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Eldeeb MH, Camacho Lopez LJ, Fontanesi F. Mitochondrial respiratory supercomplexes of the yeast Saccharomyces cerevisiae. IUBMB Life 2024. [PMID: 38529880 DOI: 10.1002/iub.2817] [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: 12/07/2023] [Accepted: 02/28/2024] [Indexed: 03/27/2024]
Abstract
The functional and structural relationship among the individual components of the mitochondrial respiratory chain constitutes a central aspect of our understanding of aerobic catabolism. This interplay has been a subject of intense debate for over 50 years. It is well established that individual respiratory enzymes associate into higher-order structures known as respiratory supercomplexes, which represent the evolutionarily conserved organizing principle of the mitochondrial respiratory chain. In the yeast Saccharomyces cerevisiae, supercomplexes are formed by a complex III homodimer flanked by one or two complex IV monomers, and their high-resolution structures have been recently elucidated. Despite the wealth of structural information, several proposed supercomplex functions remain speculative and our understanding of their physiological relevance is still limited. Recent advances in the field were made possible by the construction of yeast strains where the association of complex III and IV into supercomplexes is impeded, leading to diminished respiratory capacity and compromised cellular competitive fitness. Here, we discuss the experimental evidence and hypotheses relative to the functional roles of yeast respiratory supercomplexes. Moreover, we review the current models of yeast complex III and IV assembly in the context of supercomplex formation and highlight the data scattered throughout the literature suggesting the existence of cross talk between their biogenetic processes.
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Affiliation(s)
- Mazzen H Eldeeb
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Lizeth J Camacho Lopez
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA
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2
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Dong J, Chen L, Ye F, Tang J, Liu B, Lin J, Zhou PH, Lu B, Wu M, Lu JH, He JJ, Engelender S, Meng Q, Song Z, He H. Mic19 depletion impairs endoplasmic reticulum-mitochondrial contacts and mitochondrial lipid metabolism and triggers liver disease. Nat Commun 2024; 15:168. [PMID: 38168065 PMCID: PMC10762189 DOI: 10.1038/s41467-023-44057-6] [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: 02/13/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
Endoplasmic reticulum (ER)-mitochondria contacts are critical for the regulation of lipid transport, synthesis, and metabolism. However, the molecular mechanism and physiological function of endoplasmic reticulum-mitochondrial contacts remain unclear. Here, we show that Mic19, a key subunit of MICOS (mitochondrial contact site and cristae organizing system) complex, regulates ER-mitochondria contacts by the EMC2-SLC25A46-Mic19 axis. Mic19 liver specific knockout (LKO) leads to the reduction of ER-mitochondrial contacts, mitochondrial lipid metabolism disorder, disorganization of mitochondrial cristae and mitochondrial unfolded protein stress response in mouse hepatocytes, impairing liver mitochondrial fatty acid β-oxidation and lipid metabolism, which may spontaneously trigger nonalcoholic steatohepatitis (NASH) and liver fibrosis in mice. Whereas, the re-expression of Mic19 in Mic19 LKO hepatocytes blocks the development of liver disease in mice. In addition, Mic19 overexpression suppresses MCD-induced fatty liver disease. Thus, our findings uncover the EMC2-SLC25A46-Mic19 axis as a pathway regulating ER-mitochondria contacts, and reveal that impairment of ER-mitochondria contacts may be a mechanism associated with the development of NASH and liver fibrosis.
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Affiliation(s)
- Jun Dong
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Li Chen
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
- Department of pathology, School of Basic Medicine, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fei Ye
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Junhui Tang
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Bing Liu
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Jiacheng Lin
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Pang-Hu Zhou
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Bin Lu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Min Wu
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Jia-Hong Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Jing-Jing He
- Department of Pediatric Intensive Care Unit, Anhui Provincial Children's Hospital, Hefei, Anhui, China
| | - Simone Engelender
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Qingtao Meng
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Zhiyin Song
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China.
- Department of pathology, School of Basic Medicine, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - He He
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Frontier Science Center for Immunology and Metabolism, Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China.
- Department of pathology, School of Basic Medicine, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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3
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Ježek P, Jabůrek M, Holendová B, Engstová H, Dlasková A. Mitochondrial Cristae Morphology Reflecting Metabolism, Superoxide Formation, Redox Homeostasis, and Pathology. Antioxid Redox Signal 2023; 39:635-683. [PMID: 36793196 PMCID: PMC10615093 DOI: 10.1089/ars.2022.0173] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/17/2023]
Abstract
Significance: Mitochondrial (mt) reticulum network in the cell possesses amazing ultramorphology of parallel lamellar cristae, formed by the invaginated inner mitochondrial membrane. Its non-invaginated part, the inner boundary membrane (IBM) forms a cylindrical sandwich with the outer mitochondrial membrane (OMM). Crista membranes (CMs) meet IBM at crista junctions (CJs) of mt cristae organizing system (MICOS) complexes connected to OMM sorting and assembly machinery (SAM). Cristae dimensions, shape, and CJs have characteristic patterns for different metabolic regimes, physiological and pathological situations. Recent Advances: Cristae-shaping proteins were characterized, namely rows of ATP-synthase dimers forming the crista lamella edges, MICOS subunits, optic atrophy 1 (OPA1) isoforms and mitochondrial genome maintenance 1 (MGM1) filaments, prohibitins, and others. Detailed cristae ultramorphology changes were imaged by focused-ion beam/scanning electron microscopy. Dynamics of crista lamellae and mobile CJs were demonstrated by nanoscopy in living cells. With tBID-induced apoptosis a single entirely fused cristae reticulum was observed in a mitochondrial spheroid. Critical Issues: The mobility and composition of MICOS, OPA1, and ATP-synthase dimeric rows regulated by post-translational modifications might be exclusively responsible for cristae morphology changes, but ion fluxes across CM and resulting osmotic forces might be also involved. Inevitably, cristae ultramorphology should reflect also mitochondrial redox homeostasis, but details are unknown. Disordered cristae typically reflect higher superoxide formation. Future Directions: To link redox homeostasis to cristae ultramorphology and define markers, recent progress will help in uncovering mechanisms involved in proton-coupled electron transfer via the respiratory chain and in regulation of cristae architecture, leading to structural determination of superoxide formation sites and cristae ultramorphology changes in diseases. Antioxid. Redox Signal. 39, 635-683.
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Affiliation(s)
- Petr Ježek
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Martin Jabůrek
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Blanka Holendová
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Hana Engstová
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Andrea Dlasková
- Department No. 75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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4
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Guan Y, Chang G, Zhao J, Wang Q, Qin J, Tang M, Wang S, Ma L, Ma J, Sun G, Zhou Y, Huang J. Parallel evolution of two AIM24 protein subfamilies and their conserved functions in ER stress tolerance in land plants. PLANT COMMUNICATIONS 2023; 4:100513. [PMID: 36578211 DOI: 10.1016/j.xplc.2022.100513] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/25/2022] [Accepted: 12/23/2022] [Indexed: 05/11/2023]
Abstract
Despite decades of efforts in genome sequencing and functional characterization, some important protein families remain poorly understood. In this study, we report the classification, evolution, and functions of the largely uncharacterized AIM24 protein family in plants, including the identification of a novel subfamily. We show that two AIM24 subfamilies (AIM24-A and AIM24-B) are commonly distributed in major plant groups. These two subfamilies not only have modest sequence similarities and different gene structures but also are of independent bacterial ancestry. We performed comparative functional investigations on the two AIM24 subfamilies using three model plants: the moss Physcomitrium patens, the liverwort Marchantia polymorpha, and the flowering plant Arabidopsis thaliana. Intriguingly, despite their significant differences in sequence and gene structure, both AIM24 subfamilies are involved in ER stress tolerance and the unfolded protein response (UPR). In addition, transformation of the AIM24-A gene from P. patens into the AIM24-B null mutant of A. thaliana could at least partially rescue ER stress tolerance and the UPR. We also discuss the role of AIM24 genes in plant development and other cellular activities. This study provides a unique example of parallel evolution in molecular functions and can serve as a foundation for further investigation of the AIM24 family in plants.
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Affiliation(s)
- Yanlong Guan
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Guanxiao Chang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Jinjie Zhao
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Qia Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Jiali Qin
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Mengmeng Tang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Shuanghua Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Lan Ma
- Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Jianchao Ma
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Guiling Sun
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Yun Zhou
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Jinling Huang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Yunnan Key Laboratory for Fungal Diversity and Green Development, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China; Department of Biology, East Carolina University, Greenville, NC 27858, USA.
