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Zohar K, Linial M. Knockdown of DJ-1 Resulted in a Coordinated Activation of the Innate Immune Antiviral Response in HEK293 Cell Line. Int J Mol Sci 2024; 25:7550. [PMID: 39062793 PMCID: PMC11277157 DOI: 10.3390/ijms25147550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/04/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
PARK7, also known as DJ-1, plays a critical role in protecting cells by functioning as a sensitive oxidation sensor and modulator of antioxidants. DJ-1 acts to maintain mitochondrial function and regulate transcription in response to different stressors. In this study, we showed that cell lines vary based on their antioxidation potential under basal conditions. The transcriptome of HEK293 cells was tested following knockdown (KD) of DJ-1 using siRNAs, which reduced the DJ-1 transcripts to only 12% of the original level. We compared the expression levels of 14k protein-coding transcripts and 4.2k non-coding RNAs relative to cells treated with non-specific siRNAs. Among the coding genes, approximately 200 upregulated differentially expressed genes (DEGs) signified a coordinated antiviral innate immune response. Most genes were associated with the regulation of type 1 interferons (IFN) and the induction of inflammatory cytokines. About a quarter of these genes were also induced in cells treated with non-specific siRNAs that were used as a negative control. Beyond the antiviral-like response, 114 genes were specific to the KD of DJ-1 with enrichment in RNA metabolism and mitochondrial functions. A smaller set of downregulated genes (58 genes) was associated with dysregulation in membrane structure, cell viability, and mitophagy. We propose that the KD DJ-1 perturbation diminishes the protective potency against oxidative stress. Thus, it renders the cells labile and responsive to the dsRNA signal by activating a large number of genes, many of which drive apoptosis, cell death, and inflammatory signatures. The KD of DJ-1 highlights its potency in regulating genes associated with antiviral responses, RNA metabolism, and mitochondrial functions, apparently through alteration in STAT activity and downstream signaling. Given that DJ-1 also acts as an oncogene in metastatic cancers, targeting DJ-1 could be a promising therapeutic strategy where manipulation of the DJ-1 level may reduce cancer cell viability and enhance the efficacy of cancer treatments.
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Affiliation(s)
| | - Michal Linial
- Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel;
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2
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Watanabe H, Dijkstra JM, Nagatsu T. Parkinson's Disease: Cells Succumbing to Lifelong Dopamine-Related Oxidative Stress and Other Bioenergetic Challenges. Int J Mol Sci 2024; 25:2009. [PMID: 38396687 PMCID: PMC10888576 DOI: 10.3390/ijms25042009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
The core pathological event in Parkinson's disease (PD) is the specific dying of dopamine (DA) neurons of the substantia nigra pars compacta (SNc). The reasons why SNc DA neurons are especially vulnerable and why idiopathic PD has only been found in humans are still puzzling. The two main underlying factors of SNc DA neuron vulnerability appear related to high DA production, namely (i) the toxic effects of cytoplasmic DA metabolism and (ii) continuous cytosolic Ca2+ oscillations in the absence of the Ca2+-buffer protein calbindin. Both factors cause oxidative stress by producing highly reactive quinones and increasing intra-mitochondrial Ca2+ concentrations, respectively. High DA expression in human SNc DA neuron cell bodies is suggested by the abundant presence of the DA-derived pigment neuromelanin, which is not found in such abundance in other species and has been associated with toxicity at higher levels. The oxidative stress created by their DA production system, despite the fact that the SN does not use unusually high amounts of energy, explains why SNc DA neurons are sensitive to various genetic and environmental factors that create mitochondrial damage and thereby promote PD. Aging increases multiple risk factors for PD, and, to a large extent, PD is accelerated aging. To prevent PD neurodegeneration, possible approaches that are discussed here are (1) reducing cytoplasmic DA accumulation, (2) blocking cytoplasmic Ca2+ oscillations, and (3) providing bioenergetic support.
