1801
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Dynamic recruitment and activation of ALS-associated TBK1 with its target optineurin are required for efficient mitophagy. Proc Natl Acad Sci U S A 2016; 113:E3349-58. [PMID: 27247382 DOI: 10.1073/pnas.1523810113] [Citation(s) in RCA: 240] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondria play an essential role in maintaining cellular homeostasis. The removal of damaged or depolarized mitochondria occurs via mitophagy, in which damaged mitochondria are targeted for degradation via ubiquitination induced by PTEN-induced putative kinase 1 (PINK1) and Parkin. Mitophagy receptors, including optineurin (OPTN), nuclear dot 52 kDa protein (NDP52), and Tax1-binding protein 1 (TAX1BP1), are recruited to mitochondria via ubiquitin binding and mediate autophagic engulfment through their association with microtubule-associated protein light chain 3 (LC3). Here, we use live-cell imaging to demonstrate that OPTN, NDP52, and TAX1BP1 are recruited to mitochondria with similar kinetics following either mitochondrial depolarization or localized generation of reactive oxygen species, leading to sequestration by the autophagosome within ∼45 min after insult. Despite this corecruitment, we find that depletion of OPTN, but not NDP52, significantly slows the efficiency of sequestration. OPTN is phosphorylated by the kinase TANK-binding kinase 1 (TBK1) at serine 177; we find that TBK1 is corecruited with OPTN to depolarized mitochondria. Inhibition or depletion of TBK1, or expression of amyotrophic lateral sclerosis (ALS)-associated OPTN or TBK1 mutant blocks efficient autophagosome formation. Together, these results indicate that although there is some functional redundancy among mitophagy receptors, efficient sequestration of damaged mitochondria in response to mitochondrial stress requires both TBK1 and OPTN. Notably, ALS-linked mutations in OPTN and TBK1 can interfere with mitophagy, suggesting that inefficient turnover of damaged mitochondria may represent a key pathophysiological mechanism contributing to neurodegenerative disease.
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1802
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Zhang J, Chen K, Wang L, Wan X, Shrestha C, Zhou J, Mo Z. Phosphatase and tensin homologue (PTEN)-induced putative kinase 1 reduces pancreatic β-cells apoptosis in glucotoxicity through activation of autophagy. Biochem Biophys Res Commun 2016; 476:299-305. [PMID: 27233610 DOI: 10.1016/j.bbrc.2016.05.116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 05/23/2016] [Indexed: 10/21/2022]
Abstract
Chronic elevated glucose is harmful to pancreatic β-cells, resulting in pancreatic β-cells dysfunction and apoptosis. Understanding the molecular mechanisms associated with β-cells survival is pivotal for the prevention of β-cells injury caused by glucotoxicity. The role of Phosphatase and tensin homologue (PTEN)-induced putative kinase 1 (PINK1) in the fate of pancreatic β-cells constantly exposed to high glucose was studied. Sustained high glucose increased PINK1 protein expression both in rat pancreatic β-cells and INS-1 β-cells, and that this increase can be inhibited by PINK1 knockdown and further enhanced by PINK1 over-expression. PINK1 deficiency aggravated glucotoxicity-induced pancreatic β-cells apoptosis and inhibition of autophagy whereas PINK1 could reverse these adverse effects. This study provides fundamental data supporting the potential protective role of PINK1 as a new therapeutic target necessary to preserve β-cells survival under non-physiological hyperglycemia conditions.
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Affiliation(s)
- Juan Zhang
- Department of Endocrinology and Metabolism, The Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, PR China.
| | - Ke Chen
- Department of Endocrinology and Metabolism, The Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, PR China.
| | - Linghao Wang
- Department of Endocrinology and Metabolism, The Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, PR China.
| | - Xinxin Wan
- Department of Endocrinology and Metabolism, The Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, PR China.
| | - Chandrama Shrestha
- Department of Endocrinology and Metabolism, The Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, PR China.
| | - Jingsong Zhou
- Department of Physiology, Kansas City University of Medicine and Biosciences, 1750 Independence Ave, Kansas City, MO 64106, USA.
| | - Zhaohui Mo
- Department of Endocrinology and Metabolism, The Third Xiangya Hospital of Central South University, 138 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, PR China.
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1803
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Fanconi Anemia Genes, of Menders and Sweepers. Dev Cell 2016; 37:299-300. [PMID: 27219059 DOI: 10.1016/j.devcel.2016.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Reporting recently in Cell, Sumpter et al. (2016) provide evidence that Fanconi anemia (FA) pathway genes, which are mutated in the homonymous disease and are tumor suppressors known as damaged nuclear DNA "menders," also act as intracellular sweepers in selective virophagy and mitophagy.
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1804
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Shirakabe A, Ikeda Y, Sciarretta S, Zablocki DK, Sadoshima J. Aging and Autophagy in the Heart. Circ Res 2016; 118:1563-76. [PMID: 27174950 PMCID: PMC4869999 DOI: 10.1161/circresaha.116.307474] [Citation(s) in RCA: 307] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 02/15/2016] [Indexed: 12/15/2022]
Abstract
The aging population is increasing in developed countries. Because the incidence of cardiac disease increases dramatically with age, it is important to understand the molecular mechanisms through which the heart becomes either more or less susceptible to stress. Cardiac aging is characterized by the presence of hypertrophy, fibrosis, and accumulation of misfolded proteins and dysfunctional mitochondria. Macroautophagy (hereafter referred to as autophagy) is a lysosome-dependent bulk degradation mechanism that is essential for intracellular protein and organelle quality control. Autophagy and autophagic flux are generally decreased in aging hearts, and murine autophagy loss-of-function models develop exacerbated cardiac dysfunction that is accompanied by the accumulation of misfolded proteins and dysfunctional organelles. On the contrary, stimulation of autophagy generally improves cardiac function in mouse models of protein aggregation by removing accumulated misfolded proteins, dysfunctional mitochondria, and damaged DNA, thereby improving the overall cellular environment and alleviating aging-associated pathology in the heart. Increasing lines of evidence suggest that autophagy is required for many mechanisms that mediate lifespan extension, such as caloric restriction, in various organisms. These results raise the exciting possibility that autophagy may play an important role in combating the adverse effects of aging in the heart. In this review, we discuss the role of autophagy in the heart during aging, how autophagy alleviates age-dependent changes in the heart, and how the level of autophagy in the aging heart can be restored.
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Affiliation(s)
- Akihiro Shirakabe
- From the Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (A.S., Y.I., S.S., D.K.Z., J.S.); Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Science, Kagoshima University, Japan (Y.I.); Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy (S.S.); and Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S.)
| | - Yoshiyuki Ikeda
- From the Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (A.S., Y.I., S.S., D.K.Z., J.S.); Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Science, Kagoshima University, Japan (Y.I.); Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy (S.S.); and Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S.)
| | - Sebastiano Sciarretta
- From the Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (A.S., Y.I., S.S., D.K.Z., J.S.); Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Science, Kagoshima University, Japan (Y.I.); Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy (S.S.); and Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S.)
| | - Daniela K Zablocki
- From the Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (A.S., Y.I., S.S., D.K.Z., J.S.); Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Science, Kagoshima University, Japan (Y.I.); Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy (S.S.); and Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S.)
| | - Junichi Sadoshima
- From the Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (A.S., Y.I., S.S., D.K.Z., J.S.); Department of Cardiovascular Medicine and Hypertension, Graduate School of Medical and Dental Science, Kagoshima University, Japan (Y.I.); Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Rome, Italy (S.S.); and Department of AngioCardioNeurology, IRCCS Neuromed, Pozzilli, Italy (S.S.).
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1805
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Montagna C, Rizza S, Maiani E, Piredda L, Filomeni G, Cecconi F. To eat, or NOt to eat: S-nitrosylation signaling in autophagy. FEBS J 2016; 283:3857-3869. [PMID: 27083138 DOI: 10.1111/febs.13736] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/14/2016] [Accepted: 04/08/2016] [Indexed: 12/15/2022]
Abstract
Autophagy is the main catabolic cellular process through which cells adapt their needs (e.g., growth and proliferation) to environmental availability of nutrients (e.g., amino acid and glucose) and growth factors. The rapid activation of the autophagy response essentially depends on protein post-translational modifications (PTMs), which act as molecular switches triggering signaling cascades. Deregulation of autophagy contributes to pathological conditions, such as cancer and neurodegeneration. Therefore, understanding how PTMs affect the occurrence of autophagy is of the highest importance for clinical applications. Besides phosphorylation and ubiquitylation, which represent the best known examples of PTMs, redox-based modifications are also emerging as contributing to the regulation of intracellular signaling. Of note, S-nitrosylation of cysteine residues is a redox PTM and is the principal mechanism of nitric oxide-based signaling. Results emerging in recent years suggest that NO has a role in modulating autophagy. However, the function of S-nitrosylation in autophagy regulation remains still unveiled. By this review, we describe the upstream events regulating autophagy activation focusing on recently published evidence implying a S-nitrosylation-dependent regulation.
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Affiliation(s)
| | | | | | - Lucia Piredda
- Department of Biology, University of Rome Tor Vergata, Italy
| | - Giuseppe Filomeni
- Danish Cancer Society Research Center, Copenhagen, Denmark.,Department of Biology, University of Rome Tor Vergata, Italy
| | - Francesco Cecconi
- Danish Cancer Society Research Center, Copenhagen, Denmark.,Department of Biology, University of Rome Tor Vergata, Italy.,IRCCS Fondazione Santa Lucia, Rome, Italy
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1806
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Meena NP, Zhu G, Mittelstadt PR, Giardino Torchia ML, Pourcelot M, Arnoult D, Ashwell JD, Munitic I. The TBK1-binding domain of optineurin promotes type I interferon responses. FEBS Lett 2016; 590:1498-508. [PMID: 27086836 DOI: 10.1002/1873-3468.12176] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 01/24/2023]
Abstract
Pathogen-associated molecular pattern (PAMP) recognition leads to TANK-binding kinase (TBK1) polyubiquitination and activation by transautophosphorylation, resulting in IFN-β production. Here, we describe a mouse model of optineurin insufficiency (OptnΔ(157) ) in which the TBK1-interacting N-terminus of optineurin was deleted. PAMP-stimulated cells from OptnΔ(157) mice had reduced TBK1 activity, no phosphorylation of optineurin Ser(187) , and mounted low IFN-β responses. In contrast to pull-down assays where the presence of N-terminus was sufficient for TBK1 binding, both the N-terminal and the ubiquitin-binding regions of optineurin were needed for PAMP-induced binding. This report establishes optineurin as a positive regulator TBK1 via a bipartite interaction between these molecules.