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5
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Pang J, Bao Y, Mitchell-Silbaugh K, Veevers J, Fang X. Barth Syndrome Cardiomyopathy: An Update. Genes (Basel) 2022; 13:genes13040656. [PMID: 35456462 PMCID: PMC9030331 DOI: 10.3390/genes13040656] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/23/2022] [Accepted: 04/02/2022] [Indexed: 12/28/2022] Open
Abstract
Barth syndrome (BTHS) is an X-linked mitochondrial lipid disorder caused by mutations in the TAFAZZIN (TAZ) gene, which encodes a mitochondrial acyltransferase/transacylase required for cardiolipin (CL) biosynthesis. Cardiomyopathy is a major clinical feature of BTHS. During the past four decades, we have witnessed many landmark discoveries that have led to a greater understanding of clinical features of BTHS cardiomyopathy and their molecular basis, as well as the therapeutic targets for this disease. Recently published Taz knockout mouse models provide useful experimental models for studying BTHS cardiomyopathy and testing potential therapeutic approaches. This review aims to summarize key findings of the clinical features, molecular mechanisms, and potential therapeutic approaches for BTHS cardiomyopathy, with particular emphasis on the most recent studies.
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Affiliation(s)
- Jing Pang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Department of Biological Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Yutong Bao
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Department of Biological Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Kalia Mitchell-Silbaugh
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
| | - Jennifer Veevers
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
| | - Xi Fang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Correspondence: ; Tel.: +1-858-246-4637
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6
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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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7
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Marco-Hernández AV, Tomás-Vila M, Montoya-Filardi A, Barranco-González H, Vilchez Padilla JJ, Azorín I, Smeyers Dura P, Monfort-Membrado S, Pitarch-Castellano I, Martínez-Castellano F. Mitochondrial developmental encephalopathy with bilateral optic neuropathy related to homozygous variants in IMMT gene. Clin Genet 2021; 101:233-241. [PMID: 34842280 DOI: 10.1111/cge.14093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 12/14/2022]
Abstract
IMMT gene codes for mitofilin, a mitochondrial inner membrane protein that regulates the morphology of mitochondrial cristae. The phenotype associated with mutations in this gene has not been yet established, but functional studies carried out show that its loss causes a mitochondrial alteration, both in the morphology of the mitochondrial crests and in their function. We present two cousins from an extended highly consanguineous family with developmental encephalopathy, hypotonia, nystagmus due to optic neuropathy. The likely pathogenic homozygous c.895A>G (p.Lys299Glu) variant in the IMMT gene co-segregates with the disease and associates altered mitochondrial cristae observed by electron microscopy.
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Affiliation(s)
- Ana Victoria Marco-Hernández
- Genomics Unit, La Fe Health Research Institute, Valencia, Spain.,Genetics Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Miguel Tomás-Vila
- Neuropediatrics Section, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | | | | | - Juan Jesus Vilchez Padilla
- Neuromuscular Pathology Laboratory, Health Research Institute La Fe; CIBERER. European Reference for rare Neuromuscular Diseases, Valencia, Spain
| | - Inmaculada Azorín
- Neuromuscular Pathology Laboratory, Health Research Institute La Fe; CIBERER. European Reference for rare Neuromuscular Diseases, Valencia, Spain
| | | | | | | | - Francisco Martínez-Castellano
- Genomics Unit, La Fe Health Research Institute, Valencia, Spain.,Genetics Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
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8
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Emerging Roles of the MICOS Complex in Cristae Dynamics and Biogenesis. BIOLOGY 2021; 10:biology10070600. [PMID: 34209580 PMCID: PMC8301002 DOI: 10.3390/biology10070600] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/19/2022]
Abstract
Simple Summary Mitochondria possess an outer and inner membrane. The part of the inner membrane parallel to the outer membrane is termed the inner boundary membrane, while the cristae membrane folds towards the mitochondrial matrix and houses the respiratory chain complexes. Crista junctions are located at the interface of the inner boundary membrane and the cristae membrane and contain the important ‘mitochondrial contact site and cristae organizing system’ complex. Despite the growing evidence that the mitochondrial inner membrane could remodel, cristae membranes were largely considered static for nearly seventy years, as the observations were mostly based on electron microscopy and tomography. Recently, using fluorescence super-resolution techniques, several studies showed that cristae membranes undergo dynamic remodeling in living cells, and probably even fission and fusion of the inner membrane. In this review, we discuss the important recent literature conveying the emerging role of the MICOS complex in cristae dynamics and its relation to cristae biogenesis. As the aberrant inner membrane architecture is connected to various pathologies such as cardiomyopathies, neurodegeneration and diabetes, understanding the roles of various molecules connected with cristae biogenesis and dynamics would shed light on the pathophysiology, probably leading to therapeutics in the near future. Abstract Mitochondria are double membrane-enclosed organelles performing important cellular and metabolic functions such as ATP generation, heme biogenesis, apoptosis, ROS production and calcium buffering. The mitochondrial inner membrane (IM) is folded into cristae membranes (CMs) of variable shapes using molecular players including the ‘mitochondrial contact site and cristae organizing system’ (MICOS) complex, the dynamin-like GTPase OPA1, the F1FO ATP synthase and cardiolipin. Aberrant cristae structures are associated with different disorders such as diabetes, neurodegeneration, cancer and hepato-encephalopathy. In this review, we provide an updated view on cristae biogenesis by focusing on novel roles of the MICOS complex in cristae dynamics and shaping of cristae. For over seven decades, cristae were considered as static structures. It was recently shown that cristae constantly undergo rapid dynamic remodeling events. Several studies have re-oriented our perception on the dynamic internal ambience of mitochondrial compartments. In addition, we discuss the recent literature which sheds light on the still poorly understood aspect of cristae biogenesis, focusing on the role of MICOS and its subunits. Overall, we provide an integrated and updated view on the relation between the biogenesis of cristae and the novel aspect of cristae dynamics.
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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: 53] [Impact Index Per Article: 17.7] [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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10
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Wang LJ, Hsu T, Lin HL, Fu CY. Drosophila MICOS knockdown impairs mitochondrial structure and function and promotes mitophagy in muscle tissue. Biol Open 2020; 9:bio054262. [PMID: 33268479 PMCID: PMC7725604 DOI: 10.1242/bio.054262] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 11/10/2020] [Indexed: 12/24/2022] Open
Abstract
The mitochondrial contact site and cristae organizing system (MICOS) is a multi-protein interaction hub that helps define mitochondrial ultrastructure. While the functional importance of MICOS is mostly characterized in yeast and mammalian cells in culture, the contributions of MICOS to tissue homeostasis in vivo remain further elucidation. In this study, we examined how knocking down expression of Drosophila MICOS genes affects mitochondrial function and muscle tissue homeostasis. We found that CG5903/MIC26-MIC27 colocalizes and functions with Mitofilin/MIC60 and QIL1/MIC13 as a Drosophila MICOS component; knocking down expression of any of these three genes predictably altered mitochondrial morphology, causing loss of cristae junctions, and disruption of cristae packing. Furthermore, the knockdown flies exhibited low mitochondrial membrane potential, fusion/fission imbalances, increased mitophagy, and limited cell death. Reductions in climbing ability indicated deficits in muscle function. Knocking down MICOS genes also caused reduced mtDNA content and fragmented mitochondrial nucleoid structure in Drosophila Together, our data demonstrate an essential role of Drosophila MICOS in maintaining proper homeostasis of mitochondrial structure and function to promote the function of muscle tissue.
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Affiliation(s)
- Li-Jie Wang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Tian Hsu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Hsiang-Ling Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Chi-Yu Fu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
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11
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Perkins G, Lee JH, Park S, Kang M, Perez-Flores MC, Ju S, Phillips G, Lysakowski A, Gratton MA, Yamoah EN. Altered Outer Hair Cell Mitochondrial and Subsurface Cisternae Connectomics Are Candidate Mechanisms for Hearing Loss in Mice. J Neurosci 2020; 40:8556-8572. [PMID: 33020216 PMCID: PMC7605424 DOI: 10.1523/jneurosci.2901-19.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 11/21/2022] Open
Abstract
Organelle crosstalk is vital for cellular functions. The propinquity of mitochondria, ER, and plasma membrane promote regulation of multiple functions, which include intracellular Ca2+ flux, and cellular biogenesis. Although the purposes of apposing mitochondria and ER have been described, an understanding of altered organelle connectomics related to disease states is emerging. Since inner ear outer hair cell (OHC) degeneration is a common trait of age-related hearing loss, the objective of this study was to investigate whether the structural and functional coupling of mitochondria with subsurface cisternae (SSC) was affected by aging. We applied functional and structural probes to equal numbers of male and female mice with a hearing phenotype akin to human aging. We discovered the polarization of cristae and crista junctions in mitochondria tethered to the SSC in OHCs. Aging was associated with SSC stress and decoupling of mitochondria with the SSC, mitochondrial fission/fusion imbalance, a remarkable reduction in mitochondrial and cytoplasmic Ca2+ levels, reduced K+-induced Ca2+ uptake, and marked plasticity of cristae membranes. A model of structure-based ATP production predicts profound energy stress in older OHCs. This report provides data suggesting that altered membrane organelle connectomics may result in progressive hearing loss.