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Affiliation(s)
- Hirohisa Watanabe
- Department of Neurology, School of Medicine, Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Johannes M. Dijkstra
- Center for Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Toshiharu Nagatsu
- Center for Research Promotion and Support, Fujita Health University, Toyoake 470-1192, Aichi, Japan;
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3
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Abeliovich H. Mitophagy in yeast: known unknowns and unknown unknowns. Biochem J 2023; 480:1639-1657. [PMID: 37850532 PMCID: PMC10586778 DOI: 10.1042/bcj20230279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/06/2023] [Accepted: 09/22/2023] [Indexed: 10/19/2023]
Abstract
Mitophagy, the autophagic breakdown of mitochondria, is observed in eukaryotic cells under various different physiological circumstances. These can be broadly categorized into two types: mitophagy related to quality control events and mitophagy induced during developmental transitions. Quality control mitophagy involves the lysosomal or vacuolar degradation of malfunctioning or superfluous mitochondria within lysosomes or vacuoles, and this is thought to serve as a vital maintenance function in respiring eukaryotic cells. It plays a crucial role in maintaining physiological balance, and its disruption has been associated with the progression of late-onset diseases. Developmentally induced mitophagy has been reported in the differentiation of metazoan tissues which undergo metabolic shifts upon developmental transitions, such as in the differentiation of red blood cells and muscle cells. Although the mechanistic studies of mitophagy in mammalian cells were initiated after the initial mechanistic findings in Saccharomyces cerevisiae, our current understanding of the physiological role of mitophagy in yeast remains more limited, despite the presence of better-defined assays and tools. In this review, I present my perspective on our present knowledge of mitophagy in yeast, focusing on physiological and mechanistic aspects. I aim to focus on areas where our understanding is still incomplete, such as the role of mitochondrial dynamics and the phenomenon of protein-level selectivity.
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Affiliation(s)
- Hagai Abeliovich
- Institute of Biochemistry, Food Science and Nutrition, Hebrew University of Jerusalem, 1 Hankin St, Rehovot 7610001, Israel
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4
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Onishi M, Kubota M, Duan L, Tian Y, Okamoto K. The GET pathway serves to activate Atg32-mediated mitophagy by ER targeting of the Ppg1-Far complex. Life Sci Alliance 2023; 6:e202201640. [PMID: 36697253 PMCID: PMC9880027 DOI: 10.26508/lsa.202201640] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Mitophagy removes defective or superfluous mitochondria via selective autophagy. In yeast, the pro-mitophagic protein Atg32 localizes to the mitochondrial surface and interacts with the scaffold protein Atg11 to promote degradation of mitochondria. Although Atg32-Atg11 interactions are thought to be stabilized by Atg32 phosphorylation, how this posttranslational modification is regulated remains obscure. Here, we show that cells lacking the guided entry of the tail-anchored protein (GET) pathway exhibit reduced Atg32 phosphorylation and Atg32-Atg11 interactions, which can be rescued by additional loss of the ER-resident Ppg1-Far complex, a multi-subunit phosphatase negatively acting in mitophagy. In GET-deficient cells, Ppg1-Far is predominantly localized to mitochondria. An artificial ER anchoring of Ppg1-Far in GET-deficient cells significantly ameliorates defects in Atg32-Atg11 interactions and mitophagy. Moreover, disruption of GET and Msp1, an AAA-ATPase that extracts non-mitochondrial proteins localized to the mitochondrial surface, elicits synthetic defects in mitophagy. Collectively, we propose that the GET pathway mediates ER targeting of Ppg1-Far, thereby preventing dysregulated suppression of mitophagy activation.
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Affiliation(s)
- Mashun Onishi
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Mitsutaka Kubota
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Lan Duan
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Yuan Tian
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Koji Okamoto
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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5
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Vanacloig-Pedros E, Fisher KJ, Liu L, Debrauske DJ, Young MKM, Place M, Hittinger CT, Sato TK, Gasch AP. Comparative chemical genomic profiling across plant-based hydrolysate toxins reveals widespread antagonism in fitness contributions. FEMS Yeast Res 2022; 21:6650360. [PMID: 35883225 PMCID: PMC9508847 DOI: 10.1093/femsyr/foac036] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 07/06/2022] [Accepted: 07/21/2022] [Indexed: 11/15/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae has been used extensively in fermentative industrial processes, including biofuel production from sustainable plant-based hydrolysates. Myriad toxins and stressors found in hydrolysates inhibit microbial metabolism and product formation. Overcoming these stresses requires mitigation strategies that include strain engineering. To identify shared and divergent mechanisms of toxicity and to implicate gene targets for genetic engineering, we used a chemical genomic approach to study fitness effects across a library of S. cerevisiae deletion mutants cultured anaerobically in dozens of individual compounds found in different types of hydrolysates. Relationships in chemical genomic profiles identified classes of toxins that provoked similar cellular responses, spanning inhibitor relationships that were not expected from chemical classification. Our results also revealed widespread antagonistic effects across inhibitors, such that the same gene deletions were beneficial for surviving some toxins but detrimental for others. This work presents a rich dataset relating gene function to chemical compounds, which both expands our understanding of plant-based hydrolysates and provides a useful resource to identify engineering targets.
