 3, 60438 Frankfurt am Main, Germany
- Institute
of Biophysics, Goethe University Frankfurt, Max-von-Laue-Straße 1, 60438 Frankfurt am Main, Germany
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14
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Xie P, Zhang H, Qin Y, Xiong H, Shi C, Zhou Z. Membrane Proteins and Membrane Curvature: Mutual Interactions and a Perspective on Disease Treatments. Biomolecules 2023; 13:1772. [PMID: 38136643 PMCID: PMC10741411 DOI: 10.3390/biom13121772] [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: 11/01/2023] [Revised: 11/30/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
The pathogenesis of various diseases often involves an intricate interplay between membrane proteins and membrane curvature. Understanding the underlying mechanisms of this interaction could offer novel perspectives on disease treatment. In this review, we provide an introduction to membrane curvature and its association with membrane proteins. Furthermore, we delve into the impact and potential implications of this interaction in the context of disease treatment. Lastly, we discuss the prospects and challenges associated with harnessing these interactions for effective disease management, aiming to provide fresh insights into therapeutic strategies.
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Affiliation(s)
| | | | | | | | | | - Zijian Zhou
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory & Center for Molecular Imaging and Translational Medicine, School of Public Health, Shenzhen Research Institute of Xiamen University, Xiamen University, Xiamen 361102, China; (P.X.); (H.Z.); (Y.Q.); (H.X.); (C.S.)
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15
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Qian X, He L, Yang J, Sun J, Peng X, Zhang Y, Mao Y, Zhang Y, Cui Y. UVRAG cooperates with cargo receptors to assemble the ER-phagy site. EMBO J 2023; 42:e113625. [PMID: 37902287 PMCID: PMC10690450 DOI: 10.15252/embj.2023113625] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 10/04/2023] [Accepted: 10/11/2023] [Indexed: 10/31/2023] Open
Abstract
ER-phagy is a selective autophagy process that targets specific regions of the endoplasmic reticulum (ER) for removal via lysosomal degradation. During cellular stress induced by starvation, cargo receptors concentrate at distinct ER-phagy sites (ERPHS) to recruit core autophagy proteins and initiate ER-phagy. However, the molecular mechanism responsible for ERPHS formation remains unclear. In our study, we discovered that the autophagy regulator UV radiation Resistance-Associated Gene (UVRAG) plays a crucial role in orchestrating the assembly of ERPHS. Upon starvation, UVRAG localizes to ERPHS and interacts with specific ER-phagy cargo receptors, such as FAM134B, ATL3, and RTN3L. UVRAG regulates the oligomerization of cargo receptors and facilitates the recruitment of Atg8 family proteins. Consequently, UVRAG promotes efficient ERPHS assembly and turnover of both ER sheets and tubules. Importantly, UVRAG-mediated ER-phagy contributes to the clearance of pathogenic proinsulin aggregates. Remarkably, the involvement of UVRAG in ER-phagy initiation is independent of its canonical function as a subunit of class III phosphatidylinositol 3-kinase complex II.
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Affiliation(s)
- Xuehong Qian
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Lingang He
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Jiejie Yang
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Jiajia Sun
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Xueying Peng
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Yuting Zhang
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Yizhou Mao
- Department of Rheumatology and Immunology, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Ying Zhang
- Department of Rheumatology and Immunology, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
| | - Yixian Cui
- Department of Neurosurgery, Medical Research Institute, Frontier Science Center for Immunology and MetabolismZhongnan Hospital of Wuhan University, Wuhan UniversityWuhanChina
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16
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Hoyer MJ, Capitanio C, Smith IR, Paoli JC, Bieber A, Jiang Y, Paulo JA, Gonzalez-Lozano MA, Baumeister W, Wilfling F, Schulman BA, Harper JW. Combinatorial selective ER-phagy remodels the ER during neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546565. [PMID: 37425907 PMCID: PMC10326971 DOI: 10.1101/2023.06.26.546565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The endoplasmic reticulum (ER) employs a diverse proteome landscape to orchestrate many cellular functions ranging from protein and lipid synthesis to calcium ion flux and inter-organelle communication. A case in point concerns the process of neurogenesis: a refined tubular ER network is assembled via ER shaping proteins into the newly formed neuronal projections to create highly polarized dendrites and axons. Previous studies have suggested a role for autophagy in ER remodeling, as autophagy-deficient neurons in vivo display axonal ER accumulation within synaptic boutons, and the membrane-embedded ER-phagy receptor FAM134B has been genetically linked with human sensory and autonomic neuropathy. However, our understanding of the mechanisms underlying selective removal of ER and the role of individual ER-phagy receptors is limited. Here, we combine a genetically tractable induced neuron (iNeuron) system for monitoring ER remodeling during in vitro differentiation with proteomic and computational tools to create a quantitative landscape of ER proteome remodeling via selective autophagy. Through analysis of single and combinatorial ER-phagy receptor mutants, we delineate the extent to which each receptor contributes to both magnitude and selectivity of ER protein clearance. We define specific subsets of ER membrane or lumenal proteins as preferred clients for distinct receptors. Using spatial sensors and flux reporters, we demonstrate receptor-specific autophagic capture of ER in axons, and directly visualize tubular ER membranes within autophagosomes in neuronal projections by cryo-electron tomography. This molecular inventory of ER proteome remodeling and versatile genetic toolkit provides a quantitative framework for understanding contributions of individual ER-phagy receptors for reshaping ER during cell state transitions.
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17
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Hickey KL, Swarup S, Smith IR, Paoli JC, Miguel Whelan E, Paulo JA, Harper JW. Proteome census upon nutrient stress reveals Golgiphagy membrane receptors. Nature 2023; 623:167-174. [PMID: 37757899 PMCID: PMC10620096 DOI: 10.1038/s41586-023-06657-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023]
Abstract
During nutrient stress, macroautophagy degrades cellular macromolecules, thereby providing biosynthetic building blocks while simultaneously remodelling the proteome1,2. Although the machinery responsible for initiation of macroautophagy has been well characterized3,4, our understanding of the extent to which individual proteins, protein complexes and organelles are selected for autophagic degradation, and the underlying targeting mechanisms, is limited. Here we use orthogonal proteomic strategies to provide a spatial proteome census of autophagic cargo during nutrient stress in mammalian cells. We find that macroautophagy has selectivity for recycling membrane-bound organelles (principally Golgi and endoplasmic reticulum). Through autophagic cargo prioritization, we identify a complex of membrane-embedded proteins, YIPF3 and YIPF4, as receptors for Golgiphagy. During nutrient stress, YIPF3 and YIPF4 interact with ATG8 proteins through LIR motifs and are mobilized into autophagosomes that traffic to lysosomes in a process that requires the canonical autophagic machinery. Cells lacking YIPF3 or YIPF4 are selectively defective in elimination of a specific cohort of Golgi membrane proteins during nutrient stress. Moreover, YIPF3 and YIPF4 play an analogous role in Golgi remodelling during programmed conversion of stem cells to the neuronal lineage in vitro. Collectively, the findings of this study reveal prioritization of membrane protein cargo during nutrient-stress-dependent proteome remodelling and identify a Golgi remodelling pathway that requires membrane-embedded receptors.