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Affiliation(s)
- Guy Perkins
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, California 92093
| | | | | | | | | | - Saeyeon Ju
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, California 92093
| | - Grady Phillips
- Washington University School of Medicine, St. Louis, Missouri 63110
| | - Anna Lysakowski
- Departments of Anatomy and Cell Biology and Otolaryngology, University of Illinois at Chicago, Chicago, Illinois 60612
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12
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Ahmadpour ST, Mahéo K, Servais S, Brisson L, Dumas JF. Cardiolipin, the Mitochondrial Signature Lipid: Implication in Cancer. Int J Mol Sci 2020; 21:E8031. [PMID: 33126604 PMCID: PMC7662448 DOI: 10.3390/ijms21218031] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/20/2020] [Accepted: 10/26/2020] [Indexed: 12/24/2022] Open
Abstract
Cardiolipins (CLs) are specific phospholipids of the mitochondria composing about 20% of the inner mitochondria membrane (IMM) phospholipid mass. Dysregulation of CL metabolism has been observed in several types of cancer. In most cases, the evidence for a role for CL in cancer is merely correlative, suggestive, ambiguous, and cancer-type dependent. In addition, CLs could play a pivotal role in several mitochondrial functions/parameters such as bioenergetics, dynamics, mitophagy, and apoptosis, which are involved in key steps of cancer aggressiveness (i.e., migration/invasion and resistance to treatment). Therefore, this review focuses on studies suggesting that changes in CL content and/or composition, as well as CL metabolism enzyme levels, may be linked with the progression and the aggressiveness of some types of cancer. Finally, we also introduce the main mitochondrial function in which CL could play a pivotal role with a special focus on its implication in cancer development and therapy.
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Affiliation(s)
| | | | | | | | - Jean-François Dumas
- Université de Tours, Inserm, Nutrition, Croissance et Cancer UMR1069, 37032 Tours, France; (S.T.A.); (K.M.); (S.S.); (L.B.)
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13
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Anand R, Kondadi AK, Meisterknecht J, Golombek M, Nortmann O, Riedel J, Peifer-Weiß L, Brocke-Ahmadinejad N, Schlütermann D, Stork B, Eichmann TO, Wittig I, Reichert AS. MIC26 and MIC27 cooperate to regulate cardiolipin levels and the landscape of OXPHOS complexes. Life Sci Alliance 2020; 3:e202000711. [PMID: 32788226 PMCID: PMC7425215 DOI: 10.26508/lsa.202000711] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 12/14/2022] Open
Abstract
Homologous apolipoproteins of MICOS complex, MIC26 and MIC27, show an antagonistic regulation of their protein levels, making it difficult to deduce their individual functions using a single gene deletion. We obtained single and double knockout (DKO) human cells of MIC26 and MIC27 and found that DKO show more concentric onion-like cristae with loss of CJs than any single deletion indicating overlapping roles in formation of CJs. Using a combination of complexome profiling, STED nanoscopy, and blue-native gel electrophoresis, we found that MIC26 and MIC27 are dispensable for the stability and integration of the remaining MICOS subunits into the complex suggesting that they assemble late into the MICOS complex. MIC26 and MIC27 are cooperatively required for the integrity of respiratory chain (super) complexes (RCs/SC) and the F1Fo-ATP synthase complex and integration of F1 subunits into the monomeric F1Fo-ATP synthase. While cardiolipin was reduced in DKO cells, overexpression of cardiolipin synthase in DKO restores the stability of RCs/SC. Overall, we propose that MIC26 and MIC27 are cooperatively required for global integrity and stability of multimeric OXPHOS complexes by modulating cardiolipin levels.
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Affiliation(s)
- Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Arun Kumar Kondadi
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Jana Meisterknecht
- Functional Proteomics, Sonderforschungsbereich (SFB) 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
- Cluster of Excellence "Macromolecular Complexes", Goethe University, Frankfurt am Main, Germany
- German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Mathias Golombek
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Oliver Nortmann
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Julia Riedel
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Leon Peifer-Weiß
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Nahal Brocke-Ahmadinejad
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - David Schlütermann
- Institute of Molecular Medicine I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Björn Stork
- Institute of Molecular Medicine I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
| | - Thomas O Eichmann
- Center for Explorative Lipidomics, BioTechMed-Graz, Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Ilka Wittig
- Functional Proteomics, Sonderforschungsbereich (SFB) 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
- Cluster of Excellence "Macromolecular Complexes", Goethe University, Frankfurt am Main, Germany
- German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
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14
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Abstract
The mitochondrial contact site and cristae organizing system (MICOS) is a multisubunit protein complex that is essential for the proper architecture of the mitochondrial inner membrane. MICOS plays a key role in establishing and maintaining crista junctions, tubular or slit-like structures that connect the cristae membrane with the inner boundary membrane, thereby ensuring a contiguous inner membrane. MICOS is enriched at crista junctions, but the detailed distribution of its subunits around crista junctions is unclear because such small length scales are inaccessible with established fluorescence microscopy. By targeting individually activated fluorophores with an excitation beam featuring a central zero-intensity point, the nanoscopy method called MINFLUX delivers single-digit nanometer-scale three-dimensional (3D) resolution and localization precision. We employed MINFLUX nanoscopy to investigate the submitochondrial localization of the core MICOS subunit Mic60 in relation to two other MICOS proteins, Mic10 and Mic19. We demonstrate that dual-color 3D MINFLUX nanoscopy is applicable to the imaging of organellar substructures, yielding a 3D localization precision of ∼5 nm in human mitochondria. This isotropic precision facilitated the development of an analysis framework that assigns localization clouds to individual molecules, thus eliminating a source of bias when drawing quantitative conclusions from single-molecule localization microscopy data. MINFLUX recordings of Mic60 indicate ringlike arrangements of multiple molecules with a diameter of 40 to 50 nm, suggesting that Mic60 surrounds individual crista junctions. Statistical analysis of dual-color MINFLUX images demonstrates that Mic19 is generally in close proximity to Mic60, whereas the spatial coordination of Mic10 with Mic60 is less regular, suggesting structural heterogeneity of MICOS.
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15
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Stephan T, Brüser C, Deckers M, Steyer AM, Balzarotti F, Barbot M, Behr TS, Heim G, Hübner W, Ilgen P, Lange F, Pacheu-Grau D, Pape JK, Stoldt S, Huser T, Hell SW, Möbius W, Rehling P, Riedel D, Jakobs S. MICOS assembly controls mitochondrial inner membrane remodeling and crista junction redistribution to mediate cristae formation. EMBO J 2020; 39:e104105. [PMID: 32567732 PMCID: PMC7361284 DOI: 10.15252/embj.2019104105] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 05/08/2020] [Accepted: 05/13/2020] [Indexed: 12/26/2022] Open
Abstract
Mitochondrial function is critically dependent on the folding of the mitochondrial inner membrane into cristae; indeed, numerous human diseases are associated with aberrant crista morphologies. With the MICOS complex, OPA1 and the F1 Fo -ATP synthase, key players of cristae biogenesis have been identified, yet their interplay is poorly understood. Harnessing super-resolution light and 3D electron microscopy, we dissect the roles of these proteins in the formation of cristae in human mitochondria. We individually disrupted the genes of all seven MICOS subunits in human cells and re-expressed Mic10 or Mic60 in the respective knockout cell line. We demonstrate that assembly of the MICOS complex triggers remodeling of pre-existing unstructured cristae and de novo formation of crista junctions (CJs) on existing cristae. We show that the Mic60-subcomplex is sufficient for CJ formation, whereas the Mic10-subcomplex controls lamellar cristae biogenesis. OPA1 stabilizes tubular CJs and, along with the F1 Fo -ATP synthase, fine-tunes the positioning of the MICOS complex and CJs. We propose a new model of cristae formation, involving the coordinated remodeling of an unstructured crista precursor into multiple lamellar cristae.
