1
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Hanada K. Metabolic channeling of lipids via the contact zones between different organelles. Bioessays 2024:e2400045. [PMID: 38932642 DOI: 10.1002/bies.202400045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024]
Abstract
Various lipid transfer proteins (LTPs) mediate the inter-organelle transport of lipids. By working at membrane contact zones between donor and acceptor organelles, LTPs achieve rapid and accurate inter-organelle transfer of lipids. This article will describe the emerging paradigm that the action of LTPs at organelle contact zones generates metabolic channeling events in lipid metabolism, mainly referring to how ceramide synthesized in the endoplasmic reticulum is preferentially metabolized to sphingomyelin in the distal Golgi region, how cholesterol and phospholipids receive specific metabolic reactions in mitochondria, and how the hijacking of host LTPs by intracellular pathogens may generate new channeling-like events. In addition, the article will discuss how the function of LTPs is regulated, exemplified by a few representative LTP systems, and will briefly touch on experiments that will be necessary to establish the paradigm that LTP-mediated inter-organelle transport of lipids is one of the mechanisms of compartmentalization-based metabolic channeling events.
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Affiliation(s)
- Kentaro Hanada
- Center for Quality Management Systems, National Institute of Infectious Diseases, Tokyo, Japan
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2
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Kan KT, Wilcock J, Lu H. Role of Yme1 in mitochondrial protein homeostasis: from regulation of protein import, OXPHOS function to lipid synthesis and mitochondrial dynamics. Biochem Soc Trans 2024; 52:1539-1548. [PMID: 38864432 DOI: 10.1042/bst20240450] [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: 04/16/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/13/2024]
Abstract
Mitochondria are essential organelles of eukaryotic cells and thus mitochondrial proteome is under constant quality control and remodelling. Yme1 is a multi-functional protein and subunit of the homo-hexametric complex i-AAA proteinase. Yme1 plays vital roles in the regulation of mitochondrial protein homeostasis and mitochondrial plasticity, ranging from substrate degradation to the regulation of protein functions involved in mitochondrial protein biosynthesis, energy production, mitochondrial dynamics, and lipid biosynthesis and signalling. In this mini review, we focus on discussing the current understanding of the roles of Yme1 in mitochondrial protein import via TIM22 and TIM23 pathways, oxidative phosphorylation complex function, as well as mitochondrial lipid biosynthesis and signalling, as well as a brief discussion of the role of Yme1 in modulating mitochondrial dynamics.
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Affiliation(s)
- Kwan Ting Kan
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, U.K
| | - Joel Wilcock
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, U.K
| | - Hui Lu
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester M13 9PT, U.K
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3
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Xiao T, English AM, Wilson ZN, Maschek J, Cox JE, Hughes AL. The phospholipids cardiolipin and phosphatidylethanolamine differentially regulate MDC biogenesis. J Cell Biol 2024; 223:e202302069. [PMID: 38497895 PMCID: PMC10949074 DOI: 10.1083/jcb.202302069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 01/04/2024] [Accepted: 02/20/2024] [Indexed: 03/19/2024] Open
Abstract
Cells utilize multiple mechanisms to maintain mitochondrial homeostasis. We recently characterized a pathway that remodels mitochondria in response to metabolic alterations and protein overload stress. This remodeling occurs via the formation of large membranous structures from the mitochondrial outer membrane called mitochondrial-derived compartments (MDCs), which are eventually released from mitochondria and degraded. Here, we conducted a microscopy-based screen in budding yeast to identify factors that regulate MDC formation. We found that two phospholipids, cardiolipin (CL) and phosphatidylethanolamine (PE), differentially regulate MDC biogenesis. CL depletion impairs MDC biogenesis, whereas blocking mitochondrial PE production leads to constitutive MDC formation. Additionally, in response to metabolic MDC activators, cellular and mitochondrial PE declines, and overexpressing mitochondrial PE synthesis enzymes suppress MDC biogenesis. Altogether, our data indicate a requirement for CL in MDC biogenesis and suggest that PE depletion may stimulate MDC formation downstream of MDC-inducing metabolic stress.
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Affiliation(s)
- Tianyao Xiao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Alyssa M. English
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Zachary N. Wilson
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - J.Alan. Maschek
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integration. Physiology, University of Utah College of Health, Salt Lake City, UT, USA
| | - James E. Cox
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT, USA
| | - Adam L. Hughes
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
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4
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Shiino H, Tashiro S, Hashimoto M, Sakata Y, Hosoya T, Endo T, Kojima H, Tamura Y. Chemical inhibition of phosphatidylcholine biogenesis reveals its role in mitochondrial division. iScience 2024; 27:109189. [PMID: 38420588 PMCID: PMC10901091 DOI: 10.1016/j.isci.2024.109189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/19/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Phospholipids are major components of biological membranes and play structural and regulatory roles in various biological processes. To determine the biological significance of phospholipids, the use of chemical inhibitors of phospholipid metabolism offers an effective approach; however, the availability of such compounds is limited. In this study, we performed a chemical-genetic screening using yeast and identified small molecules capable of inhibiting phosphatidylcholine (PC) biogenesis, which we designated PC inhibitors 1, 2, 3, and 4 (PCiB-1, 2, 3, and 4). Biochemical analyses indicated that PCiB-2, 3, and 4 inhibited the phosphatidylethanolamine (PE) methyltransferase activity of Cho2, whereas PCiB-1 may inhibit PE transport from mitochondria to the endoplasmic reticulum (ER). Interestingly, we found that PCiB treatment resulted in mitochondrial fragmentation, which was suppressed by expression of a dominant-negative mutant of the mitochondrial division factor Dnm1. These results provide evidence that normal PC biogenesis is important for the regulation of mitochondrial division.
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Affiliation(s)
- Hiroya Shiino
- Graduate School of Global Symbiotic Sciences, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Shinya Tashiro
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Michiko Hashimoto
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Yuki Sakata
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Takamitsu Hosoya
- Laboratory of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University (TMDU), 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kyoto 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kyoto 603-8555, Japan
| | - Hirotatsu Kojima
- Drug Discovery Initiative, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
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5
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Radkohl A, Schusterbauer V, Bernauer L, Rechberger GN, Wolinski H, Schittmayer M, Birner-Gruenberger R, Thallinger GG, Leitner E, Baeck M, Pichler H, Emmerstorfer-Augustin A. Human Sterols Are Overproduced, Stored and Excreted in Yeasts. Int J Mol Sci 2024; 25:781. [PMID: 38255855 PMCID: PMC10815178 DOI: 10.3390/ijms25020781] [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: 12/07/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
Sterols exert a profound influence on numerous cellular processes, playing a crucial role in both health and disease. However, comprehending the effects of sterol dysfunction on cellular physiology is challenging. Consequently, numerous processes affected by impaired sterol biosynthesis still elude our complete understanding. In this study, we made use of yeast strains that produce cholesterol instead of ergosterol and investigated the cellular response mechanisms on the transcriptome as well as the lipid level. The exchange of ergosterol for cholesterol caused the downregulation of phosphatidylethanolamine and phosphatidylserine and upregulation of phosphatidylinositol and phosphatidylcholine biosynthesis. Additionally, a shift towards polyunsaturated fatty acids was observed. While the sphingolipid levels dropped, the total amounts of sterols and triacylglycerol increased, which resulted in 1.7-fold enlarged lipid droplets in cholesterol-producing yeast cells. In addition to internal storage, cholesterol and its precursors were excreted into the culture supernatant, most likely by the action of ABC transporters Snq2, Pdr12 and Pdr15. Overall, our results demonstrate that, similarly to mammalian cells, the production of non-native sterols and sterol precursors causes lipotoxicity in K. phaffii, mainly due to upregulated sterol biosynthesis, and they highlight the different survival and stress response mechanisms on multiple, integrative levels.
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Affiliation(s)
- Astrid Radkohl
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Veronika Schusterbauer
- Bisy GmbH, 8200 Hofstaetten an der Raab, Austria
- Institute of Biomedical Informatics, Graz University of Technology, 8010 Graz, Austria
| | - Lukas Bernauer
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Gerald N. Rechberger
- Department of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
| | - Heimo Wolinski
- Department of Molecular Biosciences, University of Graz, NAWI Graz, 8010 Graz, Austria
- Field of Excellence BioHealth, University of Graz, 8010 Graz, Austria
| | - Matthias Schittmayer
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, 1040 Vienna, Austria (R.B.-G.)
| | - Ruth Birner-Gruenberger
- Institute of Chemical Technologies and Analytics, Technische Universität Wien, 1040 Vienna, Austria (R.B.-G.)
| | - Gerhard G. Thallinger
- Institute of Biomedical Informatics, Graz University of Technology, 8010 Graz, Austria
| | - Erich Leitner
- Institute of Analytical Chemistry and Food Chemistry, University of Graz, NAWI Graz, 8010 Graz, Austria;
| | - Melanie Baeck
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Harald Pichler
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Acib—Austrian Centre of Industrial Biotechnology, 8010 Graz, Austria
| | - Anita Emmerstorfer-Augustin
- Institute of Molecular Biotechnology, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
- Acib—Austrian Centre of Industrial Biotechnology, 8010 Graz, Austria
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6
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Sun H, Zhang J, Ye Q, Jiang T, Liu X, Zhang X, Zeng F, Li J, Zheng Y, Han X, Su C, Shi Y. LPGAT1 controls MEGDEL syndrome by coupling phosphatidylglycerol remodeling with mitochondrial transport. Cell Rep 2023; 42:113214. [PMID: 37917582 PMCID: PMC10729602 DOI: 10.1016/j.celrep.2023.113214] [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: 05/08/2023] [Revised: 08/21/2023] [Accepted: 09/19/2023] [Indexed: 11/04/2023] Open
Abstract
Phosphatidylglycerol (PG) is a mitochondrial phospholipid required for mitochondrial cristae structure and cardiolipin synthesis. PG must be remodeled to its mature form at the endoplasmic reticulum (ER) after mitochondrial biosynthesis to achieve its biological functions. Defective PG remodeling causes MEGDEL (non-alcohol fatty liver disease and 3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-like) syndrome through poorly defined mechanisms. Here, we identify LPGAT1, an acyltransferase that catalyzes PG remodeling, as a candidate gene for MEGDEL syndrome. We show that PG remodeling by LPGAT1 at the ER is closely coordinated with mitochondrial transport through interaction with the prohibitin/TIMM14 mitochondrial import motor. Accordingly, ablation of LPGAT1 or TIMM14 not only causes aberrant fatty acyl compositions but also ER retention of newly remodeled PG, leading to profound loss in mitochondrial crista structure and respiration. Consequently, genetic deletion of the LPGAT1 in mice leads to cardinal features of MEGDEL syndrome, including 3-methylglutaconic aciduria, deafness, dilated cardiomyopathy, and premature death, which are highly reminiscent of those caused by TIMM14 mutations in humans.