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Affiliation(s)
- Kelsey L Hickey
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Sharan Swarup
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
- Casma Therapeutics, Cambridge, MA, USA
| | - Ian R Smith
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Velia Therapeutics, San Diego, CA, USA
| | - Julia C Paoli
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | | | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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18
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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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19
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Boyle E, Wilfling F. Autophagy as a caretaker of nuclear integrity. FEBS Lett 2023; 597:2728-2738. [PMID: 37567863 DOI: 10.1002/1873-3468.14719] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023]
Abstract
Due to their essential functions, dysregulation of nuclear pore complexes (NPCs) is strongly associated with numerous human diseases, including neurodegeneration and cancer. On a cellular level, longevity of scaffold nucleoporins in postmitotic cells of both C. elegans and mammals renders them vulnerable to age-related damage, which is associated with an increase in pore leakiness and accumulation of intranuclear aggregates in rat brain cells. Thus, understanding the mechanisms which underpin the homeostasis of this complex, as well as other nuclear proteins, is essential. In this review, autophagy-mediated degradation pathways governing nuclear components in yeast will be discussed, with a particular focus on NPCs. Furthermore, the various nuclear degradation mechanisms identified thus far in diverse eukaryotes will also be highlighted.
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Affiliation(s)
- Emily Boyle
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max Planck Institute of Biophysics, Frankfurt, Germany
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20
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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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21
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Garcia-Pardo J, Badaczewska-Dawid AE, Pintado-Grima C, Iglesias V, Kuriata A, Kmiecik S, Ventura S. A3DyDB: exploring structural aggregation propensities in the yeast proteome. Microb Cell Fact 2023; 22:186. [PMID: 37716955 PMCID: PMC10504709 DOI: 10.1186/s12934-023-02182-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/18/2023] [Indexed: 09/18/2023] Open
Abstract
BACKGROUND The budding yeast Saccharomyces cerevisiae (S. cerevisiae) is a well-established model system for studying protein aggregation due to the conservation of essential cellular structures and pathways found across eukaryotes. However, limited structural knowledge of its proteome has prevented a deeper understanding of yeast functionalities, interactions, and aggregation. RESULTS In this study, we introduce the A3D yeast database (A3DyDB), which offers an extensive catalog of aggregation propensity predictions for the S. cerevisiae proteome. We used Aggrescan 3D (A3D) and the newly released protein models from AlphaFold2 (AF2) to compute the structure-based aggregation predictions for 6039 yeast proteins. The A3D algorithm exploits the information from 3D protein structures to calculate their intrinsic aggregation propensities. To facilitate simple and intuitive data analysis, A3DyDB provides a user-friendly interface for querying, browsing, and visualizing information on aggregation predictions from yeast protein structures. The A3DyDB also allows for the evaluation of the influence of natural or engineered mutations on protein stability and solubility. The A3DyDB is freely available at http://biocomp.chem.uw.edu.pl/A3D2/yeast . CONCLUSION The A3DyDB addresses a gap in yeast resources by facilitating the exploration of correlations between structural aggregation propensity and diverse protein properties at the proteome level. We anticipate that this comprehensive database will become a standard tool in the modeling of protein aggregation and its implications in budding yeast.
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Affiliation(s)
- Javier Garcia-Pardo
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | | | - Carlos Pintado-Grima
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Valentín Iglesias
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Aleksander Kuriata
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw, 02-093, Poland
| | - Sebastian Kmiecik
- Biological and Chemical Research Center, Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw, 02-093, Poland.
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain.
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22
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Sitarska E, Almeida SD, Beckwith MS, Stopp J, Czuchnowski J, Siggel M, Roessner R, Tschanz A, Ejsing C, Schwab Y, Kosinski J, Sixt M, Kreshuk A, Erzberger A, Diz-Muñoz A. Sensing their plasma membrane curvature allows migrating cells to circumvent obstacles. Nat Commun 2023; 14:5644. [PMID: 37704612 PMCID: PMC10499897 DOI: 10.1038/s41467-023-41173-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 08/22/2023] [Indexed: 09/15/2023] Open
Abstract
To navigate through diverse tissues, migrating cells must balance persistent self-propelled motion with adaptive behaviors to circumvent obstacles. We identify a curvature-sensing mechanism underlying obstacle evasion in immune-like cells. Specifically, we propose that actin polymerization at the advancing edge of migrating cells is inhibited by the curvature-sensitive BAR domain protein Snx33 in regions with inward plasma membrane curvature. The genetic perturbation of this machinery reduces the cells' capacity to evade obstructions combined with faster and more persistent cell migration in obstacle-free environments. Our results show how cells can read out their surface topography and utilize actin and plasma membrane biophysics to interpret their environment, allowing them to adaptively decide if they should move ahead or turn away. On the basis of our findings, we propose that the natural diversity of BAR domain proteins may allow cells to tune their curvature sensing machinery to match the shape characteristics in their environment.
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Affiliation(s)
- Ewa Sitarska
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, EMBL and Heidelberg University, Heidelberg, Germany
| | - Silvia Dias Almeida
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
- Division of Medical Image Computing, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | | | - Julian Stopp
- Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria
| | - Jakub Czuchnowski
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Marc Siggel
- EMBL Hamburg, European Molecular Biology Laboratory, 22607, Hamburg, Germany
- Centre for Structural Systems Biology, 22607, Hamburg, Germany
| | - Rita Roessner
- EMBL Hamburg, European Molecular Biology Laboratory, 22607, Hamburg, Germany
- Centre for Structural Systems Biology, 22607, Hamburg, Germany
| | - Aline Tschanz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, EMBL and Heidelberg University, Heidelberg, Germany
| | - Christer Ejsing
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
- Department of Biochemistry and Molecular Biology, Villum Center for Bioanalytical Sciences, University of Southern Denmark, Campusvej 55, 5230, Odense, Denmark
| | - Yannick Schwab
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Jan Kosinski
- EMBL Hamburg, European Molecular Biology Laboratory, 22607, Hamburg, Germany
- Centre for Structural Systems Biology, 22607, Hamburg, Germany
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Michael Sixt
- Institute of Science and Technology Austria, 3400, Klosterneuburg, Austria
| | - Anna Kreshuk
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Anna Erzberger
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany.
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23
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Álvarez D, Sapia J, Vanni S. Computational modeling of membrane trafficking processes: From large molecular assemblies to chemical specificity. Curr Opin Cell Biol 2023; 83:102205. [PMID: 37451175 DOI: 10.1016/j.ceb.2023.102205] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/16/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023]
Abstract
In the last decade, molecular dynamics (MD) simulations have become an essential tool to investigate the molecular properties of membrane trafficking processes, often in conjunction with experimental approaches. The combination of MD simulations with recent developments in structural biology, such as cryo-electron microscopy and artificial intelligence-based structure determination, opens new, exciting possibilities for future investigations. However, the full potential of MD simulations to provide a molecular view of the complex and dynamic processes involving membrane trafficking can only be realized if certain limitations are addressed, and especially those concerning the quality of coarse-grain models, which, despite recent successes in describing large-scale systems, still suffer from far-from-ideal chemical accuracy. In this review, we will highlight recent success stories of MD simulations in the investigation of membrane trafficking processes, their implications for future research, and the challenges that lie ahead in this specific research domain.
