1
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Wu Z, Berlemann LA, Bader V, Sehr DA, Dawin E, Covallero A, Meschede J, Angersbach L, Showkat C, Michaelis JB, Münch C, Rieger B, Namgaladze D, Herrera MG, Fiesel FC, Springer W, Mendes M, Stepien J, Barkovits K, Marcus K, Sickmann A, Dittmar G, Busch KB, Riedel D, Brini M, Tatzelt J, Cali T, Winklhofer KF. LUBAC assembles a ubiquitin signaling platform at mitochondria for signal amplification and transport of NF-κB to the nucleus. EMBO J 2022; 41:e112006. [PMID: 36398858 PMCID: PMC9753471 DOI: 10.15252/embj.2022112006] [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: 06/29/2022] [Revised: 10/20/2022] [Accepted: 10/25/2022] [Indexed: 11/19/2022] Open
Abstract
Mitochondria are increasingly recognized as cellular hubs to orchestrate signaling pathways that regulate metabolism, redox homeostasis, and cell fate decisions. Recent research revealed a role of mitochondria also in innate immune signaling; however, the mechanisms of how mitochondria affect signal transduction are poorly understood. Here, we show that the NF-κB pathway activated by TNF employs mitochondria as a platform for signal amplification and shuttling of activated NF-κB to the nucleus. TNF treatment induces the recruitment of HOIP, the catalytic component of the linear ubiquitin chain assembly complex (LUBAC), and its substrate NEMO to the outer mitochondrial membrane, where M1- and K63-linked ubiquitin chains are generated. NF-κB is locally activated and transported to the nucleus by mitochondria, leading to an increase in mitochondria-nucleus contact sites in a HOIP-dependent manner. Notably, TNF-induced stabilization of the mitochondrial kinase PINK1 furthermore contributes to signal amplification by antagonizing the M1-ubiquitin-specific deubiquitinase OTULIN. Overall, our study reveals a role for mitochondria in amplifying TNF-mediated NF-κB activation, both serving as a signaling platform, as well as a transport mode for activated NF-κB to the nuclear.
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Affiliation(s)
- Zhixiao Wu
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Lena A Berlemann
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Verian Bader
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
- Department Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Dominik A Sehr
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Eva Dawin
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
- Leibniz‐Institut für Analytische Wissenschaften—ISAS—e.VDortmundGermany
| | | | - Jens Meschede
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Lena Angersbach
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Cathrin Showkat
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Jonas B Michaelis
- Faculty of Medicine, Institute of Biochemistry IIGoethe University FrankfurtFrankfurt am MainGermany
| | - Christian Münch
- Faculty of Medicine, Institute of Biochemistry IIGoethe University FrankfurtFrankfurt am MainGermany
| | - Bettina Rieger
- Institute for Integrative Cell Biology and Physiology, Faculty of BiologyUniversity of MünsterMünsterGermany
| | - Dmitry Namgaladze
- Institute of Biochemistry I, Faculty of MedicineGoethe‐University FrankfurtFrankfurtGermany
| | - Maria Georgina Herrera
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
| | - Fabienne C Fiesel
- Department of NeuroscienceMayo ClinicJacksonvilleFLUSA
- Neuroscience PhD ProgramMayo Clinic Graduate School of Biomedical SciencesJacksonvilleFLUSA
| | - Wolfdieter Springer
- Department of NeuroscienceMayo ClinicJacksonvilleFLUSA
- Neuroscience PhD ProgramMayo Clinic Graduate School of Biomedical SciencesJacksonvilleFLUSA
| | - Marta Mendes
- Proteomics of Cellular Signaling, Department of Infection and ImmunityLuxembourg Institute of HealthStrassenLuxembourg
| | - Jennifer Stepien
- Medizinisches Proteom‐CenterRuhr‐Universität BochumBochumGermany
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI)Ruhr‐University BochumBochumGermany
| | - Katalin Barkovits
- Medizinisches Proteom‐CenterRuhr‐Universität BochumBochumGermany
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI)Ruhr‐University BochumBochumGermany
| | - Katrin Marcus
- Medizinisches Proteom‐CenterRuhr‐Universität BochumBochumGermany
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI)Ruhr‐University BochumBochumGermany
| | - Albert Sickmann
- Leibniz‐Institut für Analytische Wissenschaften—ISAS—e.VDortmundGermany
| | - Gunnar Dittmar
- Proteomics of Cellular Signaling, Department of Infection and ImmunityLuxembourg Institute of HealthStrassenLuxembourg
- Department of Life Sciences and MedicineUniversity of LuxembourgBelvauxLuxembourg
| | - Karin B Busch
- Institute for Integrative Cell Biology and Physiology, Faculty of BiologyUniversity of MünsterMünsterGermany
| | - Dietmar Riedel