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Affiliation(s)
- Haoran Sun
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Jun Zhang
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX 78229, USA
| | - Qianqian Ye
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China; Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX 78229, USA
| | - Ting Jiang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Xueling Liu
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Xiaoyang Zhang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Fanyu Zeng
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China; Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX 78229, USA
| | - Jie Li
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Yue Zheng
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Xianlin Han
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX 78229, USA
| | - Chuan Su
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, 101 Longmian Avenue, Nanjing, Jiangsu Province 211166, China
| | - Yuguang Shi
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, 4939 Charles Katz Drive, San Antonio, TX 78229, USA.
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7
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Nusir A, Sinclair P, Kabbani N. Mitochondrial Proteomes in Neural Cells: A Systematic Review. Biomolecules 2023; 13:1638. [PMID: 38002320 PMCID: PMC10669788 DOI: 10.3390/biom13111638] [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: 10/10/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
Mitochondria are ancient endosymbiotic double membrane organelles that support a wide range of eukaryotic cell functions through energy, metabolism, and cellular control. There are over 1000 known proteins that either reside within the mitochondria or are transiently associated with it. These mitochondrial proteins represent a functional subcellular protein network (mtProteome) that is encoded by mitochondrial and nuclear genomes and significantly varies between cell types and conditions. In neurons, the high metabolic demand and differential energy requirements at the synapses are met by specific modifications to the mtProteome, resulting in alterations in the expression and functional properties of the proteins involved in energy production and quality control, including fission and fusion. The composition of mtProteomes also impacts the localization of mitochondria in axons and dendrites with a growing number of neurodegenerative diseases associated with changes in mitochondrial proteins. This review summarizes the findings on the composition and properties of mtProteomes important for mitochondrial energy production, calcium and lipid signaling, and quality control in neural cells. We highlight strategies in mass spectrometry (MS) proteomic analysis of mtProteomes from cultured cells and tissue. The research into mtProteome composition and function provides opportunities in biomarker discovery and drug development for the treatment of metabolic and neurodegenerative disease.
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Affiliation(s)
- Aya Nusir
- Interdisciplinary Program in Neuroscience, School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
| | - Patricia Sinclair
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
| | - Nadine Kabbani
- Interdisciplinary Program in Neuroscience, School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
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8
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Joshi A, Richard TH, Gohil VM. Mitochondrial phospholipid metabolism in health and disease. J Cell Sci 2023; 136:jcs260857. [PMID: 37655851 PMCID: PMC10482392 DOI: 10.1242/jcs.260857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
Studies of rare human genetic disorders of mitochondrial phospholipid metabolism have highlighted the crucial role that membrane phospholipids play in mitochondrial bioenergetics and human health. The phospholipid composition of mitochondrial membranes is highly conserved from yeast to humans, with each class of phospholipid performing a specific function in the assembly and activity of various mitochondrial membrane proteins, including the oxidative phosphorylation complexes. Recent studies have uncovered novel roles of cardiolipin and phosphatidylethanolamine, two crucial mitochondrial phospholipids, in organismal physiology. Studies on inter-organellar and intramitochondrial phospholipid transport have significantly advanced our understanding of the mechanisms that maintain mitochondrial phospholipid homeostasis. Here, we discuss these recent advances in the function and transport of mitochondrial phospholipids while describing their biochemical and biophysical properties and biosynthetic pathways. Additionally, we highlight the roles of mitochondrial phospholipids in human health by describing the various genetic diseases caused by disruptions in their biosynthesis and discuss advances in therapeutic strategies for Barth syndrome, the best-studied disorder of mitochondrial phospholipid metabolism.
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Affiliation(s)
- Alaumy Joshi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Travis H. Richard
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Vishal M. Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
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9
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Perea V, Cole C, Lebeau J, Dolina V, Baron KR, Madhavan A, Kelly JW, Grotjahn DA, Wiseman RL. PERK signaling promotes mitochondrial elongation by remodeling membrane phosphatidic acid. EMBO J 2023; 42:e113908. [PMID: 37306086 PMCID: PMC10390871 DOI: 10.15252/embj.2023113908] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/05/2023] [Accepted: 05/12/2023] [Indexed: 06/13/2023] Open
Abstract
Endoplasmic reticulum (ER) stress and mitochondrial dysfunction are linked in the onset and pathogenesis of numerous diseases. This has led to considerable interest in defining the mechanisms responsible for regulating mitochondria during ER stress. The PERK signaling arm of the unfolded protein response (UPR) has emerged as a prominent ER stress-responsive signaling pathway that regulates diverse aspects of mitochondrial biology. Here, we show that PERK activity promotes adaptive remodeling of mitochondrial membrane phosphatidic acid (PA) to induce protective mitochondrial elongation during acute ER stress. We find that PERK activity is required for ER stress-dependent increases in both cellular PA and YME1L-dependent degradation of the intramitochondrial PA transporter PRELID1. These two processes lead to the accumulation of PA on the outer mitochondrial membrane where it can induce mitochondrial elongation by inhibiting mitochondrial fission. Our results establish a new role for PERK in the adaptive remodeling of mitochondrial phospholipids and demonstrate that PERK-dependent PA regulation adapts organellar shape in response to ER stress.
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Affiliation(s)
- Valerie Perea
- Department of Molecular MedicineScripps ResearchLa JollaCAUSA
| | | | - Justine Lebeau
- Department of Molecular MedicineScripps ResearchLa JollaCAUSA
| | - Vivian Dolina
- Department of Molecular MedicineScripps ResearchLa JollaCAUSA
| | - Kelsey R Baron
- Department of Molecular MedicineScripps ResearchLa JollaCAUSA
| | | | - Jeffery W Kelly
- Department of ChemistryScripps ResearchLa JollaCAUSA
- Skaggs Institute for Chemical BiologyScripps ResearchLa JollaCAUSA
| | - Danielle A Grotjahn
- Department of Integrative, Structural, and Computational BiologyScripps ResearchLa JollaCAUSA
| | - R Luke Wiseman
- Department of Molecular MedicineScripps ResearchLa JollaCAUSA
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10
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Zhao W, Kong L, Guan W, Liu J, Cui H, Cai M, Fang B, Liu X. Yeast UPS1 deficiency leads to UVC radiation sensitivity and shortened lifespan. Antonie Van Leeuwenhoek 2023:10.1007/s10482-023-01847-8. [PMID: 37222845 DOI: 10.1007/s10482-023-01847-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 05/16/2023] [Indexed: 05/25/2023]
Abstract
UPS1/YLR193C of Saccharomyces cerevisiae (S. cerevisiae) encodes a mitochondrial intermembrane space protein. A previous study found that Ups1p is needed for normal mitochondrial morphology and that UPS1 deficiency disrupts the intramitochondrial transport of phosphatidic acid in yeast cells and leads to an altered unfolded protein response and mTORC1 signaling activation. In this paper, we first provide evidence showing that the UPS1 gene is involved in the UVC-induced DNA damage response and aging. We show that UPS1 deficiency leads to sensitivity to ultraviolet C (UVC) radiation and that this effect is accompanied by elevated DNA damage, increased intracellular ROS levels, abnormal mitochondrial respiratory function, an increased early apoptosis rate, and shortened replicative lifespan and chronological lifespan. Moreover, we show that overexpression of the DNA damage-induced checkpoint gene RAD9 effectively eliminates the senescence-related defects observed in the UPS1-deficient strain. Collectively, these results suggest a novel role for UPS1 in the UVC-induced DNA damage response and aging.
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Affiliation(s)
- Wei Zhao
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Institute of Aging Research, Guangdong Medical University, Dongguan, 523808, China
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Lingyue Kong
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Institute of Aging Research, Guangdong Medical University, Dongguan, 523808, China
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Wenbin Guan
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Institute of Aging Research, Guangdong Medical University, Dongguan, 523808, China
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Jiaxin Liu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Institute of Aging Research, Guangdong Medical University, Dongguan, 523808, China
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Hongjing Cui
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Institute of Aging Research, Guangdong Medical University, Dongguan, 523808, China
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Mianshan Cai
- Precision Medicine Centre, Department of Pediatrics, Puning People's Hospital, Puning, 515300, Guangdong, China
| | - Bingxiong Fang
- Precision Medicine Centre, Department of Pediatrics, Puning People's Hospital, Puning, 515300, Guangdong, China.
| | - Xinguang Liu
- Guangdong Provincial Key Laboratory of Medical Molecular Diagnostics, Institute of Aging Research, Guangdong Medical University, Dongguan, 523808, China.
- School of Medical Technology, Guangdong Medical University, Dongguan, China.
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11
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Sassano ML, van Vliet AR, Vervoort E, Van Eygen S, Van den Haute C, Pavie B, Roels J, Swinnen JV, Spinazzi M, Moens L, Casteels K, Meyts I, Pinton P, Marchi S, Rochin L, Giordano F, Felipe-Abrio B, Agostinis P. PERK recruits E-Syt1 at ER-mitochondria contacts for mitochondrial lipid transport and respiration. J Cell Biol 2023; 222:213891. [PMID: 36821088 PMCID: PMC9998969 DOI: 10.1083/jcb.202206008] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 12/07/2022] [Accepted: 01/19/2023] [Indexed: 02/24/2023] Open
Abstract
The integrity of ER-mitochondria appositions ensures transfer of ions and phospholipids (PLs) between these organelles and exerts crucial effects on mitochondrial bioenergetics. Malfunctions within the ER-mitochondria contacts altering lipid trafficking homeostasis manifest in diverse pathologies, but the molecular effectors governing this process remain ill-defined. Here, we report that PERK promotes lipid trafficking at the ER-mitochondria contact sites (EMCS) through a non-conventional, unfolded protein response-independent, mechanism. PERK operates as an adaptor for the recruitment of the ER-plasma membrane tether and lipid transfer protein (LTP) Extended-Synaptotagmin 1 (E-Syt1), within the EMCS. In resting cells, the heterotypic E-Syt1-PERK interaction endorses transfer of PLs between the ER and mitochondria. Weakening the E-Syt1-PERK interaction or removing the lipid transfer SMP-domain of E-Syt1, compromises mitochondrial respiration. Our findings unravel E-Syt1 as a PERK interacting LTP and molecular component of the lipid trafficking machinery of the EMCS, which critically maintains mitochondrial homeostasis and fitness.