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Affiliation(s)
- Daniel Álvarez
- Department of Biology, University of Fribourg, Switzerland; Departamento de Química Física y Analítica, Universidad de Oviedo, Spain
| | - Jennifer Sapia
- Department of Biology, University of Fribourg, Switzerland
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Switzerland; Université Côte d'Azur, Inserm, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France.
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24
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Hoyer MJ, Harper JW. ER membrane curvature and ubiquitin as drivers of ER-phagy. Dev Cell 2023; 58:1219-1220. [PMID: 37490852 DOI: 10.1016/j.devcel.2023.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 06/28/2023] [Accepted: 06/28/2023] [Indexed: 07/27/2023]
Abstract
In a recent issue of Nature, González et al. and Foronda et al. examine the role of ubiquitin in autophagic capture of ER by ER-phagy. They propose that ubiquitylation of ER-phagy receptor FAM134B and ER-shaping protein ARL61PL1 promotes receptor clustering in nanodomains, which generates membrane curvature, facilitating autophagosomal capture.
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Affiliation(s)
- Melissa J Hoyer
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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25
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Kallergi E, Siva Sankar D, Matera A, Kolaxi A, Paolicelli RC, Dengjel J, Nikoletopoulou V. Profiling of purified autophagic vesicle degradome in the maturing and aging brain. Neuron 2023:S0896-6273(23)00384-7. [PMID: 37279748 DOI: 10.1016/j.neuron.2023.05.011] [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: 09/08/2022] [Revised: 03/19/2023] [Accepted: 05/11/2023] [Indexed: 06/08/2023]
Abstract
Autophagy disorders prominently affect the brain, entailing neurodevelopmental and neurodegenerative phenotypes in adolescence or aging, respectively. Synaptic and behavioral deficits are largely recapitulated in mouse models with ablation of autophagy genes in brain cells. Yet, the nature and temporal dynamics of brain autophagic substrates remain insufficiently characterized. Here, we immunopurified LC3-positive autophagic vesicles (LC3-pAVs) from the mouse brain and proteomically profiled their content. Moreover, we characterized the LC3-pAV content that accumulates after macroautophagy impairment, validating a brain autophagic degradome. We reveal selective pathways for aggrephagy, mitophagy, and ER-phagy via selective autophagy receptors, and the turnover of numerous synaptic substrates, under basal conditions. To gain insight into the temporal dynamics of autophagic protein turnover, we quantitatively compared adolescent, adult, and aged brains, revealing critical periods of enhanced mitophagy or degradation of synaptic substrates. Overall, this resource unbiasedly characterizes the contribution of autophagy to proteostasis in the maturing, adult, and aged brain.
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Affiliation(s)
- Emmanouela Kallergi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Alessandro Matera
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Angeliki Kolaxi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | | | - Joern Dengjel
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.
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26
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González A, Covarrubias-Pinto A, Bhaskara RM, Glogger M, Kuncha SK, Xavier A, Seemann E, Misra M, Hoffmann ME, Bräuning B, Balakrishnan A, Qualmann B, Dötsch V, Schulman BA, Kessels MM, Hübner CA, Heilemann M, Hummer G, Dikić I. Ubiquitination regulates ER-phagy and remodelling of endoplasmic reticulum. Nature 2023:10.1038/s41586-023-06089-2. [PMID: 37225996 DOI: 10.1038/s41586-023-06089-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 04/14/2023] [Indexed: 05/26/2023]
Abstract
The endoplasmic reticulum (ER) undergoes continuous remodelling via a selective autophagy pathway, known as ER-phagy1. ER-phagy receptors have a central role in this process2, but the regulatory mechanism remains largely unknown. Here we report that ubiquitination of the ER-phagy receptor FAM134B within its reticulon homology domain (RHD) promotes receptor clustering and binding to lipidated LC3B, thereby stimulating ER-phagy. Molecular dynamics (MD) simulations showed how ubiquitination perturbs the RHD structure in model bilayers and enhances membrane curvature induction. Ubiquitin molecules on RHDs mediate interactions between neighbouring RHDs to form dense receptor clusters that facilitate the large-scale remodelling of lipid bilayers. Membrane remodelling was reconstituted in vitro with liposomes and ubiquitinated FAM134B. Using super-resolution microscopy, we discovered FAM134B nanoclusters and microclusters in cells. Quantitative image analysis revealed a ubiquitin-mediated increase in FAM134B oligomerization and cluster size. We found that the E3 ligase AMFR, within multimeric ER-phagy receptor clusters, catalyses FAM134B ubiquitination and regulates the dynamic flux of ER-phagy. Our results show that ubiquitination enhances RHD functions via receptor clustering, facilitates ER-phagy and controls ER remodelling in response to cellular demands.
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Affiliation(s)
- Alexis González
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Adriana Covarrubias-Pinto
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ramachandra M Bhaskara
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Marius Glogger
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Santosh K Kuncha
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Audrey Xavier
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Mohit Misra
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Marina E Hoffmann
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Bastian Bräuning
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Ashwin Balakrishnan
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Frankfurt, Germany
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - Christian A Hübner
- Institute of Human Genetics, University Hospital Jena, Friedrich Schiller University, Jena, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ivan Dikić
- Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.
- Fraunhofer Institute of Translational Medicine and Pharmacology, Frankfurt am Main, Germany.
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27
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Foronda H, Fu Y, Covarrubias-Pinto A, Bocker HT, González A, Seemann E, Franzka P, Bock A, Bhaskara RM, Liebmann L, Hoffmann ME, Katona I, Koch N, Weis J, Kurth I, Gleeson JG, Reggiori F, Hummer G, Kessels MM, Qualmann B, Mari M, Dikić I, Hübner CA. Heteromeric clusters of ubiquitinated ER-shaping proteins drive ER-phagy. Nature 2023:10.1038/s41586-023-06090-9. [PMID: 37225994 DOI: 10.1038/s41586-023-06090-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 04/17/2023] [Indexed: 05/26/2023]
Abstract
Membrane-shaping proteins characterized by reticulon homology domains play an important part in the dynamic remodelling of the endoplasmic reticulum (ER). An example of such a protein is FAM134B, which can bind LC3 proteins and mediate the degradation of ER sheets through selective autophagy (ER-phagy)1. Mutations in FAM134B result in a neurodegenerative disorder in humans that mainly affects sensory and autonomic neurons2. Here we report that ARL6IP1, another ER-shaping protein that contains a reticulon homology domain and is associated with sensory loss3, interacts with FAM134B and participates in the formation of heteromeric multi-protein clusters required for ER-phagy. Moreover, ubiquitination of ARL6IP1 promotes this process. Accordingly, disruption of Arl6ip1 in mice causes an expansion of ER sheets in sensory neurons that degenerate over time. Primary cells obtained from Arl6ip1-deficient mice or from patients display incomplete budding of ER membranes and severe impairment of ER-phagy flux. Therefore, we propose that the clustering of ubiquitinated ER-shaping proteins facilitates the dynamic remodelling of the ER during ER-phagy and is important for neuronal maintenance.
