1
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Chung T, Choi YE, Song K, Jung H. How coat proteins shape autophagy in plant cells. PLANT PHYSIOLOGY 2024:kiae426. [PMID: 39259569 DOI: 10.1093/plphys/kiae426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 08/07/2024] [Indexed: 09/13/2024]
Abstract
Autophagy is a membrane trafficking pathway through which eukaryotic cells target their own cytoplasmic constituents for degradation in the lytic compartment. Proper biogenesis of autophagic organelles requires a conserved set of autophagy-related (ATG) proteins and their interacting factors, such as signalling phospholipid phosphatidylinositol 3-phosphate (PI3P) and coat complex II (COPII). The COPII machinery, which was originally identified as a membrane coat involved in the formation of vesicles budding from the endoplasmic reticulum, contributes to the initiation of autophagic membrane formation in yeast, metazoan, and plant cells; however, the exact mechanisms remain elusive. Recent studies using the plant model species Arabidopsis thaliana have revealed that plant-specific PI3P effectors are involved in autophagy. The PI3P effector FYVE2 interacts with the conserved PI3P effector ATG18 and with COPII components, indicating an additional role for the COPII machinery in the later stages of autophagosome biogenesis. In this Update, we examined recent research on plant autophagosome biogenesis and proposed working models on the functions of the COPII machinery in autophagy, including its potential roles in stabilizing membrane curvature and sealing the phagophore.
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Affiliation(s)
- Taijoon Chung
- Department of Biological Sciences, Pusan National University, Busan, 46241, Republic of Korea
- Institute of Systems Biology, Pusan National University, Busan, 46241, Republic of Korea
| | - Ye Eun Choi
- Department of Biological Sciences, Pusan National University, Busan, 46241, Republic of Korea
| | - Kyoungjun Song
- Department of Biological Sciences, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyera Jung
- Department of Biological Sciences, Pusan National University, Busan, 46241, Republic of Korea
- Institute of Systems Biology, Pusan National University, Busan, 46241, Republic of Korea
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2
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Maddaluno M, Settembre C. Micronuclear collapse mechanisms in cancer. Science 2024; 385:930-931. [PMID: 39208121 DOI: 10.1126/science.adr7417] [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: 09/04/2024]
Abstract
Oxidative damage triggers micronuclear membrane rupture and defective repair.
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Affiliation(s)
- Marianna Maddaluno
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
| | - Carmine Settembre
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
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3
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Deretic V, Duque T, Trosdal E, Paddar M, Javed R, Akepati P. Membrane atg8ylation in Canonical and Noncanonical Autophagy. J Mol Biol 2024; 436:168532. [PMID: 38479594 PMCID: PMC11260254 DOI: 10.1016/j.jmb.2024.168532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/04/2024] [Accepted: 03/07/2024] [Indexed: 04/13/2024]
Abstract
Membrane atg8ylation is a homeostatic process responding to membrane remodeling and stress signals. Membranes are atg8ylated by mammalian ATG8 ubiquitin-like proteins through a ubiquitylation-like cascade. A model has recently been put forward which posits that atg8ylation of membranes is conceptually equivalent to ubiquitylation of proteins. Like ubiquitylation, membrane atg8ylation involves E1, E2 and E3 enzymes. The E3 ligases catalyze the final step of atg8ylation of aminophospholipids in membranes. Until recently, the only known E3 ligase for membrane atg8ylation was ATG16L1 in a noncovalent complex with the ATG12-ATG5 conjugate. ATG16L1 was first identified as a factor in canonical autophagy. During canonical autophagy, the ATG16L1-based E3 ligase complex includes WIPI2, which in turn recognizes phosphatidylinositiol 3-phosphate and directs atg8ylation of autophagic phagophores. As an alternative to WIPIs, binding of ATG16L1 to the proton pump V-ATPase guides atg8ylation of endolysosomal and phagosomal membranes in response to lumenal pH changes. Recently, a new E3 complex containing TECPR1 instead of ATG16L1, has been identified that responds to sphingomyelin's presence on the cytofacial side of perturbed endolysosomal membranes. In present review, we cover the principles of membrane atg8ylation, catalog its various presentations, and provide a perspective on the growing repertoire of E3 ligase complexes directing membrane atg8ylation at diverse locations.