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Affiliation(s)
- Maria Livia Sassano
- Cell Death Research and Therapy Group, Department of Cellular and Molecular Medicine, KU Leuven , Leuven, Belgium.,VIB Center for Cancer Biology , Leuven, Belgium
| | - Alexander R van Vliet
- Cell Death Research and Therapy Group, Department of Cellular and Molecular Medicine, KU Leuven , Leuven, Belgium
| | - Ellen Vervoort
- Cell Death Research and Therapy Group, Department of Cellular and Molecular Medicine, KU Leuven , Leuven, Belgium.,VIB Center for Cancer Biology , Leuven, Belgium
| | - Sofie Van Eygen
- Cell Death Research and Therapy Group, Department of Cellular and Molecular Medicine, KU Leuven , Leuven, Belgium.,VIB Center for Cancer Biology , Leuven, Belgium
| | - Chris Van den Haute
- Research Group for Neurobiology and Gene Therapy, Department of Neuroscience, Leuven Viral Vector Core, KU Leuven , Leuven, Belgium
| | | | - Joris Roels
- VIB-bioimaging Center UGent , Ghent, Belgium.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay , Gif-sur-Yvette, France
| | - Johannes V Swinnen
- Laboratory of Lipid Metabolism and Cancer, Department of Oncology, KU Leuven , Leuven, Belgium
| | - Marco Spinazzi
- Neuromuscular Reference Center, CHU Angers , Angers, France
| | - Leen Moens
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Department of Pediatrics, University Hospitals Leuven , Leuven, Belgium
| | - Kristina Casteels
- Woman and Child, Department for Development and Regeneration, KU Leuven, Department of Pediatrics, University Hospitals Leuven , Leuven, Belgium
| | - Isabelle Meyts
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Department of Pediatrics, University Hospitals Leuven , Leuven, Belgium
| | - Paolo Pinton
- Department of Medical Sciences, University of Ferrara , Ferrara, Italy
| | - Saverio Marchi
- Department of Clinical and Molecular Sciences, Marche Polytechnic University , Ancona, Italy
| | | | | | - Blanca Felipe-Abrio
- Cell Death Research and Therapy Group, Department of Cellular and Molecular Medicine, KU Leuven , Leuven, Belgium.,VIB Center for Cancer Biology , Leuven, Belgium
| | - Patrizia Agostinis
- Cell Death Research and Therapy Group, Department of Cellular and Molecular Medicine, KU Leuven , Leuven, Belgium.,VIB Center for Cancer Biology , Leuven, Belgium
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12
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Kakimoto-Takeda Y, Kojima R, Shiino H, Shinmyo M, Kurokawa K, Nakano A, Endo T, Tamura Y. Dissociation of ERMES clusters plays a key role in attenuating the endoplasmic reticulum stress. iScience 2022; 25:105362. [PMID: 36339260 PMCID: PMC9626684 DOI: 10.1016/j.isci.2022.105362] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/24/2022] [Accepted: 10/12/2022] [Indexed: 11/27/2022] Open
Abstract
In yeast, ERMES, which mediates phospholipid transport between the ER and mitochondria, forms a limited number of oligomeric clusters at ER-mitochondria contact sites in a cell. Although the number of the ERMES clusters appears to be regulated to maintain proper inter-organelle phospholipid trafficking, its underlying mechanism and physiological relevance remain poorly understood. Here, we show that mitochondrial dynamics control the number of ERMES clusters. Moreover, we find that ER stress causes dissociation of the ERMES clusters independently of Ire1 and Hac1, canonical ER-stress response pathway components, leading to a delay in the phospholipid transport from the ER to mitochondria. Our biochemical and genetic analyses strongly suggest that the impaired phospholipid transport contributes to phospholipid accumulation in the ER, expanding the ER for ER stress attenuation. We thus propose that the ERMES dissociation constitutes an overlooked pathway of the ER stress response that operates in addition to the canonical Ire1/Hac1-dependent pathway. Mitochondrial fusion and division regulate the clustering of the ERMES complex ER stress leads to dissociation of the ERMES clusters independently of Ire1 and Hac1 The dissociated ERMES complexes have less activity in transporting phospholipids The defective phospholipid transport may cause the ER expansion to relieve ER stress
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Affiliation(s)
- Yuriko Kakimoto-Takeda
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, 2-2-2 Iidanishi, Yamagata 990-9585, Japan
| | - Rieko Kojima
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Hiroya Shiino
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Manatsu Shinmyo
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
| | - Kazuo Kurokawa
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
- Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan
- Corresponding author
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13
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Abstract
Mitochondria are complex organelles with two membranes. Their architecture is determined by characteristic folds of the inner membrane, termed cristae. Recent studies in yeast and other organisms led to the identification of four major pathways that cooperate to shape cristae membranes. These include dimer formation of the mitochondrial ATP synthase, assembly of the mitochondrial contact site and cristae organizing system (MICOS), inner membrane remodelling by a dynamin-related GTPase (Mgm1/OPA1), and modulation of the mitochondrial lipid composition. In this review, we describe the function of the evolutionarily conserved machineries involved in mitochondrial cristae biogenesis with a focus on yeast and present current models to explain how their coordinated activities establish mitochondrial membrane architecture.
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Affiliation(s)
- Till Klecker
- Institut für Zellbiologie, Universität Bayreuth, 95440 Bayreuth, Germany
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14
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UbiB proteins regulate cellular CoQ distribution in Saccharomyces cerevisiae. Nat Commun 2021; 12:4769. [PMID: 34362905 PMCID: PMC8346625 DOI: 10.1038/s41467-021-25084-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/22/2021] [Indexed: 11/08/2022] Open
Abstract
Beyond its role in mitochondrial bioenergetics, Coenzyme Q (CoQ, ubiquinone) serves as a key membrane-embedded antioxidant throughout the cell. However, how CoQ is mobilized from its site of synthesis on the inner mitochondrial membrane to other sites of action remains a longstanding mystery. Here, using a combination of Saccharomyces cerevisiae genetics, biochemical fractionation, and lipid profiling, we identify two highly conserved but poorly characterized mitochondrial proteins, Ypl109c (Cqd1) and Ylr253w (Cqd2), that reciprocally affect this process. Loss of Cqd1 skews cellular CoQ distribution away from mitochondria, resulting in markedly enhanced resistance to oxidative stress caused by exogenous polyunsaturated fatty acids, whereas loss of Cqd2 promotes the opposite effects. The activities of both proteins rely on their atypical kinase/ATPase domains, which they share with Coq8-an essential auxiliary protein for CoQ biosynthesis. Overall, our results reveal protein machinery central to CoQ trafficking in yeast and lend insights into the broader interplay between mitochondria and the rest of the cell.
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15
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Tamura Y, Kawano S, Endo T. Lipid homeostasis in mitochondria. Biol Chem 2021; 401:821-833. [PMID: 32229651 DOI: 10.1515/hsz-2020-0121] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/10/2020] [Indexed: 12/13/2022]
Abstract
Mitochondria are surrounded by the two membranes, the outer and inner membranes, whose lipid compositions are optimized for proper functions and structural organizations of mitochondria. Although a part of mitochondrial lipids including their characteristic lipids, phosphatidylethanolamine and cardiolipin, are synthesized within mitochondria, their precursor lipids and other lipids are transported from other organelles, mainly the ER. Mitochondrially synthesized lipids are re-distributed within mitochondria and to other organelles, as well. Recent studies pointed to the important roles of inter-organelle contact sites in lipid trafficking between different organelle membranes. Identification of Ups/PRELI proteins as lipid transfer proteins shuttling between the mitochondrial outer and inner membranes established a part of the molecular and structural basis of the still elusive intra-mitochondrial lipid trafficking.
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Affiliation(s)
- Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12, Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Shin Kawano
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
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16
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Acoba MG, Senoo N, Claypool SM. Phospholipid ebb and flow makes mitochondria go. J Cell Biol 2021; 219:151918. [PMID: 32614384 PMCID: PMC7401802 DOI: 10.1083/jcb.202003131] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 01/19/2023] Open
Abstract
Mitochondria, so much more than just being energy factories, also have the capacity to synthesize macromolecules including phospholipids, particularly cardiolipin (CL) and phosphatidylethanolamine (PE). Phospholipids are vital constituents of mitochondrial membranes, impacting the plethora of functions performed by this organelle. Hence, the orchestrated movement of phospholipids to and from the mitochondrion is essential for cellular integrity. In this review, we capture recent advances in the field of mitochondrial phospholipid biosynthesis and trafficking, highlighting the significance of interorganellar communication, intramitochondrial contact sites, and lipid transfer proteins in maintaining membrane homeostasis. We then discuss the physiological functions of CL and PE, specifically how they associate with protein complexes in mitochondrial membranes to support bioenergetics and maintain mitochondrial architecture.
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Affiliation(s)
- Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nanami Senoo
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
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17
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Sam PN, Calzada E, Acoba MG, Zhao T, Watanabe Y, Nejatfard A, Trinidad JC, Shutt TE, Neal SE, Claypool SM. Impaired phosphatidylethanolamine metabolism activates a reversible stress response that detects and resolves mutant mitochondrial precursors. iScience 2021; 24:102196. [PMID: 33718843 PMCID: PMC7921845 DOI: 10.1016/j.isci.2021.102196] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/27/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylethanolamine (PE) made in mitochondria has long been recognized as an important precursor for phosphatidylcholine production that occurs in the endoplasmic reticulum (ER). Recently, the strict mitochondrial localization of the enzyme that makes PE in the mitochondrion, phosphatidylserine decarboxylase 1 (Psd1), was questioned. Since a dual localization of Psd1 to the ER would have far-reaching implications, we initiated our study to independently re-assess the subcellular distribution of Psd1. Our results support the unavoidable conclusion that the vast majority, if not all, of functional Psd1 resides in the mitochondrion. Through our efforts, we discovered that mutant forms of Psd1 that impair a self-processing step needed for it to become functional are dually localized to the ER when expressed in a PE-limiting environment. We conclude that severely impaired cellular PE metabolism provokes an ER-assisted adaptive response that is capable of identifying and resolving nonfunctional mitochondrial precursors.
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Affiliation(s)
- Pingdewinde N. Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Tian Zhao
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Yasunori Watanabe
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Anahita Nejatfard
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | | | - Timothy E. Shutt
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Sonya E. Neal
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Steven M. Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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18
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Dynamic Remodeling of Membranes and Their Lipids during Acute Hormone-Induced Steroidogenesis in MA-10 Mouse Leydig Tumor Cells. Int J Mol Sci 2021; 22:ijms22052554. [PMID: 33806352 PMCID: PMC7961408 DOI: 10.3390/ijms22052554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 02/24/2021] [Accepted: 02/27/2021] [Indexed: 12/14/2022] Open
Abstract
Lipids play essential roles in numerous cellular processes, including membrane remodeling, signal transduction, the modulation of hormone activity, and steroidogenesis. We chose steroidogenic MA-10 mouse tumor Leydig cells to investigate subcellular lipid localization during steroidogenesis. Electron microscopy showed that cAMP stimulation increased associations between the plasma membrane (PM) and the endoplasmic reticulum (ER) and between the ER and mitochondria. cAMP stimulation also increased the movement of cholesterol from the PM compared to untreated cells, which was partially inhibited when ATPase family AAA-domain containing protein 3 A (ATAD3A), which functions in ER and mitochondria interactions, was knocked down. Mitochondria, ER, cytoplasm, PM, PM-associated membranes (PAMs), and mitochondria-associated membranes (MAMs) were isolated from control and hormone-stimulated cells. Lipidomic analyses revealed that each isolated compartment had a unique lipid composition, and the induction of steroidogenesis caused the significant remodeling of its lipidome. cAMP-induced changes in lipid composition included an increase in phosphatidylserine and cardiolipin levels in PAM and PM compartments, respectively; an increase in phosphatidylinositol in the ER, mitochondria, and MAMs; and a reorganization of phosphatidic acid, cholesterol ester, ceramide, and phosphatidylethanolamine. Abundant lipids, such as phosphatidylcholine, were not affected by hormone treatment. Our data suggested that PM–ER–mitochondria tethering may be involved in lipid trafficking between organelles and indicated that hormone-induced acute steroid production involves extensive organelle remodeling.