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Affiliation(s)
- Till Stephan
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Christian Brüser
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Markus Deckers
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Anna M Steyer
- Department of Neurogenetics, Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Francisco Balzarotti
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Mariam Barbot
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Tiana S Behr
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Gudrun Heim
- Laboratory of Electron Microscopy, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Wolfgang Hübner
- Department of Physics, University Bielefeld, Bielefeld, Germany
| | - Peter Ilgen
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Felix Lange
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - David Pacheu-Grau
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Jasmin K Pape
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Stefan Stoldt
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Huser
- Department of Physics, University Bielefeld, Bielefeld, Germany
| | - Stefan W Hell
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
| | - Dietmar Riedel
- Laboratory of Electron Microscopy, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Clinic of Neurology, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Goettingen, Germany
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16
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Colina-Tenorio L, Horten P, Pfanner N, Rampelt H. Shaping the mitochondrial inner membrane in health and disease. J Intern Med 2020; 287:645-664. [PMID: 32012363 DOI: 10.1111/joim.13031] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/19/2019] [Accepted: 01/20/2020] [Indexed: 12/16/2022]
Abstract
Mitochondria play central roles in cellular energetics, metabolism and signalling. Efficient respiration, mitochondrial quality control, apoptosis and inheritance of mitochondrial DNA depend on the proper architecture of the mitochondrial membranes and a dynamic remodelling of inner membrane cristae. Defects in mitochondrial architecture can result in severe human diseases affecting predominantly the nervous system and the heart. Inner membrane morphology is generated and maintained in particular by the mitochondrial contact site and cristae organizing system (MICOS), the F1 Fo -ATP synthase, the fusion protein OPA1/Mgm1 and the nonbilayer-forming phospholipids cardiolipin and phosphatidylethanolamine. These protein complexes and phospholipids are embedded in a network of functional interactions. They communicate with each other and additional factors, enabling them to balance different aspects of cristae biogenesis and to dynamically remodel the inner mitochondrial membrane. Genetic alterations disturbing these membrane-shaping factors can lead to human pathologies including fatal encephalopathy, dominant optic atrophy, Leigh syndrome, Parkinson's disease and Barth syndrome.
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Affiliation(s)
- L Colina-Tenorio
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - P Horten
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - N Pfanner
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - H Rampelt
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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17
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Bertero E, Kutschka I, Maack C, Dudek J. Cardiolipin remodeling in Barth syndrome and other hereditary cardiomyopathies. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165803. [PMID: 32348916 DOI: 10.1016/j.bbadis.2020.165803] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/19/2019] [Accepted: 04/13/2020] [Indexed: 12/18/2022]
Abstract
Mitochondria play a prominent role in cardiac energy metabolism, and their function is critically dependent on the integrity of mitochondrial membranes. Disorders characterized by mitochondrial dysfunction are commonly associated with cardiac disease. The mitochondrial phospholipid cardiolipin directly interacts with a number of essential protein complexes in the mitochondrial membranes including the respiratory chain, mitochondrial metabolite carriers, and proteins critical for mitochondrial morphology. Barth syndrome is an X-linked disorder caused by an inherited defect in the biogenesis of the mitochondrial phospholipid cardiolipin. How cardiolipin deficiency impacts on mitochondrial function and how mitochondrial dysfunction causes cardiomyopathy has been intensively studied in cellular and animal models of Barth syndrome. These findings may also have implications for the molecular mechanisms underlying other inherited disorders associated with defects in cardiolipin, such as Sengers syndrome and dilated cardiomyopathy with ataxia (DCMA).
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Affiliation(s)
- Edoardo Bertero
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany
| | - Ilona Kutschka
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany
| | - Jan Dudek
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, 97078 Würzburg, Germany.
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18
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Absolute yeast mitochondrial proteome quantification reveals trade-off between biosynthesis and energy generation during diauxic shift. Proc Natl Acad Sci U S A 2020; 117:7524-7535. [PMID: 32184324 PMCID: PMC7132131 DOI: 10.1073/pnas.1918216117] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This work offers a unique portrayal of yeast mitochondria through the characterization of its absolute proteome. The study of biophysical changes in the mitochondrial network associated with proteome profiling, throughout yeast growth and the transition from fermentative to respiratory metabolism, lays out the crucial role this organelle has in balancing the overall metabolic status of the cell. Using proteomic mass spectrometry, state of the art fluorescence microscopy, and lipidomics analysis, these data provide a highly quantitative description of key mitochondrial processes across three states of metabolism. In particular, the work highlights the significant contribution of functional and structural remodeling occurring during the diauxic shift of this subcellular organelle. Saccharomyces cerevisiae constitutes a popular eukaryal model for research on mitochondrial physiology. Being Crabtree-positive, this yeast has evolved the ability to ferment glucose to ethanol and respire ethanol once glucose is consumed. Its transition phase from fermentative to respiratory metabolism, known as the diauxic shift, is reflected by dramatic rearrangements of mitochondrial function and structure. To date, the metabolic adaptations that occur during the diauxic shift have not been fully characterized at the organelle level. In this study, the absolute proteome of mitochondria was quantified alongside precise parametrization of biophysical properties associated with the mitochondrial network using state-of-the-art optical-imaging techniques. This allowed the determination of absolute protein abundances at a subcellular level. By tracking the transformation of mitochondrial mass and volume, alongside changes in the absolute mitochondrial proteome allocation, we could quantify how mitochondria balance their dual role as a biosynthetic hub as well as a center for cellular respiration. Furthermore, our findings suggest that in the transition from a fermentative to a respiratory metabolism, the diauxic shift represents the stage where major structural and functional reorganizations in mitochondrial metabolism occur. This metabolic transition, initiated at the mitochondria level, is then extended to the rest of the yeast cell.
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19
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CmAim24 Is Essential for Mitochondrial Morphology, Conidiogenesis, and Mycoparasitism in Coniothyrium minitans. Appl Environ Microbiol 2020; 86:AEM.02291-19. [PMID: 31836578 DOI: 10.1128/aem.02291-19] [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: 10/07/2019] [Accepted: 11/25/2019] [Indexed: 11/20/2022] Open
Abstract
Coniothyrium minitans is an important mycoparasite of the notorious phytopathogenic fungus Sclerotinia sclerotiorum The mycoparasitism system of C. minitans-S. sclerotiorum is unique and important in probing fungi and fungal interactions. Here, we report a conidiation-deficient mutant, ZS-1TN1961, which was screened from a transfer DNA (T-DNA) insertional library of C. minitans A single-copy gene, encoding a protein with high sequence similarity to Aim24 (altered inheritance of mitochondria protein 24) in Saccharomyces cerevisiae, was disrupted by T-DNA insertion in this mutant. Gene replacement and complementation experiments confirmed that mutants lacking CmAim24 exhibited significantly reduced conidial production and germination as well as reduced sclerotial mycoparasitic ability. Furthermore, cellular localization assays showed that CmAim24 localized to mitochondria, and abnormal mitochondria were observed in the ΔCmAim24 mutant. The ΔCmAim24 mutant exhibited significant accumulation of reactive oxygen species (ROS) and a reduced ATP content in mycelia. In summary, our results suggest that CmAim24 plays a key role in mitochondrial architecture and function, conidiogenesis, and mycoparasitism in C. minitans IMPORTANCE Aim24 proteins are involved in mitochondrial biogenesis and accumulate between the two membranes of a mitochondrion. Their function in prokaryotes and filamentous fungi is as yet unknown. In the present study, we characterized an Aim24 protein, CmAim24, in the mycoparasite Coniothyrium minitans and proved its critical role in mitochondrial morphology and function, conidiogenesis, conidial germination, and mycoparasitism to S. sclerotiorum.
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20
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Abstract
Mitochondria are essential organelles of eukaryotic cells. They consist of hundreds of different proteins that exhibit crucial activities in respiration, catabolic metabolism and the synthesis of amino acids, lipids, heme and iron-sulfur clusters. With the exception of a handful of hydrophobic mitochondrially encoded membrane proteins, all these proteins are synthesized on cytosolic ribosomes, targeted to receptors on the mitochondrial surface, and transported across or inserted into the outer and inner mitochondrial membrane before they are folded and assembled into their final native structure. This review article provides a comprehensive overview of the mechanisms and components of the mitochondrial protein import systems with a particular focus on recent developments in the field.
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Affiliation(s)
- Katja G Hansen
- Cell Biology, University of Kaiserslautern, Erwin-Schrödinger-Strasse 13, 67663, Kaiserslautern, Germany
| | - Johannes M Herrmann
- Cell Biology, University of Kaiserslautern, Erwin-Schrödinger-Strasse 13, 67663, Kaiserslautern, Germany.
