1
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Raj N, Weiß MS, Vos BE, Weischer S, Brinkmann F, Betz T, Trappmann B, Gerke V. Membrane Tension Regulation is Required for Wound Repair. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2402317. [PMID: 39360573 DOI: 10.1002/advs.202402317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 09/17/2024] [Indexed: 10/04/2024]
Abstract
Disruptions of the eukaryotic plasma membrane due to chemical and mechanical challenges are frequent and detrimental and thus need to be repaired to maintain proper cell function and avoid cell death. However, the cellular mechanisms involved in wound resealing and restoration of homeostasis are diverse and contended. Here, it is shown that clathrin-mediated endocytosis is induced at later stages of plasma membrane wound repair following the actual resealing of the wound. This compensatory endocytosis occurs near the wound, predominantly at sites of previous early endosome exocytosis which is required in the initial stage of membrane resealing, suggesting a spatio-temporal co-ordination of exo- and endocytosis during wound repair. Using cytoskeletal alterations and modulations of membrane tension and membrane area, membrane tension is identified as a major regulator of the wounding-associated exo- and endocytic events that mediate efficient wound repair. Thus, membrane tension changes are a universal trigger for plasma membrane wound repair modulating the exocytosis of early endosomes required for resealing and subsequent clathrin-mediated endocytosis acting at later stages to restore cell homeostasis and function.
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Affiliation(s)
- Nikita Raj
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Multiscale Imaging Centre, Cells in Motion Interfaculty Center, University of Münster, 48149, Münster, Germany
| | - Martin S Weiß
- Bioactive Materials Laboratory, Max Planck Institute for Molecular Biomedicine, 48149, Münster, Germany
| | - Bart E Vos
- Third Institute of Physics, University of Göttingen, 37077, Göttingen, Germany
| | - Sarah Weischer
- Multiscale Imaging Centre, Cells in Motion Interfaculty Center, University of Münster, 48149, Münster, Germany
| | - Frauke Brinkmann
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), University of Münster, 48149, Münster, Germany
| | - Timo Betz
- Third Institute of Physics, University of Göttingen, 37077, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, 37077, Göttingen, Germany
| | - Britta Trappmann
- Bioactive Materials Laboratory, Max Planck Institute for Molecular Biomedicine, 48149, Münster, Germany
- Department of Chemistry and Chemical Biology, TU Dortmund University, 44227, Dortmund, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Multiscale Imaging Centre, Cells in Motion Interfaculty Center, University of Münster, 48149, Münster, Germany
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2
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Kang J, Li CM, Kim N, Baek J, Jung YK. Non-autophagic Golgi-LC3 lipidation facilitates TFE3 stress response against Golgi dysfunction. EMBO J 2024:10.1038/s44318-024-00233-y. [PMID: 39284911 DOI: 10.1038/s44318-024-00233-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 08/19/2024] [Accepted: 08/21/2024] [Indexed: 09/19/2024] Open
Abstract
Lipidated ATG8/LC3 proteins are recruited to single membrane compartments as well as autophagosomes, supporting their functions. Although recent studies have shown that Golgi-LC3 lipidation follows Golgi damage, its molecular mechanism and function under Golgi stress remain unknown. Here, by combining DLK1 overexpression as a new strategy for induction of Golgi-specific LC3 lipidation, and the application of Golgi-damaging reagents, we unravel the mechanism and role of Golgi-LC3 lipidation. Upon DLK1 overexpression, LC3 is lipidated on the Golgi apparatus in an ATG12-ATG5-ATG16L1 complex-dependent manner; a post-Golgi trafficking blockade is the primary cause of this lipidation. During Golgi stress, ATG16L1 is recruited through its interaction with V-ATPase for Golgi-LC3 lipidation. After post-Golgi trafficking inhibition, TFE3, a key regulator of the Golgi stress response, is translocated to the nucleus. Defects in LC3 lipidation disrupt this translocation, leading to an attenuation of the Golgi stress response. Together, our results reveal the mechanism and unexplored function of Golgi-LC3 lipidation in the Golgi stress response.
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Affiliation(s)
- Jaemin Kang
- School of biological sciences, Seoul National University, Seoul, 08826, Korea
| | - Cathena Meiling Li
- School of biological sciences, Seoul National University, Seoul, 08826, Korea
| | - Namhoon Kim
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, 08826, Korea
| | - Jongyeon Baek
- School of biological sciences, Seoul National University, Seoul, 08826, Korea
| | - Yong-Keun Jung
- School of biological sciences, Seoul National University, Seoul, 08826, Korea.
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, 08826, Korea.
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3
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Chao X, Yang Y, Gong W, Zou S, Tu H, Li D, Feng W, Cai H. Leep2A and Leep2B function as a RasGAP complex to regulate macropinosome formation. J Cell Biol 2024; 223:e202401110. [PMID: 38888895 PMCID: PMC11187982 DOI: 10.1083/jcb.202401110] [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: 01/22/2024] [Revised: 05/12/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024] Open
Abstract
Macropinocytosis mediates the non-selective bulk uptake of extracellular fluid, enabling cells to survey the environment and obtain nutrients. A conserved set of signaling proteins orchestrates the actin dynamics that lead to membrane ruffling and macropinosome formation across various eukaryotic organisms. At the center of this signaling network are Ras GTPases, whose activation potently stimulates macropinocytosis. However, how Ras signaling is initiated and spatiotemporally regulated during macropinocytosis is not well understood. By using the model system Dictyostelium and a proteomics-based approach to identify regulators of macropinocytosis, we uncovered Leep2, consisting of Leep2A and Leep2B, as a RasGAP complex. The Leep2 complex specifically localizes to emerging macropinocytic cups and nascent macropinosomes, where it modulates macropinosome formation by regulating the activities of three Ras family small GTPases. Deletion or overexpression of the complex, as well as disruption or sustained activation of the target Ras GTPases, impairs macropinocytic activity. Our data reveal the critical role of fine-tuning Ras activity in directing macropinosome formation.
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Affiliation(s)
- Xiaoting Chao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yihong Yang
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Weibin Gong
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Songlin Zou
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Hui Tu
- Beijing Key Laboratory of Tumor Systems Biology, School of Basic Medical Sciences, Institute of Systems Biomedicine, Peking University Health Science Center, Peking University, Beijing, China
| | - Dong Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Wei Feng
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Huaqing Cai
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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4
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McMann E, Gorski SM. Last but not least: emerging roles of the autophagy-related protein ATG4D. Autophagy 2024; 20:1916-1927. [PMID: 38920354 PMCID: PMC11346562 DOI: 10.1080/15548627.2024.2369436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 06/05/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024] Open
Abstract
The evolutionarily conserved ATG4 cysteine proteases regulate macroautophagy/autophagy through the priming and deconjugation of the Atg8-family proteins. In mammals there are four ATG4 family members (ATG4A, ATG4B, ATG4C, ATG4D) but ATG4D has been relatively understudied. Heightened interest in ATG4D has been stimulated by recent links to human disease. Notably, genetic variations in human ATG4D were implicated in a heritable neurodevelopmental disorder. Genetic analyses in dogs, along with loss-of-function zebrafish and mouse models, further support a neuroprotective role for ATG4D. Here we discuss the evidence connecting ATG4D to neurological diseases and other pathologies and summarize its roles in both autophagy-dependent and autophagy-independent cellular processes.Abbrevation: ATG: autophagy related; BafA1: bafilomycin A1; BCL2: BCL2 apoptosis regulator; BH3: BCL2 homology region 3; CASP3: caspase 3; EV: extracellular vesicle; GABA: gamma aminobutyric acid; GABARAP: GABA type A receptor-associated protein; GABARAPL1: GABA type A receptor associated protein like 1; GABARAPL2: GABA type A receptor associated protein like 2; GFP: green fluorescent protein; LIR: LC3-interacting region; MAP1LC3: microtubule associated protein 1 light chain 3; MEF: mouse embryonic fibroblast; MYC: MYC proto-oncogene, bHLH transcription factor; PE: phosphatidylethanolamine; PS: phosphatidylserine; QKO: quadruple knockout; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel; SQSTM1: sequestosome 1.
