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Oh S, Mandell MA. Regulation of Mitochondria-Derived Immune Activation by 'Antiviral' TRIM Proteins. Viruses 2024; 16:1161. [PMID: 39066323 PMCID: PMC11281404 DOI: 10.3390/v16071161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Mitochondria are key orchestrators of antiviral responses that serve as platforms for the assembly and activation of innate immune-signaling complexes. In response to viral infection, mitochondria can be triggered to release immune-stimulatory molecules that can boost interferon production. These same molecules can be released by damaged mitochondria to induce pathogenic, antiviral-like immune responses in the absence of infection. This review explores how members of the tripartite motif-containing (TRIM) protein family, which are recognized for their roles in antiviral defense, regulate mitochondria-based innate immune activation. In antiviral defense, TRIMs are essential components of immune signal transduction pathways and function as directly acting viral restriction factors. TRIMs carry out conceptually similar activities when controlling immune activation related to mitochondria. First, they modulate immune-signaling pathways that can be activated by mitochondrial molecules. Second, they co-ordinate the direct removal of mitochondria and associated immune-activating factors through mitophagy. These insights broaden the scope of TRIM actions in innate immunity and may implicate TRIMs in diseases associated with mitochondria-derived inflammation.
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Affiliation(s)
- Seeun Oh
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA;
| | - Michael A. Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA;
- Autophagy, Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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Saha B, Olsvik H, Williams GL, Oh S, Evjen G, Sjøttem E, Mandell MA. TBK1 is ubiquitinated by TRIM5α to assemble mitophagy machinery. Cell Rep 2024; 43:114294. [PMID: 38814780 PMCID: PMC11216866 DOI: 10.1016/j.celrep.2024.114294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 04/05/2024] [Accepted: 05/14/2024] [Indexed: 06/01/2024] Open
Abstract
Ubiquitination of mitochondrial proteins provides a basis for the downstream recruitment of mitophagy machinery, yet whether ubiquitination of the machinery itself contributes to mitophagy is unknown. Here, we show that K63-linked polyubiquitination of the key mitophagy regulator TBK1 is essential for its mitophagy functions. This modification is catalyzed by the ubiquitin ligase TRIM5α and is required for TBK1 to interact with and activate a set of ubiquitin-binding autophagy adaptors including NDP52, p62/SQSTM1, and NBR1. Autophagy adaptors, along with TRIM27, enable TRIM5α to engage with TBK1 following mitochondrial damage. TRIM5α's ubiquitin ligase activity is required for the accumulation of active TBK1 on damaged mitochondria in Parkin-dependent and Parkin-independent mitophagy pathways. Our data support a model in which TRIM5α provides a mitochondria-localized, ubiquitin-based, self-amplifying assembly platform for TBK1 and mitophagy adaptors that is ultimately necessary for the recruitment of the core autophagy machinery.
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Affiliation(s)
- Bhaskar Saha
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Hallvard Olsvik
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
| | - Geneva L Williams
- Biomedical Sciences Graduate Program, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Seeun Oh
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Gry Evjen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
| | - Eva Sjøttem
- Autophagy Research Group, Department of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway
| | - Michael A Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA; Autophagy, Inflammation, and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.
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Lyu Z, Genereux JC. Quantitative Measurement of Transthyretin Mistargeting by Proximity Labeling and Parallel Reaction Monitoring. FRONTIERS IN CHEMICAL BIOLOGY 2023; 2:1288188. [PMID: 38173467 PMCID: PMC10764115 DOI: 10.3389/fchbi.2023.1288188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Proximity labeling is a powerful approach for characterizing subcellular proteomes. We recently demonstrated that proximity labeling can be used to identify mistrafficking of secretory proteins, such as occurs during pre-emptive quality control (pre-QC) following endoplasmic reticulum (ER) stress. This assay depends on protein quantification by immunoblotting and densitometry, which sometimes suffers from poor sensitivity. Here, we integrate parallel reaction monitoring (PRM) mass spectrometry to enable a more quantitative platform, and assess how chemical ER stressors impact pre-QC of the model secretory protein transthyretin in HEK293T cells. We find that some drug treatments affect labeling efficiency, which can be controlled for by normalizing to APEX2 auto-labeling. While some chemical ER stress inducers including Brefeldin A and thapsigargin induce pre-QC, tunicamycin and dithiothreitol do not, indicating ER stress alone is not sufficient. This finding contrasts with the canonical model of pre-QC induction, and establishes the utility of our platform.