- Laboratory for Electron MicroscopyMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Marisa Brini
- Department of BiologyUniversity of PaduaPaduaItaly
- Centro Studi per la Neurodegenerazione (CESNE)University of PadovaPaduaItaly
| | - Jörg Tatzelt
- Department Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
- RESOLV Cluster of ExcellenceRuhr University BochumBochumGermany
| | - Tito Cali
- Department of Biomedical SciencesUniversity of PaduaPaduaItaly
- Centro Studi per la Neurodegenerazione (CESNE)University of PadovaPaduaItaly
- Padua Neuroscience Center (PNC)University of PaduaPaduaItaly
| | - Konstanze F Winklhofer
- Department Molecular Cell Biology, Institute of Biochemistry and PathobiochemistryRuhr University BochumBochumGermany
- RESOLV Cluster of ExcellenceRuhr University BochumBochumGermany
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2
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Xiao B, Kuruvilla J, Tan EK. Mitophagy and reactive oxygen species interplay in Parkinson's disease. NPJ Parkinsons Dis 2022; 8:135. [PMID: 36257956 PMCID: PMC9579202 DOI: 10.1038/s41531-022-00402-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/28/2022] [Indexed: 11/08/2022] Open
Abstract
Mitophagy impairment and oxidative stress are cardinal pathological hallmarks in Parkinson's disease (PD), a common age-related neurodegenerative condition. The specific interactions between mitophagy and reactive oxygen species (ROS) have attracted considerable attention even though their exact interplay in PD has not been fully elucidated. We highlight the interactions between ROS and mitophagy, with a focus on the signalling pathways downstream to ROS that triggers mitophagy and draw attention to potential therapeutic compounds that target these pathways in both experimental and clinical models. Identifying a combination of ROS inhibitors and mitophagy activators to provide a physiologic balance in this complex signalling pathways may lead to a more optimal outcome. Deciphering the exact temporal relationship between mitophagy and oxidative stress and their triggers early in the course of neurodegeneration can unravel mechanistic clues that potentially lead to the development of compounds for clinical drug trials focusing on prodromic PD or at-risk individuals.
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Affiliation(s)
- Bin Xiao
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore.
- Neuroscience Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.
| | - Joshua Kuruvilla
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore.
- Neuroscience Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.
- Neuroscience and Behavioral Disorders Program, Duke-NUS Medical School, Singapore, Singapore.
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3
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Soman SK, Dagda RK. Role of Cleaved PINK1 in Neuronal Development, Synaptogenesis, and Plasticity: Implications for Parkinson's Disease. Front Neurosci 2021; 15:769331. [PMID: 34795558 PMCID: PMC8593325 DOI: 10.3389/fnins.2021.769331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/11/2021] [Indexed: 12/28/2022] Open
Abstract
Mitochondrial dysfunction plays a significant role in the pathogenesis of Parkinson's disease (PD). Consistent with this concept, loss of function mutations in the serine/threonine kinase- PINK1 (PTEN-induced putative kinase-1) causes autosomal recessive early onset PD. While the functional role of f-PINK1 (full-length PINK1) in clearing dysfunctional mitochondria via mitophagy is extensively documented, our understanding of specific physiological roles that the non-mitochondrial pool of PINK1 imparts in neurons is more limited. PINK1 is proteolytically processed in the intermembrane space and matrix of the mitochondria into functional cleaved products (c-PINK1) that are exported to the cytosol. While it is clear that posttranslational processing of PINK1 depends on the mitochondria's oxidative state and structural integrity, the functional roles of c-PINK1 in modulating neuronal functions are poorly understood. Here, we review the diverse roles played by c-PINK1 in modulating various neuronal functions. Specifically, we describe the non-canonical functional roles of PINK1, including but not limited to: governing mitochondrial movement, neuronal development, neuronal survival, and neurogenesis. We have published that c-PINK1 stimulates neuronal plasticity and differentiation via the PINK1-PKA-BDNF signaling cascade. In addition, we provide insight into how mitochondrial membrane potential-dependent processing of PINK1 confers conditional retrograde signaling functions to PINK1. Further studies delineating the role of c-PINK1 in neurons would increase our understanding regarding the role played by PINK1 in PD pathogenesis.