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Affiliation(s)
- Emily McMann
- Canada’s Michael Smith Genome Sciences Centre at BC Cancer, Vancouver, British Columbia, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Sharon M. Gorski
- Canada’s Michael Smith Genome Sciences Centre at BC Cancer, Vancouver, British Columbia, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
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5
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Xiao Q, Cruz G, Botham R, Fox SG, Yu A, Allen S, Morimoto RI, Kelly JW. HaloTag as a substrate-based macroautophagy reporter. Proc Natl Acad Sci U S A 2024; 121:e2322500121. [PMID: 39074281 PMCID: PMC11317570 DOI: 10.1073/pnas.2322500121] [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: 12/28/2023] [Accepted: 06/25/2024] [Indexed: 07/31/2024] Open
Abstract
Macroautophagy is a conserved cellular degradation pathway that, upon upregulation, confers resilience toward various stress conditions, including protection against proteotoxicity associated with neurodegenerative diseases, leading to cell survival. Monitoring autophagy regulation in living cells is important to understand its role in physiology and pathology, which remains challenging. Here, we report that when HaloTag is expressed within a cell of interest and reacts with tetramethylrhodamine (TMR; its ligand attached to a fluorophore), the rate of fluorescent TMR-HaloTag conjugate accumulation in autophagosomes and lysosomes, observed by fluorescence microscopy, reflects the rate of autophagy. Notably, we found that TMR-HaloTag conjugates were mainly degraded by the proteasome (~95%) under basal conditions, while lysosomal degradation (~10% upon pharmacological autophagy activation) was slow and incomplete, forming a degraded product that remained fluorescent within a SDS-PAGE gel, in agreement with previous reports that HaloTag is resistant to lysosomal degradation when fused to proteins of interest. Autophagy activation is distinguished from autophagy inhibition by the increased production of the degraded TMR-HaloTag band relative to the full-length TMR-HaloTag band as assessed by SDS-PAGE and by a faster rate of TMR-HaloTag conjugate lysosomal puncta accumulation as observed by fluorescence microscopy. Pharmacological proteasome inhibition leads to accumulation of TMR-HaloTag in lysosomes, indicating possible cross talk between autophagy and proteasomal degradation.
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Affiliation(s)
- Qiang Xiao
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA92037
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Gabrielle Cruz
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA92037
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
- Department of Biology, State University of New York College at Fredonia, Fredonia, NY14063
| | - Rachel Botham
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA92037
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Susan G. Fox
- Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL60208
| | - Anan Yu
- Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL60208
| | - Seth Allen
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA92037
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
| | - Richard I. Morimoto
- Department of Molecular Biosciences, Rice Institute for Biomedical Research, Northwestern University, Evanston, IL60208
| | - Jeffery W. Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA92037
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA92037
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6
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Paddar MA, Wang F, Trosdal ES, Hendrix E, He Y, Salemi M, Mudd M, Jia J, Duque TLA, Javed R, Phinney B, Deretic V. Noncanonical roles of ATG5 and membrane atg8ylation in retromer assembly and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.10.602886. [PMID: 39026874 PMCID: PMC11257513 DOI: 10.1101/2024.07.10.602886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
ATG5 is one of the core autophagy proteins with additional functions such as noncanonical membrane atg8ylation, which among a growing number of biological outputs includes control of tuberculosis in animal models. Here we show that ATG5 associates with retromer's core components VPS26, VPS29 and VPS35 and modulates retromer function. Knockout of ATG5 blocked trafficking of a key glucose transporter sorted by the retromer, GLUT1, to the plasma membrane. Knockouts of other genes essential for membrane atg8ylation, of which ATG5 is a component, affected GLUT1 sorting, indicating that membrane atg8ylation as a process affects retromer function and endosomal sorting. The contribution of membrane atg8ylation to retromer function in GLUT1 sorting was independent of canonical autophagy. These findings expand the scope of membrane atg8ylation to specific sorting processes in the cell dependent on the retromer and its known interactors.
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Affiliation(s)
- Masroor Ahmad Paddar
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Fulong Wang
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Einar S Trosdal
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Emily Hendrix
- Department of Chemistry & Chemical Biology, The University of New Mexico, Albuquerque, NM, USA
| | - Yi He
- Department of Chemistry & Chemical Biology, The University of New Mexico, Albuquerque, NM, USA
| | - Michelle Salemi
- Proteomics Core Facility, UC Davis Genome Center, University of California, Davis, CA 95616, USA
| | - Michal Mudd
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Jingyue Jia
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Thabata L A Duque
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Ruheena Javed
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Brett Phinney
- Proteomics Core Facility, UC Davis Genome Center, University of California, Davis, CA 95616, USA
| | - Vojo Deretic
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
- Lead Contact
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7
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Klenow MB, Vigsø MS, Pezeshkian W, Nylandsted J, Lomholt MA, Simonsen AC. Shape of the membrane neck around a hole during plasma membrane repair. Biophys J 2024; 123:1827-1837. [PMID: 38824389 PMCID: PMC11267432 DOI: 10.1016/j.bpj.2024.05.027] [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: 11/12/2023] [Revised: 04/05/2024] [Accepted: 05/28/2024] [Indexed: 06/03/2024] Open
Abstract
Plasma membrane damage and rupture occurs frequently in cells, and holes must be sealed rapidly to ensure homeostasis and cell survival. The membrane repair machinery is known to involve recruitment of curvature-inducing annexin proteins, but the connection between membrane remodeling and hole closure is poorly described. The induction of curvature by repair proteins leads to the possible formation of a membrane neck around the hole as a key intermediate structure before sealing. We formulate a theoretical model of equilibrium neck shapes to examine the potential connection to a repair mechanism. Using variational calculus, the shape equations for the membrane near a hole are formulated and solved numerically. The system is described under a condition of fixed area, and a shooting approach is applied to fulfill the boundary conditions at the free membrane edge. A state diagram of neck shapes is produced describing the variation in neck morphology with respect to the membrane area. Two distinct types of necks are predicted, one with conformations curved beyond π existing at positive excess area, whereas flat neck conformations (curved below π) have negative excess area. The results indicate that in cells, the supply of additional membrane area and a change in edge tension is linked to the formation of narrow and curved necks. Such necks may be susceptible to passive or actively induced membrane fission as a possible mechanism for hole sealing during membrane repair in cells.