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Affiliation(s)
- Ziqi Lyu
- Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Joseph C. Genereux
- Department of Chemistry, University of California, Riverside, Riverside, CA, United States
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4
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Saha B, Olsvik H, Williams GL, Oh S, Evjen G, Sjøttem E, Mandell MA. TBK1 is ubiquitinated by TRIM5α to assemble mitophagy machinery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.19.563195. [PMID: 37905089 PMCID: PMC10614974 DOI: 10.1101/2023.10.19.563195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Ubiquitination of mitochondrial proteins provides a basis for the downstream recruitment of mitophagy machinery, yet whether ubiquitination of the machinery itself contributes to mitophagy is unknown. Here, we show that K63-linked polyubiquitination of the key mitophagy regulator TBK1 is essential for its mitophagy functions. This modification is catalyzed by the ubiquitin ligase TRIM5α. Mitochondrial damage triggers TRIM5α's auto-ubiquitination and its interaction with ubiquitin-binding autophagy adaptors including NDP52, optineurin, and NBR1. Autophagy adaptors, along with TRIM27, enable TRIM5α to engage with TBK1. TRIM5α with intact ubiquitination function is required for the proper accumulation of active TBK1 on damaged mitochondria in Parkin-dependent and Parkin-independent mitophagy pathways. Additionally, we show that TRIM5α can directly recruit autophagy initiation machinery to damaged mitochondria. Our data support a model in which TRIM5α provides a self-amplifying, mitochondria-localized, ubiquitin-based, assembly platform for TBK1 and mitophagy adaptors that is ultimately required to recruit the core autophagy machinery.
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Affiliation(s)
- Bhaskar Saha
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 USA
| | - Hallvard Olsvik
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Geneva L Williams
- Biomedical Sciences Graduate Program, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 USA
| | - Seeun Oh
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 USA
| | - Gry Evjen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Eva Sjøttem
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Michael A Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 USA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center
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Akiso M, Ameka M, Naidoo K, Langat R, Kombo J, Sikuku D, Ndung’u T, Altfeld M, Anzala O, Mureithi M. Metabolic and mitochondrial dysregulation in CD4+ T cells from HIV-positive women on combination anti-retroviral therapy. PLoS One 2023; 18:e0286436. [PMID: 37816026 PMCID: PMC10564234 DOI: 10.1371/journal.pone.0286436] [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: 05/25/2023] [Accepted: 09/20/2023] [Indexed: 10/12/2023] Open
Abstract
BACKGROUND For optimal functionality, immune cells require a robust and adaptable metabolic program that is fueled by dynamic mitochondrial activity. In this study, we investigate the metabolic alterations occurring in immune cells during HIV infection and antiretroviral therapy by analyzing the uptake of metabolic substrates and mitochondrial phenotypes. By delineating changes in immune cell metabolic programming during HIV, we may identify novel potential therapeutic targets to improve anti-viral immune responses. METHODS After consent and voluntary participation was confirmed, whole blood was drawn from HIV uninfected women and women with chronic HIV infection on long-term combination antiretroviral therapy (HIV/cART). Peripheral blood mononuclear cells-derived immune cells were directly incubated with different fluorescently tagged metabolites and markers of mitochondrial activity: FITC-2-NBDG (2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose), FITC-BODIPY (4,4-Difluoro-5,7-Dimethyl-4-Bora-3a,4a-Diaza-s-Indacene-3-Hexadecanoic Acid), FITC-MitoTracker Green and APC-MitoTracker Deep Red. The uptake of glucose and fats and the mitochondrial mass and potential were measured using flow cytometry. All values are reported quantitatively as geometric means of fluorescence intensity. RESULTS During chronic HIV infection, cellular uptake of glucose increases in HIV+ dendritic cells in particular. CD4+ T cells had the lowest uptake of glucose and fats compared to all other cells regardless of HIV status, while CD8+ T cells took up more fatty acids. Interestingly, despite the lower utilization of glucose and fats in CD4+ T cells, mitochondrial mass increased in HIV+ CD4+ T cells compared to HIV negative CD4+ T-cells. HIV+ CD4+ T cells also had the highest mitochondrial potential. CONCLUSIONS Significant disparities in the utilization of substrates by leukocytes during chronic HIV/cART exist. Innate immune cells increased utilization of sugars and fats while adaptive immune cells displayed lower glucose and fat utilization despite having a higher mitochondrial activity. Our findings suggest that cART treated HIV-infected CD4+ T cells be dysfunctional or may prefer alternative fuel sources not included in these studies. This underscores the importance of understanding the metabolic effects of HIV treatment on immune function.