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Affiliation(s)
- Smijin K Soman
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, Reno, NV, United States
| | - Ruben K Dagda
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, Reno, NV, United States
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4
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Soman SK, Tingle D, Dagda RY, Torres M, Dagda M, Dagda RK. Cleaved PINK1 induces neuronal plasticity through PKA-mediated BDNF functional regulation. J Neurosci Res 2021; 99:2134-2155. [PMID: 34046942 DOI: 10.1002/jnr.24854] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/17/2022]
Abstract
Mutations in PTEN-induced kinase 1 (PINK1) lead to early onset autosomal recessive Parkinson's disease in humans. In healthy neurons, full-length PINK1 (fPINK1) is post-translationally cleaved into different lower molecular weight forms, and cleaved PINK1 (cPINK1) gets shuttled to the cytosolic compartments to support extra-mitochondrial functions. While numerous studies have exemplified the role of mitochondrially localized PINK1 in modulating mitophagy in oxidatively stressed neurons, little is known regarding the physiological role of cPINK1 in healthy neurons. We have previously shown that cPINK1, but not fPINK1, modulates the neurite outgrowth and the maintenance of dendritic arbors by activating downstream protein kinase A (PKA) signaling in healthy neurons. However, the molecular mechanisms by which cPINK1 promotes neurite outgrowth remain to be elucidated. In this report, we show that cPINK1 supports neuronal development by modulating the expression and extracellular release of brain-derived neurotrophic factor (BDNF). Consistent with this role, we observed a progressive increase in the level of endogenous cPINK1 but not fPINK1 during prenatal and postnatal development of mouse brains and during development in primary cortical neurons. In cultured primary neurons, the pharmacological activation of endogenous PINK1 leads to enhanced downstream PKA activity, subsequent activation of the PKA-modulated transcription factor cAMP response element-binding protein (CREB), increased intracellular production and extracellular release of BDNF, and enhanced activation of the BDNF receptor-TRKβ. Mechanistically, cPINK1-mediated increased dendrite complexity requires the binding of extracellular BDNF to TRKβ. In summary, our data support a physiological role of cPINK1 in stimulating neuronal development by activating the PKA-CREB-BDNF signaling axis in a feedforward loop.
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Affiliation(s)
- Smijin K Soman
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - David Tingle
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Raul Y Dagda
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Mariana Torres
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Marisela Dagda
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Ruben K Dagda
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, NV, USA
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5
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Liu Y, Li L, Pan N, Gu J, Qiu Z, Cao G, Dou Y, Dong L, Shuai J, Sang A. TNF-α released from retinal Müller cells aggravates retinal pigment epithelium cell apoptosis by upregulating mitophagy during diabetic retinopathy. Biochem Biophys Res Commun 2021; 561:143-150. [PMID: 34023779 DOI: 10.1016/j.bbrc.2021.05.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 05/08/2021] [Indexed: 12/20/2022]
Abstract
Retinal pigment epithelium (RPE) cell damage, including mitophagy-associated cell apoptosis, accelerates the pathogenesis of diabetic retinopathy (DR), a common complication of diabetes that causes blindness. Müller cells interact with RPE cells via pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α). Herein, we investigated the role of the RPE cell epidermal growth factor receptor (EGFR)/p38 mitogen-activated protein kinase (p38)/nuclear factor kappa B (NF-κB) pathway in Müller cell-derived TNF-α-induced mitophagy-associated apoptosis during DR. Our results showed that TNF-α released from Müller cells activated the EGFR/p38/NF-κB/p62 pathway to increase mitophagy and apoptosis in RPE cells under high glucose (HG) conditions. Additionally, blockade of the TNF-α/EGFR axis alleviates blood-retina barrier breakdown in diabetic mice. Our data further illustrate the effects of the Müller cell inflammatory response on RPE cell survival, implying potential molecular targets for DR treatment.
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Affiliation(s)
- Yu Liu
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China
| | - Lele Li
- Department of Ophthalmology, Affiliated Hospital 2 of Nantong University, Nantong, China
| | - Ningxin Pan
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China
| | - Jiayi Gu
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China
| | - Zhaoxian Qiu
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China
| | - Guoping Cao
- Department of Ophthalmology, Affiliated Hospital 5 of Nantong University, Taizhou, China
| | - Yuping Dou
- Department of Ophthalmology, Affiliated Hospital 5 of Nantong University, Taizhou, China
| | - Lili Dong
- Department of Ophthalmology, Affiliated Hospital 5 of Nantong University, Taizhou, China
| | - Jie Shuai
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China.
| | - Aimin Sang
- Department of Ophthalmology, Affiliated Hospital of Nantong University, Nantong, China.