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Affiliation(s)
- Netra Pal Meena
- Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Guozhi Zhu
- Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Paul R Mittelstadt
- Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Marie Pourcelot
- INSERM, UMR_S 1197, Hôpital Paul Brousse, Villejuif, France.,Université Paris-Saclay, Villejuif, France
| | - Damien Arnoult
- INSERM, UMR_S 1197, Hôpital Paul Brousse, Villejuif, France.,Université Paris-Saclay, Villejuif, France
| | - Jonathan D Ashwell
- Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ivana Munitic
- Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.,Laboratory of Molecular Immunology, Department of Biotechnology, University of Rijeka, Croatia
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1807
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Pabon MA, Ma KC, Choi AMK. Autophagy and Obesity-Related Lung Disease. Am J Respir Cell Mol Biol 2016; 54:636-46. [PMID: 26900794 PMCID: PMC5455357 DOI: 10.1165/rcmb.2016-0045ps] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 02/22/2016] [Indexed: 12/11/2022] Open
Abstract
Obesity-related disease is a significant source of premature death and economic burden globally. It is also a common comorbidity in patients suffering from lung disease, affecting both severity and treatment success. However, this complex association between obesity and the lung is poorly understood. Autophagy is a self-recycling homeostatic process that has been linked to beneficial or deleterious effects, depending on the specific lung disease. Obesity affects autophagy in a tissue-specific manner, activating autophagy in adipocytes and impairing autophagy in hepatocytes, immune cells, and pancreatic β-cells, among others. Obesity is also characterized by chronic low-grade inflammation that can be modulated by the pro- and antiinflammatory effects of the autophagic machinery. Scant evidence exists regarding the impact of autophagy in obesity-related lung diseases, but there are communal pathways that could be related to disease pathogenesis. Important signaling molecules in obesity, including IL-17, leptin, adiponectin, NLRP3 inflammasome, and TLR-4, have been implicated in the pathogenesis of lung disease. These mediators are known to be modulated by autophagy activity. In this perspective, we highlight the recent advances in the understanding of autophagy in obesity-related conditions, as well as the potential mechanisms that can link autophagy and obesity in the pathogenesis of lung disease.
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Affiliation(s)
- Maria A Pabon
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York
| | - Kevin C Ma
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York
| | - Augustine M K Choi
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, New York
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1808
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Pao KC, Stanley M, Han C, Lai YC, Murphy P, Balk K, Wood NT, Corti O, Corvol JC, Muqit MM, Virdee S. Probes of ubiquitin E3 ligases enable systematic dissection of parkin activation. Nat Chem Biol 2016; 12:324-31. [PMID: 26928937 PMCID: PMC4909137 DOI: 10.1038/nchembio.2045] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 02/08/2016] [Indexed: 12/17/2022]
Abstract
E3 ligases represent an important class of enzymes, yet there are currently no chemical probes for profiling their activity. We develop a new class of activity-based probe by re-engineering a ubiquitin-charged E2 conjugating enzyme and demonstrate the utility of these probes by profiling the transthiolation activity of the RING-in-between-RING (RBR) E3 ligase parkin in vitro and in cellular extracts. Our study provides valuable insight into the roles, and cellular hierarchy, of distinct phosphorylation events in parkin activation. We also profile parkin mutations associated with patients with Parkinson's disease and demonstrate that they mediate their effect largely by altering transthiolation activity. Furthermore, our probes enable direct and quantitative measurement of endogenous parkin activity, revealing that endogenous parkin is activated in neuronal cell lines (≥75%) in response to mitochondrial depolarization. This new technology also holds promise as a novel biomarker of PINK1-parkin signaling, as demonstrated by its compatibility with samples derived from individuals with Parkinson's disease.
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Affiliation(s)
- Kuan-Chuan Pao
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Mathew Stanley
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Cong Han
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Yu-Chiang Lai
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Paul Murphy
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Kristin Balk
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Nicola T. Wood
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
| | - Olga Corti
- Sorbonne Universités, UPMC Univ Paris 06; and INSERM UMRS_1127, CIC_1422; CNRS UMR_7225; AP-HP and ICM, Hôpital Pitié-Salpêtrière, Department of Neurology, F-75013, Paris, France
| | - Jean-Christophe Corvol
- Sorbonne Universités, UPMC Univ Paris 06; and INSERM UMRS_1127, CIC_1422; CNRS UMR_7225; AP-HP and ICM, Hôpital Pitié-Salpêtrière, Department of Neurology, F-75013, Paris, France
| | - Miratul M.K. Muqit
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
- School of Medicine, University of Dundee, Dundee, Scotland, UK, DD1 9SY
| | - Satpal Virdee
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Scotland, UK, DD1 5EH
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1809
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Fang EF, Scheibye-Knudsen M, Chua KF, Mattson MP, Croteau DL, Bohr VA. Nuclear DNA damage signalling to mitochondria in ageing. Nat Rev Mol Cell Biol 2016; 17:308-21. [PMID: 26956196 PMCID: PMC5161407 DOI: 10.1038/nrm.2016.14] [Citation(s) in RCA: 268] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondrial dysfunction is a hallmark of ageing, and mitochondrial maintenance may lead to increased healthspan. Emerging evidence suggests a crucial role for signalling from the nucleus to mitochondria (NM signalling) in regulating mitochondrial function and ageing. An important initiator of NM signalling is nuclear DNA damage, which accumulates with age and may contribute to the development of age-associated diseases. DNA damage-dependent NM signalling constitutes a network that includes nuclear sirtuins and controls genomic stability and mitochondrial integrity. Pharmacological modulation of NM signalling is a promising novel approach for the prevention and treatment of age-associated diseases.
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Affiliation(s)
- Evandro Fei Fang
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Morten Scheibye-Knudsen
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Katrin F Chua
- Department of Medicine, Division of Endocrinology, Gerontology, and Metabolism, School of Medicine, Stanford University, Stanford, California 94305, USA
- Geriatric Research, Education, and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
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1810
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Endophilin B2 promotes inner mitochondrial membrane degradation by forming heterodimers with Endophilin B1 during mitophagy. Sci Rep 2016; 6:25153. [PMID: 27112121 PMCID: PMC4845016 DOI: 10.1038/srep25153] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/11/2016] [Indexed: 11/21/2022] Open
Abstract
Mitochondrial sequestration by autophagosomes is a key step in mitophagy while the mechanisms mediating this process are not fully understood. It has been reported that Endophilin B1 (EB1) promotes mitochondrial sequestration by binding and shaping membrane. However, the role of EB1 homolog Endophilin B2 (EB2) in mitophagy remains unclear. Here we report that EB2 plays an indispensable role in mitochondria sequestration and inner mitochondrial membrane (IMM) protein degradation during mitophagy. Similar to EB1, EB2 aggregates into foci and then translocates to damaged mitochondria. Loss of either EB2 and/or EB1 significantly enervates the foci translocation to fragmented mitochondria and IMM degradation, and the EB1/EB2 heterodimer formed by EB1/EB2 interaction promotes the above process. We noticed that, it is the dimer domain of EB2 but not that of EB1 mediating the heterodimer formation, manifesting the importance of EB2 in mitophagy. Furthermore, we demonstrate that the EB foci formation is closely regulated by the PINK1-Parkin signaling pathway. From these results, we propose that EB1/EB2 heterodimers may serve as linkers between damaged mitochondria and phagophores during mitophagy.
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1811
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Sellier C, Campanari ML, Julie Corbier C, Gaucherot A, Kolb-Cheynel I, Oulad-Abdelghani M, Ruffenach F, Page A, Ciura S, Kabashi E, Charlet-Berguerand N. Loss of C9ORF72 impairs autophagy and synergizes with polyQ Ataxin-2 to induce motor neuron dysfunction and cell death. EMBO J 2016; 35:1276-97. [PMID: 27103069 DOI: 10.15252/embj.201593350] [Citation(s) in RCA: 306] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/15/2016] [Indexed: 12/12/2022] Open
Abstract
An intronic expansion of GGGGCC repeats within the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD). Ataxin-2 with intermediate length of polyglutamine expansions (Ataxin-2 Q30x) is a genetic modifier of the disease. Here, we found that C9ORF72 forms a complex with the WDR41 and SMCR8 proteins to act as a GDP/GTP exchange factor for RAB8a and RAB39b and to thereby control autophagic flux. Depletion of C9orf72 in neurons partly impairs autophagy and leads to accumulation of aggregates of TDP-43 and P62 proteins, which are histopathological hallmarks of ALS-FTD SMCR8 is phosphorylated by TBK1 and depletion of TBK1 can be rescued by phosphomimetic mutants of SMCR8 or by constitutively active RAB39b, suggesting that TBK1, SMCR8, C9ORF72, and RAB39b belong to a common pathway regulating autophagy. While depletion of C9ORF72 only has a partial deleterious effect on neuron survival, it synergizes with Ataxin-2 Q30x toxicity to induce motor neuron dysfunction and neuronal cell death. These results indicate that partial loss of function of C9ORF72 is not deleterious by itself but synergizes with Ataxin-2 toxicity, suggesting a double-hit pathological mechanism in ALS-FTD.