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Affiliation(s)
- Matrona Akiso
- Department of Medical Microbiology & Immunology, Faculty of Health Sciences, University of Nairobi, Nairobi, Kenya
- KAVI-Institute of Clinical Research (KAVI-ICR), University of Nairobi, Nairobi, Kenya
| | - Magdalene Ameka
- KAVI-Institute of Clinical Research (KAVI-ICR), University of Nairobi, Nairobi, Kenya
| | - Kewreshini Naidoo
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Robert Langat
- KAVI-Institute of Clinical Research (KAVI-ICR), University of Nairobi, Nairobi, Kenya
- Division of Surgical Outcomes and Precision Medicine Research, Department of Surgery, University of Minnesota Twin Cities, United States of America
| | - Janet Kombo
- Department of Medical Microbiology & Immunology, Faculty of Health Sciences, University of Nairobi, Nairobi, Kenya
- KAVI-Institute of Clinical Research (KAVI-ICR), University of Nairobi, Nairobi, Kenya
| | - Delories Sikuku
- Department of Medical Microbiology & Immunology, Faculty of Health Sciences, University of Nairobi, Nairobi, Kenya
| | - Thumbi Ndung’u
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Marcus Altfeld
- Institute of Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Virus Immunology Department, Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Omu Anzala
- Department of Medical Microbiology & Immunology, Faculty of Health Sciences, University of Nairobi, Nairobi, Kenya
- KAVI-Institute of Clinical Research (KAVI-ICR), University of Nairobi, Nairobi, Kenya
| | - Marianne Mureithi
- Department of Medical Microbiology & Immunology, Faculty of Health Sciences, University of Nairobi, Nairobi, Kenya
- KAVI-Institute of Clinical Research (KAVI-ICR), University of Nairobi, Nairobi, Kenya
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Jiménez-Loygorri JI, Benítez-Fernández R, Viedma-Poyatos Á, Zapata-Muñoz J, Villarejo-Zori B, Gómez-Sintes R, Boya P. Mitophagy in the retina: Viewing mitochondrial homeostasis through a new lens. Prog Retin Eye Res 2023; 96:101205. [PMID: 37454969 DOI: 10.1016/j.preteyeres.2023.101205] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/11/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Mitochondrial function is key to support metabolism and homeostasis in the retina, an organ that has one of the highest metabolic rates body-wide and is constantly exposed to photooxidative damage and external stressors. Mitophagy is the selective autophagic degradation of mitochondria within lysosomes, and can be triggered by distinct stimuli such as mitochondrial damage or hypoxia. Here, we review the importance of mitophagy in retinal physiology and pathology. In the developing retina, mitophagy is essential for metabolic reprogramming and differentiation of retina ganglion cells (RGCs). In basal conditions, mitophagy acts as a quality control mechanism, maintaining a healthy mitochondrial pool to meet cellular demands. We summarize the different autophagy- and mitophagy-deficient mouse models described in the literature, and discuss the potential role of mitophagy dysregulation in retinal diseases such as glaucoma, diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration. Finally, we provide an overview of methods used to monitor mitophagy in vitro, ex vivo, and in vivo. This review highlights the important role of mitophagy in sustaining visual function, and its potential as a putative therapeutic target for retinal and other diseases.