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6
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Decreased Mitochondrial Function, Biogenesis, and Degradation in Peripheral Blood Mononuclear Cells from Amyotrophic Lateral Sclerosis Patients as a Potential Tool for Biomarker Research. Mol Neurobiol 2020; 57:5084-5102. [PMID: 32840822 PMCID: PMC7541388 DOI: 10.1007/s12035-020-02059-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/07/2020] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a multifactorial and progressive neurodegenerative disease of unknown etiology. Due to ALS’s unpredictable onset and progression rate, the search for biomarkers that allow the detection and tracking of its development and therapeutic efficacy would be of significant medical value. Considering that alterations of energy supply are one of ALS’s main hallmarks and that a correlation has been established between gene expression in human brain tissue and peripheral blood mononuclear cells (PBMCs), the present work investigates whether changes in mitochondrial function could be used to monitor ALS. To achieve this goal, PBMCs from ALS patients and control subjects were used; blood sampling is a quite non-invasive method and is cost-effective. Different parameters were evaluated, namely cytosolic calcium levels, mitochondrial membrane potential, oxidative stress, and metabolic compounds levels, as well as mitochondrial dynamics and degradation. Altogether, we observed lower mitochondrial calcium uptake/retention, mitochondria depolarization, and redox homeostasis deregulation, in addition to a decrease in critical metabolic genes, a diminishment in mitochondrial biogenesis, and an augmentation in mitochondrial fission and autophagy-related gene expression. All of these changes can contribute to the decreased ATP and pyruvate levels observed in ALS PBMCs. Our data indicate that PBMCs from ALS patients show a significant mitochondrial dysfunction, resembling several findings from ALS’ neural cells/models, which could be exploited as a powerful tool in ALS research. Our findings can also guide future studies on new pharmacological interventions for ALS since assessments of brain samples are challenging and represent a relevant limited strategy. Graphical abstract ![]()
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7
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Ravanidis S, Doxakis E. RNA-Binding Proteins Implicated in Mitochondrial Damage and Mitophagy. Front Cell Dev Biol 2020; 8:372. [PMID: 32582692 PMCID: PMC7287033 DOI: 10.3389/fcell.2020.00372] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 04/27/2020] [Indexed: 01/19/2023] Open
Abstract
The mitochondrial lifecycle comprises biogenesis, fusion and cristae remodeling, fission, and breakdown by the autophagosome. This cycle is essential for maintaining proper cellular function, and inhibition of any of these processes results in deterioration of bioenergetics and swift induction of apoptosis, particularly in energy-craving cells such as myocytes and neurons. Regulation of gene expression is a fundamental step in maintaining mitochondrial plasticity, mediated by (1) transcription factors that control the expression of mitochondrial mRNAs and (2) RNA-binding proteins (RBPs) that regulate mRNA splicing, stability, targeting to mitochondria, and translation. More recently, RBPs have been also shown to interact with proteins modulating the mitochondrial lifecycle. Importantly, misexpression or mutations in RBPs give rise to mitochondrial dysfunctions, and there is strong evidence to support that these mitochondrial impairments occur early in disease development, constituting leading causes of pathogenesis. This review presents key aspects of the molecular network of the disease-relevant RBPs, including transactive response DNA-binding protein 43 (TDP43), fused in sarcoma (FUS), T-cell intracellular antigen 1 (TIA1), TIA-related protein (TIAR), and pumilio (PUM) that drive mitochondrial dysfunction in the nervous system.
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Affiliation(s)
- Stylianos Ravanidis
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Epaminondas Doxakis
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
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8
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Shires SE, Quiles JM, Najor RH, Leon LJ, Cortez MQ, Lampert MA, Mark A, Gustafsson ÅB. Nuclear Parkin Activates the ERRα Transcriptional Program and Drives Widespread Changes in Gene Expression Following Hypoxia. Sci Rep 2020; 10:8499. [PMID: 32444656 PMCID: PMC7244578 DOI: 10.1038/s41598-020-65438-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/30/2020] [Indexed: 11/09/2022] Open
Abstract
Parkin is an E3 ubiquitin ligase well-known for facilitating clearance of damaged mitochondria by ubiquitinating proteins on the outer mitochondrial membrane. However, knowledge of Parkin's functions beyond mitophagy is still limited. Here, we demonstrate that Parkin has functions in the nucleus and that Parkinson's disease-associated Parkin mutants, ParkinR42P and ParkinG430D, are selectively excluded from the nucleus. Further, Parkin translocates to the nucleus in response to hypoxia which correlates with increased ubiquitination of nuclear proteins. The serine-threonine kinase PINK1 is responsible for recruiting Parkin to mitochondria, but translocation of Parkin to the nucleus occurs independently of PINK1. Transcriptomic analyses of HeLa cells overexpressing wild type or a nuclear-targeted Parkin revealed that during hypoxia, Parkin contributes to both increased and decreased transcription of genes involved in regulating multiple metabolic pathways. Furthermore, a proteomics screen comparing ubiquitinated proteins in hearts from Parkin-/- and Parkin transgenic mice identified the transcription factor estrogen-related receptor α (ERRα) as a potential Parkin target. Co-immunoprecipitation confirmed that nuclear-targeted Parkin interacts with and ubiquitinates ERRα. Further analysis uncovered that nuclear Parkin increases the transcriptional activity of ERRα. Overall, our study supports diverse roles for Parkin and demonstrates that nuclear Parkin regulates transcription of genes involved in multiple metabolic pathways.
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Affiliation(s)
- Sarah E Shires
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Justin M Quiles
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Rita H Najor
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Leonardo J Leon
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Melissa Q Cortez
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Mark A Lampert
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Adam Mark
- Center for Computational Biology & Bioinformatics, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Åsa B Gustafsson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.