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Affiliation(s)
- Martin Berg Klenow
- PhyLife - Physical LifeScience, Department of Physics Chemistry and Pharmacy, University of Southern Denmark (SDU), Campusvej 55, Odense M, Denmark
| | - Magnus Staal Vigsø
- PhyLife - Physical LifeScience, Department of Physics Chemistry and Pharmacy, University of Southern Denmark (SDU), Campusvej 55, Odense M, Denmark
| | - Weria Pezeshkian
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Nylandsted
- Danish Cancer Institute (DCI), Copenhagen Ø, Denmark; Department of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Michael Andersen Lomholt
- PhyLife - Physical LifeScience, Department of Physics Chemistry and Pharmacy, University of Southern Denmark (SDU), Campusvej 55, Odense M, Denmark
| | - Adam Cohen Simonsen
- PhyLife - Physical LifeScience, Department of Physics Chemistry and Pharmacy, University of Southern Denmark (SDU), Campusvej 55, Odense M, Denmark.
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8
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Dias C, Nylandsted J. Neural membrane repair at the core of regeneration. Neural Regen Res 2024; 19:1399-1400. [PMID: 38051866 PMCID: PMC10883513 DOI: 10.4103/1673-5374.386408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 09/06/2023] [Indexed: 12/07/2023] Open
Affiliation(s)
- Catarina Dias
- Danish Cancer Institute, Membrane Integrity, Copenhagen, Denmark
- Champalimaud Research, Champalimaud Foundation, Lisbon, Portugal
| | - Jesper Nylandsted
- Danish Cancer Institute, Membrane Integrity, Copenhagen, Denmark
- Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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9
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Tang J, Fang D, Zhong J, Li M. Missing WD40 Repeats in ATG16L1 Delays Canonical Autophagy and Inhibits Noncanonical Autophagy. Int J Mol Sci 2024; 25:4493. [PMID: 38674078 PMCID: PMC11050548 DOI: 10.3390/ijms25084493] [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: 03/13/2024] [Revised: 04/13/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Canonical autophagy is an evolutionarily conserved process that forms double-membrane structures and mediates the degradation of long-lived proteins (LLPs). Noncanonical autophagy (NCA) is an important alternative pathway involving the formation of microtubule-associated protein 1 light chain 3 (LC3)-positive structures that are independent of partial core autophagy proteins. NCA has been defined by the conjugation of ATG8s to single membranes (CASM). During canonical autophagy and NCA/CASM, LC3 undergoes a lipidation modification, and ATG16L1 is a crucial protein in this process. Previous studies have reported that the WDR domain of ATG16L1 is not necessary for canonical autophagy. However, our study found that WDR domain deficiency significantly impaired LLP degradation in basal conditions and slowed down LC3-II accumulation in canonical autophagy. We further demonstrated that the observed effect was due to a reduced interaction between ATG16L1 and FIP200/WIPI2, without affecting lysosome function or fusion. Furthermore, we also found that the WDR domain of ATG16L1 is crucial for chemical-induced NCA/CASM. The results showed that removing the WDR domain or introducing the K490A mutation in ATG16L1 significantly inhibited the NCA/CASM, which interrupted the V-ATPase-ATG16L1 axis. In conclusion, this study highlights the significance of the WDR domain of ATG16L1 for both canonical autophagy and NCA functions, improving our understanding of its role in autophagy.
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Affiliation(s)
- Jiuge Tang
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou 510006, China
| | - Dongmei Fang
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou 510006, China
| | - Jialing Zhong
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou 510006, China
| | - Min Li
- State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou 510006, China
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10
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Ebstrup ML, Sønder SL, Fogde DL, Heitmann ASB, Dietrich TN, Dias C, Jäättelä M, Maeda K, Nylandsted J. Annexin A7 mediates lysosome repair independently of ESCRT-III. Front Cell Dev Biol 2024; 11:1211498. [PMID: 38348092 PMCID: PMC10860759 DOI: 10.3389/fcell.2023.1211498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 12/21/2023] [Indexed: 02/15/2024] Open
Abstract
Lysosomes are crucial organelles essential for various cellular processes, and any damage to them can severely compromise cell viability. This study uncovers a previously unrecognized function of the calcium- and phospholipid-binding protein Annexin A7 in lysosome repair, which operates independently of the Endosomal Sorting Complex Required for Transport (ESCRT) machinery. Our research reveals that Annexin A7 plays a role in repairing damaged lysosomes, different from its role in repairing the plasma membrane, where it facilitates repair through the recruitment of ESCRT-III components. Notably, our findings strongly suggest that Annexin A7, like the ESCRT machinery, is dispensable for membrane contact site formation within the newly discovered phosphoinositide-initiated membrane tethering and lipid transport (PITT) pathway. Instead, we speculate that Annexin A7 is recruited to damaged lysosomes and promotes repair through its membrane curvature and cross-linking capabilities. Our findings provide new insights into the diverse mechanisms underlying lysosomal membrane repair and highlight the multifunctional role of Annexin A7 in membrane repair.
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Affiliation(s)
| | | | | | | | | | - Catarina Dias
- Membrane Integrity, Danish Cancer Institute, Copenhagen, Denmark
| | - Marja Jäättelä
- Cell Death and Metabolism, Danish Cancer Institute, Copenhagen, Denmark
- Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kenji Maeda
- Cell Death and Metabolism, Danish Cancer Institute, Copenhagen, Denmark
| | - Jesper Nylandsted
- Membrane Integrity, Danish Cancer Institute, Copenhagen, Denmark
- Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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11
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Todorova PK, Jackson BT, Garg V, Paras KI, Brunner JS, Bridgeman AE, Chen Y, Baksh SC, Yan J, Hadjantonakis AK, Finley LWS. Amino acid intake strategies define pluripotent cell states. Nat Metab 2024; 6:127-140. [PMID: 38172382 PMCID: PMC10842923 DOI: 10.1038/s42255-023-00940-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 11/07/2023] [Indexed: 01/05/2024]
Abstract
Mammalian preimplantation development is associated with marked metabolic robustness, and embryos can develop under a wide variety of nutrient conditions, including even the complete absence of soluble amino acids. Here we show that mouse embryonic stem cells (ESCs) capture the unique metabolic state of preimplantation embryos and proliferate in the absence of several essential amino acids. Amino acid independence is enabled by constitutive uptake of exogenous protein through macropinocytosis, alongside a robust lysosomal digestive system. Following transition to more committed states, ESCs reduce digestion of extracellular protein and instead become reliant on exogenous amino acids. Accordingly, amino acid withdrawal selects for ESCs that mimic the preimplantation epiblast. More broadly, we find that all lineages of preimplantation blastocysts exhibit constitutive macropinocytic protein uptake and digestion. Taken together, these results highlight exogenous protein uptake and digestion as an intrinsic feature of preimplantation development and provide insight into the catabolic strategies that enable embryos to sustain viability before implantation.