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Affiliation(s)
- Juan Ignacio Jiménez-Loygorri
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Rocío Benítez-Fernández
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland
| | - Álvaro Viedma-Poyatos
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Juan Zapata-Muñoz
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Beatriz Villarejo-Zori
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Raquel Gómez-Sintes
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Patricia Boya
- Autophagy Lab, Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; Departament of Neuroscience and Movement Science, Faculty of Science and Medicine, University of Fribourg, 1700, Fribourg, Switzerland.
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7
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Lyu Z, Genereux JC. Quantitative Measurement of Secretory Protein Mistargeting by Proximity Labeling and Parallel Reaction Monitoring. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.19.549095. [PMID: 37503147 PMCID: PMC10370094 DOI: 10.1101/2023.07.19.549095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Proximity labeling is a powerful approach for characterizing subcellular proteomes. We recently demonstrated that proximity labeling can be used to identify mistrafficking of secretory proteins, such as occurs during pre-emptive quality control (pre-QC) following endoplasmic reticulum (ER) stress. This assay depends on protein quantification by immunoblotting and densitometry, which is only semi-quantitative and suffers from poor sensitivity. Here, we integrate parallel reaction monitoring mass spectrometry to enable a more quantitative platform for ER import. PRM as opposed to densitometry improves quantification of transthyretin mistargeting while also achieving at least a ten-fold gain in sensitivity. The multiplexing of PRM also enabled us to evaluate a series of normalization approaches, revealing that normalization to auto-labeled APEX2 peroxidase is necessary to account for drug treatment-dependent changes in labeling efficiency. We apply this approach to systematically characterize the relationship between chemical ER stressors and ER pre-QC induction in HEK293T cells. Using dual-FLAG-tagged transthyretin (FLAGTTR) as a model secretory protein, we find that Brefeldin A treatment as well as ER calcium depletion cause pre-QC, while tunicamycin and dithiothreitol do not, indicating ER stress alone is not sufficient. This finding contrasts with the canonical model of pre-QC induction, and establishes the utility of our platform.
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Affiliation(s)
- Ziqi Lyu
- Department of Chemistry, University of California, Riverside, Riverside, CA 92521
| | - Joseph C. Genereux
- Department of Chemistry, University of California, Riverside, Riverside, CA 92521
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8
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Tian L, Jia Z, Yan Y, Jia Q, Shi W, Cui S, Chen H, Han Y, Zhao X, He K. Low-dose of caffeine alleviates high altitude pulmonary edema via regulating mitochondrial quality control process in AT1 cells. Front Pharmacol 2023; 14:1155414. [PMID: 37081967 PMCID: PMC10110878 DOI: 10.3389/fphar.2023.1155414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/23/2023] [Indexed: 04/07/2023] Open
Abstract
Backgrounds: High-altitude pulmonary edema (HAPE) is a life-threatening disease without effective drugs. Caffeine is a small molecule compound with antioxidant biological activity used to treat respiratory distress syndrome. However, it is unclear whether caffeine plays a role in alleviating HAPE.Methods: We combined a series of biological experiments and label-free quantitative proteomics analysis to detect the effect of caffeine on treating HAPE and explore its mechanism in vivo and in vitro.Results: Dry and wet weight ratio and HE staining of pulmonary tissues showed that the HAPE model was constructed successfully, and caffeine relieved pulmonary edema. The proteomic results of mice lungs indicated that regulating mitochondria might be the mechanism by which caffeine reduced HAPE. We found that caffeine blocked the reduction of ATP production and oxygen consumption rate, decreased ROS accumulation, and stabilized mitochondrial membrane potential to protect AT1 cells from oxidative stress damage under hypoxia. Caffeine promoted the PINK1/parkin-dependent mitophagy and enhanced mitochondrial fission to maintain the mitochondria quality control process.Conclusion: Low-dose of caffeine alleviated HAPE by promoting PINK1/parkin-dependent mitophagy and mitochondrial fission to control the mitochondria quality. Therefore, caffeine could be a potential treatment for HAPE.