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Affiliation(s)
- Chantal Sellier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Maria-Letizia Campanari
- Sorbonne Université, Université Pierre et Marie Curie (UPMC), Université de Paris 06, Unité Mixte 75, Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1127, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225 Institut du Cerveau et de la Moelle Épinière (ICM), 75013, Paris, France
| | - Camille Julie Corbier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Angeline Gaucherot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Isabelle Kolb-Cheynel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Mustapha Oulad-Abdelghani
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Frank Ruffenach
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Adeline Page
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
| | - Sorana Ciura
- Sorbonne Université, Université Pierre et Marie Curie (UPMC), Université de Paris 06, Unité Mixte 75, Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1127, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225 Institut du Cerveau et de la Moelle Épinière (ICM), 75013, Paris, France
| | - Edor Kabashi
- Sorbonne Université, Université Pierre et Marie Curie (UPMC), Université de Paris 06, Unité Mixte 75, Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 1127, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche 7225 Institut du Cerveau et de la Moelle Épinière (ICM), 75013, Paris, France
| | - Nicolas Charlet-Berguerand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, Strasbourg University, Illkirch, France
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1812
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Pryde KR, Smith HL, Chau KY, Schapira AHV. PINK1 disables the anti-fission machinery to segregate damaged mitochondria for mitophagy. J Cell Biol 2016; 213:163-71. [PMID: 27091447 PMCID: PMC5084273 DOI: 10.1083/jcb.201509003] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 03/08/2016] [Indexed: 01/08/2023] Open
Abstract
In addition to recruiting Parkin/autophagy receptors to damaged mitochondria, the authors show that PINK1 triggers PKA displacement from AKAP1 after damage to trigger mitochondrial fission in a Parkin-independent manner, suggesting that PINK1 is a master mitophagy regulator. Mitochondrial fission is essential for the degradation of damaged mitochondria. It is currently unknown how the dynamin-related protein 1 (DRP1)–associated fission machinery is selectively targeted to segregate damaged mitochondria. We show that PTEN-induced putative kinase (PINK1) serves as a pro-fission signal, independently of Parkin. Normally, the scaffold protein AKAP1 recruits protein kinase A (PKA) to the outer mitochondrial membrane to phospho-inhibit DRP1. We reveal that after damage, PINK1 triggers PKA displacement from A-kinase anchoring protein 1. By ejecting PKA, PINK1 ensures the requisite fission of damaged mitochondria for organelle degradation. We propose that PINK1 functions as a master mitophagy regulator by activating Parkin and DRP1 in response to damage. We confirm that PINK1 mutations causing Parkinson disease interfere with the orchestration of selective fission and mitophagy by PINK1.
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Affiliation(s)
- Kenneth R Pryde
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, England, UK
| | - Heather L Smith
- Faculty of Brain Sciences, University College London, London W1T 7NF, England, UK
| | - Kai-Yin Chau
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, England, UK
| | - Anthony H V Schapira
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, England, UK
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1813
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Osellame LD, Singh AP, Stroud DA, Palmer CS, Stojanovski D, Ramachandran R, Ryan MT. Cooperative and independent roles of the Drp1 adaptors Mff, MiD49 and MiD51 in mitochondrial fission. J Cell Sci 2016; 129:2170-81. [PMID: 27076521 DOI: 10.1242/jcs.185165] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/07/2016] [Indexed: 12/30/2022] Open
Abstract
Cytosolic dynamin-related protein 1 (Drp1, also known as DNM1L) is required for both mitochondrial and peroxisomal fission. Drp1-dependent division of these organelles is facilitated by a number of adaptor proteins at mitochondrial and peroxisomal surfaces. To investigate the interplay of these adaptor proteins, we used gene-editing technology to create a suite of cell lines lacking the adaptors MiD49 (also known as MIEF2), MiD51 (also known as MIEF1), Mff and Fis1. Increased mitochondrial connectivity was observed following loss of individual adaptors, and this was further enhanced following the combined loss of MiD51 and Mff. Moreover, loss of adaptors also conferred increased resistance of cells to intrinsic apoptotic stimuli, with MiD49 and MiD51 showing the more prominent role. Using a proximity-based biotin labeling approach, we found close associations between MiD51, Mff and Drp1, but not Fis1. Furthermore, we found that MiD51 can suppress Mff-dependent enhancement of Drp1 GTPase activity. Our data indicates that Mff and MiD51 regulate Drp1 in specific ways to promote mitochondrial fission.
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Affiliation(s)
- Laura D Osellame
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Australia
| | - Abeer P Singh
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Australia Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne 3086, Australia
| | - David A Stroud
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Australia
| | - Catherine S Palmer
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, 3010, Australia
| | - Rajesh Ramachandran
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Michael T Ryan
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Australia
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1814
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Sun L, Xia WY, Zhao SH, Liu N, Liu SS, Xiu P, Li LF, Cao XL, Gao JX. An asymmetrically dimethylarginated nuclear 90 kDa protein (p90aDMA) induced by interleukin (IL)-2, IL-4 or IL-6 in the tumor microenvironment is selectively degraded by autophagy. Int J Oncol 2016; 48:2461-71. [PMID: 27035405 DOI: 10.3892/ijo.2016.3450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 10/19/2015] [Indexed: 11/06/2022] Open
Abstract
Protein arginine methylation is a common posttranslational modification resulting in the generation of asymmetric dimethylarginine (aDMA) and symmetric dimethylarginine (sDMA). Currently, the regulation of aDMA or sDMA by hypoxia, nutrient stavation or cytokines in the tumor microenvironment remains largely unknown. Here we show that p90aDMA, p70aDMA and p90sDMA, endogenous proteins containing aDMA or sDMA with mass 70 or 90 kDa, were widely and dominantly expressed in breast cancer cell lines. Notably, it was p90aDMA rather than p90sDMA that accumulated in the nucleus upon stimulation of cancer cells with interleukin (IL)-2, IL-4, IL-6 but not IL-8. In addition, the p90aDMA accumulation could be inhibited after treatment with a global methyltrasferase inhibitor, adenosine-2',3'-dialdehyde (AdOx). It seemed that some endogenous proteins in cancer cells were asymmetrically arginine-methylated upon exposure to some cytokines.. Furthermore, endogenous proteins of aDMA, such as p90aDMA and p70aDMA, were degraded in response to hypoxia, nutrient starvation and rapamycin treatment in breast and cervical cancer cells. IL-2/4/6 slightly increased basal autophagy but slightly decreased the rapamycin‑induced autophagy in cancer cells, suggesting that IL-2/4/6 and autophagy inducers play distinct roles in the regulation of aDMA of proteins. Conversely, rapamycin accumulated p90sDMA in MDA-MB‑231 and MCF-7 cells. Taken together, our results add a new dimension to the complexity of arginine methylated regulation in response to various stimuli and provide the first evidence that aDMA serves as one specific degradation signal of selective autophagy.
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Affiliation(s)
- Lei Sun
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Wu-Yan Xia
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Shao-Hua Zhao
- Department of Geriatric Cardiology, Qi Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Ning Liu
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Shan-Shan Liu
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Peng Xiu
- Department of Biliary-Pancreatic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Lin-Feng Li
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Xue-Lei Cao
- Department of Clinical Laboratory, Qi Lu Hospital of Shandong University, Jinan, Shandong 250012, P.R. China
| | - Jian-Xin Gao
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Clinical Stem Cell Research Center, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
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1815
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Martini-Stoica H, Xu Y, Ballabio A, Zheng H. The Autophagy-Lysosomal Pathway in Neurodegeneration: A TFEB Perspective. Trends Neurosci 2016; 39:221-234. [PMID: 26968346 PMCID: PMC4928589 DOI: 10.1016/j.tins.2016.02.002] [Citation(s) in RCA: 288] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/03/2016] [Accepted: 02/09/2016] [Indexed: 02/08/2023]
Abstract
The autophagy-lysosomal pathway (ALP) is involved in the degradation of long-lived proteins. Deficits in the ALP result in protein aggregation, the generation of toxic protein species, and accumulation of dysfunctional organelles, which are hallmarks of Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and prion disease. Decades of research have therefore focused on enhancing the ALP in neurodegenerative diseases. More recently, transcription factor EB (TFEB), a major regulator of autophagy and lysosomal biogenesis, has emerged as a leading factor in addressing disease pathology. We review the regulation of the ALP and TFEB and their impact on neurodegenerative diseases. We also offer our perspective on the complex role of autophagy and TFEB in disease pathogenesis and its therapeutic implications through the examination of prion disease.
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Affiliation(s)
- Heidi Martini-Stoica
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Yin Xu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Andrea Ballabio
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Dan and Jan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA; Telethon Institute of Genetics and Medicine (TIGEM) and Department of Translational Medical Sciences, Frederico II University, Naples, Italy
| | - Hui Zheng
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX.
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1816
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Schreij AMA, Fon EA, McPherson PS. Endocytic membrane trafficking and neurodegenerative disease. Cell Mol Life Sci 2016; 73:1529-45. [PMID: 26721251 PMCID: PMC11108351 DOI: 10.1007/s00018-015-2105-x] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/26/2015] [Accepted: 11/26/2015] [Indexed: 12/11/2022]
Abstract
Neurodegenerative diseases are amongst the most devastating of human disorders. New technologies have led to a rapid increase in the identification of disease-related genes with an enhanced appreciation of the key roles played by genetics in the etiology of these disorders. Importantly, pinpointing the normal function of disease gene proteins leads to new understanding of the cellular machineries and pathways that are altered in the disease process. One such emerging pathway is membrane trafficking in the endosomal system. This key cellular process controls the localization and levels of a myriad of proteins and is thus critical for normal cell function. In this review we will focus on three neurodegenerative diseases; Parkinson disease, amyotrophic lateral sclerosis, and hereditary spastic paraplegias, for which a large number of newly discovered disease genes encode proteins that function in endosomal membrane trafficking. We will describe how alterations in these proteins affect endosomal function and speculate on the contributions of these disruptions to disease pathophysiology.