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Affiliation(s)
- Vojo Deretic
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA.
| | - Thabata Duque
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Einar Trosdal
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Masroor Paddar
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Ruheena Javed
- Autophagy Inflammation and Metabolism Center of Biochemical Research Excellence, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Prithvi Akepati
- Gastroenterology Division, Department of Internal Medicine, University of New Mexico School of Medicine, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
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4
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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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5
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Guallar-Garrido S, Soldati T. Exploring host-pathogen interactions in the Dictyostelium discoideum-Mycobacterium marinum infection model of tuberculosis. Dis Model Mech 2024; 17:dmm050698. [PMID: 39037280 DOI: 10.1242/dmm.050698] [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: 07/23/2024] Open
Abstract
Mycobacterium tuberculosis is a pathogenic mycobacterium that causes tuberculosis. Tuberculosis is a significant global health concern that poses numerous clinical challenges, particularly in terms of finding effective treatments for patients. Throughout evolution, host immune cells have developed cell-autonomous defence strategies to restrain and eliminate mycobacteria. Concurrently, mycobacteria have evolved an array of virulence factors to counteract these host defences, resulting in a dynamic interaction between host and pathogen. Here, we review recent findings, including those arising from the use of the amoeba Dictyostelium discoideum as a model to investigate key mycobacterial infection pathways. D. discoideum serves as a scalable and genetically tractable model for human phagocytes, providing valuable insights into the intricate mechanisms of host-pathogen interactions. We also highlight certain similarities between M. tuberculosis and Mycobacterium marinum, and the use of M. marinum to more safely investigate mycobacteria in D. discoideum.
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Affiliation(s)
- Sandra Guallar-Garrido
- Department of Biochemistry, Faculty of Science, University of Geneva, 30 quai Ernest-Ansermet, Science II, 1211 Geneva-4, Switzerland
| | - Thierry Soldati
- Department of Biochemistry, Faculty of Science, University of Geneva, 30 quai Ernest-Ansermet, Science II, 1211 Geneva-4, Switzerland
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6
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Xue VW, Wong SCC, Zhao H, Cho WCS. Proteomic characterization of extracellular vesicles in programmed cell death. Proteomics 2024; 24:e2300024. [PMID: 38491383 DOI: 10.1002/pmic.202300024] [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: 07/19/2023] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 03/18/2024]
Abstract
Programmed cell death (PCD) is a fundamental biological process that plays a critical role in cell development, differentiation, and homeostasis. The secretion and uptake of extracellular vesicles (EVs) is one of the important regulatory mechanisms for PCD. EVs are natural membrane structures secreted by cells that contain a variety of proteins, lipids, nucleic acids, and other bioactive molecules. Due to their important roles in intercellular communication and disease progression, there is great interest in studying EVs and their cargo. Different protein components are sorted and packaged in EVs, allowing EVs to perform their functions. The study of EV proteomics helps us understand the role of PCD in the development of diseases. Meanwhile, proteomics is a powerful tool for studying the composition and function of EVs, which assists in the identification, quantification, and profiling of protein components of EVs, and provides insight into the molecular mechanisms involved in PCD and related diseases. In this review, we summarize the characteristics of EV proteomics in different types of PCD, compare different proteomic profiling strategies for EVs, and discuss the impact of EV proteomics on cell function and regulation during PCD, to understand its role in the pathogenesis of related diseases.
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Affiliation(s)
- Vivian Weiwen Xue
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
| | - Sze Chuen Cesar Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Huafu Zhao
- Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, China
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7
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Ye Y, Liang X, Wang G, Bewley MC, Hamamoto K, Liu X, Flanagan JM, Wang HG, Takahashi Y, Tian F. Identification of membrane curvature sensing motifs essential for VPS37A phagophore recruitment and autophagosome closure. Commun Biol 2024; 7:334. [PMID: 38491121 PMCID: PMC10942982 DOI: 10.1038/s42003-024-06026-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/07/2024] [Indexed: 03/18/2024] Open
Abstract
VPS37A, an ESCRT-I complex component, is required for recruiting a subset of ESCRT proteins to the phagophore for autophagosome closure. However, the mechanism by which VPS37A is targeted to the phagophore remains obscure. Here, we demonstrate that the VPS37A N-terminal domain exhibits selective interactions with highly curved membranes, mediated by two membrane-interacting motifs within the disordered regions surrounding its Ubiquitin E2 variant-like (UEVL) domain. Site-directed mutations of residues in these motifs disrupt ESCRT-I localization to the phagophore and result in defective phagophore closure and compromised autophagic flux in vivo, highlighting their essential role during autophagy. In conjunction with the UEVL domain, we postulate that these motifs guide a functional assembly of the ESCRT machinery at the highly curved tip of the phagophore for autophagosome closure. These results advance the notion that the distinctive membrane architecture of the cup-shaped phagophore spatially regulates autophagosome biogenesis.