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21
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Sacchetto C, Sequeira V, Bertero E, Dudek J, Maack C, Calore M. Metabolic Alterations in Inherited Cardiomyopathies. J Clin Med 2019; 8:E2195. [PMID: 31842377 PMCID: PMC6947282 DOI: 10.3390/jcm8122195] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 12/12/2022] Open
Abstract
The normal function of the heart relies on a series of complex metabolic processes orchestrating the proper generation and use of energy. In this context, mitochondria serve a crucial role as a platform for energy transduction by supplying ATP to the varying demand of cardiomyocytes, involving an intricate network of pathways regulating the metabolic flux of substrates. The failure of these processes results in structural and functional deficiencies of the cardiac muscle, including inherited cardiomyopathies. These genetic diseases are characterized by cardiac structural and functional anomalies in the absence of abnormal conditions that can explain the observed myocardial abnormality, and are frequently associated with heart failure. Since their original description, major advances have been achieved in the genetic and phenotype knowledge, highlighting the involvement of metabolic abnormalities in their pathogenesis. This review provides a brief overview of the role of mitochondria in the energy metabolism in the heart and focuses on metabolic abnormalities, mitochondrial dysfunction, and storage diseases associated with inherited cardiomyopathies.
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Affiliation(s)
- Claudia Sacchetto
- IMAiA—Institute for Molecular Biology and RNA Technology, Faculty of Health, Universiteitssingel 50, 6229ER Maastricht, The Netherlands;
- Medicine and Life Sciences, Faculty of Science and Engineering, Universiteitssingel 50, 6229ER Maastricht, The Netherlands
- Department of Biology, University of Padova, via Ugo Bassi 58B, 35121 Padova, Italy
| | - Vasco Sequeira
- Department of Translational Science, Comprehensive Heart Failure Center, University Clinic Würzburg, Am Schwarzenberg 15, 9708 Würzburg, Germany; (V.S.); (E.B.); (J.D.)
| | - Edoardo Bertero
- Department of Translational Science, Comprehensive Heart Failure Center, University Clinic Würzburg, Am Schwarzenberg 15, 9708 Würzburg, Germany; (V.S.); (E.B.); (J.D.)
| | - Jan Dudek
- Department of Translational Science, Comprehensive Heart Failure Center, University Clinic Würzburg, Am Schwarzenberg 15, 9708 Würzburg, Germany; (V.S.); (E.B.); (J.D.)
| | - Christoph Maack
- Department of Translational Science, Comprehensive Heart Failure Center, University Clinic Würzburg, Am Schwarzenberg 15, 9708 Würzburg, Germany; (V.S.); (E.B.); (J.D.)
| | - Martina Calore
- IMAiA—Institute for Molecular Biology and RNA Technology, Faculty of Health, Universiteitssingel 50, 6229ER Maastricht, The Netherlands;
- Medicine and Life Sciences, Faculty of Science and Engineering, Universiteitssingel 50, 6229ER Maastricht, The Netherlands
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22
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Eichenberger C, Oeljeklaus S, Bruggisser J, Mani J, Haenni B, Kaurov I, Niemann M, Zuber B, Lukeš J, Hashimi H, Warscheid B, Schimanski B, Schneider A. The highly diverged trypanosomal MICOS complex is organized in a nonessential integral membrane and an essential peripheral module. Mol Microbiol 2019; 112:1731-1743. [DOI: 10.1111/mmi.14389] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Claudia Eichenberger
- Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012Switzerland
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty of Biology University of Freiburg Freiburg 79104Germany
- Signalling Research Centres BIOSS and CIBSS University of Freiburg Freiburg 79104Germany
| | - Julia Bruggisser
- Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012Switzerland
| | - Jan Mani
- Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012Switzerland
| | - Beat Haenni
- Institute of Anatomy University of Bern Baltzerstrasse 2 Bern 3012Switzerland
| | - Iosif Kaurov
- Institute of Parasitology, Biology Center Czech Academy of Sciences České Budějovice (Budweis) Czech Republic
- Faculty of Science University of South Bohemia 370 05České Budějovice (Budweis) Czech Republic
| | - Moritz Niemann
- Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012Switzerland
| | - Benoît Zuber
- Institute of Anatomy University of Bern Baltzerstrasse 2 Bern 3012Switzerland
| | - Julius Lukeš
- Institute of Parasitology, Biology Center Czech Academy of Sciences České Budějovice (Budweis) Czech Republic
- Faculty of Science University of South Bohemia 370 05České Budějovice (Budweis) Czech Republic
| | - Hassan Hashimi
- Institute of Parasitology, Biology Center Czech Academy of Sciences České Budějovice (Budweis) Czech Republic
- Faculty of Science University of South Bohemia 370 05České Budějovice (Budweis) Czech Republic
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty of Biology University of Freiburg Freiburg 79104Germany
- Signalling Research Centres BIOSS and CIBSS University of Freiburg Freiburg 79104Germany
| | - Bernd Schimanski
- Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012Switzerland
| | - André Schneider
- Department of Chemistry and Biochemistry University of Bern Freiestrasse 3 Bern CH‐3012Switzerland
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23
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PAWH1 and PAWH2 are plant-specific components of an Arabidopsis endoplasmic reticulum-associated degradation complex. Nat Commun 2019; 10:3492. [PMID: 31375683 PMCID: PMC6677890 DOI: 10.1038/s41467-019-11480-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 07/16/2019] [Indexed: 01/23/2023] Open
Abstract
Endoplasmic reticulum-associated degradation (ERAD) is a unique mechanism to degrade misfolded proteins via complexes containing several highly-conserved ER-anchored ubiquitin ligases such as HMG-CoA reductase degradation1 (Hrd1). Arabidopsis has a similar Hrd1-containing ERAD machinery; however, our knowledge of this complex is limited. Here we report two closely-related Arabidopsis proteins, Protein Associated With Hrd1-1 (PAWH1) and PAWH2, which share a conserved domain with yeast Altered Inheritance of Mitochondria24. PAWH1 and PAWH2 localize to the ER membrane and associate with Hrd1 via EMS-mutagenized Bri1 Suppressor7 (EBS7), a plant-specific component of the Hrd1 complex. Simultaneously elimination of two PAWHs constitutively activates the unfolded protein response and compromises stress tolerance. Importantly, the pawh1 pawh2 double mutation reduces the protein abundance of EBS7 and Hrd1 and inhibits degradation of several ERAD substrates. Our study not only discovers additional plant-specific components of the Arabidopsis Hrd1 complex but also reveals a distinct mechanism for regulating the Hrd1 stability.
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24
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Zhou W, Ma D, Sun AX, Tran HD, Ma DL, Singh BK, Zhou J, Zhang J, Wang D, Zhao Y, Yen PM, Goh E, Tan EK. PD-linked CHCHD2 mutations impair CHCHD10 and MICOS complex leading to mitochondria dysfunction. Hum Mol Genet 2019; 28:1100-1116. [PMID: 30496485 PMCID: PMC6423417 DOI: 10.1093/hmg/ddy413] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 10/31/2018] [Accepted: 11/22/2018] [Indexed: 12/13/2022] Open
Abstract
Coiled-coil-helix-coiled-coil-helix domain containing protein 2 (CHCHD2) mutations were linked with autosomal dominant Parkinson's disease (PD) and recently, Alzheimer's disease/frontotemporal dementia. In the current study, we generated isogenic human embryonic stem cell (hESC) lines harboring PD-associated CHCHD2 mutation R145Q or Q126X via clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) method, aiming to unravel pathophysiologic mechanism and seek potential intervention strategy against CHCHD2 mutant-caused defects. By engaging super-resolution microscopy, we identified a physical proximity and similar distribution pattern of CHCHD2 along mitochondria with mitochondrial contact site and cristae organizing system (MICOS), a large protein complex maintaining mitochondria cristae. Isogenic hESCs and differentiated neural progenitor cells (NPCs) harboring CHCHD2 R145Q or Q126X mutation showed impaired mitochondria function, reduced CHCHD2 and MICOS components and exhibited nearly hollow mitochondria with reduced cristae. Furthermore, PD-linked CHCHD2 mutations lost their interaction with coiled-coil-helix-coiled-coil-helix domain containing protein 10 (CHCHD10), while transient knockdown of either CHCHD2 or CHCHD10 reduced MICOS and mitochondria cristae. Importantly, a specific mitochondria-targeted peptide, Elamipretide/MTP-131, now tested in phase 3 clinical trials for mitochondrial diseases, was found to enhance CHCHD2 with MICOS and mitochondria oxidative phosphorylation enzymes in isogenic NPCs harboring heterozygous R145Q, suggesting that Elamipretide is able to attenuate CHCHD2 R145Q-induced mitochondria dysfunction. Taken together, our results suggested CHCHD2-CHCHD10 complex may be a novel therapeutic target for PD and related neurodegenerative disorders, and Elamipretide may benefit CHCHD2 mutation-linked PD.