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Affiliation(s)
- Andrea M A Schreij
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada
| | - Edward A Fon
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada
| | - Peter S McPherson
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
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1817
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Abstract
Protein ubiquitination is a dynamic multifaceted post-translational modification involved in nearly all aspects of eukaryotic biology. Once attached to a substrate, the 76-amino acid protein ubiquitin is subjected to further modifications, creating a multitude of distinct signals with distinct cellular outcomes, referred to as the 'ubiquitin code'. Ubiquitin can be ubiquitinated on seven lysine (Lys) residues or on the N-terminus, leading to polyubiquitin chains that can encompass complex topologies. Alternatively or in addition, ubiquitin Lys residues can be modified by ubiquitin-like molecules (such as SUMO or NEDD8). Finally, ubiquitin can also be acetylated on Lys, or phosphorylated on Ser, Thr or Tyr residues, and each modification has the potential to dramatically alter the signaling outcome. While the number of distinctly modified ubiquitin species in cells is mind-boggling, much progress has been made to characterize the roles of distinct ubiquitin modifications, and many enzymes and receptors have been identified that create, recognize or remove these ubiquitin modifications. We here provide an overview of the various ubiquitin modifications present in cells, and highlight recent progress on ubiquitin chain biology. We then discuss the recent findings in the field of ubiquitin acetylation and phosphorylation, with a focus on Ser65-phosphorylation and its role in mitophagy and Parkin activation.
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Affiliation(s)
- Kirby N Swatek
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Komander
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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1818
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Phosphorylation of OPTN by TBK1 enhances its binding to Ub chains and promotes selective autophagy of damaged mitochondria. Proc Natl Acad Sci U S A 2016; 113:4039-44. [PMID: 27035970 DOI: 10.1073/pnas.1523926113] [Citation(s) in RCA: 524] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Selective autophagy of damaged mitochondria requires autophagy receptors optineurin (OPTN), NDP52 (CALCOCO2), TAX1BP1, and p62 (SQSTM1) linking ubiquitinated cargo to autophagic membranes. By using quantitative proteomics, we show that Tank-binding kinase 1 (TBK1) phosphorylates all four receptors on several autophagy-relevant sites, including the ubiquitin- and LC3-binding domains of OPTN and p62/SQSTM1 as well as the SKICH domains of NDP52 and TAX1BP1. Constitutive interaction of TBK1 with OPTN and the ability of OPTN to bind to ubiquitin chains are essential for TBK1 recruitment and kinase activation on mitochondria. TBK1 in turn phosphorylates OPTN's UBAN domain at S473, thereby expanding the binding capacity of OPTN to diverse Ub chains. In combination with phosphorylation of S177 and S513, this posttranslational modification promotes recruitment and retention of OPTN/TBK1 on ubiquitinated, damaged mitochondria. Moreover, phosphorylation of OPTN on S473 enables binding to pS65 Ub chains and is also implicated in PINK1-driven and Parkin-independent mitophagy. Thus, TBK1-mediated phosphorylation of autophagy receptors creates a signal amplification loop operating in selective autophagy of damaged mitochondria.
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1819
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Maday S. Mechanisms of neuronal homeostasis: Autophagy in the axon. Brain Res 2016; 1649:143-150. [PMID: 27038755 DOI: 10.1016/j.brainres.2016.03.047] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 03/08/2016] [Accepted: 03/28/2016] [Indexed: 12/14/2022]
Abstract
Autophagy is an evolutionarily conserved lysosomal degradation pathway that removes damaged organelles and protein aggregates from the cytoplasm. Being post-mitotic, neurons are particularly vulnerable to the accumulation of proteotoxins and are thus heavily dependent on autophagy to maintain homeostasis. In fact, CNS-specific and neuron-specific loss of autophagy is sufficient to cause neurodegeneration in mice. Further, mutations in genes that encode PINK1 and Parkin, proteins that selectively remove damaged mitochondria, cause Parkinson's disease, linking defective autophagy with neurodegenerative disease in humans. This review provides an overview of the mechanisms of autophagy in the axon and the role of neuronal autophagy in axonal homeostasis and degeneration. The pathway for autophagosome biogenesis and maturation along the axon will be discussed as well as several key insights revealing the diverse functions of axonal autophagy. Evidence linking altered autophagy with axonal degeneration and neuronal death will be presented. Appropriate manipulation of autophagy may lead to promising therapeutics for neurodegenerative diseases. This article is part of a Special Issue entitled SI:Autophagy.
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Affiliation(s)
- Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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1820
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Yamaguchi O, Murakawa T, Nishida K, Otsu K. Receptor-mediated mitophagy. J Mol Cell Cardiol 2016; 95:50-6. [PMID: 27021519 DOI: 10.1016/j.yjmcc.2016.03.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/21/2016] [Accepted: 03/21/2016] [Indexed: 12/20/2022]
Abstract
Mitochondria are essential organelles that supply ATP through oxidative phosphorylation to maintain cellular homeostasis. Extrinsic or intrinsic agents can impair mitochondria, and these impaired mitochondria can generate reactive oxygen species (ROS) as byproducts, inducing cellular damage and cell death. The quality control of mitochondria is essential for the maintenance of normal cellular functions, particularly in cardiomyocytes, because they are terminally differentiated. Accumulation of damaged mitochondria is characteristic of various diseases, including heart failure, neurodegenerative disease, and aging-related diseases. Mitochondria are generally degraded through autophagy, an intracellular degradation system that is conserved from yeast to mammals. Autophagy is thought to be a nonselective degradation process in which cytoplasmic proteins and organelles are engulfed by isolation membrane to form autophagosomes in eukaryotic cells. However, recent studies have described the process of selective autophagy, which targets specific proteins or organelles such as mitochondria. Mitochondria-specific autophagy is called mitophagy. Dysregulation of mitophagy is implicated in the development of chronic diseases including neurodegenerative diseases, metabolic diseases, and heart failure. In this review, we discuss recent progress in research on mitophagy receptors.
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Affiliation(s)
- Osamu Yamaguchi
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Tomokazu Murakawa
- Department of Cardiovascular Medicine, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kazuhiko Nishida
- Cardiovascular Division, King's College London British Heart Foundation Centre of Excellence, London SE5 9NU, United Kingdom
| | - Kinya Otsu
- Cardiovascular Division, King's College London British Heart Foundation Centre of Excellence, London SE5 9NU, United Kingdom
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1821
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HSP27 Alleviates Cardiac Aging in Mice via a Mechanism Involving Antioxidation and Mitophagy Activation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:2586706. [PMID: 27110324 PMCID: PMC4821973 DOI: 10.1155/2016/2586706] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/30/2016] [Accepted: 02/22/2016] [Indexed: 11/20/2022]
Abstract
Aging-induced cardiac dysfunction is a prominent feature of cardiac aging. Heat shock protein 27 (HSP27) protects cardiac function against ischemia or chemical challenge. We hypothesized that HSP27 attenuates cardiac aging. Transgenic (Tg) mice with cardiac-specific expression of the HSP27 gene and wild-type (WT) littermates were employed in the experiments. Echocardiography revealed a significant decline in the cardiac function of old WT mice compared with young WT mice. In striking contrast, the aging-induced impairment of cardiac function was attenuated in old Tg mice compared with old WT mice. Levels of cardiac aging markers were lower in old Tg mouse hearts than in old WT mouse hearts. Less interstitial fibrosis and lower contents of reactive oxygen species and ubiquitin-conjugated proteins were detected in old Tg hearts than in old WT hearts. Furthermore, old Tg hearts demonstrated lower accumulation of LC3-II and p62 than old WT hearts. Levels of Atg13, Vps34, and Rab7 were also higher in old Tg hearts than in old WT hearts. Additionally, old Tg hearts had higher levels of PINK1 and Parkin than old WT hearts, suggesting that mitophagy was activated in old Tg hearts. Taken together, HSP27 alleviated cardiac aging and this action involved antioxidation and mitophagy activation.
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1822
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Mitochondrial autophagy in cardiomyopathy. Curr Opin Genet Dev 2016; 38:8-15. [PMID: 27003723 DOI: 10.1016/j.gde.2016.02.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/11/2016] [Accepted: 02/21/2016] [Indexed: 12/17/2022]
Abstract
Cardiac mitochondria produce vast amounts of ATP through oxidative phosphorylation to maintain contractile function. They are also the primary source of reactive oxygen species, which contribute to mitochondrial dysfunction, cardiomyocyte death, and heart failure. To protect against mitochondrial damage, cardiomyocytes develop well-coordinated quality control mechanisms that maintain the overall mitochondrial health through mitochondrial biogenesis, mitochondrial dynamics, and mitochondrial autophagy (mitophagy). Mitophagy removes dysfunctional mitochondria in the heart not only under normal physiological conditions, but also in response to pathological stresses. Accumulating evidence suggests that mitophagy dysregulation can induce cardiomyocyte death and cardiomyopathy. In this review, we discuss what is currently known about mitophagic mechanisms, regulatory pathways, and function in the heart.
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1823
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Protection against Mitochondrial and Metal Toxicity Depends on Functional Lipid Binding Sites in ATP13A2. PARKINSONS DISEASE 2016; 2016:9531917. [PMID: 27073711 PMCID: PMC4814700 DOI: 10.1155/2016/9531917] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/23/2016] [Indexed: 12/29/2022]
Abstract
The late endo-/lysosomal P-type ATPase ATP13A2 (PARK9) is implicated in Parkinson's disease (PD) and Kufor-Rakeb syndrome, early-onset atypical Parkinsonism. ATP13A2 interacts at the N-terminus with the signaling lipids phosphatidic acid (PA) and phosphatidylinositol (3,5) bisphosphate (PI(3,5)P2), which modulate ATP13A2 activity under cellular stress conditions. Here, we analyzed stable human SHSY5Y cell lines overexpressing wild-type (WT) or ATP13A2 mutants in which three N-terminal lipid binding sites (LBS1–3) were mutated. We explored the regulatory role of LBS1–3 in the cellular protection by ATP13A2 against mitochondrial stress induced by rotenone and found that the LBS2-3 mutants displayed an abrogated protective effect. Moreover, in contrast to WT, the LBS2 and LBS3 mutants responded poorly to pharmacological inhibition of, respectively, PI(3,5)P2 and PA formation. We further demonstrate that PA and PI(3,5)P2 are also required for the ATP13A2-mediated protection against the toxic metals Mn2+, Zn2+, and Fe3+, suggesting a general lipid-dependent activation mechanism of ATP13A2 in various PD-related stress conditions. Our results indicate that the ATP13A2-mediated protection requires binding of PI(3,5)P2 to LBS2 and PA to LBS3. Thus, targeting the N-terminal lipid binding sites of ATP13A2 might offer a therapeutic approach to reduce cellular toxicity of various PD insults including mitochondrial stress.