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19
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Shiino H, Furuta S, Kojima R, Kimura K, Endo T, Tamura Y. Phosphatidylserine flux into mitochondria unveiled by organelle-targeted Escherichia coli phosphatidylserine synthase PssA. FEBS J 2020; 288:3285-3299. [PMID: 33283454 DOI: 10.1111/febs.15657] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 11/12/2020] [Accepted: 12/04/2020] [Indexed: 11/26/2022]
Abstract
Most phospholipids are synthesised in the endoplasmic reticulum and distributed to other cellular membranes. Although the vesicle transport contributes to the phospholipid distribution among the endomembrane system, exactly how phospholipids are transported to, from and between mitochondrial membranes remains unclear. To gain insights into phospholipid transport routes into mitochondria, we expressed the Escherichia coli phosphatidylserine (PS) synthase PssA in various membrane compartments with distinct membrane topologies in yeast cells lacking a sole PS synthase (Cho1). Interestingly, PssA could complement loss of Cho1 when targeted to the endoplasmic reticulum (ER), peroxisome, or lipid droplet membranes. Synthesised PS could be converted to phosphatidylethanolamine (PE) by Psd1, the mitochondrial PS decarboxylase, suggesting that phospholipids synthesised in the peroxisomes and low doses (LDs) can efficiently reach mitochondria. Furthermore, we found that PssA which has been integrated into the mitochondrial inner membrane (MIM) from the matrix side could partially complement the loss of Cho1. The PS synthesised in the MIM was also converted to PE, indicating that PS flops across the MIM to become PE. These findings expand our understanding of the intracellular phospholipid transport routes via mitochondria.
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Affiliation(s)
| | | | | | | | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Japan
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20
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Tang L, Chi H, Li W, Zhang L, Zhang L, Chen L, Zou S, Liu H, Liang Y, Yu J, Dong H. FgPsd2, a phosphatidylserine decarboxylase of Fusarium graminearum, regulates development and virulence. Fungal Genet Biol 2020; 146:103483. [PMID: 33176219 DOI: 10.1016/j.fgb.2020.103483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 10/21/2020] [Accepted: 11/03/2020] [Indexed: 11/25/2022]
Abstract
Phosphatidylserine decarboxylases (Psds) are enzymes regulating phosphatidylethanolamine biosynthesis in prokaryotes and eukaryotes, and have the central role in lipid metabolism. To date, the functions of Psds in plant pathogenic fungi are not fully understood. In this study, we have characterized two yeast Psd orthologues: FgPsd1 and FgPsd2, in Fusarium graminearum. Our results indicate that FgPsd1 and FgPsd2 are localized in mitochondria and Golgi, respectively. In addition, we have determined that FgPsd1 is a lethal gene and deletion of FgPsd2 resulted in a significant reduction of mycelial growth and conidiation. Futhermore, the FgPsd2 deletion mutant (ΔFgPsd2) is defective in ascospore production and virulence in wheat. Our study has also found that the ΔFgPsd2 mutant is more sensitive to osmotic and oxygen stresses. Moreover, deletion of FgPsd2 reduced the formation of lipid droplets and aggravated autophagy in F. graminearum. In summary, our findings indicate that FgPsd2 is important for mycelial growth, sexual and asexual reproduction, virulence, lipid droplet formation and autophagy in F. graminearum.
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Affiliation(s)
- Lin Tang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Haowen Chi
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Weidong Li
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Li Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Liyuan Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Lei Chen
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Shenshen Zou
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Huixiang Liu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Yuancun Liang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China.
| | - Jinfeng Yu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Hansong Dong
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
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21
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Kundu D, Pasrija R. The ERMES (Endoplasmic Reticulum and Mitochondria Encounter Structures) mediated functions in fungi. Mitochondrion 2020; 52:89-99. [PMID: 32105794 DOI: 10.1016/j.mito.2020.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/21/2019] [Accepted: 02/21/2020] [Indexed: 01/01/2023]
Abstract
Cellular organelles are membrane-bound and provide a microenvironment for specific functions. A mitochondrion is a double membranous and dynamic organelle that undergoes numerous fusion/fission events, which depends on various cellular factors. However, it is still dependent on other organelles and requires both communications as well as the movement of physical metabolites between them. Mitochondria interact with different organelles counting lipid droplets (LD), peroxisomes, vacuoles, endoplasmic reticulum (ER) and plasma membrane (PM), etc. Apart from them, mitochondria maintain multiple interactions with ER including ERMES (Endoplasmic Reticulum and Mitochondria encounter structures). ERMES is actually a multi-protein complex, and imperative in the maintenance of mitochondrial morphology and its functions. Its disruption also compromises phospholipid exchange, drug resistance and pathogenicity. This assembly is reportedly unique to fungal systems and proposed as a target for development of new antifungal. In the light of separate reports across diverse fungal systems, we have summarised the information about its distribution and effect on mitochondrial fitness.
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Affiliation(s)
- Deepika Kundu
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Ritu Pasrija
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, India.
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22
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Abstract
Synthesis and regulation of lipid levels and identities is critical for a wide variety of cellular functions, including structural and morphological properties of organelles, energy storage, signaling, and stability and function of membrane proteins. Proteolytic cleavage events regulate and/or influence some of these lipid metabolic processes and as a result help modulate their pleiotropic cellular functions. Proteins involved in lipid regulation are proteolytically cleaved for the purpose of their relocalization, processing, turnover, and quality control, among others. The scope of this review includes proteolytic events governing cellular lipid dynamics. After an initial discussion of the classic example of sterol regulatory element-binding proteins, our focus will shift to the mitochondrion, where a range of proteolytic events are critical for normal mitochondrial phospholipid metabolism and enforcing quality control therein. Recently, mitochondrial phospholipid metabolic pathways have been implicated as important for the proliferative capacity of cancers. Thus, the assorted proteases that regulate, monitor, or influence the activity of proteins that are important for phospholipid metabolism represent attractive targets to be manipulated for research purposes and clinical applications.
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Affiliation(s)
- Pingdewinde N. Sam
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Erica Avery
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Steven M. Claypool
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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23
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Hahn O, Drews LF, Nguyen A, Tatsuta T, Gkioni L, Hendrich O, Zhang Q, Langer T, Pletcher S, Wakelam MJO, Beyer A, Grönke S, Partridge L. A nutritional memory effect counteracts benefits of dietary restriction in old mice. Nat Metab 2019; 1:1059-1073. [PMID: 31742247 PMCID: PMC6861129 DOI: 10.1038/s42255-019-0121-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Dietary restriction (DR) during adulthood can greatly extend lifespan and improve metabolic health in diverse species. However, whether DR in mammals is still effective when applied for the first time at old age remains elusive. Here, we report results of a late-life DR switch experiment employing 800 mice, in which 24 months old female mice were switched from ad libitum (AL) to DR or vice versa. Strikingly, the switch from DR-to-AL acutely increases mortality, whereas the switch from AL-to-DR causes only a weak and gradual increase in survival, suggesting a memory of earlier nutrition. RNA-seq profiling in liver, brown (BAT) and white adipose tissue (WAT) demonstrate a largely refractory transcriptional and metabolic response to DR after AL feeding in fat tissue, particularly in WAT, and a proinflammatory signature in aged preadipocytes, which is prevented by chronic DR feeding. Our results provide evidence for a nutritional memory as a limiting factor for DR-induced longevity and metabolic remodeling of WAT in mammals.
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Affiliation(s)
- Oliver Hahn
- Max Planck Institute for Biology of Ageing, Cologne, Germany
- Cellular Networks and Systems Biology, CECAD, University of Cologne, Cologne, Germany
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Lisa F Drews
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - An Nguyen
- Inositide lab, The Babraham Institute, Cambridge, UK
| | - Takashi Tatsuta
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Lisonia Gkioni
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Oliver Hendrich
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Qifeng Zhang
- Inositide lab, The Babraham Institute, Cambridge, UK
| | - Thomas Langer
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Scott Pletcher
- Department of Molecular & Integrative Physiology and the Geriatrics Center, University of Michigan, Ann Arbor, USA
| | | | - Andreas Beyer
- Cellular Networks and Systems Biology, CECAD, University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK.
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24
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Odendall F, Backes S, Tatsuta T, Weill U, Schuldiner M, Langer T, Herrmann JM, Rapaport D, Dimmer KS. The mitochondrial intermembrane space-facing proteins Mcp2 and Tgl2 are involved in yeast lipid metabolism. Mol Biol Cell 2019; 30:2681-2694. [PMID: 31483742 PMCID: PMC6761770 DOI: 10.1091/mbc.e19-03-0166] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are unique organelles harboring two distinct membranes, the mitochondrial inner and outer membrane (MIM and MOM, respectively). Mitochondria comprise only a subset of metabolic pathways for the synthesis of membrane lipids; therefore most lipid species and their precursors have to be imported from other cellular compartments. One such import process is mediated by the ER mitochondria encounter structure (ERMES) complex. Both mitochondrial membranes surround the hydrophilic intermembrane space (IMS). Therefore, additional systems are required that shuttle lipids between the MIM and MOM. Recently, we identified the IMS protein Mcp2 as a high-copy suppressor for cells that lack a functional ERMES complex. To understand better how mitochondria facilitate transport and biogenesis of lipids, we searched for genetic interactions of this suppressor. We found that MCP2 has a negative genetic interaction with the gene TGL2 encoding a neutral lipid hydrolase. We show that this lipase is located in the intermembrane space of the mitochondrion and is imported via the Mia40 disulfide relay system. Furthermore, we show a positive genetic interaction of double deletion of MCP2 and PSD1, the gene encoding the enzyme that synthesizes the major amount of cellular phosphatidylethanolamine. Finally, we demonstrate that the nucleotide-binding motifs of the predicted atypical kinase Mcp2 are required for its proper function. Taken together, our data suggest that Mcp2 is involved in mitochondrial lipid metabolism and an increase of this involvement by overexpression suppresses loss of ERMES.