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Affiliation(s)
- Pavlina K Todorova
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Benjamin T Jackson
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Louis V. Gerstner Jr Graduate School of Biomedical Sciences, New York, NY, USA
| | - Vidur Garg
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Katrina I Paras
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY, USA
| | - Julia S Brunner
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Anna E Bridgeman
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Yanyang Chen
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sanjeethan C Baksh
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jielin Yan
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Louis V. Gerstner Jr Graduate School of Biomedical Sciences, New York, NY, USA
| | | | - Lydia W S Finley
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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12
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Lazki-Hagenbach P, Kleeblatt E, Fukuda M, Ali H, Sagi-Eisenberg R. The Underlying Rab Network of MRGPRX2-Stimulated Secretion Unveils the Impact of Receptor Trafficking on Secretory Granule Biogenesis and Secretion. Cells 2024; 13:93. [PMID: 38201297 PMCID: PMC10778293 DOI: 10.3390/cells13010093] [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: 12/02/2023] [Revised: 12/18/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
MRGPRX2, the human member of the MAS-related G-protein-coupled receptors (GPCRs), mediates the immunoglobulin E (IgE)-independent responses of a subset of mast cells (MCs) that are associated with itch, pain, neurogenic inflammation, and pseudoallergy to drugs. The mechanisms underlying the responses of MRGPRX2 to its multiple and diverse ligands are still not completely understood. Given the close association between GPCR location and function, and the key role played by Rab GTPases in controlling discrete steps along vesicular trafficking, we aimed to reveal the vesicular pathways that directly impact MRGPRX2-mediated exocytosis by identifying the Rabs that influence this process. For this purpose, we screened 43 Rabs for their functional and phenotypic impacts on MC degranulation in response to the synthetic MRGPRX2 ligand compound 48/80 (c48/80), which is often used as the gold standard of MRGPRX2 ligands, or to substance P (SP), an important trigger of neuroinflammatory MC responses. Results of this study highlight the important roles played by macropinocytosis and autophagy in controlling MRGPRX2-mediated exocytosis, demonstrating a close feedback control between the internalization and post-endocytic trafficking of MRGPRX2 and its triggered exocytosis.
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Affiliation(s)
- Pia Lazki-Hagenbach
- Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; (P.L.-H.); (E.K.)
| | - Elisabeth Kleeblatt
- Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; (P.L.-H.); (E.K.)
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai 980-8578, Miyagi, Japan;
| | - Hydar Ali
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; (P.L.-H.); (E.K.)
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
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13
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Park SH, Han J, Jeong BC, Song JH, Jang SH, Jeong H, Kim BH, Ko YG, Park ZY, Lee KE, Hyun J, Song HK. Structure and activation of the RING E3 ubiquitin ligase TRIM72 on the membrane. Nat Struct Mol Biol 2023; 30:1695-1706. [PMID: 37770719 PMCID: PMC10643145 DOI: 10.1038/s41594-023-01111-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/16/2023] [Indexed: 09/30/2023]
Abstract
Defects in plasma membrane repair can lead to muscle and heart diseases in humans. Tripartite motif-containing protein (TRIM)72 (mitsugumin 53; MG53) has been determined to rapidly nucleate vesicles at the site of membrane damage, but the underlying molecular mechanisms remain poorly understood. Here we present the structure of Mus musculus TRIM72, a complete model of a TRIM E3 ubiquitin ligase. We demonstrated that the interaction between TRIM72 and phosphatidylserine-enriched membranes is necessary for its oligomeric assembly and ubiquitination activity. Using cryogenic electron tomography and subtomogram averaging, we elucidated a higher-order model of TRIM72 assembly on the phospholipid bilayer. Combining structural and biochemical techniques, we developed a working molecular model of TRIM72, providing insights into the regulation of RING-type E3 ligases through the cooperation of multiple domains in higher-order assemblies. Our findings establish a fundamental basis for the study of TRIM E3 ligases and have therapeutic implications for diseases associated with membrane repair.
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Affiliation(s)
- Si Hoon Park
- Department of Life Sciences, Korea University, Seoul, South Korea
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Juhyun Han
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Byung-Cheon Jeong
- Department of Life Sciences, Korea University, Seoul, South Korea
- CSL Seqirus, Waltham, MA, USA
| | - Ju Han Song
- Department of Life Sciences, Korea University, Seoul, South Korea
- Department of Pharmacology and Dental Therapeutics, School of Dentistry, Chonnam National University, Gwangju, South Korea
| | - Se Hwan Jang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Hyeongseop Jeong
- Center for Electron Microscopy Research, Korea Basic Science Institute, Cheongju-si, South Korea
| | - Bong Heon Kim
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Young-Gyu Ko
- Department of Life Sciences, Korea University, Seoul, South Korea
| | - Zee-Yong Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Kyung Eun Lee
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul, South Korea
| | - Jaekyung Hyun
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Hyun Kyu Song
- Department of Life Sciences, Korea University, Seoul, South Korea.
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14
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Bittel DC, Jaiswal JK. Early Endosomes Undergo Calcium-Triggered Exocytosis and Enable Repair of Diffuse and Focal Plasma Membrane Injury. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2300245. [PMID: 37705135 PMCID: PMC10667805 DOI: 10.1002/advs.202300245] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/27/2023] [Indexed: 09/15/2023]
Abstract
Cells are routinely exposed to agents that cause plasma membrane (PM) injury. While pore-forming toxins (PFTs), and chemicals cause nanoscale holes dispersed throughout the PM, mechanical trauma causes focal lesions in the PM. To examine if these distinct injuries share common repair mechanism, membrane trafficking is monitored as the PM repairs from such injuries. During the course of repair, dispersed PM injury by the PFT Streptolysin O activates endocytosis, while focal mechanical injury to the PM inhibits endocytosis. Consequently, acute block of endocytosis prevents repair of diffuse, but not of focal injury. In contrast, a chronic block in endocytosis depletes cells of early endosomes and inhibits repair of focal injury. This study finds that both focal and diffuse PM injury activate Ca2+ -triggered exocytosis of early endosomes. The use of markers including endocytosed cargo, Rab5, Rab11, and VAMP3, all reveal injury-triggered exocytosis of early endosomes. Inhibiting Rab5 prevents injury-triggered early endosome exocytosis and phenocopies the failed PM repair of cells chronically depleted of early endosomes. These results identify early endosomes as a Ca2+ -regulated exocytic compartment, and uncover the requirement of their dual functions - endocytosis and regulated exocytosis, to differentially support PM repair based on the nature of the injury.
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Affiliation(s)
- Daniel C. Bittel
- Center for Genetic Medicine ResearchChildren's National Research Institute7144 13th Pl NWWashington, DC20012USA
| | - Jyoti K. Jaiswal
- Center for Genetic Medicine ResearchChildren's National Research Institute7144 13th Pl NWWashington, DC20012USA
- Department of Genomics and Precision MedicineGeorge Washington University School of Medicine and Health SciencesWashington, DC20012USA
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15
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Deretic V. Atg8ylation as a host-protective mechanism against Mycobacterium tuberculosis. FRONTIERS IN TUBERCULOSIS 2023; 1:1275882. [PMID: 37901138 PMCID: PMC10612523 DOI: 10.3389/ftubr.2023.1275882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Nearly two decades have passed since the first report on autophagy acting as a cell-autonomous defense against Mycobacterium tuberculosis. This helped usher a new area of research within the field of host-pathogen interactions and led to the recognition of autophagy as an immunological mechanism. Interest grew in the fundamental mechanisms of antimicrobial autophagy and in the prophylactic and therapeutic potential for tuberculosis. However, puzzling in vivo data have begun to emerge in murine models of M. tuberculosis infection. The control of infection in mice affirmed the effects of certain autophagy genes, specifically ATG5, but not of other ATGs. Recent studies with a more complete inactivation of ATG genes now show that multiple ATG genes are indeed necessary for protection against M. tuberculosis. These particular ATG genes are involved in the process of membrane atg8ylation. Atg8ylation in mammalian cells is a broad response to membrane stress, damage and remodeling of which canonical autophagy is one of the multiple downstream outputs. The current developments clarify the controversies and open new avenues for both fundamental and translational studies.