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Affiliation(s)
- Hector Foronda
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Yangxue Fu
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | | | - Hartmut T Bocker
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
- Blink AG, Jena, Germany
| | - Alexis González
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | - Eric Seemann
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Patricia Franzka
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Andrea Bock
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Ramachandra M Bhaskara
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Lutz Liebmann
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Marina E Hoffmann
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany
| | - Istvan Katona
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Nicole Koch
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Joseph G Gleeson
- Department of Neurosciences, Rady Children's Institute for Genomic Medicine Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
- Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus C, Denmark
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Michael M Kessels
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Britta Qualmann
- Institute for Biochemistry I, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Muriel Mari
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Ivan Dikić
- Institute of Biochemistry II, Goethe University School of Medicine, Frankfurt am Main, Germany.
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany.
| | - Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
- Center for Rare Diseases, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
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28
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Liang T, Smith CE, Hu Y, Zhang H, Zhang C, Xu Q, Lu Y, Qi L, Hu JCC, Simmer JP. Dentin defects caused by a Dspp -1 frameshift mutation are associated with the activation of autophagy. Sci Rep 2023; 13:6393. [PMID: 37076504 PMCID: PMC10115861 DOI: 10.1038/s41598-023-33362-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023] Open
Abstract
Dentin sialophosphoprotein (DSPP) is primarily expressed by differentiated odontoblasts (dentin-forming cells), and transiently expressed by presecretory ameloblasts (enamel-forming cells). Disease-causing DSPP mutations predominantly fall into two categories: 5' mutations affecting targeting and trafficking, and 3' - 1 frameshift mutations converting the repetitive, hydrophilic, acidic C-terminal domain into a hydrophobic one. We characterized the dental phenotypes and investigated the pathological mechanisms of DsppP19L and Dspp-1fs mice that replicate the two categories of human DSPP mutations. In DsppP19L mice, dentin is less mineralized but contains dentinal tubules. Enamel mineral density is reduced. Intracellular accumulation and ER retention of DSPP is observed in odontoblasts and ameloblasts. In Dspp-1fs mice, a thin layer of reparative dentin lacking dentinal tubules is deposited. Odontoblasts show severe pathosis, including intracellular accumulation and ER retention of DSPP, strong ubiquitin and autophagy activity, ER-phagy, and sporadic apoptosis. Ultrastructurally, odontoblasts show extensive autophagic vacuoles, some of which contain fragmented ER. Enamel formation is comparable to wild type. These findings distinguish molecular mechanisms underlying the dental phenotypes of DsppP19L and Dspp-1fs mice and support the recently revised Shields classification of dentinogenesis imperfecta caused by DSPP mutations in humans. The Dspp-1fs mice may be valuable for the study of autophagy and ER-phagy.
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Affiliation(s)
- Tian Liang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA.
| | - Charles E Smith
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA
- Department of Anatomy & Cell Biology, Faculty of Medicine & Health Sciences, McGill University, Montreal, QC, Canada
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA
| | - Hong Zhang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA
| | - Chuhua Zhang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA
| | - Qian Xu
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, 3302 Gaston Ave., Dallas, TX, 75246, USA
| | - Yongbo Lu
- Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A&M University College of Dentistry, 3302 Gaston Ave., Dallas, TX, 75246, USA
| | - Ling Qi
- Department of Molecular & Integrative Physiology, Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, 1000 Wall St., Ann Arbor, MI, 48105, USA
| | - Jan C-C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, 48109-1078, USA
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29
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Divya S, Ravanan P. Cellular battle against endoplasmic reticulum stress and its adverse effect on health. Life Sci 2023; 323:121705. [PMID: 37075943 DOI: 10.1016/j.lfs.2023.121705] [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: 01/17/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023]
Abstract
The endoplasmic reticulum (ER) is a dynamic organelle and a reliable performer for precisely folded proteins. To maintain its function and integrity, arrays of sensory and quality control systems enhance protein folding fidelity and resolve the highest error-prone areas. Yet numerous internal and external factors disrupt its homeostasis and trigger ER stress responses. Cells try to reduce the number of misfolded proteins via the UPR mechanism, and ER-related garbage disposals systems like ER-associated degradation (ERAD), ER-lysosome-associated degradation (ERLAD), ER-Associated RNA Silencing (ERAS), extracellular chaperoning, and autophagy systems, which activates and increase the cell survival rate by degrading misfolded proteins, prevent the aggregated proteins and remove the dysfunctional organelles. Throughout life, organisms must confront environmental stress to survive and develop. Communication between the ER & other organelles, signaling events mediated by calcium, reactive oxygen species, and inflammation are linked to diverse stress signaling pathways and regulate cell survival or cell death mechanisms. Unresolved cellular damages can cross the threshold limit of their survival, resulting in cell death or driving for various diseases. The multifaceted ability of unfolded protein response facilitates the therapeutic target and a biomarker for various diseases, helping with early diagnosis and detecting the severity of diseases.
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Affiliation(s)
- Subramaniyan Divya
- Functional Genomics Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610005, Tamil Nadu, India
| | - Palaniyandi Ravanan
- Functional Genomics Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610005, Tamil Nadu, India.
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30
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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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31
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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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32
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Cyanobacterial membrane dynamics in the light of eukaryotic principles. Biosci Rep 2023; 43:232406. [PMID: 36602300 PMCID: PMC9950537 DOI: 10.1042/bsr20221269] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023] Open
Abstract
Intracellular compartmentalization is a hallmark of eukaryotic cells. Dynamic membrane remodeling, involving membrane fission/fusion events, clearly is crucial for cell viability and function, as well as membrane stabilization and/or repair, e.g., during or after injury. In recent decades, several proteins involved in membrane stabilization and/or dynamic membrane remodeling have been identified and described in eukaryotes. Yet, while typically not having a cellular organization as complex as eukaryotes, also bacteria can contain extra internal membrane systems besides the cytoplasmic membranes (CMs). Thus, also in bacteria mechanisms must have evolved to stabilize membranes and/or trigger dynamic membrane remodeling processes. In fact, in recent years proteins, which were initially defined being eukaryotic inventions, have been recognized also in bacteria, and likely these proteins shape membranes also in these organisms. One example of a complex prokaryotic inner membrane system is the thylakoid membrane (TM) of cyanobacteria, which contains the complexes of the photosynthesis light reaction. Cyanobacteria are evolutionary closely related to chloroplasts, and extensive remodeling of the internal membrane systems has been observed in chloroplasts and cyanobacteria during membrane biogenesis and/or at changing light conditions. We here discuss common principles guiding eukaryotic and prokaryotic membrane dynamics and the proteins involved, with a special focus on the dynamics of the cyanobacterial TMs and CMs.