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9
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Semmler S, Gagné M, Garg P, Pickles SR, Baudouin C, Hamon-Keromen E, Destroismaisons L, Khalfallah Y, Chaineau M, Caron E, Bayne AN, Trempe JF, Cashman NR, Star AT, Haqqani AS, Durcan TM, Meiering EM, Robertson J, Grandvaux N, Plotkin SS, McBride HM, Vande Velde C. TNF receptor-associated factor 6 interacts with ALS-linked misfolded superoxide dismutase 1 and promotes aggregation. J Biol Chem 2020; 295:3808-3825. [PMID: 32029478 DOI: 10.1074/jbc.ra119.011215] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 01/17/2020] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the selective loss of motor neurons leading to paralysis. Mutations in the gene encoding superoxide dismutase 1 (SOD1) are the second most common cause of familial ALS, and considerable evidence suggests that these mutations result in an increase in toxicity due to protein misfolding. We previously demonstrated in the SOD1G93A rat model that misfolded SOD1 exists as distinct conformers and forms deposits on mitochondrial subpopulations. Here, using SOD1G93A rats and conformation-restricted antibodies specific for misfolded SOD1 (B8H10 and AMF7-63), we identified the interactomes of the mitochondrial pools of misfolded SOD1. This strategy identified binding proteins that uniquely interacted with either AMF7-63 or B8H10-reactive SOD1 conformers as well as a high proportion of interactors common to both conformers. Of this latter set, we identified the E3 ubiquitin ligase TNF receptor-associated factor 6 (TRAF6) as a SOD1 interactor, and we determined that exposure of the SOD1 functional loops facilitates this interaction. Of note, this conformational change was not universally fulfilled by all SOD1 variants and differentiated TRAF6 interacting from TRAF6 noninteracting SOD1 variants. Functionally, TRAF6 stimulated polyubiquitination and aggregation of the interacting SOD1 variants. TRAF6 E3 ubiquitin ligase activity was required for the former but was dispensable for the latter, indicating that TRAF6-mediated polyubiquitination and aggregation of the SOD1 variants are independent events. We propose that the interaction between misfolded SOD1 and TRAF6 may be relevant to the etiology of ALS.
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Affiliation(s)
- Sabrina Semmler
- Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec H3A 2B4, Canada.,Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada
| | - Myriam Gagné
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Pranav Garg
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Sarah R Pickles
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Charlotte Baudouin
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada.,Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
| | - Emeline Hamon-Keromen
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada.,Université Pierre et Marie Curie, 75005 Paris, France
| | - Laurie Destroismaisons
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada
| | - Yousra Khalfallah
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada.,Department of Neurosciences, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Mathilde Chaineau
- Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec H3A 2B4, Canada.,Montreal Neurological Institute, McGill University, Montréal, Quebec H3A 2B4, Canada
| | - Elise Caron
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada
| | - Andrew N Bayne
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec H3A 2B4, Canada
| | - Jean-François Trempe
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec H3A 2B4, Canada
| | - Neil R Cashman
- Department of Medicine (Neurology), University of British Columbia and Vancouver Coastal Health Research Institute, Brain Research Centre, Vancouver, British Columbia V6T 2B5, Canada
| | - Alexandra T Star
- Human Health Therapeutics Portfolio, National Research Council of Canada, Ottawa, Ontario, K1A 0R6, Canada
| | - Arsalan S Haqqani
- Human Health Therapeutics Portfolio, National Research Council of Canada, Ottawa, Ontario, K1A 0R6, Canada
| | - Thomas M Durcan
- Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec H3A 2B4, Canada.,Montreal Neurological Institute, McGill University, Montréal, Quebec H3A 2B4, Canada
| | - Elizabeth M Meiering
- Department of Chemistry, Guelph-Waterloo Centre for Graduate Work in Chemistry and Biochemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Janice Robertson
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5T 0S8, Canada
| | - Nathalie Grandvaux
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Steven S Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Heidi M McBride
- Department of Neurology and Neurosurgery, McGill University, Montréal, Quebec H3A 2B4, Canada.,Montreal Neurological Institute, McGill University, Montréal, Quebec H3A 2B4, Canada
| | - Christine Vande Velde
- Centre de Recherche du Centre Hospitalier de Université de Montréal, Montréal, Quebec H2X 0A9, Canada .,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,Department of Neurosciences, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
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10
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Sun L, Büeler H. Proteasome inhibition promotes mono-ubiquitination and nuclear translocation of mature (52 kDa) PINK1. Biochem Biophys Res Commun 2019; 517:376-382. [DOI: 10.1016/j.bbrc.2019.07.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 07/17/2019] [Indexed: 12/31/2022]
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11
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Distinct multilevel misregulations of Parkin and PINK1 revealed in cell and animal models of TDP-43 proteinopathy. Cell Death Dis 2018; 9:953. [PMID: 30237395 PMCID: PMC6148241 DOI: 10.1038/s41419-018-1022-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/07/2018] [Accepted: 09/03/2018] [Indexed: 12/13/2022]
Abstract
Parkin and PINK1 play an important role in mitochondrial quality control, whose malfunction may also be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). Excessive TDP-43 accumulation is a pathological hallmark of ALS and is associated with Parkin protein reduction in spinal cord neurons from sporadic ALS patients. In this study, we reveal that Parkin and PINK1 are differentially misregulated in TDP-43 proteinopathy at RNA and protein levels. Using knock-in flies, mouse primary neurons, and TDP-43Q331K transgenic mice, we further unveil that TDP-43 downregulates Parkin mRNA, which involves an unidentified, intron-independent mechanism and requires the RNA-binding and the protein–protein interaction functions of TDP-43. Unlike Parkin, TDP-43 does not regulate PINK1 at an RNA level. Instead, excess of TDP-43 causes cytosolic accumulation of cleaved PINK1 due to impaired proteasomal activity, leading to compromised mitochondrial functions. Consistent with the alterations at the molecular and cellular levels, we show that transgenic upregulation of Parkin but downregulation of PINK1 suppresses TDP-43-induced degenerative phenotypes in a Drosophila model of ALS. Together, these findings highlight the challenge associated with the heterogeneity and complexity of ALS pathogenesis, while pointing to Parkin–PINK1 as a common pathway that may be differentially misregulated in TDP-43 proteinopathy.