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Affiliation(s)
- Vojo Deretic
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
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16
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Tsai CY, Sakakibara S, Kuan YD, Omori H, El Hussien MA, Okuzaki D, Lu SL, Noda T, Tabata K, Nakamura S, Yoshimori T, Kikutani H. Opposing roles of RUBCN isoforms in autophagy and memory B cell generation. Sci Signal 2023; 16:eade3599. [PMID: 37725663 DOI: 10.1126/scisignal.ade3599] [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: 08/10/2022] [Accepted: 08/23/2023] [Indexed: 09/21/2023]
Abstract
RUBCN (also known as Rubicon) was originally identified as a negative regulator of autophagy, a process by which cells degrade and recycle damaged components or organelles and that requires the activity of the class III PI3K VPS34 and the mTORC1 protein complex. Here, we characterized the role of a shorter isoform, RUBCN100, as an autophagy-promoting factor in B cells. RUBCN100 was translated from alternative translation initiation sites and lacked the RUN domain of the longer, previously characterized RUBCN130 isoform. Specific deficiency of RUBCN130 in B cells enhanced autophagy, which promoted memory B cell generation. In contrast to RUBCN130, which is localized in late endosomes and lysosomes and suppresses the enzymatic activity of VPS34, an effect thought to mediated by its RUN domain, RUBCN100 was preferentially located in early endosomes and enhanced VPS34 activity, presumably because of the absence of the RUN domain. Furthermore, RUBCN100, but not RUBCN130, enhanced autophagy and suppressed mTORC1 activation. Our findings reveal that the opposing roles of two RUBCN isoforms are critical for autophagy regulation and memory B cell differentiation.
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Affiliation(s)
- Chao-Yuan Tsai
- Laboratory of Immune Regulation, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shuhei Sakakibara
- Laboratory of Immune Regulation, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Yu-Diao Kuan
- Laboratory of Immune Regulation, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hiroko Omori
- Core Instrumentation Facility, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Maruwa Ali El Hussien
- Laboratory of Immune Regulation, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Daisuke Okuzaki
- Single Cell Genomics, Human Immunology, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shiou-Ling Lu
- Center for Frontier Oral Science, Graduate School of Dentistry, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takeshi Noda
- Center for Frontier Oral Science, Graduate School of Dentistry, Osaka University, Suita, Osaka 565-0871, Japan
| | - Keisuke Tabata
- Department of Genetics, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shuhei Nakamura
- Department of Genetics, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tamotsu Yoshimori
- Department of Genetics, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
- Laboratory of Intracellular Membrane Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Hitoshi Kikutani
- Laboratory of Immune Regulation, Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
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17
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Elashiry MM, Raafat SN, Tay FR, Saber SM. Effect of rapamycin on human periodontal ligament stem cells that have been exposed to sodium hypochlorite. Life Sci 2023; 329:121989. [PMID: 37524163 DOI: 10.1016/j.lfs.2023.121989] [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: 05/31/2023] [Revised: 07/20/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023]
Abstract
AIMS The present study investigated the effect of rapamycin on the viability and osteogenic differentiation potential of human periodontal ligament stem cells (hPDLSCs) in the presence of sodium hypochlorite (NaOCl). MAIN METHODS After determining the minimum inhibitory concentration of NaOCl and optimum concentration of rapamycin, the viability of hPDLSCs was evaluated using the MTT assay subsequent to their exposure to NaOCl, rapamycin, or a combination of both. Osteogenic differentiation was evaluated by the cell mineralization assay performed by alizarin red S staining, alkaline phosphatase activity, and monitoring the expression of osteogenic genes markers Runt-related transcription factor 2, osteocalcin, and osteoprotegerin, using real-time quantitative polymerase chain reaction (RT-qPCR). The expression of autophagy-related genes PI3K, Akt, and mTOR, was also analyzed with RT-qPCR. KEY FINDINGS Stem cells treated with rapamycin showed the highest percentage of viable cells in the presence of NaOCl. The same trend was observed for all osteogenic differentiation assays. The hPDLSCs treated with rapamycin demonstrated the highest calcium nodule deposition, alkaline phosphatase activity, and the expression of osteogenic gene markers. These effects were not adversely affected by the presence of NaOCl. Rapamycin significantly inhibited mTOR gene expression, while there were no differences in the gene expression of PI3K and Akt. SIGNIFICANCE Rapamycin counteracts the cytotoxic effect of NaOCl by enhancing the viability and osteogenic differentiation potential of hPDLSCs. Rapamycin appears to accomplish these processes via autophagy activation, by inhibiting mTOR gene expression. The incorporation of rapamycin in regenerative endodontic therapy may encourage a higher success rate.
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Affiliation(s)
- Mohamed M Elashiry
- Department of Endodontics, Dental College of Georgia, Augusta University, GA, USA; Department of Endodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt.
| | - Shereen N Raafat
- Department of Pharmacology, Faculty of Dentistry, The British University in Egypt, Egypt; Center of Innovative Dental Sciences (CIDS), Faculty of Dentistry, The British University in Egypt, Egypt
| | - Franklin R Tay
- Department of Endodontics, Dental College of Georgia, Augusta University, GA, USA
| | - Shehabeldin M Saber
- Department of Endodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt; Center of Innovative Dental Sciences (CIDS), Faculty of Dentistry, The British University in Egypt, Egypt; Department of Endodontics, Faculty of Dentistry, The British University in Egypt, Egypt
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18
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Ravid Y, Penič S, Mimori-Kiyosue Y, Suetsugu S, Iglič A, Gov NS. Theoretical model of membrane protrusions driven by curved active proteins. Front Mol Biosci 2023; 10:1153420. [PMID: 37228585 PMCID: PMC10203436 DOI: 10.3389/fmolb.2023.1153420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 04/21/2023] [Indexed: 05/27/2023] Open
Abstract
Eukaryotic cells intrinsically change their shape, by changing the composition of their membrane and by restructuring their underlying cytoskeleton. We present here further studies and extensions of a minimal physical model, describing a closed vesicle with mobile curved membrane protein complexes. The cytoskeletal forces describe the protrusive force due to actin polymerization which is recruited to the membrane by the curved protein complexes. We characterize the phase diagrams of this model, as function of the magnitude of the active forces, nearest-neighbor protein interactions and the proteins' spontaneous curvature. It was previously shown that this model can explain the formation of lamellipodia-like flat protrusions, and here we explore the regimes where the model can also give rise to filopodia-like tubular protrusions. We extend the simulation with curved components of both convex and concave species, where we find the formation of complex ruffled clusters, as well as internalized invaginations that resemble the process of endocytosis and macropinocytosis. We alter the force model representing the cytoskeleton to simulate the effects of bundled instead of branched structure, resulting in shapes which resemble filopodia.