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33
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Paul S, Audhya A, Cui Q. Molecular mechanism of GTP binding- and dimerization-induced enhancement of Sar1-mediated membrane remodeling. Proc Natl Acad Sci U S A 2023; 120:e2212513120. [PMID: 36780528 PMCID: PMC9974494 DOI: 10.1073/pnas.2212513120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 01/18/2023] [Indexed: 02/15/2023] Open
Abstract
The Sar1 GTPase initiates coat protein II (COPII)-mediated protein transport by generating membrane curvature at subdomains on the endoplasmic reticulum, where it is activated by the guanine nucleotide exchange factor (GEF) Sec12. Crystal structures of GDP- and GTP-bound forms of Sar1 suggest that it undergoes a conformational switch in which GTP binding enhances the exposure of an amino-terminal amphipathic helix necessary for efficient membrane penetration. However, key residues in the amino terminus were not resolved in crystal structures, and experimental studies have suggested that the amino terminus of Sar1 is solvent-exposed in the absence of a membrane, even in the GDP-bound state. Therefore, the molecular mechanism by which GTP binding activates the membrane-remodeling activity of Sar1 remains unclear. Using atomistic molecular dynamics simulations, we compare the membrane-binding and curvature generation activities of Sar1 in its GDP- and GTP-bound states. We show that in the GTP-bound state, Sar1 inserts into the membrane with its complete (residues 1 to 23) amphipathic amino-terminal helix, while Sar1-GDP binds to the membrane only through its first 12 residues. Such differential membrane-binding modes translate into significant differences in the protein volume inserted into the membrane. As a result, Sar1-GTP generates positive membrane curvature 10 to 20 times higher than Sar1-GDP. Dimerization of the GTP-bound form of Sar1 further amplifies curvature generation. Taken together, our results present a detailed molecular mechanism for how the nucleotide-bound state of Sar1 regulates its membrane-binding and remodeling activities in a concentration-dependent manner, paving the way toward a better understanding COPII-mediated membrane transport.
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Affiliation(s)
- Sanjoy Paul
- Department of Chemistry, Boston University, Boston, MA02215
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Qiang Cui
- Department of Chemistry, Boston University, Boston, MA02215
- Departments of Physics, Boston University, Boston, MA02215
- Departments of Biomedical Engineering, Boston University, Boston, MA02215
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34
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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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35
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Abstract
Cellular homeostasis requires the swift and specific removal of damaged material. Selective autophagy represents a major pathway for the degradation of such cargo material. This is achieved by the sequestration of the cargo within double-membrane vesicles termed autophagosomes, which form de novo around the cargo and subsequently deliver their content to lysosomes for degradation. The importance of selective autophagy is exemplified by the various neurodegenerative diseases associated with defects in this pathway, including Parkinson's disease, amyotrophic lateral sclerosis, and frontotemporal dementia. It has become evident that cargo receptors are acting as Swiss army knives in selective autophagy by recognizing the cargo, orchestrating the recruitment of the machinery for autophagosome biogenesis, and closely aligning the membrane with the cargo. Furthermore, cargo receptors sequester ubiquitinated proteins into larger condensates upstream of autophagy induction. Here, we review recent insights into the mechanisms of action of cargo receptors in selective autophagy by focusing on the roles of sequestosome-like cargo receptors in the degradation of misfolded, ubiquitinated proteins and damaged mitochondria. We also highlight at which steps defects in their function result in the accumulation of harmful material and how this knowledge may guide the design of future therapies.
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Affiliation(s)
- Elias Adriaenssens
- Max Perutz Labs, Vienna BioCenter, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA.
| | - Luca Ferrari
- Max Perutz Labs, Vienna BioCenter, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria.
| | - Sascha Martens
- Max Perutz Labs, Vienna BioCenter, University of Vienna, Dr. Bohr-Gasse 9, 1030 Vienna, Austria; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA.
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36
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Jensen LE, Rao S, Schuschnig M, Cada AK, Martens S, Hummer G, Hurley JH. Membrane curvature sensing and stabilization by the autophagic LC3 lipidation machinery. SCIENCE ADVANCES 2022; 8:eadd1436. [PMID: 36516251 PMCID: PMC9750143 DOI: 10.1126/sciadv.add1436] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 11/10/2022] [Indexed: 05/28/2023]
Abstract
How the highly curved phagophore membrane is stabilized during autophagy initiation is a major open question in autophagosome biogenesis. Here, we use in vitro reconstitution on membrane nanotubes and molecular dynamics simulations to investigate how core autophagy proteins in the LC3 (Microtubule-associated proteins 1A/1B light chain 3) lipidation cascade interact with curved membranes, providing insight into their possible roles in regulating membrane shape during autophagosome biogenesis. ATG12(Autophagy-related 12)-ATG5-ATG16L1 was up to 100-fold enriched on highly curved nanotubes relative to flat membranes. At high surface density, ATG12-ATG5-ATG16L1 binding increased the curvature of the nanotubes. While WIPI2 (WD repeat domain phosphoinositide-interacting protein 2) binding directs membrane recruitment, the amphipathic helix α2 of ATG16L1 is responsible for curvature sensitivity. Molecular dynamics simulations revealed that helix α2 of ATG16L1 inserts shallowly into the membrane, explaining its curvature-sensitive binding to the membrane. These observations show how the binding of the ATG12-ATG5-ATG16L1 complex to the early phagophore rim could stabilize membrane curvature and facilitate autophagosome growth.
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Affiliation(s)
- Liv E. Jensen
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Shanlin Rao
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Martina Schuschnig
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
| | - A. King Cada
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
| | - Sascha Martens
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Gerhard Hummer
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University Frankfurt, Frankfurt am Main 60438, Germany
| | - James H. Hurley
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
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37
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Semeraro EF, Pajtinka P, Marx L, Kabelka I, Leber R, Lohner K, Vácha R, Pabst G. Magainin 2 and PGLa in bacterial membrane mimics IV: Membrane curvature and partitioning. Biophys J 2022; 121:4689-4701. [PMID: 36258677 PMCID: PMC9748257 DOI: 10.1016/j.bpj.2022.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 12/15/2022] Open
Abstract
We previously reported that the synergistically enhanced antimicrobial activity of magainin 2 (MG2a) and PGLa is related to membrane adhesion and fusion. Here, we demonstrate that equimolar mixtures of MG2a and L18W-PGLa induce positive monolayer curvature stress and sense, at the same time, positive mean and Gaussian bilayer curvatures already at low amounts of bound peptide. The combination of both abilities-membrane curvature sensing and inducing-is most likely the base for the synergistically enhanced peptide activity. In addition, our coarse-grained simulations suggest that fusion stalks are promoted by decreasing the free-energy barrier for their formation rather than by stabilizing their shape. We also interrogated peptide partitioning as a function of lipid and peptide concentration using tryptophan fluorescence spectroscopy and peptide-induced leakage of dyes from lipid vesicles. In agreement with a previous report, we find increased membrane partitioning of L18W-PGLa in the presence of MG2a. However, this effect does not prevail to lipid concentrations higher than 1 mM, above which all peptides associate with the lipid bilayers. This implies that synergistic effects of MG2a and L18W-PGLa in previously reported experiments with lipid concentrations >1 mM are due to peptide-induced membrane remodeling and not their specific membrane partitioning.