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Affiliation(s)
- Fenja Odendall
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Sandra Backes
- Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Takashi Tatsuta
- Max Planck Institute for Biology of Ageing, 50931 Köln, Germany
| | - Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Thomas Langer
- Max Planck Institute for Biology of Ageing, 50931 Köln, Germany
| | | | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
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25
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Esposito M, Hermann-Le Denmat S, Delahodde A. Contribution of ERMES subunits to mature peroxisome abundance. PLoS One 2019; 14:e0214287. [PMID: 30908556 PMCID: PMC6433259 DOI: 10.1371/journal.pone.0214287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/11/2019] [Indexed: 11/26/2022] Open
Abstract
Eukaryotic organelles share different components and establish physical contacts to communicate throughout the cell. One of the best-recognized examples of such interplay is the metabolic cooperation and crosstalk between mitochondria and peroxisomes, both organelles being functionally and physically connected and linked to the endoplasmic reticulum (ER). In Saccharomyces cerevisiae, mitochondria are linked to the ER by the ERMES complex that facilitates inter-organelle calcium and phospholipid exchanges. Recently, peroxisome-mitochondria contact sites (PerMit) have been reported and among Permit tethers, one component of the ERMES complex (Mdm34) was shown to interact with the peroxin Pex11, suggesting that the ERMES complex or part of it may be involved in two membrane contact sites (ER-mitochondria and peroxisome- mitochondria). This opens the possibility of exchanges between these three membrane compartments. Here, we investigated in details the role of each ERMES subunit on peroxisome abundance. First, we confirmed previous studies from other groups showing that absence of Mdm10 or Mdm12 leads to an increased number of mature peroxisomes. Secondly, we showed that this is not simply due to respiratory function defect, mitochondrial DNA (mtDNA) loss or mitochondrial network alteration. Finally, we present evidence that the contribution of ERMES subunits Mdm10 and Mdm12 to peroxisome number involves two different mechanisms.
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Affiliation(s)
- Michela Esposito
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
| | - Sylvie Hermann-Le Denmat
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
- Ecole Normale Supérieure, PSL Research University, Paris, France
| | - Agnès Delahodde
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris‐Sud, Université Paris‐Saclay, Gif‐sur‐Yvette cedex, France
- * E-mail:
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26
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Tamura Y, Kawano S, Endo T. Organelle contact zones as sites for lipid transfer. J Biochem 2019; 165:115-123. [PMID: 30371789 DOI: 10.1093/jb/mvy088] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/26/2018] [Indexed: 01/06/2023] Open
Abstract
Since the 1950s, electron microscopic observations have suggested the existence of special regions where the distinct organelle membranes are closely apposed to each other, yet their molecular basis and functions have not been examined for a long time. Recent studies using yeast as a model organism identified multiple organelle-membrane tethering sites/factors, such as ERMES (ER-mitochondria encounter structure), NVJ (Nuclear-vacuole junction), vCLAMP (Vacuole and mitochondria patch) and MICOS (Mitochondrial contact site). Among them, ERMES is the best-characterized contact-site protein complex, which was found to function as not only an organelle-tethering factor but also a phospholipid transfer protein complex. In this review, we will discuss recent advances in the characterization of ERMES and other organelle contact zones, vCLAMP, NVJ and MICOS in yeast.
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Affiliation(s)
- Yasushi Tamura
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Japan
| | - Shin Kawano
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan.,Research Center for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan.,Research Center for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, Japan
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27
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Martins VM, Fernandes TR, Lopes D, Afonso CB, Domingues MRM, Côrte-Real M, Sousa MJ. Contacts in Death: The Role of the ER-Mitochondria Axis in Acetic Acid-Induced Apoptosis in Yeast. J Mol Biol 2018; 431:273-288. [PMID: 30414966 DOI: 10.1016/j.jmb.2018.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/12/2018] [Accepted: 11/05/2018] [Indexed: 02/08/2023]
Abstract
Endoplasmic reticulum-mitochondria contact sites have been a subject of increasing scientific interest since the discovery that these structures are disrupted in several pathologies. Due to the emerging data that correlate endoplasmic reticulum-mitochondria contact sites function with known events of the apoptotic program, we aimed to dissect this interplay using our well-established model of acetic acid-induced apoptosis in Saccharomyces cerevisiae. Until recently, the only known tethering complex between ER and mitochondria in this organism was the ER-mitochondria encounter structure (ERMES). Following our results from a screening designed to identify genes whose deletion rendered cells with an altered sensitivity to acetic acid, we hypothesized that the ERMES complex could be involved in cell death mediated by this stressor. Herein we demonstrate that single ablation of the ERMES components Mdm10p, Mdm12p and Mdm34p increases the resistance of S. cerevisiae to acetic acid-induced apoptosis, which is associated with a prominent delay in the appearance of several apoptotic markers. Moreover, abrogation of Mdm10p or Mdm34p abolished cytochrome c release from mitochondria. Since these two proteins are embedded in the mitochondrial outer membrane, we propose that the ERMES complex plays a part in cytochrome c release, a key event of the apoptotic cascade. In all, these findings will aid in targeted therapies for diseases where apoptosis is disrupted, as well as assist in the development of acetic acid-resistant strains for industrial processes.
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Affiliation(s)
- Vítor M Martins
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
| | - Tânia R Fernandes
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Diana Lopes
- Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; Department of Chemistry & CESAM & ECOMARE, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Catarina B Afonso
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Maria R M Domingues
- Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; Department of Chemistry & CESAM & ECOMARE, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Manuela Côrte-Real
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Maria J Sousa
- Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
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28
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Miyata N, Fujii S, Kuge O. Porin proteins have critical functions in mitochondrial phospholipid metabolism in yeast. J Biol Chem 2018; 293:17593-17605. [PMID: 30237174 DOI: 10.1074/jbc.ra118.005410] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/19/2018] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial synthesis of cardiolipin (CL) and phosphatidylethanolamine requires the transport of their precursors, phosphatidic acid and phosphatidylserine, respectively, to the mitochondrial inner membrane. In yeast, the Ups1-Mdm35 and Ups2-Mdm35 complexes transfer phosphatidic acid and phosphatidylserine, respectively, between the mitochondrial outer and inner membranes. Moreover, a Ups1-independent CL accumulation pathway requires several mitochondrial proteins with unknown functions including Mdm31. Here, we identified a mitochondrial porin, Por1, as a protein that interacts with both Mdm31 and Mdm35 in budding yeast (Saccharomyces cerevisiae). Depletion of the porins Por1 and Por2 destabilized Ups1 and Ups2, decreased CL levels by ∼90%, and caused loss of Ups2-dependent phosphatidylethanolamine synthesis, but did not affect Ups2-independent phosphatidylethanolamine synthesis in mitochondria. Por1 mutations that affected its interactions with Mdm31 and Mdm35, but not respiratory growth, also decreased CL levels. Using HeLa cells, we show that mammalian porins also function in mitochondrial CL metabolism. We conclude that yeast porins have specific and critical functions in mitochondrial phospholipid metabolism and that porin-mediated regulation of CL metabolism appears to be evolutionarily conserved.
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Affiliation(s)
- Non Miyata
- From the Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Satoru Fujii
- From the Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Osamu Kuge
- From the Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
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29
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Hanada K. Lipid transfer proteins rectify inter-organelle flux and accurately deliver lipids at membrane contact sites. J Lipid Res 2018; 59:1341-1366. [PMID: 29884707 PMCID: PMC6071762 DOI: 10.1194/jlr.r085324] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/24/2018] [Indexed: 12/22/2022] Open
Abstract
The endoplasmic reticulum (ER) is the main center for the synthesis of various lipid types in cells, and newly synthesized lipids are delivered from the ER to other organelles. In the past decade, various lipid transfer proteins (LTPs) have been recognized as mediators of lipid transport from the ER to other organelles; inter-organelle transport occurs at membrane contact sites (MCSs) and in a nonvesicular manner. Although the intermembrane transfer reaction catalyzed by LTPs is an equilibrium reaction, various types of newly synthesized lipids are transported unidirectionally in cells. This review provides a brief history of the inter-organelle trafficking of lipids and summarizes the structural and biochemical characteristics of the ceramide transport protein (CERT) as a typical LTP acting at MCSs. In addition, this review compares several LTP-mediated inter-organelle lipid trafficking systems and proposes that LTPs generate unidirectional fluxes of specific lipids between different organelles by indirect coupling with the metabolic reactions that occur in specific organelles. Moreover, the available data also suggest that the major advantage of LTP-mediated lipid transport at MCSs may be the accuracy of delivery. Finally, how cholesterol is enriched in the plasma membrane is discussed from a thermodynamic perspective.
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Affiliation(s)
- Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
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30
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Kakimoto Y, Tashiro S, Kojima R, Morozumi Y, Endo T, Tamura Y. Visualizing multiple inter-organelle contact sites using the organelle-targeted split-GFP system. Sci Rep 2018; 8:6175. [PMID: 29670150 PMCID: PMC5906596 DOI: 10.1038/s41598-018-24466-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/04/2018] [Indexed: 12/18/2022] Open
Abstract
Functional integrity of eukaryotic organelles relies on direct physical contacts between distinct organelles. However, the entity of organelle-tethering factors is not well understood due to lack of means to analyze inter-organelle interactions in living cells. Here we evaluate the split-GFP system for visualizing organelle contact sites in vivo and show its advantages and disadvantages. We observed punctate GFP signals from the split-GFP fragments targeted to any pairs of organelles among the ER, mitochondria, peroxisomes, vacuole and lipid droplets in yeast cells, which suggests that these organelles form contact sites with multiple organelles simultaneously although it is difficult to rule out the possibilities that these organelle contacts sites are artificially formed by the irreversible associations of the split-GFP probes. Importantly, split-GFP signals in the overlapped regions of the ER and mitochondria were mainly co-localized with ERMES, an authentic ER-mitochondria tethering structure, suggesting that split-GFP assembly depends on the preexisting inter-organelle contact sites. We also confirmed that the split-GFP system can be applied to detection of the ER-mitochondria contact sites in HeLa cells. We thus propose that the split-GFP system is a potential tool to observe and analyze inter-organelle contact sites in living yeast and mammalian cells.
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Affiliation(s)
- Yuriko Kakimoto
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Shinya Tashiro
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Rieko Kojima
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Yuki Morozumi
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata, 990-8560, Japan.
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31
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Kawano S, Tamura Y, Kojima R, Bala S, Asai E, Michel AH, Kornmann B, Riezman I, Riezman H, Sakae Y, Okamoto Y, Endo T. Structure-function insights into direct lipid transfer between membranes by Mmm1-Mdm12 of ERMES. J Cell Biol 2017; 217:959-974. [PMID: 29279306 PMCID: PMC5839780 DOI: 10.1083/jcb.201704119] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 11/06/2017] [Accepted: 12/01/2017] [Indexed: 12/26/2022] Open
Abstract
The ER–mitochondrial encounter structure (ERMES) physically links ER and mitochondrial membranes in yeast, but it is unclear whether ERMES directly facilitates lipid exchange between these organelles. Kawano et al. reveal by reconstitution experiments that a complex of Mmm1–Mdm12, two core subunits of ERMES, functions as a minimal unit for lipid transfer between membranes. The endoplasmic reticulum (ER)–mitochondrial encounter structure (ERMES) physically links the membranes of the ER and mitochondria in yeast. Although the ER and mitochondria cooperate to synthesize glycerophospholipids, whether ERMES directly facilitates the lipid exchange between the two organelles remains controversial. Here, we compared the x-ray structures of an ERMES subunit Mdm12 from Kluyveromyces lactis with that of Mdm12 from Saccharomyces cerevisiae and found that both Mdm12 proteins possess a hydrophobic pocket for phospholipid binding. However in vitro lipid transfer assays showed that Mdm12 alone or an Mmm1 (another ERMES subunit) fusion protein exhibited only a weak lipid transfer activity between liposomes. In contrast, Mdm12 in a complex with Mmm1 mediated efficient lipid transfer between liposomes. Mutations in Mmm1 or Mdm12 impaired the lipid transfer activities of the Mdm12–Mmm1 complex and furthermore caused defective phosphatidylserine transport from the ER to mitochondrial membranes via ERMES in vitro. Therefore, the Mmm1–Mdm12 complex functions as a minimal unit that mediates lipid transfer between membranes.