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Affiliation(s)
- Yoav Ravid
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Samo Penič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Yuko Mimori-Kiyosue
- Laboratory for Molecular and Cellular Dynamics, RIKEN Center for Biosystems Dynamics Research, Minatojima-minaminachi, Kobe, Hyogo, Japan
| | - Shiro Suetsugu
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Nara, Japan
- Data Science Center, Nara Institute of Science and Technology, Ikoma, Japan
- Center for Digital Green-innovation, Nara Institute of Science and Technology, Ikoma, Japan
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Nir S. Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
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19
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Raj N, Greune L, Kahms M, Mildner K, Franzkoch R, Psathaki OE, Zobel T, Zeuschner D, Klingauf J, Gerke V. Early Endosomes Act as Local Exocytosis Hubs to Repair Endothelial Membrane Damage. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2300244. [PMID: 36938863 PMCID: PMC10161044 DOI: 10.1002/advs.202300244] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/21/2023] [Indexed: 05/06/2023]
Abstract
The plasma membrane of a cell is subject to stresses causing ruptures that must be repaired immediately to preserve membrane integrity and ensure cell survival. Yet, the spatio-temporal membrane dynamics at the wound site and the source of the membrane required for wound repair are poorly understood. Here, it is shown that early endosomes, previously only known to function in the uptake of extracellular material and its endocytic transport, are involved in plasma membrane repair in human endothelial cells. Using live-cell imaging and correlative light and electron microscopy, it is demonstrated that membrane injury triggers a previously unknown exocytosis of early endosomes that is induced by Ca2+ entering through the wound. This exocytosis is restricted to the vicinity of the wound site and mediated by the endosomal soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) VAMP2, which is crucial for efficient membrane repair. Thus, the newly identified Ca2+ -evoked and localized exocytosis of early endosomes supplies the membrane material required for rapid resealing of a damaged plasma membrane, thereby providing the first line of defense against damage in mechanically challenged endothelial cells.
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Affiliation(s)
- Nikita Raj
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Cells in Motion Interfaculty Center, University of Münster, 48149, Münster, Germany
| | - Lilo Greune
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), University of Münster, 48149, Münster, Germany
| | - Martin Kahms
- Institute of Medical Physics and Biophysics, University of Münster, 48149, Münster, Germany
| | - Karina Mildner
- Electron Microscopy Facility, Max Planck Institute for Molecular Biomedicine, 48149, Münster, Germany
| | - Rico Franzkoch
- Department of Biology, integrated Bioimaging Facility (iBiOs), Center of Cellular Nanoanalytics (CellNanO), University of Osnabrück, 49076, Osnabrück, Germany
| | - Olympia Ekaterini Psathaki
- Department of Biology, integrated Bioimaging Facility (iBiOs), Center of Cellular Nanoanalytics (CellNanO), University of Osnabrück, 49076, Osnabrück, Germany
| | - Thomas Zobel
- Imaging Network, Cells in Motion Interfaculty Centre, University of Münster, 48149, Münster, Germany
| | - Dagmar Zeuschner
- Electron Microscopy Facility, Max Planck Institute for Molecular Biomedicine, 48149, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, University of Münster, 48149, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Cells in Motion Interfaculty Center, University of Münster, 48149, Münster, Germany
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20
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Mencel ML, Bittner GD. Repair of traumatic lesions to the plasmalemma of neurons and other cells: Commonalities, conflicts, and controversies. Front Physiol 2023; 14:1114779. [PMID: 37008019 PMCID: PMC10050709 DOI: 10.3389/fphys.2023.1114779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/14/2023] [Indexed: 03/17/2023] Open
Abstract
Neuroscientists and Cell Biologists have known for many decades that eukaryotic cells, including neurons, are surrounded by a plasmalemma/axolemma consisting of a phospholipid bilayer that regulates trans-membrane diffusion of ions (including calcium) and other substances. Cells often incur plasmalemmal damage via traumatic injury and various diseases. If the damaged plasmalemma is not rapidly repaired within minutes, activation of apoptotic pathways by calcium influx often results in cell death. We review publications reporting what is less-well known (and not yet covered in neuroscience or cell biology textbooks): that calcium influx at the lesion sites ranging from small nm-sized holes to complete axonal transection activates parallel biochemical pathways that induce vesicles/membrane-bound structures to migrate and interact to restore original barrier properties and eventual reestablishment of the plasmalemma. We assess the reliability of, and problems with, various measures (e.g., membrane voltage, input resistance, current flow, tracer dyes, confocal microscopy, transmission and scanning electron microscopy) used individually and in combination to assess plasmalemmal sealing in various cell types (e.g., invertebrate giant axons, oocytes, hippocampal and other mammalian neurons). We identify controversies such as plug versus patch hypotheses that attempt to account for currently available data on the subcellular mechanisms of plasmalemmal repair/sealing. We describe current research gaps and potential future developments, such as much more extensive correlations of biochemical/biophysical measures with sub-cellular micromorphology. We compare and contrast naturally occurring sealing with recently-discovered artificially-induced plasmalemmal sealing by polyethylene glycol (PEG) that bypasses all natural pathways for membrane repair. We assess other recent developments such as adaptive membrane responses in neighboring cells following injury to an adjacent cell. Finally, we speculate how a better understanding of the mechanisms involved in natural and artificial plasmalemmal sealing is needed to develop better clinical treatments for muscular dystrophies, stroke and other ischemic conditions, and various cancers.
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Affiliation(s)
- Marshal L. Mencel
- Institute of Cell and Molecular Biology, University of Texas at Austin, Austin, TX, United States
| | - George D. Bittner
- Department of Neuroscience, University of Texas at Austin, Austin, TX, United States
- *Correspondence: George D. Bittner,
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21
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Salloum G, Bresnick AR, Backer JM. Macropinocytosis: mechanisms and regulation. Biochem J 2023; 480:335-362. [PMID: 36920093 DOI: 10.1042/bcj20210584] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/22/2023] [Accepted: 02/27/2023] [Indexed: 03/16/2023]
Abstract
Macropinocytosis is defined as an actin-dependent but coat- and dynamin-independent endocytic uptake process, which generates large intracellular vesicles (macropinosomes) containing a non-selective sampling of extracellular fluid. Macropinocytosis provides an important mechanism of immune surveillance by dendritic cells and macrophages, but also serves as an essential nutrient uptake pathway for unicellular organisms and tumor cells. This review examines the cell biological mechanisms that drive macropinocytosis, as well as the complex signaling pathways - GTPases, lipid and protein kinases and phosphatases, and actin regulatory proteins - that regulate macropinosome formation, internalization, and disposition.
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Affiliation(s)
- Gilbert Salloum
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
| | - Jonathan M Backer
- Department of Molecular Pharamacology, Albert Einstein College of Medicine, Bronx, NY, U.S.A
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, U.S.A
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22
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Reid SE, Kolapalli SP, Nielsen TM, Frankel LB. Canonical and non-canonical roles for ATG8 proteins in autophagy and beyond. Front Mol Biosci 2022; 9:1074701. [PMID: 36601581 PMCID: PMC9806848 DOI: 10.3389/fmolb.2022.1074701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
During autophagy, the ATG8 family proteins have several well-characterized roles in facilitating early, mid, and late steps of autophagy, including autophagosome expansion, cargo recruitment and autophagosome-lysosome fusion. Their discovery has importantly allowed for precise experimental monitoring of the pathway, bringing about a huge expansion of research in the field over the last decades. In this review, we discuss both canonical and non-canonical roles of the autophagic lipidation machinery, with particular focus on the ATG8 proteins, their post-translational modifications and their increasingly uncovered alternative roles mediated through their anchoring at different membranes. These include endosomes, macropinosomes, phagosomes and the plasma membrane, to which ATG8 proteins can bind through canonical or alternative lipidation. Beyond new ATG8 binding partners and cargo types, we also explore several open questions related to alternative outcomes of autophagic machinery engagement beyond degradation. These include their roles in plasma membrane repair and secretion of selected substrates as well as the physiological implications hereof in health and disease.