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Affiliation(s)
- Wei Zhou
- Neuroscience Research Laboratory, National Neuroscience Institute, Singapore
| | - Dongrui Ma
- Department of Neurology, Singapore General Hospital, Singapore
| | - Alfred Xuyang Sun
- Neuroscience Research Laboratory, National Neuroscience Institute, Singapore.,Stem Cell and Regenerative Biology Laboratory, Genome Institute of Singapore, Singapore
| | - Hoang-Dai Tran
- Neuroscience Research Laboratory, National Neuroscience Institute, Singapore.,Stem Cell and Regenerative Biology Laboratory, Genome Institute of Singapore, Singapore
| | - Dong-Liang Ma
- Neuroregeneration Laboratory, Singhealth Duke-NUS Neuroscience Academic Clinical Program, Singapore
| | - Brijesh K Singh
- Programs in Metabolic and Cardiovascular Disorders, Duke-NUS Graduate Medical School, Singapore
| | - Jin Zhou
- Programs in Metabolic and Cardiovascular Disorders, Duke-NUS Graduate Medical School, Singapore
| | - Jinyan Zhang
- Department of Neurology, Singapore General Hospital, Singapore
| | - Danlei Wang
- Stem Cell and Regenerative Biology Laboratory, Genome Institute of Singapore, Singapore
| | - Yi Zhao
- Department of Clinical Research, Singapore General Hospital, Singapore
| | - Paul M Yen
- Programs in Metabolic and Cardiovascular Disorders, Duke-NUS Graduate Medical School, Singapore
| | - Eyleen Goh
- Neuroregeneration Laboratory, Singhealth Duke-NUS Neuroscience Academic Clinical Program, Singapore.,Neuroregeneration Laboratory, National Neuroscience Institute, Singapore
| | - Eng-King Tan
- Neuroscience Research Laboratory, National Neuroscience Institute, Singapore.,Department of Neurology, Singapore General Hospital, Singapore
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25
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Baker N, Patel J, Khacho M. Linking mitochondrial dynamics, cristae remodeling and supercomplex formation: How mitochondrial structure can regulate bioenergetics. Mitochondrion 2019; 49:259-268. [PMID: 31207408 DOI: 10.1016/j.mito.2019.06.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/18/2019] [Accepted: 06/06/2019] [Indexed: 01/21/2023]
Abstract
The dynamic and fluid nature of mitochondria allows for modifications in mitochondrial shape, connectivity and cristae architecture. The precise balance of mitochondrial dynamics is among the most critical features in the control of mitochondrial function. In the past few years, mitochondrial shape has emerged as a key regulatory factor in the determination of the bioenergetic capacity of cells. This is mostly due to the recent discoveries linking changes in cristae organization with supercomplex assembly of the electron transport chain (ETC), also defined as the formation of respirosomes. Here we will review the most current advances demonstrating the impact of mitochondrial dynamics and cristae shape on oxidative metabolism, respiratory efficiency, and redox state. Furthermore, we will discuss the implications of mitochondrial dynamics and supercomplex assembly under physiological and pathological conditions.
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Affiliation(s)
- Nicole Baker
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology (OISB), Center for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada
| | - Jeel Patel
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology (OISB), Center for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada
| | - Mireille Khacho
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology (OISB), Center for Neuromuscular Disease, University of Ottawa, Ottawa, Ontario, Canada.
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26
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The role of cardiolipin concentration and acyl chain composition on mitochondrial inner membrane molecular organization and function. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1039-1052. [PMID: 30951877 DOI: 10.1016/j.bbalip.2019.03.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/19/2019] [Accepted: 03/30/2019] [Indexed: 12/28/2022]
Abstract
Cardiolipin (CL) is a key phospholipid of the mitochondria. A loss of CL content and remodeling of CL's acyl chains is observed in several pathologies. Strong shifts in CL concentration and acyl chain composition would presumably disrupt mitochondrial inner membrane biophysical organization. However, it remains unclear in the literature as to which is the key regulator of mitochondrial membrane biophysical properties. We review the literature to discriminate the effects of CL concentration and acyl chain composition on mitochondrial membrane organization. A widely applicable theme emerges across several pathologies, including cardiovascular diseases, diabetes, Barth syndrome, and neurodegenerative ailments. The loss of CL, often accompanied by increased levels of lyso-CLs, impairs mitochondrial inner membrane organization. Modest remodeling of CL acyl chains is not a major driver of impairments and only in cases of extreme remodeling is there an influence on membrane properties.
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27
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Van Laar VS, Otero PA, Hastings TG, Berman SB. Potential Role of Mic60/Mitofilin in Parkinson's Disease. Front Neurosci 2019; 12:898. [PMID: 30740041 PMCID: PMC6357844 DOI: 10.3389/fnins.2018.00898] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/16/2018] [Indexed: 12/21/2022] Open
Abstract
There are currently no treatments that hinder or halt the inexorable progression of Parkinson's disease (PD). While the etiology of PD remains elusive, evidence suggests that early dysfunction of mitochondrial respiration and homeostasis play a major role in PD pathogenesis. The mitochondrial structural protein Mic60, also known as mitofilin, is critical for maintaining mitochondrial architecture and function. Loss of Mic60 is associated with detrimental effects on mitochondrial homeostasis. Growing evidence now implicates Mic60 in the pathogenesis of PD. In this review, we discuss the data supporting a role of Mic60 and mitochondrial dysfunction in PD. We will also consider the potential of Mic60 as a therapeutic target for treating neurological disorders.
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Affiliation(s)
- Victor S Van Laar
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States
| | - P Anthony Otero
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States.,Division of Neuropathology, Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Cellular and Molecular Pathology (CMP) Program, Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Teresa G Hastings
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sarah B Berman
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, United States.,Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, United States
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28
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Kaurov I, Vancová M, Schimanski B, Cadena LR, Heller J, Bílý T, Potěšil D, Eichenberger C, Bruce H, Oeljeklaus S, Warscheid B, Zdráhal Z, Schneider A, Lukeš J, Hashimi H. The Diverged Trypanosome MICOS Complex as a Hub for Mitochondrial Cristae Shaping and Protein Import. Curr Biol 2018; 28:3393-3407.e5. [PMID: 30415698 DOI: 10.1016/j.cub.2018.09.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/02/2018] [Accepted: 09/04/2018] [Indexed: 12/20/2022]
Abstract
The mitochondrial contact site and cristae organization system (MICOS) is a multiprotein complex responsible for cristae formation. Even though cristae are found in all mitochondria capable of oxidative phosphorylation, only Mic10 and Mic60 appear to be conserved throughout eukaryotes. The remaining 4 or 5 known MICOS subunits are specific to the supergroup Opisthokonta, which includes yeast and mammals that are the only organisms in which this complex has been analyzed experimentally. We have isolated the MICOS from Trypanosoma brucei, a member of the supergroup Excavata that is profoundly diverged from opisthokonts. We show that it is required for the maintenance of the unique discoidal cristae that typify excavates, such as euglenids and kinetoplastids, the latter of which include trypanosomes. The trypanosome MICOS consists of 9 subunits, most of which are essential for normal growth. Unlike in opisthokonts, it contains two distinct Mic10 orthologs and an unconventional putative Mic60 that lacks a mitofilin domain. Interestingly, one of the essential trypanosomatid-specific MICOS subunits called TbMic20 is a thioredoxin-like protein that appears to be involved in import of intermembrane space proteins, including respiratory chain complex assembly factors. This result points to trypanosome MICOS coordinating cristae shaping and population of its membrane with proteins involved in respiration, the latter via the catalytic activity of TbMic20. Thus, trypanosome MICOS allows us to define which of its features are conserved in all eukaryotes and decipher those that represent lineage-specific adaptations.
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Affiliation(s)
- Iosif Kaurov
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Marie Vancová
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Bernd Schimanski
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Lawrence Rudy Cadena
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Jiří Heller
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic
| | - Tomáš Bílý
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - David Potěšil
- Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic
| | - Claudia Eichenberger
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Hannah Bruce
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Silke Oeljeklaus
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, 79104 Freiburg, Germany
| | - Bettina Warscheid
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Zbyněk Zdráhal
- Central European Institute of Technology, Masaryk University, 62500 Brno, Czech Republic
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Julius Lukeš
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic
| | - Hassan Hashimi
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czech Republic.