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Affiliation(s)
- Shin Kawano
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan.,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Kyoto Sangyo University, Kyoto, Japan.,Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan.,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Nagoya University, Nagoya, Japan
| | - Yasushi Tamura
- Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Nagoya University, Nagoya, Japan.,Research Center for Materials Science, Nagoya University, Nagoya, Japan.,Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata, Japan
| | - Rieko Kojima
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata, Japan
| | - Siqin Bala
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Eri Asai
- Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Agnès H Michel
- Institute of Biochemistry, ETH Zürich, Zürich, Switzerland
| | | | - Isabelle Riezman
- Department of Biochemistry, National Centre of Competence in Research Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Howard Riezman
- Department of Biochemistry, National Centre of Competence in Research Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Yoshitake Sakae
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Yuko Okamoto
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan .,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Kyoto Sangyo University, Kyoto, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan.,Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan.,Japan Science and Technology Agency/Core Research for Evolutional Science and Technology, Nagoya University, Nagoya, Japan
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32
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Cooperative function of Fmp30, Mdm31, and Mdm32 in Ups1-independent cardiolipin accumulation in the yeast Saccharomyces cerevisiae. Sci Rep 2017; 7:16447. [PMID: 29180659 PMCID: PMC5703896 DOI: 10.1038/s41598-017-16661-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/15/2017] [Indexed: 11/23/2022] Open
Abstract
Cardiolipin (CL) is synthesized from phosphatidic acid (PA) through a series of enzymatic reactions occurring at the mitochondrial inner membrane (MIM). Ups1-Mdm35 mediates PA transfer from the mitochondrial outer membrane (MOM) to the MIM in the yeast Saccharomyces cerevisiae. Deletion of UPS1 leads to a ~80% decrease in the cellular CL level. However, the CL accumulation in ups1∆ cells is enhanced by the depletion of Ups2, which forms a protein complex with Mdm35 and mediates phosphatidylserine (PS) transfer from the MOM to the MIM for phosphatidylethanolamine (PE) synthesis by a PS decarboxylase, Psd1. In this study, we found that the accumulation of CL in ups1∆ cells was enhanced by deletion of not only UPS2, but also PSD1 and CHO1 encoding a PS synthase, suggesting that low PE levels in mitochondria were relevant to the enhancement of CL accumulation in ups1∆ cells. Furthermore, the Ups1-independent and low-level PE-enhanced CL accumulation was shown to depend on the functions of FMP30, MDM31, and MDM32. In addition, the physical interactions of Fmp30 with Mdm31 and Mdm32 were revealed. Thus, when the mitochondrial PE level is reduced, Fmp30, Mdm31, and Mdm32 seem to function cooperatively for the accumulation of CL in a UPS1-independent manner.
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33
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Schorr S, van der Laan M. Integrative functions of the mitochondrial contact site and cristae organizing system. Semin Cell Dev Biol 2017; 76:191-200. [PMID: 28923515 DOI: 10.1016/j.semcdb.2017.09.021] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/13/2017] [Accepted: 09/14/2017] [Indexed: 12/23/2022]
Abstract
Mitochondria are complex double-membrane-bound organelles of eukaryotic cells that function as energy-converting powerhouses, metabolic factories and signaling centers. The outer membrane controls the exchange of material and information with other cellular compartments. The inner membrane provides an extended, highly folded surface for selective transport and energy-coupling reactions. It can be divided into an inner boundary membrane and tubular or lamellar cristae membranes that accommodate the oxidative phosphorylation units. Outer membrane, inner boundary membrane and cristae come together at crista junctions, where the mitochondrial contact site and cristae organizing system (MICOS) acts as a membrane-shaping and -connecting scaffold. This peculiar architecture is of pivotal importance for multiple mitochondrial functions. Many elaborate studies in the past years have shed light on the subunit composition and organization of MICOS. In this review article, we summarize these insights and then move on to discuss exciting recent discoveries on the integrative functions of MICOS. Multi-faceted connections to other major players of mitochondrial biogenesis and physiology, like the protein import machineries, the oxidative phosphorylation system, carrier proteins and phospholipid biosynthesis enzymes, are currently emerging. Therefore, we propose that MICOS acts as a central hub in mitochondrial membrane architecture and functionality.
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Affiliation(s)
- Stefan Schorr
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, School of Medicine, 66421, Homburg, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, School of Medicine, 66421, Homburg, Germany.
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34
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Multitiered and Cooperative Surveillance of Mitochondrial Phosphatidylserine Decarboxylase 1. Mol Cell Biol 2017; 37:MCB.00049-17. [PMID: 28606933 DOI: 10.1128/mcb.00049-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/08/2017] [Indexed: 11/20/2022] Open
Abstract
Phosphatidylserine decarboxylase 1 (Psd1p), an ancient enzyme that converts phosphatidylserine to phosphatidylethanolamine in the inner mitochondrial membrane, must undergo an autocatalytic self-processing event to gain activity. Autocatalysis severs the protein into a large membrane-anchored β subunit that noncovalently associates with the small α subunit on the intermembrane space side of the inner membrane. Here, we determined that a temperature sensitive (ts) PSD1 allele is autocatalytically impaired and that its fidelity is closely monitored throughout its life cycle by multiple mitochondrial quality control proteases. Interestingly, the proteases involved in resolving misfolded Psd1ts vary depending on its autocatalytic status. Specifically, the degradation of a Psd1ts precursor unable to undergo autocatalysis requires the unprecedented cooperative and sequential actions of two inner membrane proteases, Oma1p and Yme1p. In contrast, upon heat exposure postautocatalysis, Psd1ts β subunits accumulate in protein aggregates that are resolved by Yme1p acting alone, while the released α subunit is degraded in parallel by an unidentified protease. Importantly, the stability of endogenous Psd1p is also influenced by Yme1p. We conclude that Psd1p, the key enzyme required for the mitochondrial pathway of phosphatidylethanolamine production, is closely monitored at several levels and by multiple mitochondrial quality control mechanisms present in the intermembrane space.
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35
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Ellenrieder L, Rampelt H, Becker T. Connection of Protein Transport and Organelle Contact Sites in Mitochondria. J Mol Biol 2017; 429:2148-2160. [DOI: 10.1016/j.jmb.2017.05.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/19/2017] [Accepted: 05/23/2017] [Indexed: 12/31/2022]
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36
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Yadav PK, Rajasekharan R. The m 6A methyltransferase Ime4 epitranscriptionally regulates triacylglycerol metabolism and vacuolar morphology in haploid yeast cells. J Biol Chem 2017; 292:13727-13744. [PMID: 28655762 DOI: 10.1074/jbc.m117.783761] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 06/02/2017] [Indexed: 12/20/2022] Open
Abstract
N6-Methyladenosine (m6A) is among the most common modifications in eukaryotic mRNA. The role of yeast m6A methyltransferase, Ime4, in meiosis and sporulation in diploid strains is very well studied, but its role in haploid strains has remained unknown. Here, with the help of an immunoblotting strategy and Ime4-GFP protein localization studies, we establish the physiological role of Ime4 in haploid cells. Our data showed that Ime4 epitranscriptionally regulates triacylglycerol metabolism and vacuolar morphology through the long-chain fatty acyl-CoA synthetase Faa1, independently of the RNA methylation complex (MIS complex). The MIS complex consists of the Ime4, Mum2, and Slz1 proteins. Our affinity enrichment strategy (methylated RNA immunoprecipitation assays) using m6A polyclonal antibodies coupled with mRNA isolation, quantitative real-time PCR, and standard PCR analyses confirmed the presence of m6A-modified FAA1 transcripts in haploid yeast cells. The term "epitranscriptional regulation" encompasses the RNA modification-mediated regulation of genes. Moreover, we demonstrate that the Aft2 transcription factor up-regulates FAA1 expression. Because the m6A methylation machinery is fundamentally conserved throughout eukaryotes, our findings will help advance the rapidly emerging field of RNA epitranscriptomics. The metabolic link identified here between m6A methylation and triacylglycerol metabolism via the Ime4 protein provides new insights into lipid metabolism and the pathophysiology of lipid-related metabolic disorders, such as obesity. Because the yeast vacuole is an analogue of the mammalian lysosome, our findings pave the way to better understand the role of m6A methylation in lysosome-related functions and diseases.
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Affiliation(s)
- Pradeep Kumar Yadav
- From the Lipidomic Centre, Department of Lipid Science, and.,the Academy of Scientific and Innovative Research, CSIR-Central Food Technological Research Institute, Mysuru, Karnataka 570020, India
| | - Ram Rajasekharan
- From the Lipidomic Centre, Department of Lipid Science, and .,the Academy of Scientific and Innovative Research, CSIR-Central Food Technological Research Institute, Mysuru, Karnataka 570020, India
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37
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Xue Y, Schmollinger S, Attar N, Campos OA, Vogelauer M, Carey MF, Merchant SS, Kurdistani SK. Endoplasmic reticulum-mitochondria junction is required for iron homeostasis. J Biol Chem 2017. [PMID: 28637866 DOI: 10.1074/jbc.m117.784249] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) is a protein complex that physically tethers the two organelles to each other and creates the physical basis for communication between them. ERMES functions in lipid exchange between the ER and mitochondria, protein import into mitochondria, and maintenance of mitochondrial morphology and genome. Here, we report that ERMES is also required for iron homeostasis. Loss of ERMES components activates an Aft1-dependent iron deficiency response even in iron-replete conditions, leading to accumulation of excess iron inside the cell. This function is independent of known ERMES roles in calcium regulation, phospholipid biosynthesis, or effects on mitochondrial morphology. A mutation in the vacuolar protein sorting 13 (VPS13) gene that rescues the glycolytic phenotype of ERMES mutants suppresses the iron deficiency response and iron accumulation. Our findings reveal that proper communication between the ER and mitochondria is required for appropriate maintenance of cellular iron levels.