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12
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Zimmermann M, Reichert AS. How to get rid of mitochondria: crosstalk and regulation of multiple mitophagy pathways. Biol Chem 2017; 399:29-45. [PMID: 28976890 DOI: 10.1515/hsz-2017-0206] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
Mitochondria are indispensable cellular organelles providing ATP and numerous other essential metabolites to ensure cell survival. Reactive oxygen species (ROS), which are formed as side reactions during oxidative phosphorylation or by external agents, induce molecular damage in mitochondrial proteins, lipids/membranes and DNA. To cope with this and other sorts of organellar stress, a multi-level quality control system exists to maintain cellular homeostasis. One critical level of mitochondrial quality control is the removal of damaged mitochondria by mitophagy. This process utilizes parts of the general autophagy machinery, e.g. for the formation of autophagosomes but also employs mitophagy-specific factors. Depending on the proteins utilized mitophagy is divided into receptor-mediated and ubiquitin-mediated mitophagy. So far, at least seven receptor proteins are known to be required for mitophagy under different experimental conditions. In contrast to receptor-mediated pathways, the Pink-Parkin-dependent pathway is currently the best characterized ubiquitin-mediated pathway. Recently two additional ubiquitin-mediated pathways with distinctive similarities and differences were unraveled. We will summarize the current state of knowledge about these multiple pathways, explain their mechanism, and describe the regulation and crosstalk between these pathways. Finally, we will review recent evidence for the evolutionary conservation of ubiquitin-mediated mitophagy pathways.
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Affiliation(s)
- Marcel Zimmermann
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, D-40225 Düsseldorf, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University, Universitätsstr. 1, D-40225 Düsseldorf, Germany
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13
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Brinkmann C, Przyklenk A, Metten A, Schiffer T, Bloch W, Brixius K, Gehlert S. Influence of endurance training on skeletal muscle mitophagy regulatory proteins in type 2 diabetic men. Endocr Res 2017; 42:325-330. [PMID: 28537848 DOI: 10.1080/07435800.2017.1323914] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Mitophagy is a form of autophagy for the elimination of mitochondria. Mitochondrial content and function are reduced in the skeletal muscle of patients with type 2 diabetes mellitus (T2DM). Physical training has been shown to restore mitochondrial capacity in T2DM patients, but the role of mitophagy has not been examined in this context. This study analyzes the impact of a 3-month endurance training on important skeletal muscle mitophagy regulatory proteins and oxidative phosphorylation (OXPHOS) complexes in T2DM patients. METHODS Muscle biopsies were obtained from eight overweight/obese T2DM men (61±10 years) at T1 (6 weeks pre-training), T2 (1 week pre-training), and T3 (3 to 4 days post-training). Protein contents were determined by Western blotting. RESULTS The training increased mitochondrial complex II significantly (T2-T3: +29%, p = 0.037). The protein contents of mitophagy regulatory proteins (phosphorylated form of forkhead box O3A (pFOXO3A), mitochondrial E3 ubiquitin protein ligase-1 (MUL1), Bcl-2/adenovirus E1B 19-kD interacting protein-3 (BNIP3), microtubule-associated protein 1 light chain-3B (the ratio LC3B-II/LC3B-I was determined)) did not differ significantly between T1, T2, and T3. CONCLUSIONS The results imply that training-induced changes in OXPHOS subunits (significant increase in complex II) are not accompanied by changes in mitophagy regulatory proteins in T2DM men. Future studies should elucidate whether acute exercise might affect mitophagic processes in T2DM patients (and whether a transient regulation of mitophagy regulatory proteins is evident) to fully clarify the role of physical activity and mitophagy for mitochondrial health in this particular patient group.