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1824
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Abstract
Autophagy is a highly conserved pathway that recycles cytosolic material and organelles via lysosomal degradation. Once simplistically viewed as a non-selective survival strategy in dire straits, autophagy has emerged as a tightly regulated process ensuring organelle function, proteome plasticity, cell differentiation and tissue homeostasis, with key roles in physiology and disease. Selective target recognition, mediated by specific adapter proteins, enables autophagy to orchestrate highly specialized functions in innate and adaptive immunity. Among them, the shaping of plasma cells for sustainable antibody production through a negative control on their differentiation program. Moreover, memory B cells and long-lived plasma cells require autophagy to exist. Further, the plasma cell malignancy, multiple myeloma deploys abundant autophagy, essential for homeostasis, survival and drug resistance.
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1825
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Dorn GW. Central Parkin: The evolving role of Parkin in the heart. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1307-1312. [PMID: 26992930 DOI: 10.1016/j.bbabio.2016.03.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 02/11/2016] [Accepted: 03/13/2016] [Indexed: 11/17/2022]
Abstract
Parkin is familiar to many because of its link to Parkinson's disease, and to others because of its well-characterized role as a central factor mediating selective mitophagy of damaged mitochondria for mitochondrial quality control. The genetic connection between Parkin and Parkinson's disease derives from clinical gene-association studies, whereas our mechanistic understanding of Parkin functioning in mitophagy is based almost entirely on work performed in cultured cells. Surprisingly, experimental evidence linking the disease and the presumed mechanism derives almost entirely from fruit flies; germline Parkin deficient mice do not develop Parkinson's disease phenotypes. Moreover, genetic manipulation of Parkin signaling in mouse hearts does not support a central role for Parkin in homeostatic mitochondrial quality control in this mitochondria-rich and -dependent organ. Here, I provide an overview of data suggesting that (in mouse hearts at least) Parkin functions more as a stress-induced and developmentally-programmed facilitator of cardiomyocyte mitochondrial turnover. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016.
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Affiliation(s)
- Gerald W Dorn
- Center for Pharmacogenomics, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States.
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1826
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Paul P, Münz C. Autophagy and Mammalian Viruses: Roles in Immune Response, Viral Replication, and Beyond. Adv Virus Res 2016; 95:149-95. [PMID: 27112282 DOI: 10.1016/bs.aivir.2016.02.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is an important cellular catabolic process conserved from yeast to man. Double-membrane vesicles deliver their cargo to the lysosome for degradation. Hence, autophagy is one of the key mechanisms mammalian cells deploy to rid themselves of intracellular pathogens including viruses. However, autophagy serves many more functions during viral infection. First, it regulates the immune response through selective degradation of immune components, thus preventing possibly harmful overactivation and inflammation. Additionally, it delivers virus-derived antigens to antigen-loading compartments for presentation to T lymphocytes. Second, it might take an active part in the viral life cycle by, eg, facilitating its release from cells. Lastly, in the constant arms race between host and virus, autophagy is often hijacked by viruses and manipulated to their own advantage. In this review, we will highlight key steps during viral infection in which autophagy plays a role. We have selected some exemplary viruses and will describe the molecular mechanisms behind their intricate relationship with the autophagic machinery, a result of host-pathogen coevolution.
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Affiliation(s)
- P Paul
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - C Münz
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland.
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1827
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Mancias JD, Kimmelman AC. Mechanisms of Selective Autophagy in Normal Physiology and Cancer. J Mol Biol 2016; 428:1659-80. [PMID: 26953261 DOI: 10.1016/j.jmb.2016.02.027] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 02/25/2016] [Accepted: 02/25/2016] [Indexed: 01/04/2023]
Abstract
Selective autophagy is critical for regulating cellular homeostasis by mediating lysosomal turnover of a wide variety of substrates including proteins, aggregates, organelles, and pathogens via a growing class of molecules termed selective autophagy receptors. The molecular mechanisms of selective autophagy receptor action and regulation are complex. Selective autophagy receptors link their bound cargo to the autophagosomal membrane by interacting with lipidated ATG8 proteins (LC3/GABARAP) that are intimately associated with the autophagosome membrane. The cargo signals that selective autophagy receptors recognize are diverse but their recognition can be broadly grouped into two classes, ubiquitin-dependent cargo recognition versus ubiquitin-independent. The roles of post-translational modification of selective autophagy receptors in regulating these pathways in response to stimuli are an active area of research. Here we will review recent advances in the identification of selective autophagy receptors and their regulatory mechanisms. Given its importance in maintaining cellular homeostasis, disruption of autophagy can lead to disease including neurodegeneration and cancer. The role of autophagy in cancer is complex as autophagy can mediate promotion or inhibition of tumorigenesis. Here we will also review the importance of autophagy in cancer with a specific focus on the role of selective autophagy receptors.
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Affiliation(s)
- Joseph D Mancias
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
| | - Alec C Kimmelman
- Division of Genomic Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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1828
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Weil R, Laplantine E, Génin P. Regulation of TBK1 activity by Optineurin contributes to cell cycle-dependent expression of the interferon pathway. Cytokine Growth Factor Rev 2016; 29:23-33. [PMID: 26976762 DOI: 10.1016/j.cytogfr.2016.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 03/01/2016] [Indexed: 12/21/2022]
Abstract
The innate immune system has evolved to detect and neutralize viral invasions. Triggering of this defense mechanism relies on the production and secretion of soluble factors that stimulate intracellular antiviral defense mechanisms. The Tank Binding Kinase 1 (TBK1) is a serine/threonine kinase in the innate immune signaling pathways including the antiviral response and the host defense against cytosolic infection by bacteries. Given the critical roles of TBK1, important regulatory mechanisms are required to regulate its activity. Among these, Optineurin (Optn) was shown to negatively regulate the interferon response, in addition to its important role in membrane trafficking, protein secretion, autophagy and cell division. As Optn does not carry any enzymatic activity, its functions depend on its precise subcellular localization and its interaction with other proteins, especially with components of the innate immune pathway. This review highlights advances in our understanding of Optn mechanisms of action with focus on the relationships between Optn and TBK1 and their implication in host defense against pathogens. Specifically, how the antiviral immune system is controlled during the cell cycle by the Optn/TBK1 axis and the physiological consequences of this regulatory mechanism are described. This review may serve to a better understanding of the relationships between the different functions of Optn, including those related to immune responses and its associated pathologies such as primary open-angle glaucoma, amyotrophic lateral sclerosis and Paget's disease of bone.
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Affiliation(s)
- Robert Weil
- Institut Pasteur, Signaling and Pathogenesis Laboratory, CNRS UMR 3691, 75724 Paris Cedex 15, France
| | - Emmanuel Laplantine
- Institut Pasteur, Signaling and Pathogenesis Laboratory, CNRS UMR 3691, 75724 Paris Cedex 15, France
| | - Pierre Génin
- Institut Pasteur, Signaling and Pathogenesis Laboratory, CNRS UMR 3691, 75724 Paris Cedex 15, France.
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1829
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Edens BM, Miller N, Ma YC. Impaired Autophagy and Defective Mitochondrial Function: Converging Paths on the Road to Motor Neuron Degeneration. Front Cell Neurosci 2016; 10:44. [PMID: 26973461 PMCID: PMC4776126 DOI: 10.3389/fncel.2016.00044] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/08/2016] [Indexed: 12/12/2022] Open
Abstract
Selective motor neuron degeneration is a hallmark of amyotrophic lateral sclerosis (ALS). Around 10% of all cases present as familial ALS (FALS), while sporadic ALS (SALS) accounts for the remaining 90%. Diverse genetic mutations leading to FALS have been identified, but the underlying causes of SALS remain largely unknown. Despite the heterogeneous and incompletely understood etiology, different types of ALS exhibit overlapping pathology and common phenotypes, including protein aggregation and mitochondrial deficiencies. Here, we review the current understanding of mechanisms leading to motor neuron degeneration in ALS as they pertain to disrupted cellular clearance pathways, ATP biogenesis, calcium buffering and mitochondrial dynamics. Through focusing on impaired autophagic and mitochondrial functions, we highlight how the convergence of diverse cellular processes and pathways contributes to common pathology in motor neuron degeneration.
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Affiliation(s)
- Brittany M. Edens
- Departments of Pediatrics, Neurology, and Physiology, Northwestern University Feinberg School of MedicineChicago, IL, USA
- Lurie Children’s Hospital of ChicagoChicago, IL, USA
| | - Nimrod Miller
- Departments of Pediatrics, Neurology, and Physiology, Northwestern University Feinberg School of MedicineChicago, IL, USA
- Lurie Children’s Hospital of ChicagoChicago, IL, USA
| | - Yong-Chao Ma
- Departments of Pediatrics, Neurology, and Physiology, Northwestern University Feinberg School of MedicineChicago, IL, USA
- Lurie Children’s Hospital of ChicagoChicago, IL, USA
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1830
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Methyl-Arginine Profile of Brain from Aged PINK1-KO+A53T-SNCA Mice Suggests Altered Mitochondrial Biogenesis. PARKINSONS DISEASE 2016; 2016:4686185. [PMID: 27034888 PMCID: PMC4791501 DOI: 10.1155/2016/4686185] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 11/29/2022]
Abstract
Hereditary Parkinson's disease can be triggered by an autosomal dominant overdose of alpha-Synuclein (SNCA) or the autosomal recessive deficiency of PINK1. We recently showed that the combination of PINK1-knockout with overexpression of A53T-SNCA in double mutant (DM) mice potentiates phenotypes and reduces survival. Now we studied brain hemispheres of DM mice at age of 18 months in a hypothesis-free approach, employing a quantitative label-free global proteomic mass spectrometry scan of posttranslational modifications focusing on methyl-arginine. The strongest effects were documented for the adhesion modulator CMAS, the mRNA decapping/deadenylation factor PATL1, and the synaptic plasticity mediator CRTC1/TORC1. In addition, an intriguing effect was observed for the splicing factor PSF/SFPQ, known to interact with the dopaminergic differentiation factor NURR1 as well as with DJ-1, the protein responsible for the autosomal recessive PARK7 variant of PD. CRTC1, PSF, and DJ-1 are modulators of PGC1alpha and of mitochondrial biogenesis. This pathway was further stressed by dysregulations of oxygen sensor EGLN3 and of nuclear TMPO. PSF and TMPO cooperate with dopaminergic differentiation factors LMX1B and NURR1. Further dysregulations concerned PRR18, TRIO, HNRNPA1, DMWD, WAVE1, ILDR2, DBNDD1, and NFM. Thus, we report selective novel endogenous stress responses in brain, which highlight early dysregulations of mitochondrial homeostasis and midbrain vulnerability.