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29
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PaPro1 and IDC4, Two Genes Controlling Stationary Phase, Sexual Development and Cell Degeneration in Podospora anserina. J Fungi (Basel) 2018; 4:jof4030085. [PMID: 29997371 PMCID: PMC6162560 DOI: 10.3390/jof4030085] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 06/28/2018] [Accepted: 07/10/2018] [Indexed: 02/06/2023] Open
Abstract
Filamentous fungi frequently undergo bistable phenotypic switches. Crippled Growth of Podospora anserina is one such bistable switch, which seems to rely upon the mis-activation of a self-regulated PaMpk1 MAP kinase regulatory pathway. Here, we identify two new partners of this pathway: PaPro1, a transcription factor orthologous to Sordaria macrospora pro1 and Neurospora crassa ADV-1, and IDC4, a protein with an AIM24 domain. Both PaPro1 and IDC4 regulate stationary phase features, as described for the other actors of the PaMpk1 signaling pathway. However, PaPro1 is also involved in the control of fertilization by activating the transcription of the HMG8 and the mating type transcription factors, as well as the sexual pheromones and receptor genes. The roles of two components of the STRIPAK complex were also investigated by inactivating their encoding genes: PaPro22 and PaPro45. The mutants of these genes were found to have the same phenotypes as PaPro1 and IDC4 mutants as well as additional phenotypes including slow growth, abnormally shaped hyphae, pigment accumulation and blockage of the zygotic tissue development, indicating that the STRIPAK complex regulates, in addition to the PaMpk1 one, other pathways in P. anserina. Overall, the mutants of these four genes confirm the model by which Crippled Growth is due to the abnormal activation of the PaMpk1 MAP kinase cascade.
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30
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Rampelt H, Wollweber F, Gerke C, de Boer R, van der Klei IJ, Bohnert M, Pfanner N, van der Laan M. Assembly of the Mitochondrial Cristae Organizer Mic10 Is Regulated by Mic26–Mic27 Antagonism and Cardiolipin. J Mol Biol 2018; 430:1883-1890. [DOI: 10.1016/j.jmb.2018.04.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/20/2018] [Accepted: 04/27/2018] [Indexed: 01/05/2023]
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31
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Regulation of Cell-to-Cell Communication and Cell Wall Integrity by a Network of MAP Kinase Pathways and Transcription Factors in Neurospora crassa. Genetics 2018; 209:489-506. [PMID: 29678830 DOI: 10.1534/genetics.118.300904] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/18/2018] [Indexed: 11/18/2022] Open
Abstract
Maintenance of cell integrity and cell-to-cell communication are fundamental biological processes. Filamentous fungi, such as Neurospora crassa, depend on communication to locate compatible cells, coordinate cell fusion, and establish a robust hyphal network. Two MAP kinase (MAPK) pathways are essential for communication and cell fusion in N. crassa: the cell wall integrity/MAK-1 pathway and the MAK-2 (signal response) pathway. Previous studies have demonstrated several points of cross-talk between the MAK-1 and MAK-2 pathways, which is likely necessary for coordinating chemotropic growth toward an extracellular signal, and then mediating cell fusion. Canonical MAPK pathways begin with signal reception and end with a transcriptional response. Two transcription factors, ADV-1 and PP-1, are essential for communication and cell fusion. PP-1 is the conserved target of MAK-2, but it is unclear what targets ADV-1. We did RNA sequencing on Δadv-1, Δpp-1, and wild-type cells and found that ADV-1 and PP-1 have a shared regulon including many genes required for communication, cell fusion, growth, development, and stress response. We identified ADV-1 and PP-1 binding sites across the genome by adapting the in vitro method of DNA-affinity purification sequencing for N. crassa To elucidate the regulatory network, we misexpressed each transcription factor in each upstream MAPK deletion mutant. Misexpression of adv-1 was sufficient to fully suppress the phenotype of the Δpp-1 mutant and partially suppress the phenotype of the Δmak-1 mutant. Collectively, our data demonstrate that the MAK-1/ADV-1 and MAK-2/PP-1 pathways form a tight regulatory network that maintains cell integrity and mediates communication and cell fusion.
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32
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Abstract
Current strategies used to quantitatively describe the biological diversity of lipids by mass spectrometry are often limited in assessing the exact structural variability of individual molecular species in detail. A major challenge is represented by the extensive isobaric overlap present among lipids, hampering their accurate identification. This is especially true for cardiolipins, a mitochondria-specific class of phospholipids, which are functionally involved in many cellular functions, including energy metabolism, cristae structure, and apoptosis. Substituted with four fatty acyl side chains, cardiolipins offer a particularly high potential to achieve complex mixtures of molecular species. Here, we demonstrate how systematically generated high-performance liquid chromatography-mass spectral data can be utilized in a mathematical structural modeling approach, to comprehensively analyze and characterize the molecular diversity of mitochondrial cardiolipin compositions in cell culture and disease models, cardiolipin modulation experiments, and a broad variety of frequently studied model organisms.
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33
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Eight human OPA1 isoforms, long and short: What are they for? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:263-269. [PMID: 29382469 DOI: 10.1016/j.bbabio.2018.01.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/17/2018] [Accepted: 01/21/2018] [Indexed: 12/31/2022]
Abstract
OPA1 is a dynamin-related GTPase that controls mitochondrial dynamics, cristae integrity, energetics and mtDNA maintenance. The exceptional complexity of this protein is determined by the presence, in humans, of eight different isoforms that, in turn, are proteolytically cleaved into combinations of membrane-anchored long forms and soluble short forms. Recent advances highlight how each OPA1 isoform is able to fulfill "essential" mitochondrial functions, whereas only some variants carry out "specialized" features. Long forms determine fusion, long or short forms alone build cristae, whereas long and short forms together tune mitochondrial morphology. These findings offer novel challenging therapeutic potential to gene therapy.
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34
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Imperlini E, Gnecchi M, Rognoni P, Sabidò E, Ciuffreda MC, Palladini G, Espadas G, Mancuso FM, Bozzola M, Malpasso G, Valentini V, Palladini G, Orrù S, Ferraro G, Milani P, Perlini S, Salvatore F, Merlini G, Lavatelli F. Proteotoxicity in cardiac amyloidosis: amyloidogenic light chains affect the levels of intracellular proteins in human heart cells. Sci Rep 2017; 7:15661. [PMID: 29142197 PMCID: PMC5688098 DOI: 10.1038/s41598-017-15424-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 10/27/2017] [Indexed: 12/31/2022] Open
Abstract
AL amyloidosis is characterized by widespread deposition of immunoglobulin light chains (LCs) as amyloid fibrils. Cardiac involvement is frequent and leads to life-threatening cardiomyopathy. Besides the tissue alteration caused by fibrils, clinical and experimental evidence indicates that cardiac damage is also caused by proteotoxicity of prefibrillar amyloidogenic species. As in other amyloidoses, the damage mechanisms at cellular level are complex and largely undefined. We have characterized the molecular changes in primary human cardiac fibroblasts (hCFs) exposed in vitro to soluble amyloidogenic cardiotoxic LCs from AL cardiomyopathy patients. To evaluate proteome alterations caused by a representative cardiotropic LC, we combined gel-based with label-free shotgun analysis and performed bioinformatics and data validation studies. To assess the generalizability of our results we explored the effects of multiple LCs on hCF viability and on levels of a subset of cellular proteins. Our results indicate that exposure of hCFs to cardiotropic LCs translates into proteome remodeling, associated with apoptosis activation and oxidative stress. The proteome alterations affect proteins involved in cytoskeletal organization, protein synthesis and quality control, mitochondrial activity and metabolism, signal transduction and molecular trafficking. These results support and expand the concept that soluble amyloidogenic cardiotropic LCs exert toxic effects on cardiac cells.