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MESH Headings
- Aged
- Biopsy, Needle
- Blotting, Western
- Body Mass Index
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Diabetes Mellitus, Type 2/therapy
- Electron Transport Complex II/biosynthesis
- Enzyme Induction
- Exercise
- Forkhead Box Protein O3/metabolism
- Humans
- Male
- Membrane Proteins/metabolism
- Middle Aged
- Mitophagy
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Overweight/complications
- Overweight/metabolism
- Overweight/pathology
- Overweight/therapy
- Phosphorylation
- Physical Endurance
- Physical Exertion
- Protein Processing, Post-Translational
- Proto-Oncogene Proteins/metabolism
- Reproducibility of Results
- Ubiquitin-Protein Ligases/metabolism
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Affiliation(s)
- Christian Brinkmann
- a Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine , German Sport University Cologne , Germany
- b IST University of Applied Sciences , Düsseldorf , Germany
| | - Axel Przyklenk
- a Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine , German Sport University Cologne , Germany
| | - Alexander Metten
- a Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine , German Sport University Cologne , Germany
| | - Thorsten Schiffer
- c Outpatient Clinic for Sports Traumatology and Public Health Consultation, German Sport University Cologne , Germany
| | - Wilhelm Bloch
- a Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine , German Sport University Cologne , Germany
| | - Klara Brixius
- a Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine , German Sport University Cologne , Germany
| | - Sebastian Gehlert
- a Department of Molecular and Cellular Sport Medicine, Institute of Cardiovascular Research and Sport Medicine , German Sport University Cologne , Germany
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14
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Torres-Odio S, Key J, Hoepken HH, Canet-Pons J, Valek L, Roller B, Walter M, Morales-Gordo B, Meierhofer D, Harter PN, Mittelbronn M, Tegeder I, Gispert S, Auburger G. Progression of pathology in PINK1-deficient mouse brain from splicing via ubiquitination, ER stress, and mitophagy changes to neuroinflammation. J Neuroinflammation 2017; 14:154. [PMID: 28768533 PMCID: PMC5541666 DOI: 10.1186/s12974-017-0928-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 07/26/2017] [Indexed: 12/18/2022] Open
Abstract
Background PINK1 deficiency causes the autosomal recessive PARK6 variant of Parkinson’s disease. PINK1 activates ubiquitin by phosphorylation and cooperates with the downstream ubiquitin ligase PARKIN, to exert quality control and control autophagic degradation of mitochondria and of misfolded proteins in all cell types. Methods Global transcriptome profiling of mouse brain and neuron cultures were assessed in protein-protein interaction diagrams and by pathway enrichment algorithms. Validation by quantitative reverse transcriptase polymerase chain reaction and immunoblots was performed, including human neuroblastoma cells and patient primary skin fibroblasts. Results In a first approach, we documented Pink1-deleted mice across the lifespan regarding brain mRNAs. The expression changes were always subtle, consistently affecting “intracellular membrane-bounded organelles”. Significant anomalies involved about 250 factors at age 6 weeks, 1300 at 6 months, and more than 3500 at age 18 months in the cerebellar tissue, including Srsf10, Ube3a, Mapk8, Creb3, and Nfkbia. Initially, mildly significant pathway enrichment for the spliceosome was apparent. Later, highly significant networks of ubiquitin-mediated proteolysis and endoplasmic reticulum protein processing occurred. Finally, an enrichment of neuroinflammation factors appeared, together with profiles of bacterial invasion and MAPK signaling changes—while mitophagy had minor significance. Immunohistochemistry showed pronounced cellular response of Iba1-positive microglia and GFAP-positive astrocytes; brain lipidomics observed increases of ceramides as neuroinflammatory signs at old age. In a second approach, we assessed PINK1 deficiency in the presence of a stressor. Marked dysregulations of microbial defense factors Ifit3 and Rsad2 were consistently observed upon five analyses: (1) Pink1−/− primary neurons in the first weeks after brain dissociation, (2) aged Pink1−/− midbrain with transgenic A53T-alpha-synuclein overexpression, (3) human neuroblastoma cells with PINK1-knockdown and murine Pink1−/− embryonal fibroblasts undergoing acute starvation, (4) triggering mitophagy in these cells with trifluoromethoxy carbonylcyanide phenylhydrazone (FCCP), and (5) subjecting them to pathogenic RNA-analogue poly(I:C). The stress regulation of MAVS, RSAD2, DDX58, IFIT3, IFIT1, and LRRK2 was PINK1 dependent. Dysregulation of some innate immunity genes was also found in skin fibroblast cells from PARK6 patients. Conclusions Thus, an individual biomarker with expression correlating to progression was not identified. Instead, more advanced disease stages involved additional pathways. Hence, our results identify PINK1 deficiency as an early modulator of innate immunity in neurons, which precedes late stages of neuroinflammation during alpha-synuclein spreading. Electronic supplementary material The online version of this article (doi:10.1186/s12974-017-0928-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sylvia Torres-Odio
- Experimental Neurology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Jana Key
- Experimental Neurology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Hans-Hermann Hoepken