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Affiliation(s)
| | | | | | - Lisa B. Frankel
- Danish Cancer Society Research Center, Copenhagen, Denmark,Biotech Research and Innovation Center, University of Copenhagen, Copenhagen, Denmark,*Correspondence: Lisa B. Frankel,
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23
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Durgan J, Florey O. Many roads lead to CASM: Diverse stimuli of noncanonical autophagy share a unifying molecular mechanism. SCIENCE ADVANCES 2022; 8:eabo1274. [PMID: 36288315 PMCID: PMC9604613 DOI: 10.1126/sciadv.abo1274] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Autophagy is a fundamental catabolic process coordinated by a network of autophagy-related (ATG) proteins. These ATG proteins also perform an important parallel role in "noncanonical" autophagy, a lysosome-associated signaling pathway with key functions in immunity, inflammation, cancer, and neurodegeneration. While the noncanonical autophagy pathway shares the common ATG machinery, it bears key mechanistic and functional distinctions, and is characterized by conjugation of ATG8 to single membranes (CASM). Here, we review the diverse, and still expanding, collection of stimuli and processes now known to harness the noncanonical autophagy pathway, including engulfment processes, drug treatments, TRPML1 and STING signaling, viral infection, and other pathogenic factors. We discuss the multiple associated routes to CASM and assess their shared and distinctive molecular features. By integrating these findings, we propose an updated and unifying mechanism for noncanonical autophagy, centered on ATG16L1 and V-ATPase.
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24
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Magné J, Green DR. LC3-associated endocytosis and the functions of Rubicon and ATG16L1. SCIENCE ADVANCES 2022; 8:eabo5600. [PMID: 36288306 PMCID: PMC9604520 DOI: 10.1126/sciadv.abo5600] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
LC3-associated endocytosis (LANDO) is a noncanonical function of the autophagy machinery, in which LC3 (microtubule-associated protein light chain) is conjugated to rab5-positive endosomes, using a portion of the canonical autophagy pathway. LANDO was initially discovered in a murine model of Alzheimer's disease as a critical regulator of amyloid-β receptor recycling in microglial cells, playing a protective role against neuronal loss and memory impairment. Recent evidence suggests an emerging role of LANDO in cytokine receptor signaling and innate immunity. Here, we discuss the regulation of two crucial effectors of LANDO, Rubicon and ATG16L1, and their impact on endocytosis, autophagy, and phagocytosis.
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25
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Hui J, Stjepić V, Nakamura M, Parkhurst SM. Wrangling Actin Assemblies: Actin Ring Dynamics during Cell Wound Repair. Cells 2022; 11:2777. [PMID: 36139352 PMCID: PMC9497110 DOI: 10.3390/cells11182777] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/02/2022] [Accepted: 09/03/2022] [Indexed: 12/18/2022] Open
Abstract
To cope with continuous physiological and environmental stresses, cells of all sizes require an effective wound repair process to seal breaches to their cortex. Once a wound is recognized, the cell must rapidly plug the injury site, reorganize the cytoskeleton and the membrane to pull the wound closed, and finally remodel the cortex to return to homeostasis. Complementary studies using various model organisms have demonstrated the importance and complexity behind the formation and translocation of an actin ring at the wound periphery during the repair process. Proteins such as actin nucleators, actin bundling factors, actin-plasma membrane anchors, and disassembly factors are needed to regulate actin ring dynamics spatially and temporally. Notably, Rho family GTPases have been implicated throughout the repair process, whereas other proteins are required during specific phases. Interestingly, although different models share a similar set of recruited proteins, the way in which they use them to pull the wound closed can differ. Here, we describe what is currently known about the formation, translocation, and remodeling of the actin ring during the cell wound repair process in model organisms, as well as the overall impact of cell wound repair on daily events and its importance to our understanding of certain diseases and the development of therapeutic delivery modalities.
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Affiliation(s)
| | | | | | - Susan M. Parkhurst
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
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26
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Control of Unconventional Secretion By The Autophagy Machinery. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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27
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Deretic V, Lazarou M. A guide to membrane atg8ylation and autophagy with reflections on immunity. J Cell Biol 2022; 221:e202203083. [PMID: 35699692 PMCID: PMC9202678 DOI: 10.1083/jcb.202203083] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/16/2022] [Accepted: 05/26/2022] [Indexed: 12/11/2022] Open
Abstract
The process of membrane atg8ylation, defined herein as the conjugation of the ATG8 family of ubiquitin-like proteins to membrane lipids, is beginning to be appreciated in its broader manifestations, mechanisms, and functions. Classically, membrane atg8ylation with LC3B, one of six mammalian ATG8 family proteins, has been viewed as the hallmark of canonical autophagy, entailing the formation of characteristic double membranes in the cytoplasm. However, ATG8s are now well described as being conjugated to single membranes and, most recently, proteins. Here we propose that the atg8ylation is coopted by multiple downstream processes, one of which is canonical autophagy. We elaborate on these biological outputs, which impact metabolism, quality control, and immunity, emphasizing the context of inflammation and immunological effects. In conclusion, we propose that atg8ylation is a modification akin to ubiquitylation, and that it is utilized by different systems participating in membrane stress responses and membrane remodeling activities encompassing autophagy and beyond.
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Affiliation(s)
- Vojo Deretic
- Autophagy, Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM
| | - Michael Lazarou
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
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28
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Vasconcelos-Cardoso M, Batista-Almeida D, Rios-Barros LV, Castro-Gomes T, Girao H. Cellular and molecular mechanisms underlying plasma membrane functionality and integrity. J Cell Sci 2022; 135:275922. [PMID: 35801807 DOI: 10.1242/jcs.259806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The plasma membrane not only protects the cell from the extracellular environment, acting as a selective barrier, but also regulates cellular events that originate at the cell surface, playing a key role in various biological processes that are essential for the preservation of cell homeostasis. Therefore, elucidation of the mechanisms involved in the maintenance of plasma membrane integrity and functionality is of utmost importance. Cells have developed mechanisms to ensure the quality of proteins that inhabit the cell surface, as well as strategies to cope with injuries inflicted to the plasma membrane. Defects in these mechanisms can lead to the development or onset of several diseases. Despite the importance of these processes, a comprehensive and holistic perspective of plasma membrane quality control is still lacking. To tackle this gap, in this Review, we provide a thorough overview of the mechanisms underlying the identification and targeting of membrane proteins that are to be removed from the cell surface, as well as the membrane repair mechanisms triggered in both physiological and pathological conditions. A better understanding of the mechanisms underlying protein quality control at the plasma membrane can reveal promising and unanticipated targets for the development of innovative therapeutic approaches.