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Affiliation(s)
- Elena Vanacloig-Pedros
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 53726, Madison, WI, United States
| | - Kaitlin J Fisher
- Laboratory of Genetics, University of Wisconsin-Madison, 53706, Madison, WI, United States
- Center for Genomic Science Innovation, University of Wisconsin-Madison, 53706, Madison, WI, United States
- J.F. Crow Institute for the Study of Evolution, 53706, Madison, WI, United States
| | - Lisa Liu
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 53726, Madison, WI, United States
| | - Derek J Debrauske
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 53726, Madison, WI, United States
| | - Megan K M Young
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 53726, Madison, WI, United States
| | - Michael Place
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 53726, Madison, WI, United States
| | - Chris Todd Hittinger
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 53726, Madison, WI, United States
- Laboratory of Genetics, University of Wisconsin-Madison, 53706, Madison, WI, United States
- Center for Genomic Science Innovation, University of Wisconsin-Madison, 53706, Madison, WI, United States
- J.F. Crow Institute for the Study of Evolution, 53706, Madison, WI, United States
| | - Trey K Sato
- Corresponding author: Trey K. Sato, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 4117 Wisconsin Energy Institute, 1552 University Ave, Madison, WI 53726. Tel: (608) 890-2546; E-mail:
| | - Audrey P Gasch
- Corresponding author: Audrey P. Gasch, Center for Genomic Science Innovation, University of Wisconsin-Madison, 3422 Genetics-Biotechnology Center, 425 Henry Mall, Madison, WI 53704, United States. Tel: (608)265-0859; E-mail:
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6
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Schuster R, Okamoto K. An overview of the molecular mechanisms of mitophagy in yeast. Biochim Biophys Acta Gen Subj 2022; 1866:130203. [PMID: 35842014 DOI: 10.1016/j.bbagen.2022.130203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 05/27/2022] [Accepted: 07/11/2022] [Indexed: 11/18/2022]
Abstract
Autophagy-dependent selective degradation of excess or damaged mitochondria, termed mitophagy, is a tightly regulated process necessary for mitochondrial quality and quantity control. Mitochondria are highly dynamic and major sites for vital cellular processes such as ATP and iron‑sulfur cluster biogenesis. Due to their pivotal roles for immunity, apoptosis, and aging, the maintenance of mitochondrial function is of utmost importance for cellular homeostasis. In yeast, mitophagy is mediated by the receptor protein Atg32 that is localized to the outer mitochondrial membrane. Upon mitophagy induction, Atg32 expression is transcriptionally upregulated, which leads to its accumulation on the mitochondrial surface and to recruitment of the autophagic machinery via its direct interaction with Atg11 and Atg8. Importantly, post-translational modifications such as phosphorylation further fine-tune the mitophagic response. This review summarizes the current knowledge about mitophagy in yeast and its connection with mitochondrial dynamics and the ubiquitin-proteasome system.
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Affiliation(s)
- Ramona Schuster
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Koji Okamoto
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
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7
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Bhatia-Kissova I, Camougrand N. Mitophagy in Yeast: Decades of Research. Cells 2021; 10:3541. [PMID: 34944049 PMCID: PMC8700663 DOI: 10.3390/cells10123541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 12/02/2022] Open
Abstract
Mitophagy, the selective degradation of mitochondria by autophagy, is one of the most important mechanisms of mitochondrial quality control, and its proper functioning is essential for cellular homeostasis. In this review, we describe the most important milestones achieved during almost 2 decades of research on yeasts, which shed light on the molecular mechanisms, regulation, and role of the Atg32 receptor in this process. We analyze the role of ROS in mitophagy and discuss the physiological roles of mitophagy in unicellular organisms, such as yeast; these roles are very different from those in mammals. Additionally, we discuss some of the different tools available for studying mitophagy.
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Affiliation(s)
- Ingrid Bhatia-Kissova
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 84215 Bratislava, Slovakia;
| | - Nadine Camougrand
- CNRS, UMR 5095, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
- Institut de Biochimie et de Génétique Cellulaires, Université de Bordeaux, UMR 5095, 1 Rue Camille Saint-Saëns, 33077 Bordeaux, France
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8
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Onishi M, Okamoto K. Mitochondrial clearance: mechanisms and roles in cellular fitness. FEBS Lett 2021; 595:1239-1263. [PMID: 33615465 DOI: 10.1002/1873-3468.14060] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 01/29/2021] [Accepted: 02/12/2021] [Indexed: 12/14/2022]
Abstract
Mitophagy is one of the selective autophagy pathways that catabolizes dysfunctional or superfluous mitochondria. Under mitophagy-inducing conditions, mitochondria are labeled with specific molecular landmarks that recruit the autophagy machinery to the surface of mitochondria, enclosed into autophagosomes, and delivered to lysosomes (vacuoles in yeast) for degradation. As damaged mitochondria are the major sources of reactive oxygen species, mitophagy is critical for mitochondrial quality control and cellular health. Moreover, appropriate control of mitochondrial quantity via mitophagy is vital for the energy supply-demand balance in cells and whole organisms, cell differentiation, and developmental programs. Thus, it seems conceivable that defects in mitophagy could elicit pleiotropic pathologies such as excess inflammation, tissue injury, neurodegeneration, and aging. In this review, we will focus on the molecular basis and physiological relevance of mitophagy, and potential of mitophagy as a therapeutic target to overcome such disorders.