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Affiliation(s)
- Yong Xue
- From the Department of Biological Chemistry.,Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, Huaihai Institute of Technology, Lianyungang 222005, China
| | - Stefan Schmollinger
- Institute for Genomics and Proteomics, Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095 and
| | - Narsis Attar
- From the Department of Biological Chemistry.,Molecular Biology Institute, and
| | - Oscar A Campos
- From the Department of Biological Chemistry.,Molecular Biology Institute, and
| | | | - Michael F Carey
- From the Department of Biological Chemistry.,Molecular Biology Institute, and
| | - Sabeeha S Merchant
- Institute for Genomics and Proteomics, Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095 and
| | - Siavash K Kurdistani
- From the Department of Biological Chemistry, .,Molecular Biology Institute, and.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, and
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38
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Yadav PK, Rajasekharan R. Cardiolipin deficiency causes triacylglycerol accumulation in Saccharomyces cerevisiae. Mol Cell Biochem 2017; 434:89-103. [PMID: 28432553 DOI: 10.1007/s11010-017-3039-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/12/2017] [Indexed: 01/05/2023]
Abstract
In yeast, the synthesis of cardiolipin (CL) and phosphatidylethanolamine (PE) occurs mainly in mitochondria. CL and PE have overlapping functions, and they are required for mitochondrial function. PE is physiologically linked with triacylglycerol (TAG) metabolism in Saccharomyces cerevisiae, involving an acyl-CoA-independent pathway through the phospholipid:diacylglycerol acyltransferase activity of the Lro1 protein. There is no report on the physiological link between CL and TAG metabolism. Here we report a metabolic link between CL and TAG accumulation in the S. cerevisiae. Our data indicated that CL deficiency causes TAG accumulation, involving an acyl-CoA-dependent pathway through the diacylglycerol acyltransferase activity of the Dga1 protein with no changes in the TAG molecular species. The DGA1 gene deletion from the CL-deficient strains reduced the TAG levels. Data from in vitro and in vivo analyses showed that CL did not affect the enzymatic activity of Dga1. Our data also showed that CL deficiency leads to the up-regulation of acetyl-CoA synthetase genes (ACS1 and ACS2) of the cytosolic pyruvate dehydrogenase bypass pathway. This study establishes a physiological link between CL and TAG metabolism in S. cerevisiae.
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Affiliation(s)
- Pradeep Kumar Yadav
- Lipidomic Centre, Department of Lipid Science, CSIR-Central Food Technological Research Institute (CFTRI), Council of Scientific and Industrial Research, Mysore, Karnataka, 570020, India
- Academy of Scientific & Innovative Research, CSIR-CFTRI, Mysore, India
| | - Ram Rajasekharan
- Lipidomic Centre, Department of Lipid Science, CSIR-Central Food Technological Research Institute (CFTRI), Council of Scientific and Industrial Research, Mysore, Karnataka, 570020, India.
- Academy of Scientific & Innovative Research, CSIR-CFTRI, Mysore, India.
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39
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Michaud M, Prinz WA, Jouhet J. Glycerolipid synthesis and lipid trafficking in plant mitochondria. FEBS J 2017; 284:376-390. [PMID: 27406373 PMCID: PMC6224293 DOI: 10.1111/febs.13812] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/22/2016] [Accepted: 07/11/2016] [Indexed: 11/27/2022]
Abstract
Lipid trafficking between mitochondria and other organelles is required for mitochondrial membrane biogenesis and signaling. This lipid exchange occurs by poorly understood nonvesicular mechanisms. In yeast and mammalian cells, this lipid exchange is thought to take place at contact sites between mitochondria and the ER or vacuolar membranes. Some proteins involved in the tethering between membranes or in the transfer of lipids in mitochondria have been identified. However, in plants, little is known about the synthesis of mitochondrial membranes. Mitochondrial membrane biogenesis is particularly important and noteworthy in plants as the lipid composition of mitochondrial membranes is dramatically changed during phosphate starvation and other stresses. This review focuses on the principal pathways involved in the synthesis of the most abundant mitochondrial glycerolipids in plants and the lipid trafficking that is required for plant mitochondria membrane biogenesis.
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Affiliation(s)
- Morgane Michaud
- Laboratory of Cell and Molecular Biology, National Institutes of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, Grenoble, France
| | - William A Prinz
- Laboratory of Cell and Molecular Biology, National Institutes of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, Grenoble, France
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40
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Ceramide Transport from the Endoplasmic Reticulum to the Trans Golgi Region at Organelle Membrane Contact Sites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:69-81. [PMID: 28815522 DOI: 10.1007/978-981-10-4567-7_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Lipids are the major constituents of all cell membranes and play dynamic roles in organelle structure and function. Although the spontaneous transfer of lipids between different membranes rarely occurs, lipids are appropriately transported between different organelles for their metabolism and to exert their functions in living cells. Proteins that have the biochemical capability to catalyze the intermembrane transfer of lipids are called lipid transfer proteins (LTPs). All organisms possess many types of LTPs. Recent studies revealed that LTPs are key players in the interorganelle transport of lipids at organelle membrane contact sites (MCSs). This chapter depicts how LTPs rationally operate at MCSs by using the ceramide transport protein CERT as a typical model for the LTP-mediated interorganelle transport of lipids.
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41
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Tamura Y, Endo T. Role of Intra- and Inter-mitochondrial Membrane Contact Sites in Yeast Phospholipid Biogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:121-133. [PMID: 28815526 DOI: 10.1007/978-981-10-4567-7_9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Eukaryotic cells exhibit intracellular compartments called organelles wherein various specialized enzymatic reactions occur. Despite the specificity of the characteristic functions of organelles, recent studies have shown that distinct organelles physically connect and communicate with each other to maintain the integrity of their functions. In yeast, multiple inter- and intramitochondrial membrane contact sites (MCSs) were identified to date and were proposed to be involved in phospholipid biogenesis. In the present article, we focus on inter- and intra-organellar MCSs involving mitochondria and their tethering factors, such as the ERMES (endoplasmic reticulum (ER)-mitochondria encounter structure) complex and EMC (conserved ER membrane protein complex) between mitochondria and the ER, vCLAMP (vacuole and mitochondria patch) between mitochondria and vacuoles, and the MICOS (mitochondrial contact site) complex between the mitochondrial outer and inner membranes (MOM and MIM). All of these membrane-tethering factors were proposed to be involved in phospholipid biogenesis. Furthermore, the existence of functional interconnections among multiple organelle contact sites is suggested. In the present article, we summarize the latest discoveries in regard to MCSs and MCS-forming factors involving mitochondria and discuss their molecular functions, with particular focus on phospholipid metabolism in yeast.
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Affiliation(s)
- Yasushi Tamura
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata, 990-8560, Japan.
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan
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42
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Ellenrieder L, Opaliński Ł, Becker L, Krüger V, Mirus O, Straub SP, Ebell K, Flinner N, Stiller SB, Guiard B, Meisinger C, Wiedemann N, Schleiff E, Wagner R, Pfanner N, Becker T. Separating mitochondrial protein assembly and endoplasmic reticulum tethering by selective coupling of Mdm10. Nat Commun 2016; 7:13021. [PMID: 27721450 PMCID: PMC5476798 DOI: 10.1038/ncomms13021] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 08/25/2016] [Indexed: 01/19/2023] Open
Abstract
The endoplasmic reticulum–mitochondria encounter structure (ERMES) connects the mitochondrial outer membrane with the ER. Multiple functions have been linked to ERMES, including maintenance of mitochondrial morphology, protein assembly and phospholipid homeostasis. Since the mitochondrial distribution and morphology protein Mdm10 is present in both ERMES and the mitochondrial sorting and assembly machinery (SAM), it is unknown how the ERMES functions are connected on a molecular level. Here we report that conserved surface areas on opposite sides of the Mdm10 β-barrel interact with SAM and ERMES, respectively. We generated point mutants to separate protein assembly (SAM) from morphology and phospholipid homeostasis (ERMES). Our study reveals that the β-barrel channel of Mdm10 serves different functions. Mdm10 promotes the biogenesis of α-helical and β-barrel proteins at SAM and functions as integral membrane anchor of ERMES, demonstrating that SAM-mediated protein assembly is distinct from ER-mitochondria contact sites. The protein Mdm10 is known to be present in the endoplasmic reticulum-mitochondria encounter structure (ERMES) and in mitochondrial sorting and assembly machinery (SAM). Here, the authors examine how this protein interacts with SAM and EMRES, showing that the SAM-mediated protein machinery is independent of ERMES.
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Affiliation(s)
- Lars Ellenrieder
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,Faculty of Biology, University of Freiburg, Freiburg D-79104, Germany
| | - Łukasz Opaliński
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany
| | - Lars Becker
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany
| | - Vivien Krüger
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany
| | - Oliver Mirus
- Molecular Cell Biology of Plants, University of Frankfurt, Frankfurt D-60438, Germany
| | - Sebastian P Straub
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,Faculty of Biology, University of Freiburg, Freiburg D-79104, Germany
| | - Katharina Ebell
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany
| | - Nadine Flinner
- Molecular Cell Biology of Plants, University of Frankfurt, Frankfurt D-60438, Germany
| | - Sebastian B Stiller
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany
| | - Bernard Guiard
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, Gif-sur-Yvette 91190, France
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
| | - Enrico Schleiff
- Molecular Cell Biology of Plants, University of Frankfurt, Frankfurt D-60438, Germany.,Buchmann Institute of Molecular Life Sciences, Cluster of Excellence Macromolecular Complexes, University of Frankfurt, Frankfurt D-60438, Germany
| | - Richard Wagner
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück D-49034, Germany.,Life Sciences &Chemistry, Focus Area Health, Jacobs University Bremen, Bremen D-28759, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg, Freiburg D-79104, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg D-79104, Germany
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43
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Endoplasmic reticulum stress affects the transport of phosphatidylethanolamine from mitochondria to the endoplasmic reticulum in S.cerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1959-1967. [PMID: 27678054 DOI: 10.1016/j.bbalip.2016.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 09/19/2016] [Accepted: 09/22/2016] [Indexed: 01/08/2023]
Abstract
Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are two of the most abundant phospholipids in cells. Although both lipids can be synthesized in the endoplasmic reticulum (ER), in S. cerevisiae PE can also be produced in mitochondria and endosomes; this PE can be transported back to the ER where it is converted to PC. In this study we found that dithiothreitol (DTT), which induces ER stress, decreases PE export from mitochondria to the ER. This results in decreased levels of total cellular PC and mitochondrial PC. These decreases were not caused by changes in levels of PC synthesizing or degrading enzymes. PE export from mitochondria to the ER during ER stress was further reduced in cells lacking Mdm10p, a component of an ER-mitochondrial tethering complex that may facilitated lipid exchange between these compartments. We also found that reducing mitochondrial PC levels induces mitophagy. In conclusion, we show that ER stress affected PE export from mitochondria to ER and the Mdm10p is important for this process.
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44
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Kojima R, Kajiura S, Sesaki H, Endo T, Tamura Y. Identification of multi-copy suppressors for endoplasmic reticulum-mitochondria tethering proteins in Saccharomyces cerevisiae. FEBS Lett 2016; 590:3061-70. [PMID: 27531107 DOI: 10.1002/1873-3468.12358] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/16/2016] [Accepted: 08/09/2016] [Indexed: 11/08/2022]
Abstract
In yeast, the endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) tethers the ER to mitochondria, but its primary function remains unclear. To gain insight into ERMES functions, we screened multi-copy suppressors of the growth-defective phenotype of mmm1∆ cells, which lack a core component of ERMES, and identified MCP1, MGA2, SPT23, and YGR250C (termed RIE1). Spt23 and Mga2 are homologous transcription factors known to activate transcription of the OLE1 gene, which encodes the fatty acid ∆9 desaturase. We found that Ole1 partially relieves the growth defects of ERMES-lacking cells, thus uncovering a relationship between fatty acid metabolism and ERMES functions.