- Experimental Neurology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Júlia Canet-Pons
- Experimental Neurology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Lucie Valek
- Institute of Clinical Pharmacology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Bastian Roller
- Edinger-Institute (Institute of Neurology), Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Michael Walter
- Institute for Medical Genetics, Eberhard-Karls-University of Tuebingen, 72076, Tuebingen, Germany
| | - Blas Morales-Gordo
- Department of Neurology, University Hospital San Cecilio, 18012, Granada, Spain
| | - David Meierhofer
- Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, 14195, Berlin, Germany
| | - Patrick N Harter
- Edinger-Institute (Institute of Neurology), Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Michel Mittelbronn
- Edinger-Institute (Institute of Neurology), Goethe University Medical School, 60590, Frankfurt am Main, Germany.,Luxembourg Centre of Neuropathology (LCNP), Luxembourg, Luxembourg.,Department of Pathology, Laboratoire National de Santé, Dudelange, Luxembourg.,Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Esch-sur-Alzette, Luxembourg, Luxembourg.,Department of Oncology, Luxembourg Institute of Health, NORLUX Neuro-Oncology Laboratory, Luxembourg, Luxembourg
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Suzana Gispert
- Experimental Neurology, Goethe University Medical School, 60590, Frankfurt am Main, Germany
| | - Georg Auburger
- Experimental Neurology, Goethe University Medical School, 60590, Frankfurt am Main, Germany.
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15
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Leermakers PA, Gosker HR. Skeletal muscle mitophagy in chronic disease: implications for muscle oxidative capacity? Curr Opin Clin Nutr Metab Care 2016; 19:427-433. [PMID: 27537277 DOI: 10.1097/mco.0000000000000319] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Loss of skeletal muscle oxidative capacity is a common feature of chronic diseases such as chronic obstructive pulmonary disease, type 2 diabetes, and congestive heart failure. It may lead to physical impairments and has been suggested to contribute to metabolic inflexibility-induced cardiometabolic risk. The mechanism underlying loss of muscle oxidative capacity is incompletely understood. This review discusses the role of mitophagy as a driving force behind the loss of skeletal muscle oxidative capacity in these patients. RECENT FINDINGS Mitophagy has been studied to a very limited extent in human skeletal muscle. There are, however, clear indications that disease-related factors, including hypoxia, systemic inflammation, muscle inactivity, and iron deficiency are able to induce mitophagy, and that these factors trigger mitophagy via different regulatory mechanisms. Although mitophagy may lead to mitochondrial loss, it is also required to maintain homeostasis through clearance of damaged mitochondria. SUMMARY Based on available evidence, we propose that enhanced mitophagy is involved in chronic disease-induced loss of muscle oxidative capacity. Clearly more research is required to confirm this role and to establish to what extent mitophagy is pathological or a part of physiological adaptation to maintain muscle health.
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Affiliation(s)
- Pieter A Leermakers
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
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16
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Szargel R, Shani V, Abd Elghani F, Mekies LN, Liani E, Rott R, Engelender S. The PINK1, synphilin-1 and SIAH-1 complex constitutes a novel mitophagy pathway. Hum Mol Genet 2016; 25:3476-3490. [DOI: 10.1093/hmg/ddw189] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
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17
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Abstract
α-Synuclein inclusion bodies are a pathological hallmark of several neurodegenerative diseases, including Parkinson’s disease, and contain aggregated α-synuclein and a variety of recruited factors, including protein chaperones, proteasome components, ubiquitin and the small ubiquitin-like modifier, SUMO-1. Cell culture and animal model studies suggest that misfolded, aggregated α-synuclein is actively translocated via the cytoskeletal system to a region of the cell where other factors that help to lessen the toxic effects can also be recruited. SUMO-1 covalently conjugates to various intracellular target proteins in a way analogous to ubiquitination to alter cellular distribution, function and metabolism and also plays an important role in a growing list of cellular pathways, including exosome secretion and apoptosis. Furthermore, SUMO-1 modified proteins have recently been linked to cell stress responses, such as oxidative stress response and heat shock response, with increased SUMOylation being neuroprotective in some cases. Several recent studies have linked SUMOylation to the ubiquitin-proteasome system, while other evidence implicates the lysosomal pathway. Other reports depict a direct mechanism whereby sumoylation reduced the aggregation tendency of α-synuclein, and reduced the toxicity. However, the precise role of SUMO-1 in neurodegeneration remains unclear. In this review, we explore the potential direct or indirect role(s) of SUMO-1 in the cellular response to misfolded α-synuclein in neurodegenerative disorders.
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