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Affiliation(s)
- Maria Vasconcelos-Cardoso
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, 3000-548 Coimbra, Portugal.,University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), 3000-548 Coimbra, Portugal.,Clinical Academic Centre of Coimbra (CACC), 3000-548 Coimbra, Portugal
| | - Daniela Batista-Almeida
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, 3000-548 Coimbra, Portugal.,University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), 3000-548 Coimbra, Portugal.,Clinical Academic Centre of Coimbra (CACC), 3000-548 Coimbra, Portugal
| | - Laura Valeria Rios-Barros
- Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, CEP 31270-901, Brazil
| | - Thiago Castro-Gomes
- Department of Parasitology, Federal University of Minas Gerais, Belo Horizonte, CEP 31270-901, Brazil
| | - Henrique Girao
- University of Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, 3000-548 Coimbra, Portugal.,University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), 3000-548 Coimbra, Portugal.,Clinical Academic Centre of Coimbra (CACC), 3000-548 Coimbra, Portugal
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29
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Lazki-Hagenbach P, Kleeblatt E, Ali H, Sagi-Eisenberg R. Spatiotemporal Patterns of Substance P-Bound MRGPRX2 Reveal a Novel Connection Between Macropinosome Resolution and Secretory Granule Regeneration in Mast Cells. Front Immunol 2022; 13:892239. [PMID: 35837385 PMCID: PMC9273857 DOI: 10.3389/fimmu.2022.892239] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/30/2022] [Indexed: 12/02/2022] Open
Abstract
MRGPRX2, the human member of the MAS-related G protein coupled receptors (Mrgprs), serves as the cellular target of human mast cells (MCs) for innate ligands, including neuropeptides and antimicrobial peptides. In addition, MRGPRX2 also functions as the receptor for multiple FDA-approved drugs. As such, MRGPRX2 is a mediator of MC responses in neurogenic inflammation, host defense and pseudoallergy. We analyzed the spatiotemporal patterns of MRGPRX2 following its binding of the neuropeptide substance P (SP). Herein, we show that MRGPRX2 internalizes via both endocytosis and macropinocytosis, followed by its distribution between a perinuclear region and the secretory granules (SGs). Further, we show that MRGPRX2-containing macropinosomes undergo resolution by a mechanism that involves dynamin and LC3, giving rise to the incorporation of both LC3 and MRGPRX2 into the SGs. SP then promotes the acidification of the LC3-associated SGs, presumably by stimulating their fusion with lysosomes. Taken together, our results reveal a unique mode of MRGPRX2 trafficking that complements endocytosis and involves macropinocytosis, autophagic machinery-assisted macropinosome resolution and receptor delivery to the SGs.
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Affiliation(s)
- Pia Lazki-Hagenbach
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elisabeth Kleeblatt
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hydar Ali
- Department of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Ronit Sagi-Eisenberg,
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30
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SQSTM1, a protective factor of SOD1-linked motor neuron disease, regulates the accumulation and distribution of ubiquitinated protein aggregates in neuron. Neurochem Int 2022; 158:105364. [DOI: 10.1016/j.neuint.2022.105364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 05/04/2022] [Accepted: 05/26/2022] [Indexed: 11/19/2022]
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31
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Non-canonical roles of ATG8 for TFEB activation. Biochem Soc Trans 2022; 50:47-54. [PMID: 35166325 DOI: 10.1042/bst20210813] [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: 09/08/2021] [Revised: 12/23/2021] [Accepted: 01/18/2022] [Indexed: 11/17/2022]
Abstract
Autophagy is an evolutionally conserved cytoplasmic degradation pathway in which the double membrane structure, autophagosome sequesters cytoplasmic material and delivers them to lysosomes for degradation. Many autophagy related (ATG) proteins participate in the regulation of the several steps of autophagic process. Among ATGs, ubiquitin-like protein, ATG8 plays a pivotal role in autophagy. ATG8 is directly conjugated on lipid in autophagosome membrane upon induction of autophagy thus providing a good marker to monitor and analyze autophagy process. However, recent discoveries suggest that ATG8 has autophagy independent non-canonical functions and ATG8 positive structures are not always autophagosomes. This review briefly overviews canonical and non-canonical roles of ATG8 and introduce novel function of ATG8 to activate Transcriptional Factor EB(TFEB), a master transcription factor of autophagy and lysosome function during lysosomal damage.
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32
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Chen F, Kang R, Liu J, Tang D. The V-ATPases in cancer and cell death. Cancer Gene Ther 2022; 29:1529-1541. [PMID: 35504950 PMCID: PMC9063253 DOI: 10.1038/s41417-022-00477-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 02/04/2023]
Abstract
Transmembrane ATPases are membrane-bound enzyme complexes and ion transporters that can be divided into F-, V-, and A-ATPases according to their structure. The V-ATPases, also known as H+-ATPases, are large multi-subunit protein complexes composed of a peripheral domain (V1) responsible for the hydrolysis of ATP and a membrane-integrated domain (V0) that transports protons across plasma membrane or organelle membrane. V-ATPases play a fundamental role in maintaining pH homeostasis through lysosomal acidification and are involved in modulating various physiological and pathological processes, such as macropinocytosis, autophagy, cell invasion, and cell death (e.g., apoptosis, anoikis, alkaliptosis, ferroptosis, and lysosome-dependent cell death). In addition to participating in embryonic development, V-ATPase pathways, when dysfunctional, are implicated in human diseases, such as neurodegenerative diseases, osteopetrosis, distal renal tubular acidosis, and cancer. In this review, we summarize the structure and regulation of isoforms of V-ATPase subunits and discuss their context-dependent roles in cancer biology and cell death. Updated knowledge about V-ATPases may enable us to design new anticancer drugs or strategies.
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Affiliation(s)
- Fangquan Chen
- grid.417009.b0000 0004 1758 4591DAMP Laboratory, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120 China
| | - Rui Kang
- grid.267313.20000 0000 9482 7121Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Jiao Liu
- grid.417009.b0000 0004 1758 4591DAMP Laboratory, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong 510120 China
| | - Daolin Tang
- grid.267313.20000 0000 9482 7121Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
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33
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Actin Cytoskeletal Dynamics in Single-Cell Wound Repair. Int J Mol Sci 2021; 22:ijms221910886. [PMID: 34639226 PMCID: PMC8509258 DOI: 10.3390/ijms221910886] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 11/17/2022] Open
Abstract
The plasma membrane protects the eukaryotic cell from its surroundings and is essential for cell viability; thus, it is crucial that membrane disruptions are repaired quickly to prevent immediate dyshomeostasis and cell death. Accordingly, cells have developed efficient repair mechanisms to rapidly reseal ruptures and reestablish membrane integrity. The cortical actin cytoskeleton plays an instrumental role in both plasma membrane resealing and restructuring in response to damage. Actin directly aids membrane repair or indirectly assists auxiliary repair mechanisms. Studies investigating single-cell wound repair have often focused on the recruitment and activation of specialized repair machinery, despite the undeniable need for rapid and dynamic cortical actin modulation; thus, the role of the cortical actin cytoskeleton during wound repair has received limited attention. This review aims to provide a comprehensive overview of membrane repair mechanisms directly or indirectly involving cortical actin cytoskeletal remodeling.
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34
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Kumar S, Jia J, Deretic V. Atg8ylation as a general membrane stress and remodeling response. Cell Stress 2021; 5:128-142. [PMID: 34527862 PMCID: PMC8404385 DOI: 10.15698/cst2021.09.255] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 12/30/2022] Open
Abstract
The yeast Atg8 protein and its paralogs in mammals, mammalian Atg8s (mAtg8s), have been primarily appreciated for their participation in autophagy. However, lipidated mAtg8s, including the most frequently used autophagosomal membrane marker LC3B, are found on cellular membranes other than autophagosomes. Here we put forward a hypothesis that the lipidation of mAtg8s, termed 'Atg8ylation', is a general membrane stress and remodeling response analogous to the role that ubiquitylation plays in tagging proteins. Ubiquitin and mAtg8s are related in sequence and structure, and the lipidation of mAtg8s occurs on its C-terminal glycine, akin to the C-terminal glycine of ubiquitin. Conceptually, we propose that mAtg8s and Atg8ylation are to membranes what ubiquitin and ubiquitylation are to proteins, and that, like ubiquitylation, Atg8ylation has a multitude of downstream effector outputs, one of which is autophagy.
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Affiliation(s)
- Suresh Kumar
- Autophagy Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Jingyue Jia
- Autophagy Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Vojo Deretic
- Autophagy Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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