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Affiliation(s)
- Rieko Kojima
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan.,Department of Material and Biological Science, Faculty of Science, Yamagata University, Japan
| | - Shu Kajiura
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan
| | - Hiromi Sesaki
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Toshiya Endo
- Department of Chemistry, Graduate School of Science, Nagoya University, Japan. .,Faculty of Life Sciences, Kyoto Sangyo University, Japan. .,JST/CREST, Kyoto Sangyo University, Japan.
| | - Yasushi Tamura
- Department of Material and Biological Science, Faculty of Science, Yamagata University, Japan. .,Research Center for Materials Science, Nagoya University, Japan.
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45
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Intramitochondrial phospholipid trafficking. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:81-89. [PMID: 27542541 DOI: 10.1016/j.bbalip.2016.08.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/03/2016] [Accepted: 08/11/2016] [Indexed: 12/29/2022]
Abstract
Mitochondrial functions and architecture rely on a defined lipid composition of their outer and inner membranes, which are characterized by a high content of non-bilayer phospholipids such as cardiolipin (CL) and phosphatidylethanolamine (PE). Mitochondrial membrane lipids are synthesized in the endoplasmic reticulum (ER) or within mitochondria from ER-derived precursor lipids, are asymmetrically distributed within mitochondria and can relocate in response to cellular stress. Maintenance of lipid homeostasis thus requires multiple lipid transport processes to be orchestrated within mitochondria. Recent findings identified members of the Ups/PRELI family as specific lipid transfer proteins in mitochondria that shuttle phospholipids between mitochondrial membranes. They cooperate with membrane organizing proteins that preserve the spatial organization of mitochondrial membranes and the formation of membrane contact sites, unravelling an intimate crosstalk of membrane lipid transport and homeostasis with the structural organization of mitochondria. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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46
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A phospholipid transfer function of ER-mitochondria encounter structure revealed in vitro. Sci Rep 2016; 6:30777. [PMID: 27469264 PMCID: PMC4965753 DOI: 10.1038/srep30777] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/08/2016] [Indexed: 12/21/2022] Open
Abstract
As phospholipids are synthesized mainly in the endoplasmic reticulum (ER) and mitochondrial inner membranes, how cells properly distribute specific phospholipids to diverse cellular membranes is a crucial problem for maintenance of organelle-specific phospholipid compositions. Although the ER-mitochondria encounter structure (ERMES) was proposed to facilitate phospholipid transfer between the ER and mitochondria, such a role of ERMES is still controversial and awaits experimental demonstration. Here we developed a novel in vitro assay system with isolated yeast membrane fractions to monitor phospholipid exchange between the ER and mitochondria. With this system, we found that phospholipid transport between the ER and mitochondria relies on membrane intactness, but not energy sources such as ATP, GTP or the membrane potential across the mitochondrial inner membrane. We further found that lack of the ERMES component impairs the phosphatidylserine transport from the ER to mitochondria, but not the phosphatidylethanolamine transport from mitochondria to the ER. This in vitro assay system thus offers a powerful tool to analyze the non-vesicular phospholipid transport between the ER and mitochondria.
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47
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Yadav PK, Rajasekharan R. Misregulation of a DDHD Domain-containing Lipase Causes Mitochondrial Dysfunction in Yeast. J Biol Chem 2016; 291:18562-81. [PMID: 27402848 DOI: 10.1074/jbc.m116.733378] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Indexed: 02/06/2023] Open
Abstract
The DDHD domain-containing proteins, which belong to the intracellular phospholipase A1 (iPLA1) family, have been predicted to be involved in phospholipid metabolism, lipid trafficking, membrane turnover, and signaling. Defective cardiolipin (CL), phosphatidylethanolamine, and phosphatidylglycerol remodeling cause Barth syndrome and mitochondrial dysfunction. Here, we report that Yor022c is a Ddl1 (DDHD domain-containing lipase 1) that hydrolyzes CL, phosphatidylethanolamine, and phosphatidylglycerol. Ddl1 has been implicated in the remodeling of mitochondrial phospholipids and CL degradation. Our data also suggested that the accumulation of monolysocardiolipin is deleterious to the cells. We show that Aft1 and Aft2 transcription factors antagonistically regulate the DDL1 gene. This study reveals that the misregulation of DDL1 by Aft1/2 transcription factors alters CL metabolism and causes mitochondrial dysfunction in the cells. In humans, mutations in the DDHD1 and DDHD2 genes cause specific types of hereditary spastic paraplegia (SPG28 and SPG54, respectively), and the yeast DDL1-defective strain produces similar phenotypes of hereditary spastic paraplegia (mitochondrial dysfunction and defects in lipid metabolism). Therefore, the DDL1-defective strain could be a good model system for understanding hereditary spastic paraplegia.
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Affiliation(s)
- Pradeep Kumar Yadav
- From the Lipidomic Centre, Department of Lipid Science and the Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Central Food Technological Research Institute (CFTRI), Mysore 570020, Karnataka, India
| | - Ram Rajasekharan
- From the Lipidomic Centre, Department of Lipid Science and the Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research (CSIR)-Central Food Technological Research Institute (CFTRI), Mysore 570020, Karnataka, India
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48
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Miyata N, Watanabe Y, Tamura Y, Endo T, Kuge O. Phosphatidylserine transport by Ups2-Mdm35 in respiration-active mitochondria. J Cell Biol 2016; 214:77-88. [PMID: 27354379 PMCID: PMC4932372 DOI: 10.1083/jcb.201601082] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 06/03/2016] [Indexed: 01/07/2023] Open
Abstract
Phosphatidylethanolamine, an essential phospholipid for mitochondrial functions, is synthesized at the mitochondrial inner membrane. Miyata et al. demonstrate that Ups2–Mdm35, a protein complex in the mitochondrial intermembrane space, mediates phosphatidylserine transport for phosphatidylethanolamine synthesis in respiration-active mitochondria of Saccharomyces cerevisiae. Phosphatidylethanolamine (PE) is an essential phospholipid for mitochondrial functions and is synthesized mainly by phosphatidylserine (PS) decarboxylase at the mitochondrial inner membrane. In Saccharomyces cerevisiae, PS is synthesized in the endoplasmic reticulum (ER), such that mitochondrial PE synthesis requires PS transport from the ER to the mitochondrial inner membrane. Here, we provide evidence that Ups2–Mdm35, a protein complex localized at the mitochondrial intermembrane space, mediates PS transport for PE synthesis in respiration-active mitochondria. UPS2- and MDM35-null mutations greatly attenuated conversion of PS to PE in yeast cells growing logarithmically under nonfermentable conditions, but not fermentable conditions. A recombinant Ups2–Mdm35 fusion protein exhibited phospholipid-transfer activity between liposomes in vitro. Furthermore, UPS2 expression was elevated under nonfermentable conditions and at the diauxic shift, the metabolic transition from glycolysis to oxidative phosphorylation. These results demonstrate that Ups2–Mdm35 functions as a PS transfer protein and enhances mitochondrial PE synthesis in response to the cellular metabolic state.
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Affiliation(s)
- Non Miyata
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Yasunori Watanabe
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Yasushi Tamura
- Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Yamagata 990-8560, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Osamu Kuge
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka 819-0395, Japan
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49
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Effects of lipids on mitochondrial functions. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:102-113. [PMID: 27349299 DOI: 10.1016/j.bbalip.2016.06.015] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/16/2016] [Accepted: 06/21/2016] [Indexed: 11/23/2022]
Abstract
Mitochondria contain two membranes: the outer and inner membrane. Whereas the outer membrane is particularly enriched in phospholipids, the inner membrane has an unusual high protein content and forms large invaginations termed cristae. The proper phospholipid composition of the membranes is crucial for mitochondrial functions. Phospholipids affect activity, biogenesis and stability of protein complexes including protein translocases and respiratory chain supercomplexes. Negatively charged phospholipids such as cardiolipin are important for the architecture of the membranes and recruit soluble factors to the membranes to support mitochondrial dynamics. Thus, phospholipids not only form the hydrophobic core of biological membranes that surround mitochondria, but also create a specific environment to promote functions of various protein machineries. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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50
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Aaltonen MJ, Friedman JR, Osman C, Salin B, di Rago JP, Nunnari J, Langer T, Tatsuta T. MICOS and phospholipid transfer by Ups2-Mdm35 organize membrane lipid synthesis in mitochondria. J Cell Biol 2016; 213:525-34. [PMID: 27241913 PMCID: PMC4896057 DOI: 10.1083/jcb.201602007] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/10/2016] [Indexed: 11/22/2022] Open
Abstract
Mitochondria exert critical functions in cellular lipid metabolism and promote the synthesis of major constituents of cellular membranes, such as phosphatidylethanolamine (PE) and phosphatidylcholine. Here, we demonstrate that the phosphatidylserine decarboxylase Psd1, located in the inner mitochondrial membrane, promotes mitochondrial PE synthesis via two pathways. First, Ups2-Mdm35 complexes (SLMO2-TRIAP1 in humans) serve as phosphatidylserine (PS)-specific lipid transfer proteins in the mitochondrial intermembrane space, allowing formation of PE by Psd1 in the inner membrane. Second, Psd1 decarboxylates PS in the outer membrane in trans, independently of PS transfer by Ups2-Mdm35. This latter pathway requires close apposition between both mitochondrial membranes and the mitochondrial contact site and cristae organizing system (MICOS). In MICOS-deficient cells, limiting PS transfer by Ups2-Mdm35 and reducing mitochondrial PE accumulation preserves mitochondrial respiration and cristae formation. These results link mitochondrial PE metabolism to MICOS, combining functions in protein and lipid homeostasis to preserve mitochondrial structure and function.
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Affiliation(s)
- Mari J Aaltonen
- Institute of Genetics, University of Cologne, 50931 Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Jonathan R Friedman
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Christof Osman
- Institute of Genetics, University of Cologne, 50931 Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Bénédicte Salin
- Institut de Biochimie et Génétique Cellulaires, Centre National de la Recherche Scientifique UMR5095, Université Bordeaux Segalen, Bordeaux 33077, France
| | - Jean-Paul di Rago
- Institut de Biochimie et Génétique Cellulaires, Centre National de la Recherche Scientifique UMR5095, Université Bordeaux Segalen, Bordeaux 33077, France
| | - Jodi Nunnari
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Thomas Langer
- Institute of Genetics, University of Cologne, 50931 Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany Center for Molecular Medicine, University of Cologne, 50931 Cologne, Germany
| | - Takashi Tatsuta
- Institute of Genetics, University of Cologne, 50931 Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
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