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Affiliation(s)
- Enrico F Semeraro
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria
| | - Peter Pajtinka
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Lisa Marx
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria
| | - Ivo Kabelka
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Regina Leber
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria
| | - Karl Lohner
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic; Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Brno, Czech Republic.
| | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria.
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38
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Sanz-Martinez P, Stolz A. Mechanisms and physiological functions of ER-phagy. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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39
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Popelka H, Klionsky DJ. When acidic residues do not mimic phosphorylation: high-affinity binding of the reticulophagy receptor TEX264 to LC3/GABARAP. Autophagy 2022; 18:2515-2518. [PMID: 36041015 PMCID: PMC9629098 DOI: 10.1080/15548627.2022.2119350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Substrates that are selected for degradation by autophagy interact in more complex eukaryotes with Atg8-family proteins via the LC3-interacting region (LIR) that is often preceded by either acidic residues or phosphorylated serine or threonine. These upstream amino acid residues increase the binding affinity of the LIR motif to its binding site on the surface of LC3/GABARAP. It is not fully understood whether or how phosphorylation functionally replaces acidic residues in the LIR-Atg8-family protein interactions. A recent study by Chino et al. discussed in this article analyzed the phosphorylation of two serine residues upstream of the LIR motif in TEX264, a reticulophagy receptor that exhibits a high binding affinity to LC3/GABARAP proteins. The authors found a structural basis for the high-affinity interaction yielded by phosphorylation but not by an acidic residue in place of phosphoserine. Furthermore, finding that phosphorylation of TEX264 generates its high binding affinity to Atg8-family proteins uncovers a mechanistic alternative to that utilized by other reticulophagy receptors when they interact with LC3/GABARAP.Abbreviations: CSNK2: casein kinase 2; ER: endoplasmic reticulum; IDPR: intrinsically disordered protein region; LIR: LC3-interacting region; p-S: phosphorylated serine.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Daniel J Klionsky
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
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40
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Cail RC, Drubin DG. Membrane curvature as a signal to ensure robustness of diverse cellular processes. Trends Cell Biol 2022; 33:427-441. [PMID: 36244874 DOI: 10.1016/j.tcb.2022.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/05/2022]
Abstract
An increasing corpus of research has demonstrated that membrane shape, generated either by the external environment of the cell or by intrinsic mechanisms such as cytokinesis and vesicle or organelle formation, is an important parameter in the control of diverse cellular processes. In this review we discuss recent findings that demonstrate how membrane curvature (from nanometer to micron length-scales) alters protein function. We describe an expanding toolkit for experimentally modulating membrane curvature to reveal effects on protein function, and discuss how membrane curvature - far from being a passive consequence of the physical environment and the internal protein activity of a cell - is an important signal that controls protein affinity and enzymatic activity to ensure robust forward progression of key processes within the cell.
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41
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Angelotti T. Exploring the eukaryotic Yip and REEP/Yop superfamily of membrane-shaping adapter proteins (MSAPs): A cacophony or harmony of structure and function? Front Mol Biosci 2022; 9:912848. [PMID: 36060263 PMCID: PMC9437294 DOI: 10.3389/fmolb.2022.912848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Polytopic cargo proteins are synthesized and exported along the secretory pathway from the endoplasmic reticulum (ER), through the Golgi apparatus, with eventual insertion into the plasma membrane (PM). While searching for proteins that could enhance cell surface expression of olfactory receptors, a new family of proteins termed “receptor expression-enhancing proteins” or REEPs were identified. These membrane-shaping hairpin proteins serve as adapters, interacting with intracellular transport machinery, to regulate cargo protein trafficking. However, REEPs belong to a larger family of proteins, the Yip (Ypt-interacting protein) family, conserved in yeast and higher eukaryotes. To date, eighteen mammalian Yip family members, divided into four subfamilies (Yipf, REEP, Yif, and PRAF), have been identified. Yeast research has revealed many intriguing aspects of yeast Yip function, functions that have not completely been explored with mammalian Yip family members. This review and analysis will clarify the different Yip family nomenclature that have encumbered prior comparisons between yeast, plants, and eukaryotic family members, to provide a more complete understanding of their interacting proteins, membrane topology, organelle localization, and role as regulators of cargo trafficking and localization. In addition, the biological role of membrane shaping and sensing hairpin and amphipathic helical domains of various Yip proteins and their potential cellular functions will be described. Lastly, this review will discuss the concept of Yip proteins as members of a larger superfamily of membrane-shaping adapter proteins (MSAPs), proteins that both shape membranes via membrane-sensing and hairpin insertion, and well as act as adapters for protein-protein interactions. MSAPs are defined by their localization to specific membranes, ability to alter membrane structure, interactions with other proteins via specific domains, and specific interactions/effects on cargo proteins.
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42
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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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43
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Larsen AH. Molecular Dynamics Simulations of Curved Lipid Membranes. Int J Mol Sci 2022; 23:ijms23158098. [PMID: 35897670 PMCID: PMC9331392 DOI: 10.3390/ijms23158098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 02/04/2023] Open
Abstract
Eukaryotic cells contain membranes with various curvatures, from the near-plane plasma membrane to the highly curved membranes of organelles, vesicles, and membrane protrusions. These curvatures are generated and sustained by curvature-inducing proteins, peptides, and lipids, and describing these mechanisms is an important scientific challenge. In addition to that, some molecules can sense membrane curvature and thereby be trafficked to specific locations. The description of curvature sensing is another fundamental challenge. Curved lipid membranes and their interplay with membrane-associated proteins can be investigated with molecular dynamics (MD) simulations. Various methods for simulating curved membranes with MD are discussed here, including tools for setting up simulation of vesicles and methods for sustaining membrane curvature. The latter are divided into methods that exploit scaffolding virtual beads, methods that use curvature-inducing molecules, and methods applying virtual forces. The variety of simulation tools allow researcher to closely match the conditions of experimental studies of membrane curvatures.