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1831
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Structure and function of the ULK1 complex in autophagy. Curr Opin Cell Biol 2016; 39:61-8. [PMID: 26921696 DOI: 10.1016/j.ceb.2016.02.010] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 12/30/2022]
Abstract
The ULK1 complex initiates autophagosome formation, linking cellular nutrient status to downstream events in autophagy. Recent work suggests that the ULK1 complex might also be activated in selective autophagy independent of nutrient or energy status. In this review we will discuss our current understanding of how the ULK1 complex is regulated by different signals, as well as how this complex then regulates other components of the autophagy machinery. Recently obtained structural data both on ULK1 and the orthologous yeast Atg1 complex are beginning to shed light on the higher-order organization of ULK1 complex. Ultimately, these insights might make it possible to understand how cargo organization and structure recruits and regulates ULK1 in selective autophagy initiation.
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1832
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Zhong Z, Umemura A, Sanchez-Lopez E, Liang S, Shalapour S, Wong J, He F, Boassa D, Perkins G, Ali SR, McGeough MD, Ellisman MH, Seki E, Gustafsson AB, Hoffman HM, Diaz-Meco MT, Moscat J, Karin M. NF-κB Restricts Inflammasome Activation via Elimination of Damaged Mitochondria. Cell 2016; 164:896-910. [PMID: 26919428 PMCID: PMC4769378 DOI: 10.1016/j.cell.2015.12.057] [Citation(s) in RCA: 818] [Impact Index Per Article: 102.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/12/2015] [Accepted: 12/29/2015] [Indexed: 12/11/2022]
Abstract
Nuclear factor κB (NF-κB), a key activator of inflammation, primes the NLRP3-inflammasome for activation by inducing pro-IL-1β and NLRP3 expression. NF-κB, however, also prevents excessive inflammation and restrains NLRP3-inflammasome activation through a poorly defined mechanism. We now show that NF-κB exerts its anti-inflammatory activity by inducing delayed accumulation of the autophagy receptor p62/SQSTM1. External NLRP3-activating stimuli trigger a form of mitochondrial (mt) damage that is caspase-1- and NLRP3-independent and causes release of direct NLRP3-inflammasome activators, including mtDNA and mtROS. Damaged mitochondria undergo Parkin-dependent ubiquitin conjugation and are specifically recognized by p62, which induces their mitophagic clearance. Macrophage-specific p62 ablation causes pronounced accumulation of damaged mitochondria and excessive IL-1β-dependent inflammation, enhancing macrophage death. Therefore, the "NF-κB-p62-mitophagy" pathway is a macrophage-intrinsic regulatory loop through which NF-κB restrains its own inflammation-promoting activity and orchestrates a self-limiting host response that maintains homeostasis and favors tissue repair.
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Affiliation(s)
- Zhenyu Zhong
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Atsushi Umemura
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Elsa Sanchez-Lopez
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Shuang Liang
- Division of Gastroenterology, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Shabnam Shalapour
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Jerry Wong
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Feng He
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Daniela Boassa
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Guy Perkins
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Syed Raza Ali
- Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Matthew D McGeough
- Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Ekihiro Seki
- Division of Gastroenterology, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Division of Gastroenterology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Asa B Gustafsson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Hal M Hoffman
- Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Maria T Diaz-Meco
- Sanford-Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jorge Moscat
- Sanford-Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pathology, School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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1833
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Abstract
Autophagy is a lysosomal degradation process crucial for adaptation to stress and cellular homeostasis. In cancer, autophagy has been demonstrated to serve multifaceted roles in tumor initiation and progression. Although genetic evidence corroborates a role for autophagy as a tumor suppressor mechanism during tumor initiation, autophagy also sustains metabolic pathways in cancer cells and promotes survival within the harsh tumor microenvironment and in response to diverse anticancer therapies. Moreover, though traditionally viewed as an autodigestive process, more recent work demonstrates that autophagy also facilitates cellular secretion; the importance of these new functions of the autophagy pathway is being increasingly appreciated during cancer progression and treatment. In this review, we discuss how these evolving and diverse roles for autophagy both impede and promote tumorigenesis.
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Affiliation(s)
- J Liu
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, United States
| | - J Debnath
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, United States.
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1834
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Berezhnov AV, Soutar MPM, Fedotova EI, Frolova MS, Plun-Favreau H, Zinchenko VP, Abramov AY. Intracellular pH Modulates Autophagy and Mitophagy. J Biol Chem 2016; 291:8701-8. [PMID: 26893374 DOI: 10.1074/jbc.m115.691774] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Indexed: 12/15/2022] Open
Abstract
The specific autophagic elimination of mitochondria (mitophagy) plays the role of quality control for this organelle. Deregulation of mitophagy leads to an increased number of damaged mitochondria and triggers cell death. The deterioration of mitophagy has been hypothesized to underlie the pathogenesis of several neurodegenerative diseases, most notably Parkinson disease. Although some of the biochemical and molecular mechanisms of mitochondrial quality control are described in detail, physiological or pathological triggers of mitophagy are still not fully characterized. Here we show that the induction of mitophagy by the mitochondrial uncoupler FCCP is independent of the effect of mitochondrial membrane potential but dependent on acidification of the cytosol by FCCP. The ionophore nigericin also reduces cytosolic pH and induces PINK1/PARKIN-dependent and -independent mitophagy. The increase of intracellular pH with monensin suppresses the effects of FCCP and nigericin on mitochondrial degradation. Thus, a change in intracellular pH is a regulator of mitochondrial quality control.
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Affiliation(s)
- Alexey V Berezhnov
- From the Department of Intracellular Signaling, Institute of Cell Biophysics Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russian Federation and
| | - Marc P M Soutar
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Evgeniya I Fedotova
- From the Department of Intracellular Signaling, Institute of Cell Biophysics Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russian Federation and
| | - Maria S Frolova
- From the Department of Intracellular Signaling, Institute of Cell Biophysics Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russian Federation and
| | - Helene Plun-Favreau
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Valery P Zinchenko
- From the Department of Intracellular Signaling, Institute of Cell Biophysics Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russian Federation and
| | - Andrey Y Abramov
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
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1835
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Senft D, Ronai ZA. Regulators of mitochondrial dynamics in cancer. Curr Opin Cell Biol 2016; 39:43-52. [PMID: 26896558 DOI: 10.1016/j.ceb.2016.02.001] [Citation(s) in RCA: 193] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 01/27/2016] [Accepted: 02/03/2016] [Indexed: 01/03/2023]
Abstract
Mitochondrial dynamics encompasses processes associated with mitochondrial fission and fusion, affecting their number, degree of biogenesis, and the induction of mitophagy. These activities determine the balance between mitochondrial energy production and cell death programs. Processes governing mitochondrial dynamics are tightly controlled in physiological conditions and are often deregulated in cancer. Mitochondrial protein homeostasis, transcriptional regulation, and post-translational modification are among processes that govern the control of mitochondrial dynamics. Cancer cells alter mitochondrial dynamics to resist apoptosis and adjust their bioenergetic and biosynthetic needs to support tumor initiating and transformation properties including proliferation, migration, and therapeutic resistance. This review focuses on key regulators of mitochondrial dynamics and their role in cancer.
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Affiliation(s)
- Daniela Senft
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd, La Jolla, CA 92037, United States.
| | - Ze'ev A Ronai
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd, La Jolla, CA 92037, United States.
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1836
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Kimura T, Mandell M, Deretic V. Precision autophagy directed by receptor regulators - emerging examples within the TRIM family. J Cell Sci 2016; 129:881-91. [PMID: 26906420 DOI: 10.1242/jcs.163758] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Selective autophagy entails cooperation between target recognition and assembly of the autophagic apparatus. Target recognition is conducted by receptors that often recognize tags, such as ubiquitin and galectins, although examples of selective autophagy independent of these tags are emerging. It is less known how receptors cooperate with the upstream autophagic regulators, beyond the well-characterized association of receptors with Atg8 or its homologs, such as LC3B (encoded by MAP1LC3B), on autophagic membranes. The molecular details of the emerging role in autophagy of the family of proteins called TRIMs shed light on the coordination between cargo recognition and the assembly and activation of the principal autophagy regulators. In their autophagy roles, TRIMs act both as receptors and as platforms ('receptor regulators') for the assembly of the core autophagy regulators, such as ULK1 and Beclin 1 in their activated state. As autophagic receptors, TRIMs can directly recognize endogenous or exogenous targets, obviating a need for intermediary autophagic tags, such as ubiquitin and galectins. The receptor and regulatory features embodied within the same entity allow TRIMs to govern cargo degradation in a highly exact process termed 'precision autophagy'.
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Affiliation(s)
- Tomonori Kimura
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Michael Mandell
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
| | - Vojo Deretic
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA
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1837
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Abstract
Ubiquitin plays an essential role in modulating protein functions, and deregulation of the ubiquitin system leads to the development of multiple human diseases. Owing to its molecular features, ubiquitin can form various homo- and heterotypic polymers on substrate proteins, thereby provoking distinct cellular responses. The concept of multifaceted ubiquitin chains encoding different functions has been substantiated in recent years. It has been established that all possible ubiquitin linkage types are utilized for chain assembly and propagation of specific signals in vivo. In addition, branched ubiquitin chains and phosphorylated ubiquitin molecules have been put under the spotlight recently. The development of novel technologies has provided detailed insights into the structure and function of previously poorly understood ubiquitin signals. In this Cell Science at a Glance article and accompanying poster, we provide an update on the complexity of ubiquitin chains and their physiological relevance.