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Affiliation(s)
- Liuyang Tian
- School of Medicine, Nankai University, Tianjin, China
- Medical Big Data Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
- National Engineering Research Center for Medical Big Data Application Technology, Chinese PLA General Hospital, Beijing, China
| | - Zhilong Jia
- National Engineering Research Center for Medical Big Data Application Technology, Chinese PLA General Hospital, Beijing, China
- Center for Artificial Intelligence in Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
- *Correspondence: Zhilong Jia, ; Xiaojing Zhao, ; Kunlun He,
| | - Yan Yan
- Research Center for Translational Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Qian Jia
- National Engineering Research Center for Medical Big Data Application Technology, Chinese PLA General Hospital, Beijing, China
- Research Center for Translational Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Wenjie Shi
- Technical Research Centre for Prevention and Control of Birth Defects, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Saijia Cui
- Research Center for Translational Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Huining Chen
- Research Center for Translational Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Yang Han
- Medical Big Data Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
- National Engineering Research Center for Medical Big Data Application Technology, Chinese PLA General Hospital, Beijing, China
- Research Center for Translational Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
| | - Xiaojing Zhao
- National Engineering Research Center for Medical Big Data Application Technology, Chinese PLA General Hospital, Beijing, China
- Research Center for Translational Medicine, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
- *Correspondence: Zhilong Jia, ; Xiaojing Zhao, ; Kunlun He,
| | - Kunlun He
- School of Medicine, Nankai University, Tianjin, China
- Medical Big Data Research Center, Medical Innovation Research Division of Chinese PLA General Hospital, Beijing, China
- National Engineering Research Center for Medical Big Data Application Technology, Chinese PLA General Hospital, Beijing, China
- *Correspondence: Zhilong Jia, ; Xiaojing Zhao, ; Kunlun He,
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9
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Albarnaz JD, Weekes MP. Proteomic analysis of antiviral innate immunity. Curr Opin Virol 2023; 58:101291. [PMID: 36529073 DOI: 10.1016/j.coviro.2022.101291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/03/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022]
Abstract
The capacity of host cells to detect and restrict an infecting virus rests on an array of cell-autonomous antiviral effectors and innate immune receptors that can trigger inflammatory processes at tissue and organismal levels. Dynamic changes in protein abundance, subcellular localisation, post-translational modifications and interactions with other biomolecules govern these processes. Proteomics is therefore an ideal experimental tool to discover novel mechanisms of host antiviral immunity. Additional information can be gleaned both about host and virus by systematic analysis of viral immune evasion strategies. In this review, we summarise recent advances in proteomic technologies and their application to antiviral innate immunity.
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Affiliation(s)
- Jonas D Albarnaz
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, CB2 0XY Cambridge, UK
| | - Michael P Weekes
- Cambridge Institute for Medical Research, University of Cambridge, Hills Road, CB2 0XY Cambridge, UK.
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10
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Saha B, Mandell MA. The retroviral restriction factor TRIM5/TRIM5α regulates mitochondrial quality control. Autophagy 2023; 19:372-373. [PMID: 35659190 PMCID: PMC9809936 DOI: 10.1080/15548627.2022.2084863] [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: 01/07/2023] Open
Abstract
The protein TRIM5 is under intensive investigation related to its roles in antiviral defense, yet its underlying mechanisms of action remain elusive. In our study, we performed an unbiased identification of TRIM5-interacting partners and found proteins participating in a wide variety of cellular functions. We utilized this proteomics data set to uncover a role for TRIM5 in mitophagy, a mitochondrial quality control system that is impaired in multiple human diseases. Mitochondrial damage triggers the recruitment of TRIM5 to ER-mitochondria contact sites where TRIM5 colocalizes with markers of autophagosome biogenesis. Cells lacking TRIM5 are unable to carry out PRKN-dependent and PRKN-independent mitophagy pathways. TRIM5 knockout cells show reduced mitochondrial function and uncontrolled immune activation in response to mitochondrial damage; phenotypes consistent with a requirement for TRIM5 in mitophagy. Mechanistically, we found that TRIM5 is required for the recruitment of the autophagy initiation machinery to damaged mitochondria, where TRIM5 acts as a scaffold promoting interactions between protein markers of mitochondrial damage and the autophagy initiation machinery.