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44
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Kennedy A, Ren HY, Madden VJ, Cyr DM. Lysosome docking to WIPI1 rings and ER-connected phagophores occurs during DNAJB12- and GABARAP-dependent selective autophagy of misfolded P23H-rhodopsin. Mol Biol Cell 2022; 33:ar84. [PMID: 35704470 PMCID: PMC9582645 DOI: 10.1091/mbc.e21-10-0505] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We report on how the endoplasmic reticulum (ER)-associated-autophagy pathway (ERAA) delivers P23H-rhodopsin (P23H-R) to the lysosome. P23H-R accumulates in an ERAD-resistant conformation that is stabilized in a detergent-soluble state by DNAJB12 and Hsp70. P23H-R, DNAJB12, and FIP200 colocalize in discrete foci that punctuate the rim of omegasome rings coated by WIPI1. Loss of DNAJB12 function prevents the association of P23H-R containing ER tubules with omegasomes. P23H-R tubules thread through the wall of WIPI1 rings into their central cavity. Transfer of P23H-R from ER-connected phagophores to lysosomes requires GABARAP and is associated with the transient docking of lysosomes to WIPI1 rings. After departure from WIPI1 rings, new patches of P23H-R are seen in the membranes of lysosomes. The absence of GABARAP prevents transfer of P23H-R from phagophores to lysosomes without interfering with docking. These data identify lysosome docking to omegasomes as an important step in the DNAJB12- and GABARAP-dependent autophagic disposal of dominantly toxic P23H-R.
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Affiliation(s)
- Andrew Kennedy
- Department of Cell Biology and Physiology, School of Medicine, and
| | - Hong Yu Ren
- Department of Cell Biology and Physiology, School of Medicine, and
| | - Victoria J. Madden
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Douglas M. Cyr
- Department of Cell Biology and Physiology, School of Medicine, and,*Address correspondence to: Douglas M. Cyr ()
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45
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Mechanistic Research into the Effects of the Jianpi Xiaozhi Formula on Liver Injury in Diabetic Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:7490747. [PMID: 35911164 PMCID: PMC9328966 DOI: 10.1155/2022/7490747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/15/2022] [Accepted: 07/01/2022] [Indexed: 11/18/2022]
Abstract
Objective The purpose of this study was to explore the mechanism of Jianpi Xiaozhi Formula (JPXZF) action in attenuating liver injury in a rat model of type 2 diabetes mellitus (T2DM). Methods A rat model of T2DM was established. Forty-eight male Sprague–Dawley (SD) rats were randomly allocated to six groups: healthy untreated rats (normal control (NC)), rats with diabetes mellitus (DM), diabetic rats treated with low-dosage JPXZF (DM + JL), diabetic rats treated with an intermediate JPXZF dosage (DM + JM), diabetic rats treated with high-dosage JPXZF (DM + JH), and diabetic rats treated with 4-phenylbutyric acid (PBA) (DM + PBA). The rats in each group were given the indicated drugs for 8 weeks, and pathological changes in the liver tissues of each rat group were observed by haematoxylin-eosin (HE) staining. Reverse-transcription polymerase chain reaction (RT-PCR) and Western blotting (WB) were performed to determine the expression of glucose-regulated protein 78 (GRP78), activating transcription factor 6 (ATF6), family with sequence similarity 134, member B (FAM134B), P62, Beclin-1, and light chain 3II/I (LC3II/I) genes and proteins in the liver tissues of the rats in each group. Immunofluorescence was used to observe changes in FAM134B expression. Results After successfully establishing the rat model, RT-PCR assays revealed that, compared with those in the NC group rats, the expression levels of GRP78, ATF6, and P62 mRNA in the livers of the DM group rats were significantly increased, and the relative expression levels of FAM134B and Beclin-1 mRNA were significantly decreased. Compared with that in the DM group, the relative expression of GRP78, ATF6, and P62 mRNA in the liver of the rats in each JPXZF intervention group was decreased in a dosage-dependent manner, and the relative expression of FAM134B and Beclin-1 mRNA was increased significantly (p < 0.05). WB indicated that, compared with that in the NC group rats, the LC3II/I protein expression ratio in the liver of the DM group rats was significantly reduced, and the LC3II/I protein expression ratio in the liver of the rats in each JPXZF intervention group was significantly increased. In addition, the expression of the other measured proteins was consistent with that of the corresponding mRNA measured by RT-PCR (p < 0.05). The immunofluorescence assay results showed that FAM134B changes were consistent with the results obtained by RT-PCR and WB (p < 0.05). Conclusion Jianpi Xiaozhi Formula may be effective in treating liver injury in diabetic rats by regulating autophagy induced by endoplasmic reticulum stress (ERS).
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Jiang D, He Y, Zhou X, Cao Z, Pang L, Zhong S, Jiang L, Li R. Arabidopsis HOPS subunit VPS41 carries out plant-specific roles in vacuolar transport and vegetative growth. PLANT PHYSIOLOGY 2022; 189:1416-1434. [PMID: 35417008 PMCID: PMC9237685 DOI: 10.1093/plphys/kiac167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/25/2022] [Indexed: 05/27/2023]
Abstract
The homotypic fusion and protein sorting (HOPS) complex is a conserved, multi-subunit tethering complex in eukaryotic cells. In yeast and mammalian cells, the HOPS subunit vacuolar protein sorting-associated protein 41 (VPS41) is recruited to late endosomes after Ras-related protein 7 (Rab7) activation and is essential for vacuole fusion. However, whether VPS41 plays conserved roles in plants is not clear. Here, we demonstrate that in the model plant Arabidopsis (Arabidopsis thaliana), VPS41 localizes to distinct condensates in root cells in addition to its reported localization at the tonoplast. The formation of condensates does not rely on the known upstream regulators but depends on VPS41 self-interaction and is essential for vegetative growth regulation. Genetic evidence indicates that VPS41 is required for both homotypic vacuole fusion and cargo sorting from the adaptor protein complex 3, Rab5, and Golgi-independent pathways but is dispensable for the Rab7 cargo inositol transporter 1. We also show that VPS41 has HOPS-independent functions in vacuolar transport. Taken together, our findings indicate that Arabidopsis VPS41 is a unique subunit of the HOPS complex that carries out plant-specific roles in both vacuolar transport and developmental regulation.
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Affiliation(s)
- Dong Jiang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yilin He
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xiangui Zhou
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zhiran Cao
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lei Pang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
| | - Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at the College of Life Sciences, Peking University, Beijing 100871, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Ruixi Li
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, School of Life Sciences, Institute of Plant and Food Science, Southern University of Science and Technology, Shenzhen 518055, China
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Marrink SJ, Monticelli L, Melo MN, Alessandri R, Tieleman DP, Souza PCT. Two decades of Martini: Better beads, broader scope. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1620] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials University of Groningen Groningen The Netherlands
| | - Luca Monticelli
- Molecular Microbiology and Structural Biochemistry (MMSB ‐ UMR 5086) CNRS & University of Lyon Lyon France
| | - Manuel N. Melo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa Oeiras Portugal
| | - Riccardo Alessandri
- Pritzker School of Molecular Engineering University of Chicago Chicago Illinois USA
| | - D. Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences University of Calgary Alberta Canada
| | - Paulo C. T. Souza
- Molecular Microbiology and Structural Biochemistry (MMSB ‐ UMR 5086) CNRS & University of Lyon Lyon France
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Guo YX, Han B, Yang T, Chen YS, Yang Y, Li JY, Yang Q, Xie RJ. Family with sequence similarity 134 member B-mediated reticulophagy ameliorates hepatocyte apoptosis induced by dithiothreitol. World J Gastroenterol 2022; 28:2569-2581. [PMID: 35949353 PMCID: PMC9254142 DOI: 10.3748/wjg.v28.i23.2569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/23/2022] [Accepted: 04/28/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Endoplasmic reticulum (ER) stress-related hepatocyte apoptosis is responsible for multiple hepatic diseases. Previous studies have revealed that endoplasmic reticulophagy (ER-phagy) promotes the selective clearance of damaged ER fragments during ER stress, playing a crucial role in maintaining ER homeostasis and inhibiting apoptosis. Family with sequence similarity 134 member B (FAM134B) is a receptor involved in ER-phagy that can form a complex with calnexin (CNX) and microtubule-associated protein 1 light chain 3 (LC3). The complex can mediate the selective isolation of ER fragments to attenuate hepatocyte apoptosis. However, the precise regulatory mechanisms remain unclear.