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Affiliation(s)
- Mashun Onishi
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Koji Okamoto
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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9
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Liu Y, Okamoto K. Regulatory mechanisms of mitophagy in yeast. Biochim Biophys Acta Gen Subj 2021; 1865:129858. [PMID: 33545228 DOI: 10.1016/j.bbagen.2021.129858] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/14/2021] [Accepted: 01/25/2021] [Indexed: 12/19/2022]
Abstract
Mitochondria are dynamic organelles functioning in diverse reactions and processes such as energy metabolism, apoptosis, innate immunity, and aging, whose quality and quantity control is critical for cell homeostasis. Mitochondria-specific autophagy, termed mitophagy, is an evolutionarily conserved process that selectively degrades mitochondria via autophagy, thereby contributing to mitochondrial quality and quantity control. In the budding yeast Saccharomyces cerevisiae, the single-pass membrane protein Atg32 accumulates on the surface of mitochondria and recruit the autophagy machinery to initiate mitophagy. This catabolic process is elaborately regulated through transcriptional induction and post-translational modifications of Atg32. Notably, other factors acting in manifold pathways including protein N-terminal acetylation, phospholipid methylation, stress signaling, and endoplasmic reticulum-localized protein dephosphorylation and membrane protein insertion are also linked to mitophagy. Here we review recent discoveries of molecules regulating mitophagy in yeast.
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Affiliation(s)
- Yang Liu
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Koji Okamoto
- Laboratory of Mitochondrial Dynamics, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan.
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10
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Onishi M, Yamano K, Sato M, Matsuda N, Okamoto K. Molecular mechanisms and physiological functions of mitophagy. EMBO J 2021; 40:e104705. [PMID: 33438778 PMCID: PMC7849173 DOI: 10.15252/embj.2020104705] [Citation(s) in RCA: 622] [Impact Index Per Article: 207.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 08/03/2020] [Accepted: 10/02/2020] [Indexed: 12/12/2022] Open
Abstract
Degradation of mitochondria via a selective form of autophagy, named mitophagy, is a fundamental mechanism conserved from yeast to humans that regulates mitochondrial quality and quantity control. Mitophagy is promoted via specific mitochondrial outer membrane receptors, or ubiquitin molecules conjugated to proteins on the mitochondrial surface leading to the formation of autophagosomes surrounding mitochondria. Mitophagy-mediated elimination of mitochondria plays an important role in many processes including early embryonic development, cell differentiation, inflammation, and apoptosis. Recent advances in analyzing mitophagy in vivo also reveal high rates of steady-state mitochondrial turnover in diverse cell types, highlighting the intracellular housekeeping role of mitophagy. Defects in mitophagy are associated with various pathological conditions such as neurodegeneration, heart failure, cancer, and aging, further underscoring the biological relevance. Here, we review our current molecular understanding of mitophagy, and its physiological implications, and discuss how multiple mitophagy pathways coordinately modulate mitochondrial fitness and populations.
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Affiliation(s)
- Mashun Onishi
- Laboratory of Mitochondrial DynamicsGraduate School of Frontier BiosciencesOsaka UniversitySuitaJapan
| | - Koji Yamano
- The Ubiquitin ProjectTokyo Metropolitan Institute of Medical ScienceTokyoJapan
| | - Miyuki Sato
- Laboratory of Molecular Membrane BiologyInstitute for Molecular and Cellular RegulationGunma UniversityMaebashiJapan
| | - Noriyuki Matsuda
- The Ubiquitin ProjectTokyo Metropolitan Institute of Medical ScienceTokyoJapan
| | - Koji Okamoto
- Laboratory of Mitochondrial DynamicsGraduate School of Frontier BiosciencesOsaka UniversitySuitaJapan
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11
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Structural Basis of Tail-Anchored Membrane Protein Biogenesis by the GET Insertase Complex. Mol Cell 2020; 80:72-86.e7. [DOI: 10.1016/j.molcel.2020.08.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/24/2020] [Accepted: 08/17/2020] [Indexed: 01/31/2023]
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