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Affiliation(s)
- Yansheng Ye
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA.
| | - Xinwen Liang
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Guifang Wang
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Maria C Bewley
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Kouta Hamamoto
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Xiaoming Liu
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - John M Flanagan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Hong-Gang Wang
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Yoshinori Takahashi
- Department of Pediatrics, Division of Pediatric Hematology and Oncology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA.
| | - Fang Tian
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, Hershey, PA, 17033, USA.
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8
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Ballesteros U, Iriondo MN, Varela YR, Goñi FM, Alonso A, Montes LR, Etxaniz A. The N-terminal region of the ATG8 autophagy protein LC3C is essential for its membrane fusion properties. Int J Biol Macromol 2024; 262:129835. [PMID: 38302024 DOI: 10.1016/j.ijbiomac.2024.129835] [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: 12/08/2023] [Revised: 01/25/2024] [Accepted: 01/27/2024] [Indexed: 02/03/2024]
Abstract
Autophagy is a catabolic process in which a double-membrane organelle, the autophagosome (AP), engulfs cellular components that will be degraded in the lysosomes. ATG8 protein family members participate at various stages of AP formation. The present study compares the capacity to induce lipid-vesicle tethering and fusion of two ATG8 family members, LC3B and LC3C, with model membranes. LC3B is the most thoroughly studied ATG8 protein. It is generally considered as an autophagosomal marker and a canonical representative of the LC3 subfamily. LC3C is less studied, but recent data have reported its implication in various processes, crucial to cellular homeostasis. The results in this paper show that LC3C induces higher levels of tethering and of intervesicular lipid mixing than LC3B. As the N-terminus of LC3C is different from that of the other family members, various mutants of the N-terminal region of both LC3B and LC3C were designed, and their activities compared. It was concluded that the N-terminal region of LC3C was responsible for the enhanced vesicle tethering, membrane perturbation and vesicle-vesicle fusion activities of LC3C as compared to LC3B. The results suggest a specialized function of LC3C in the AP expansion process.
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Affiliation(s)
- Uxue Ballesteros
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain
| | - Marina N Iriondo
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain
| | - Yaiza R Varela
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain
| | - Félix M Goñi
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain
| | - Alicia Alonso
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain
| | - L Ruth Montes
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
| | - Asier Etxaniz
- Department of Biochemistry and Instituto Biofisika (CSIC, UPV/EHU), University of the Basque Country, 48940 Leioa, Spain.
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9
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Titus AS, Sung EA, Zablocki D, Sadoshima J. Mitophagy for cardioprotection. Basic Res Cardiol 2023; 118:42. [PMID: 37798455 PMCID: PMC10556134 DOI: 10.1007/s00395-023-01009-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 10/07/2023]
Abstract
Mitochondrial function is maintained by several strictly coordinated mechanisms, collectively termed mitochondrial quality control mechanisms, including fusion and fission, degradation, and biogenesis. As the primary source of energy in cardiomyocytes, mitochondria are the central organelle for maintaining cardiac function. Since adult cardiomyocytes in humans rarely divide, the number of dysfunctional mitochondria cannot easily be diluted through cell division. Thus, efficient degradation of dysfunctional mitochondria is crucial to maintaining cellular function. Mitophagy, a mitochondria specific form of autophagy, is a major mechanism by which damaged or unnecessary mitochondria are targeted and eliminated. Mitophagy is active in cardiomyocytes at baseline and in response to stress, and plays an essential role in maintaining the quality of mitochondria in cardiomyocytes. Mitophagy is mediated through multiple mechanisms in the heart, and each of these mechanisms can partially compensate for the loss of another mechanism. However, insufficient levels of mitophagy eventually lead to mitochondrial dysfunction and the development of heart failure. In this review, we discuss the molecular mechanisms of mitophagy in the heart and the role of mitophagy in cardiac pathophysiology, with the focus on recent findings in the field.
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Affiliation(s)
- Allen Sam Titus
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, 185 South Orange Ave, MSB G-609, Newark, NJ, 07103, USA
| | - Eun-Ah Sung
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, 185 South Orange Ave, MSB G-609, Newark, NJ, 07103, USA
| | - Daniela Zablocki
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, 185 South Orange Ave, MSB G-609, Newark, NJ, 07103, USA
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, Rutgers New Jersey Medical School, 185 South Orange Ave, MSB G-609, Newark, NJ, 07103, USA.