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Affiliation(s)
- Masato Akutsu
- Buchmann Institute for Molecular Life Sciences, Institute of Biochemistry II, Goethe University, Max-von Laue-Str. 15, Frankfurt 60438, Germany
| | - Ivan Dikic
- Buchmann Institute for Molecular Life Sciences, Institute of Biochemistry II, Goethe University, Max-von Laue-Str. 15, Frankfurt 60438, Germany
| | - Anja Bremm
- Buchmann Institute for Molecular Life Sciences, Institute of Biochemistry II, Goethe University, Max-von Laue-Str. 15, Frankfurt 60438, Germany
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1838
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Zaffagnini G, Martens S. Mechanisms of Selective Autophagy. J Mol Biol 2016; 428:1714-24. [PMID: 26876603 PMCID: PMC4871809 DOI: 10.1016/j.jmb.2016.02.004] [Citation(s) in RCA: 414] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 01/30/2016] [Accepted: 02/02/2016] [Indexed: 01/02/2023]
Abstract
Selective autophagy contributes to intracellular homeostasis by mediating the degradation of cytoplasmic material such as aggregated proteins, damaged or over-abundant organelles, and invading pathogens. The molecular machinery for selective autophagy must ensure efficient recognition and sequestration of the cargo within autophagosomes. Cargo specificity can be mediated by autophagic cargo receptors that specifically bind the cargo material and the autophagosomal membrane. Here we review the recent insights into the mechanisms that enable cargo receptors to confer selectivity and exclusivity to the autophagic process. We also discuss their different roles during starvation-induced and selective autophagy. We propose to classify autophagic events into cargo-independent and cargo-induced autophagosome formation events. Cargo receptors mediate selective autophagy. High-avidity interactions with Atg8 proteins target the receptors to isolation membranes. Dependent on the stimulus, cargo receptors act prior or after isolation membrane generation.
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Affiliation(s)
- Gabriele Zaffagnini
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Dr. Bohr-Gasse 9, 1030 Vienna, Austria
| | - Sascha Martens
- Max F. Perutz Laboratories, University of Vienna, Vienna Biocenter, Dr. Bohr-Gasse 9, 1030 Vienna, Austria.
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1839
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Cross Talk of Proteostasis and Mitostasis in Cellular Homeodynamics, Ageing, and Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:4587691. [PMID: 26977249 PMCID: PMC4763003 DOI: 10.1155/2016/4587691] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/24/2015] [Accepted: 12/31/2015] [Indexed: 12/26/2022]
Abstract
Mitochondria are highly dynamic organelles that provide essential metabolic functions and represent the major bioenergetic hub of eukaryotic cell. Therefore, maintenance of mitochondria activity is necessary for the proper cellular function and survival. To this end, several mechanisms that act at different levels and time points have been developed to ensure mitochondria quality control. An interconnected highly integrated system of mitochondrial and cytosolic chaperones and proteases along with the fission/fusion machinery represents the surveillance scaffold of mitostasis. Moreover, nonreversible mitochondrial damage targets the organelle to a specific autophagic removal, namely, mitophagy. Beyond the organelle dynamics, the constant interaction with the ubiquitin-proteasome-system (UPS) has become an emerging aspect of healthy mitochondria. Dysfunction of mitochondria and UPS increases with age and correlates with many age-related diseases including cancer and neurodegeneration. In this review, we discuss the functional cross talk of proteostasis and mitostasis in cellular homeodynamics and the impairment of mitochondrial quality control during ageing, cancer, and neurodegeneration.
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1840
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Yamano K, Matsuda N, Tanaka K. The ubiquitin signal and autophagy: an orchestrated dance leading to mitochondrial degradation. EMBO Rep 2016; 17:300-16. [PMID: 26882551 DOI: 10.15252/embr.201541486] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/05/2016] [Indexed: 12/21/2022] Open
Abstract
The quality of mitochondria, essential organelles that produce ATP and regulate numerous metabolic pathways, must be strictly monitored to maintain cell homeostasis. The loss of mitochondrial quality control systems is acknowledged as a determinant for many types of neurodegenerative diseases including Parkinson's disease (PD). The two gene products mutated in the autosomal recessive forms of familial early-onset PD, Parkin and PINK1, have been identified as essential proteins in the clearance of damaged mitochondria via an autophagic pathway termed mitophagy. Recently, significant progress has been made in understanding how the mitochondrial serine/threonine kinase PINK1 and the E3 ligase Parkin work together through a novel stepwise cascade to identify and eliminate damaged mitochondria, a process that relies on the orchestrated crosstalk between ubiquitin/phosphorylation signaling and autophagy. In this review, we highlight our current understanding of the detailed molecular mechanisms governing Parkin-/PINK1-mediated mitophagy and the evidences connecting Parkin/PINK1 function and mitochondrial clearance in neurons.
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Affiliation(s)
- Koji Yamano
- Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Noriyuki Matsuda
- Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
| | - Keiji Tanaka
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
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1841
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Bento CF, Renna M, Ghislat G, Puri C, Ashkenazi A, Vicinanza M, Menzies FM, Rubinsztein DC. Mammalian Autophagy: How Does It Work? Annu Rev Biochem 2016; 85:685-713. [PMID: 26865532 DOI: 10.1146/annurev-biochem-060815-014556] [Citation(s) in RCA: 500] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is a conserved intracellular pathway that delivers cytoplasmic contents to lysosomes for degradation via double-membrane autophagosomes. Autophagy substrates include organelles such as mitochondria, aggregate-prone proteins that cause neurodegeneration and various pathogens. Thus, this pathway appears to be relevant to the pathogenesis of diverse diseases, and its modulation may have therapeutic value. Here, we focus on the cell and molecular biology of mammalian autophagy and review the key proteins that regulate the process by discussing their roles and how these may be modulated by posttranslational modifications. We consider the membrane-trafficking events that impact autophagy and the questions relating to the sources of autophagosome membrane(s). Finally, we discuss data from structural studies and some of the insights these have provided.
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Affiliation(s)
- Carla F Bento
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Maurizio Renna
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Ghita Ghislat
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Claudia Puri
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Avraham Ashkenazi
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Mariella Vicinanza
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Fiona M Menzies
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
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1842
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Matsuda N. Phospho-ubiquitin: upending the PINK-Parkin-ubiquitin cascade. J Biochem 2016; 159:379-85. [PMID: 26839319 DOI: 10.1093/jb/mvv125] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/09/2015] [Indexed: 11/12/2022] Open
Abstract
Mitochondria with decreased membrane potential are characterized by defects in protein import into the matrix and impairments in high-efficiency synthesis of ATP. These low-quality mitochondria are marked with ubiquitin for selective degradation. Key factors in this mechanism are PTEN-induced putative kinase 1 (PINK1, a mitochondrial kinase) and Parkin (a ubiquitin ligase), disruption of which has been implicated in predisposition to Parkinson's disease. Previously, the clearance of damaged mitochondria had been thought to be the end result of a simple cascading reaction of PINK1-Parkin-ubiquitin. However, in the past year, several research groups including ours unexpectedly revealed that Parkin regulation is mediated by PINK1-dependent phosphorylation of ubiquitin. These results overturned the simple hierarchy that posited PINK1 and ubiquitin as the upstream and downstream factors of Parkin, respectively. Although ubiquitylation is well-known as a post-translational modification, it has recently become clear that ubiquitin itself can be modified, and that this modification unexpectedly converts ubiquitin to a factor that functions in retrograde signalling.
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Affiliation(s)
- Noriyuki Matsuda
- Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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1843
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Hamacher-Brady A, Brady NR. Mitophagy programs: mechanisms and physiological implications of mitochondrial targeting by autophagy. Cell Mol Life Sci 2016; 73:775-95. [PMID: 26611876 PMCID: PMC4735260 DOI: 10.1007/s00018-015-2087-8] [Citation(s) in RCA: 300] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 02/07/2023]
Abstract
Mitochondria are an essential source of ATP for cellular function, but when damaged, mitochondria generate a plethora of stress signals, which lead to cellular dysfunction and eventually programmed cell death. Thus, a major component of maintaining cellular homeostasis is the recognition and removal of dysfunctional mitochondria through autophagy-mediated degradation, i.e., mitophagy. Mitophagy further constitutes a developmental program, and undergoes a high degree of crosstalk with apoptosis. Reduced mitochondrial quality control is linked to disease pathogenesis, suggesting the importance of process elucidation as a clinical target. Recent work has revealed multiple mitophagy programs that operate independently or undergo crosstalk, and require modulated autophagy receptor activities at outer membranes of mitochondria. Here, we review these mitophagy programs, focusing on pathway mechanisms which recognize and target mitochondria for sequestration by autophagosomes, as well as mechanisms controlling pathway activities. Furthermore, we provide an introduction to the currently available methods for detecting mitophagy.
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Affiliation(s)
- Anne Hamacher-Brady
- Lysosomal Systems Biology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Bioquant, University of Heidelberg, INF 267, BQ0045, 69120, Heidelberg, Germany.
| | - Nathan Ryan Brady
- Systems Biology of Cell Death Mechanisms, German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Department of Surgery, Heidelberg University Hospital, Heidelberg, Germany.
- Bioquant, University of Heidelberg, INF 267, BQ0045, 69120, Heidelberg, Germany.
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1844
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Knuppertz L, Osiewacz HD. Orchestrating the network of molecular pathways affecting aging: Role of nonselective autophagy and mitophagy. Mech Ageing Dev 2016; 153:30-40. [PMID: 26814678 DOI: 10.1016/j.mad.2016.01.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/08/2016] [Accepted: 01/20/2016] [Indexed: 12/28/2022]
Abstract
Autophagy is best known as a mechanism involved in cellular recycling of biomolecules during periods of nutritional starvation. More recently, an additional function of autophagy emerged: the selective degradation of functionally impaired or surplus proteins, organelles and invading bacteria. With this function autophagy is integrated in a network of pathways involved in molecular and cellular quality control with a key impact on development and aging. Impairments in the autophagic machinery lead to accelerated aging and the development of diseases. Here we focus on the role of nonselective autophagy and mitophagy, the selective autophagic degradation of mitochondria, on aging and lifespan of biological systems.