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Affiliation(s)
- Bhaskar Saha
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Michael A. Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA,Autophagy, Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, Albuquerque, NM, USA,CONTACT Michael A. Mandell Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM87131, USA
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11
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Abstract
Mitochondria are crucial organelles that play a central role in various cell signaling and metabolic pathways. A healthy mitochondrial population is maintained through a series of quality control pathways and requires a fine-tuned balance between mitochondrial biogenesis and degradation. Defective targeting of dysfunctional mitochondria to lysosomes through mitophagy has been linked to several diseases, but the underlying mechanisms and the relative importance of distinct mitophagy pathways in vivo are largely unknown. In this Cell Science at a Glance and the accompanying poster, we describe our current understanding of how parts of, or whole, mitochondria are recognized by the autophagic machinery and targeted to lysosomes for degradation. We also discuss how this might be regulated under different physiological conditions to maintain mitochondrial and cellular health.
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Affiliation(s)
- Ian G. Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Anne Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0318 Oslo, Norway
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital Montebello, 0379 Oslo, Norway
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12
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Volk LB, Cooper KL, Jiang T, Paffett ML, Hudson LG. Impacts of arsenic on Rad18 and translesion synthesis. Toxicol Appl Pharmacol 2022; 454:116230. [PMID: 36087615 PMCID: PMC10144522 DOI: 10.1016/j.taap.2022.116230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/27/2022] [Accepted: 09/02/2022] [Indexed: 10/31/2022]
Abstract
Arsenite interferes with DNA repair protein function resulting in the retention of UV-induced DNA damage. Accumulated DNA damage promotes replication stress which is bypassed by DNA damage tolerance pathways such as translesion synthesis (TLS). Rad18 is an essential factor in initiating TLS through PCNA monoubiquitination and contains two functionally and structurally distinct zinc fingers that are potential targets for arsenite binding. Arsenite treatment displaced zinc from endogenous Rad18 protein and mass spectrometry analysis revealed arsenite binding to both the Rad18 RING finger and UBZ domains. Consequently, arsenite inhibited Rad18 RING finger dependent PCNA monoubiquitination and polymerase eta recruitment to DNA damage in UV exposed keratinocytes, both of which enhance the bypass of cyclobutane pyrimidine dimers during replication. Further analysis demonstrated multiple effects of arsenite, including the reduction in nuclear localization and UV-induced chromatin recruitment of Rad18 and its binding partner Rad6, which may also negatively impact TLS initiation. Arsenite and Rad18 knockdown in UV exposed keratinocytes significantly increased markers of replication stress and DNA strand breaks to a similar degree, suggesting arsenite mediates its effects through Rad18. Comet assay analysis confirmed an increase in both UV-induced single-stranded DNA and DNA double-strand breaks in arsenite treated keratinocytes compared to UV alone. Altogether, this study supports a mechanism by which arsenite inhibits TLS through the altered activity and regulation of Rad18. Arsenite elevated the levels of UV-induced replication stress and consequently, single-stranded DNA gaps and DNA double-strand breaks. These potentially mutagenic outcomes support a role for TLS in the cocarcinogenicity of arsenite.
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Affiliation(s)
- L B Volk
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - K L Cooper
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - T Jiang
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
| | - M L Paffett
- Fluorescence Microscopy and Cell Imaging Shared Resource, University of New Mexico Comprehensive Cancer Center, 2325 Camino de Salud, Albuquerque, NM 87131, USA.
| | - L G Hudson
- Department of Pharmaceutical Sciences, University of New Mexico Health Sciences Center, 1 University of New Mexico, Albuquerque, NM 87131, USA.
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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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