AIM To elucidate the effect of FAM134B-mediated ER-phagy on ER stress-induced apoptosis in buffalo rat liver 3A (BRL-3A) rat hepatocytes and the potential regulatory mechanisms.
METHODS ER stress-related hepatocyte apoptosis was induced using dithiothreitol (DTT). Proteins related to ER stress and autophagy were measured with western blotting. Protein complex interactions with FAM134B were isolated by co-immunoprecipitation. ER-phagy was evaluated in immunofluorescence experiments. Cell cycle distribution and apoptosis were measured by flow cytometry. Mitochondrial Ca2+ levels were evaluated by the co-localization of intracellular Ca2+-tracker and Mito-tracker. The small interfering RNA against FAM134B was used to knockdown FAM134B in BRL-3A cells.
RESULTS ER stress-related and autophagy-related proteins in BRL-3A cells were elevated by both short and long-term DTT treatment. Furthermore, co-immunoprecipitation confirmed an interaction between FAM134B, CNX, FAM134B, and LC3 in BRL-3A cells. Immunofluorescence assays revealed that autolysosomes significantly decreased following short-term DTT treatment, but increased after long-term treatment. Mitochondrial Ca2+ levels and apoptotic rates were dramatically elevated, and more cells were arrested in the G1 stage after short-term DTT treatment; however, these decreased 48 h later. Moreover, FAM134B downregulation accelerated mitochondrial apoptotic pathway activation and aggravated hepatocyte apoptosis under ER stress.
CONCLUSION FAM134B-mediated ER-phagy attenuates hepatocyte apoptosis by suppressing the mitochondrial apoptotic pathway. Our findings provide new evidence highlighting the importance of FAM134B-mediated ER-phagy in attenuating hepatocyte apoptosis.
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Affiliation(s)
- Yi-Xin Guo
- Department of Pathophysiology, Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Bing Han
- Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Ting Yang
- Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Yu-Si Chen
- Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Yi Yang
- Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Jia-Yao Li
- Department of Pathophysiology, Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Qin Yang
- Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
| | - Ru-Jia Xie
- Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
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Guan K, Su Q, Kuang K, Meng X, Zhou X, Liu B. MiR-142-5p/FAM134B Axis Manipulates ER-Phagy to Control PRRSV Replication. Front Immunol 2022; 13:842077. [PMID: 35795666 PMCID: PMC9251429 DOI: 10.3389/fimmu.2022.842077] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 05/18/2022] [Indexed: 11/13/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) can replicate its RNA genome in endoplasmic reticulum (ER) and utilize ER to facilitate its assembly and maturation. To maintain ER homeostasis, host cells initiate reticulophagy (known as ER-phagy) to effectively digest the stressed ER. In this study, we found that PRRSV infection subverted ER-phagy by downregulating ER-phagy receptor FAM134B. PRRSV-induced miR-142-5p directly targeted FAM134B and significantly promoted PRRSV replication. Meanwhile, siRNA-mediated depletion of FAM134B protein and overexpression of FAM134B mutant protein significantly disrupted ER-phagy and facilitated PRRSV replication. Furthermore, our results showed that FAM134B-mediated ER-phagy activated type I interferon signaling to inhibit PRRSV replication. Overall, this study reveals the important role of ER-phagy in PRRSV replication in a FAM134B-dependent manner. Our findings provide an insight into the pathogenesis of PRRSV and offer a theoretical basis for further development of antiviral therapeutic targets.
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Affiliation(s)
- Kaifeng Guan
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - Qiuju Su
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - Kailin Kuang
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - Xiangge Meng
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - Xiang Zhou
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
- The Engineering Technology Research Center of Hubei Province Local Pig Breed Improvement, Huazhong Agricultural University, Wuhan, China
- *Correspondence: Xiang Zhou, ; Bang Liu,
| | - Bang Liu
- Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
- The Engineering Technology Research Center of Hubei Province Local Pig Breed Improvement, Huazhong Agricultural University, Wuhan, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, China
- *Correspondence: Xiang Zhou, ; Bang Liu,
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Rath SL, Tripathy M, Mandal N. How Does Temperature Affect the Dynamics of SARS-CoV-2 M Proteins? Insights from Molecular Dynamics Simulations. J Membr Biol 2022; 255:341-356. [PMID: 35552785 PMCID: PMC9101995 DOI: 10.1007/s00232-022-00244-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/07/2022] [Indexed: 11/30/2022]
Abstract
Enveloped viruses, in general, have several transmembrane proteins and glycoproteins, which assist the virus in entry and attachment onto the host cells. These proteins also play a significant role in determining the shape and size of the newly formed virus particles. The lipid membrane and the embedded proteins affect each other in non-trivial ways during the course of the viral life cycle. Unraveling the nature of the protein-protein and protein-lipid interactions, under various environmental and physiological conditions, could therefore prove to be crucial in development of therapeutics. Here, we study the M protein of SARS-CoV-2 to understand the effect of temperature on the properties of the protein-membrane system. The membrane-embedded dimeric M proteins were studied using atomistic and coarse-grained molecular dynamics simulations at temperatures ranging between 10 and 50 °C. While temperature-induced fluctuations are expected to be monotonic, we observe a steady rise in the protein dynamics up to 40 °C, beyond which it surprisingly reverts back to the low-temperature behavior. Detailed investigation reveals disordering of the membrane lipids in the presence of the protein, which induces additional curvature around the transmembrane region. Coarse-grained simulations indicate temperature-dependent aggregation of M protein dimers. Our study clearly indicates that the dynamics of membrane lipids and integral M protein of SARS-CoV-2 enables it to better associate and aggregate only at a certain temperature range (i.e., ~ 30-40 °C). This can have important implications in the protein aggregation and subsequent viral budding/fission processes.
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Affiliation(s)
- Soumya Lipsa Rath
- Department of Biotechnology, National Institute of Technology Warangal (NITW), Telangana, 506004, India.
| | - Madhusmita Tripathy
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, 64287, Darmstadt, Germany.
| | - Nabanita Mandal
- Department of Biotechnology, National Institute of Technology Warangal (NITW), Telangana, 506004, India
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