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Affiliation(s)
- Laura Knuppertz
- Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes, Department of Biosciences, J. W. Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Heinz D Osiewacz
- Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes, Department of Biosciences, J. W. Goethe University, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
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1845
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Slowicka K, Vereecke L, Mc Guire C, Sze M, Maelfait J, Kolpe A, Saelens X, Beyaert R, van Loo G. Optineurin deficiency in mice is associated with increased sensitivity to Salmonella but does not affect proinflammatory NF-κB signaling. Eur J Immunol 2016; 46:971-80. [PMID: 26677802 DOI: 10.1002/eji.201545863] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/25/2015] [Accepted: 12/10/2015] [Indexed: 11/11/2022]
Abstract
Optineurin (OPTN) is an evolutionary conserved and ubiquitously expressed ubiquitin-binding protein that has been implicated in glaucoma, Paget bone disease, amyotrophic lateral sclerosis, and other neurodegenerative diseases. From in vitro studies, OPTN was shown to suppress TNF-induced NF-κB signaling and virus-induced IRF signaling, and was identified as an autophagy receptor required for the clearance of cytosolic Salmonella upon infection. To assess the in vivo functions of OPTN in inflammation and infection, we generated OPTN-deficient mice. OPTN knockout mice are born with normal Mendelian distribution and develop normally without any signs of spontaneous organ abnormality or inflammation. However, no differences in NF-κB activation could be observed in OPTN knockout mice or fibroblasts derived from these mice upon TNF or LPS treatment. Primary bone marrow-derived macrophages from OPTN-deficient mice had slightly impaired IRF signaling and reduced IFN type I production in response to LPS or poly(I,C). Finally, OPTN-deficient mice were more susceptible to infection with Salmonella, confirming in vivo the importance of OPTN in bacterial clearance.
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Affiliation(s)
- Karolina Slowicka
- Inflammation Research Center, Unit of Cellular and Molecular (Patho)physiology, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Lars Vereecke
- Inflammation Research Center, Unit of Cellular and Molecular (Patho)physiology, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Conor Mc Guire
- Inflammation Research Center, Unit of Cellular and Molecular (Patho)physiology, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Mozes Sze
- Inflammation Research Center, Unit of Cellular and Molecular (Patho)physiology, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jonathan Maelfait
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Annasaheb Kolpe
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Medical Biotechnology Centre, Ghent, Belgium
| | - Xavier Saelens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Medical Biotechnology Centre, Ghent, Belgium
| | - Rudi Beyaert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, Ghent, Belgium
| | - Geert van Loo
- Inflammation Research Center, Unit of Cellular and Molecular (Patho)physiology, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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1846
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Zhang CW, Hang L, Yao TP, Lim KL. Parkin Regulation and Neurodegenerative Disorders. Front Aging Neurosci 2016; 7:248. [PMID: 26793099 PMCID: PMC4709595 DOI: 10.3389/fnagi.2015.00248] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/17/2015] [Indexed: 12/13/2022] Open
Abstract
Parkin is a unique, multifunctional ubiquitin ligase whose various roles in the cell, particularly in neurons, are widely thought to be protective. The pivotal role that Parkin plays in maintaining neuronal survival is underscored by our current recognition that Parkin dysfunction represents not only a predominant cause of familial parkinsonism but also a formal risk factor for the more common, sporadic form of Parkinson’s disease (PD). Accordingly, keen research on Parkin over the past decade has led to an explosion of knowledge regarding its physiological roles and its relevance to PD. However, our understanding of Parkin is far from being complete. Indeed, surprises emerge from time to time that compel us to constantly update the paradigm of Parkin function. For example, we now know that Parkin’s function is not confined to mere housekeeping protein quality control (QC) roles but also includes mitochondrial homeostasis and stress-related signaling. Furthermore, emerging evidence also suggest a role for Parkin in several other major neurodegenerative diseases including Alzheimer’s disease (AD) and Amyotrophic Lateral Sclerosis (ALS). Yet, it remains truly amazing to note that a single enzyme could serve such multitude of functions and cellular roles. Clearly, its activity has to be tightly regulated. In this review, we shall discuss this and how dysregulated Parkin function may precipitate neuronal demise in various neurodegenerative disorders.
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Affiliation(s)
- Cheng-Wu Zhang
- Neurodegeneration Research Laboratory, National Neuroscience InstituteSingapore, Singapore; Institute of Advanced Materials, Nanjing Tech UniversityNanjing, People's Republic of China
| | - Liting Hang
- Department of Physiology, National University of Singapore Singapore, Singapore
| | - Tso-Pang Yao
- Departments of Pharmacology and Cancer Biology, Duke University Medical Center Durham, NC, USA
| | - Kah-Leong Lim
- Neurodegeneration Research Laboratory, National Neuroscience InstituteSingapore, Singapore; Institute of Advanced Materials, Nanjing Tech UniversityNanjing, People's Republic of China; Department of Physiology, National University of SingaporeSingapore, Singapore; Duke-NUS Graduate Medical School, National University of SingaporeSingapore, Singapore
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1847
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Romanello V, Sandri M. Mitochondrial Quality Control and Muscle Mass Maintenance. Front Physiol 2016; 6:422. [PMID: 26793123 PMCID: PMC4709858 DOI: 10.3389/fphys.2015.00422] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/22/2015] [Indexed: 12/24/2022] Open
Abstract
Loss of muscle mass and force occurs in many diseases such as disuse/inactivity, diabetes, cancer, renal, and cardiac failure and in aging-sarcopenia. In these catabolic conditions the mitochondrial content, morphology and function are greatly affected. The changes of mitochondrial network influence the production of reactive oxygen species (ROS) that play an important role in muscle function. Moreover, dysfunctional mitochondria trigger catabolic signaling pathways which feed-forward to the nucleus to promote the activation of muscle atrophy. Exercise, on the other hand, improves mitochondrial function by activating mitochondrial biogenesis and mitophagy, possibly playing an important part in the beneficial effects of physical activity in several diseases. Optimized mitochondrial function is strictly maintained by the coordinated activation of different mitochondrial quality control pathways. In this review we outline the current knowledge linking mitochondria-dependent signaling pathways to muscle homeostasis in aging and disease and the resulting implications for the development of novel therapeutic approaches to prevent muscle loss.
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Affiliation(s)
| | - Marco Sandri
- Venetian Institute of Molecular MedicinePadova, Italy; Department of Biomedical Science, University of PadovaPadova, Italy; Institute of Neuroscience, Consiglio Nazionale delle RicerchePadova, Italy; Department of Medicine, McGill UniversityMontreal, QC, Canada
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1848
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Song P, Li S, Wu H, Gao R, Rao G, Wang D, Chen Z, Ma B, Wang H, Sui N, Deng H, Zhang Z, Tang T, Tan Z, Han Z, Lu T, Zhu Y, Chen Q. Parkin promotes proteasomal degradation of p62: implication of selective vulnerability of neuronal cells in the pathogenesis of Parkinson's disease. Protein Cell 2016; 7:114-29. [PMID: 26746706 PMCID: PMC4742389 DOI: 10.1007/s13238-015-0230-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 10/31/2015] [Indexed: 12/14/2022] Open
Abstract
Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson’s disease (PD), respectively, which manifested with the selective vulnerability of neuronal cells in substantia nigra (SN) and striatum (STR) regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.
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Affiliation(s)
- Pingping Song
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Shanshan Li
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Hao Wu
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ruize Gao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Guanhua Rao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Dongmei Wang
- Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ziheng Chen
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Biao Ma
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Hongxia Wang
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Nan Sui
- Institute of Psychology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Haiteng Deng
- College of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhuohua Zhang
- State Key Laboratory of Medical Genetics, Xiangya Medical School, Central South University, Changsha, 410078, China
| | - Tieshan Tang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zheng Tan
- State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zehan Han
- Department of Health and Sports Science, Tianjin University of Sport, Tianjin, 300381, China
| | - Tieyuan Lu
- Department of Health and Sports Science, Tianjin University of Sport, Tianjin, 300381, China.
| | - Yushan Zhu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China.
| | - Quan Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China. .,State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
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1849
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Chin LS, Li L. Ubiquitin phosphorylation in Parkinson's disease: Implications for pathogenesis and treatment. Transl Neurodegener 2016; 5:1. [PMID: 26740872 PMCID: PMC4702311 DOI: 10.1186/s40035-015-0049-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 12/29/2015] [Indexed: 12/18/2022] Open
Abstract
Parkinson's disease (PD) is the most common neurodegenerative movement disorder, characterized primarily by the loss of dopaminergic neurons in substantia nigra. The pathogenic mechanisms of PD remain unclear, and no effective therapy currently exists to stop neurodegeneration in this debilitating disease. The identification of mutations in mitochondrial serine/threonine kinase PINK1 or E3 ubiquitin-protein ligase parkin as the cause of autosomal recessive PD opens up new avenues for uncovering neuroprotective pathways and PD pathogenic mechanisms. Recent studies reveal that PINK1 translocates to the outer mitochondrial membrane in response to mitochondrial depolarization and phosphorylates ubiquitin at the residue Ser65. The phosphorylated ubiquitin serves as a signal for activating parkin and recruiting autophagy receptors to promote clearance of damaged mitochondria via mitophagy. Emerging evidence has begun to indicate a link between impaired ubiquitin phosphorylation-dependent mitophagy and PD pathogenesis and supports the potential of Ser65-phosphorylated ubiquitin as a biomarker for PD. The new mechanistic insights and phenotypic screens have identified multiple potential therapeutic targets for PD drug discovery. This review highlights recent advances in understanding ubiquitin phosphorylation in mitochondrial quality control and PD pathogenesis and discusses how these findings can be translated into novel approaches for PD diagnostic and therapeutic development.
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Affiliation(s)
- Lih-Shen Chin
- Department of Pharmacology and Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Lian Li
- Department of Pharmacology and Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA 30322 USA
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1850
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Abstract
In this issue of Molecular Cell, Heo et al. (2015) uncover a new mechanism of signal amplification during mitophagy through cooperative regulation of the TBK1 kinase and autophagy receptors.
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Affiliation(s)
- Andrew G Manford
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Michael Rape
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
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