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10
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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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11
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Gordon CH, Hendrix E, He Y, Walker MC. AlphaFold Accurately Predicts the Structure of Ribosomally Synthesized and Post-Translationally Modified Peptide Biosynthetic Enzymes. Biomolecules 2023; 13:1243. [PMID: 37627309 PMCID: PMC10452190 DOI: 10.3390/biom13081243] [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: 07/21/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a growing class of natural products biosynthesized from a genetically encoded precursor peptide. The enzymes that install the post-translational modifications on these peptides have the potential to be useful catalysts in the production of natural-product-like compounds and can install non-proteogenic amino acids in peptides and proteins. However, engineering these enzymes has been somewhat limited, due in part to limited structural information on enzymes in the same families that nonetheless exhibit different substrate selectivities. Despite AlphaFold2's superior performance in single-chain protein structure prediction, its multimer version lacks accuracy and requires high-end GPUs, which are not typically available to most research groups. Additionally, the default parameters of AlphaFold2 may not be optimal for predicting complex structures like RiPP biosynthetic enzymes, due to their dynamic binding and substrate-modifying mechanisms. This study assessed the efficacy of the structure prediction program ColabFold (a variant of AlphaFold2) in modeling RiPP biosynthetic enzymes in both monomeric and dimeric forms. After extensive benchmarking, it was found that there were no statistically significant differences in the accuracy of the predicted structures, regardless of the various possible prediction parameters that were examined, and that with the default parameters, ColabFold was able to produce accurate models. We then generated additional structural predictions for select RiPP biosynthetic enzymes from multiple protein families and biosynthetic pathways. Our findings can serve as a reference for future enzyme engineering complemented by AlphaFold-related tools.
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Affiliation(s)
| | | | | | - Mark C. Walker
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA
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12
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Javed R, Jain A, Duque T, Hendrix E, Paddar MA, Khan S, Claude‐Taupin A, Jia J, Allers L, Wang F, Mudd M, Timmins G, Lidke K, Rusten TE, Akepati PR, He Y, Reggiori F, Eskelinen E, Deretic V. Mammalian ATG8 proteins maintain autophagosomal membrane integrity through ESCRTs. EMBO J 2023; 42:e112845. [PMID: 37272163 PMCID: PMC10350836 DOI: 10.15252/embj.2022112845] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023] Open
Abstract
The canonical autophagy pathway in mammalian cells sequesters diverse cytoplasmic cargo within the double membrane autophagosomes that eventually convert into degradative compartments via fusion with endolysosomal intermediates. Here, we report that autophagosomal membranes show permeability in cells lacking principal ATG8 proteins (mATG8s) and are unable to mature into autolysosomes. Using a combination of methods including a novel in vitro assay to measure membrane sealing, we uncovered a previously unappreciated function of mATG8s to maintain autophagosomal membranes in a sealed state. The mATG8 proteins GABARAP and LC3A bind to key ESCRT-I components contributing, along with other ESCRTs, to the integrity and imperviousness of autophagic membranes. Autophagic organelles in cells lacking mATG8s are permeant, are arrested as amphisomes, and do not progress to functional autolysosomes. Thus, autophagosomal organelles need to be maintained in a sealed state in order to become lytic autolysosomes.
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Affiliation(s)
- Ruheena Javed
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Ashish Jain
- Faculty of MedicineUniversity of OsloOsloNorway
| | - Thabata Duque
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Emily Hendrix
- Department of Chemistry & Chemical BiologyThe University of New MexicoAlbuquerqueNMUSA
| | - Masroor Ahmad Paddar
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Sajjad Khan
- Department of Physics and AstronomyThe University of New MexicoAlbuquerqueNMUSA
| | - Aurore Claude‐Taupin
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Jingyue Jia
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Lee Allers
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Fulong Wang
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Michal Mudd
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Graham Timmins
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
| | - Keith Lidke
- Department of Physics and AstronomyThe University of New MexicoAlbuquerqueNMUSA
| | | | - Prithvi Reddy Akepati
- Division of Gastroenterology and Hepatology, Department of Internal MedicineUniversity of New MexicoAlbuquerqueNMUSA
| | - Yi He
- Department of Chemistry & Chemical BiologyThe University of New MexicoAlbuquerqueNMUSA
| | - Fulvio Reggiori
- Department of BiomedicineAarhus UniversityAarhusDenmark
- Aarhus Institute for Advanced Studies (AIAS)Aarhus UniversityAarhusDenmark
| | | | - Vojo Deretic
- Department of Molecular Genetics and MicrobiologyUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research ExcellenceUniversity of New Mexico Health Sciences CenterAlbuquerqueNMUSA
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