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Affiliation(s)
- Esther Imperlini
- IRCCS SDN, Naples, Italy.,CEINGE-Biotecnologie Avanzate, Naples, Italy
| | - Massimiliano Gnecchi
- Coronary Care Unit and Laboratory of Experimental Cardiology for Cell and Molecular Therapy, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.,Department of Molecular Medicine, Unit of Cardiology, University of Pavia, Pavia, Italy.,Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Paola Rognoni
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Eduard Sabidò
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Maria Chiara Ciuffreda
- Coronary Care Unit and Laboratory of Experimental Cardiology for Cell and Molecular Therapy, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Giovanni Palladini
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Guadalupe Espadas
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Francesco Mattia Mancuso
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Margherita Bozzola
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Giuseppe Malpasso
- Coronary Care Unit and Laboratory of Experimental Cardiology for Cell and Molecular Therapy, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Veronica Valentini
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Giuseppina Palladini
- Department of Internal Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Stefania Orrù
- IRCCS SDN, Naples, Italy.,CEINGE-Biotecnologie Avanzate, Naples, Italy.,Department of Movement Sciences, "Parthenope" University, Naples, Italy
| | - Giovanni Ferraro
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Paolo Milani
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Stefano Perlini
- Department of Internal Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Francesco Salvatore
- CEINGE-Biotecnologie Avanzate, Naples, Italy. .,Department of Molecular Medicine and Medical Biotechnologies, University of Naples "Federico II", Pavia, Italy.
| | - Giampaolo Merlini
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy.
| | - Francesca Lavatelli
- Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
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35
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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: 38] [Impact Index Per Article: 5.4] [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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36
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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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37
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Regulated membrane remodeling by Mic60 controls formation of mitochondrial crista junctions. Nat Commun 2017; 8:15258. [PMID: 28561061 PMCID: PMC5460017 DOI: 10.1038/ncomms15258] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 03/14/2017] [Indexed: 01/20/2023] Open
Abstract
The mitochondrial contact site and cristae organizing system (MICOS) is crucial for the formation of crista junctions and mitochondrial inner membrane architecture. MICOS contains two core components. Mic10 shows membrane-bending activity, whereas Mic60 (mitofilin) forms contact sites between inner and outer membranes. Here we report that Mic60 deforms liposomes into thin membrane tubules and thus displays membrane-shaping activity. We identify a membrane-binding site in the soluble intermembrane space-exposed part of Mic60. This membrane-binding site is formed by a predicted amphipathic helix between the conserved coiled-coil and mitofilin domains. The mitofilin domain negatively regulates the membrane-shaping activity of Mic60. Binding of Mic19 to the mitofilin domain modulates this activity. Membrane binding and shaping by the conserved Mic60–Mic19 complex is crucial for crista junction formation, mitochondrial membrane architecture and efficient respiratory activity. Mic60 thus plays a dual role by shaping inner membrane crista junctions and forming contact sites with the outer membrane. The MICOS complex has an essential role in crista junction formation and mitochondrial inner membrane morphology. Here, the authors show that one of its components, Mic60, known to form contact sites between inner and outer membranes, also displays membrane-shaping activity.
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Mitochondrial contact site and cristae organizing system: A central player in membrane shaping and crosstalk. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1481-1489. [PMID: 28526561 DOI: 10.1016/j.bbamcr.2017.05.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/01/2017] [Indexed: 01/08/2023]
Abstract
Mitochondria are multifunctional metabolic factories and integrative signaling organelles of eukaryotic cells. The structural basis for their numerous functions is a complex and dynamic double-membrane architecture. The outer membrane connects mitochondria to the cytosol and other organelles. The inner membrane is composed of a boundary region and highly folded cristae membranes. The evolutionarily conserved mitochondrial contact site and cristae organizing system (MICOS) connects the two inner membrane domains via formation and stabilization of crista junction structures. Moreover, MICOS establishes contact sites between inner and outer mitochondrial membranes by interacting with outer membrane protein complexes. MICOS deficiency leads to a grossly altered inner membrane architecture resulting in far-reaching functional perturbations in mitochondria. Consequently, mutations affecting the function of MICOS are responsible for a diverse spectrum of human diseases. In this article, we summarize recent insights and concepts on the role of MICOS in the organization of mitochondrial membranes. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann.
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Rampelt H, Zerbes RM, van der Laan M, Pfanner N. Role of the mitochondrial contact site and cristae organizing system in membrane architecture and dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:737-746. [DOI: 10.1016/j.bbamcr.2016.05.020] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/12/2016] [Accepted: 05/17/2016] [Indexed: 12/22/2022]
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Cardiolipin and mitochondrial cristae organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1156-1163. [PMID: 28336315 DOI: 10.1016/j.bbamem.2017.03.013] [Citation(s) in RCA: 202] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/03/2017] [Accepted: 03/18/2017] [Indexed: 11/23/2022]
Abstract
A fundamental question in cell biology, under investigation for over six decades, is the structural organization of mitochondrial cristae. Long known to harbor electron transport chain proteins, crista membrane integrity is key to establishment of the proton gradient that drives oxidative phosphorylation. Visualization of cristae morphology by electron microscopy/tomography has provided evidence that cristae are tube-like extensions of the mitochondrial inner membrane (IM) that project into the matrix space. Reconciling ultrastructural data with the lipid composition of the IM provides support for a continuously curved cylindrical bilayer capped by a dome-shaped tip. Strain imposed by the degree of curvature is relieved by an asymmetric distribution of phospholipids in monolayer leaflets that comprise cristae membranes. The signature mitochondrial lipid, cardiolipin (~18% of IM phospholipid mass), and phosphatidylethanolamine (34%) segregate to the negatively curved monolayer leaflet facing the crista lumen while the opposing, positively curved, matrix-facing monolayer leaflet contains predominantly phosphatidylcholine. Associated with cristae are numerous proteins that function in distinctive ways to establish and/or maintain their lipid repertoire and structural integrity. By combining unique lipid components with a set of protein modulators, crista membranes adopt and maintain their characteristic morphological and functional properties. Once established, cristae ultrastructure has a direct impact on oxidative phosphorylation, apoptosis, fusion/fission as well as diseases of compromised energy metabolism.
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Unger AK, Geimer S, Harner M, Neupert W, Westermann B. Analysis of Yeast Mitochondria by Electron Microscopy. Methods Mol Biol 2017; 1567:293-314. [PMID: 28276026 DOI: 10.1007/978-1-4939-6824-4_18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Budding yeast Saccharomyces cerevisiae represents a widely used model organism for the study of mitochondrial biogenesis and architecture. Electron microscopy is an essential tool in the analysis of cellular ultrastructure and the precise localization of proteins to organellar subcompartments. We provide here detailed protocols for the analysis of yeast mitochondria by transmission electron microscopy: (1) chemical fixation and Epon embedding of yeast cells and isolated mitochondria, and (2) cryosectioning and immunolabeling of yeast cells and isolated mitochondria according to the Tokuyasu method.
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Affiliation(s)
- Ann-Katrin Unger
- Institut für Zellbiologie, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Stefan Geimer
- Institut für Zellbiologie, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Max Harner
- Max Planck Institut für Biochemie, Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Walter Neupert
- Max Planck Institut für Biochemie, Am Klopferspitz 18, 82152, Martinsried, Germany
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Harner ME, Unger AK, Geerts WJ, Mari M, Izawa T, Stenger M, Geimer S, Reggiori F, Westermann B, Neupert W. An evidence based hypothesis on the existence of two pathways of mitochondrial crista formation. eLife 2016; 5. [PMID: 27849155 PMCID: PMC5138035 DOI: 10.7554/elife.18853] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/14/2016] [Indexed: 12/31/2022] Open
Abstract
Metabolic function and architecture of mitochondria are intimately linked. More than 60 years ago, cristae were discovered as characteristic elements of mitochondria that harbor the protein complexes of oxidative phosphorylation, but how cristae are formed, remained an open question. Here we present experimental results obtained with yeast that support a novel hypothesis on the existence of two molecular pathways that lead to the generation of lamellar and tubular cristae. Formation of lamellar cristae depends on the mitochondrial fusion machinery through a pathway that is required also for homeostasis of mitochondria and mitochondrial DNA. Tubular cristae are formed via invaginations of the inner boundary membrane by a pathway independent of the fusion machinery. Dimerization of the F1FO-ATP synthase and the presence of the MICOS complex are necessary for both pathways. The proposed hypothesis is suggested to apply also to higher eukaryotes, since the key components are conserved in structure and function throughout evolution. DOI:http://dx.doi.org/10.7554/eLife.18853.001 Cells contain compartments called mitochondria, which are often called the powerhouses of the cell because they provide energy that drives vital cellular processes. Mitochondria have two membranes: an outer and an inner membrane. The outer membrane separates the mitochondria from the rest of the cell. The inner membrane is elaborately folded and the folds – called cristae – create a larger space to accommodate all of the protein machinery involved in producing energy. The cristae can be shaped as flat sac-like structures called lamellar cristae or as tubes known as tubular cristae. Mitochondria are dynamic and are constantly fusing with other mitochondria and splitting up. Even though the internal architecture of mitochondria was first revealed around 60 years ago, it is still not clear how the cristae form. Harner et al. now address this question in yeast cells by combining imaging, biochemistry and genetic approaches. The experiments show that lamellar cristae form when two mitochondria fuse with each other. The outer membranes merge and then the inner membranes start to fuse around their edges to generate the sac-like structure of lamellar cristae. A yeast protein called Mgm1 (known as Opa1 in mammals) drives the fusion of the inner membranes, but this process only takes place when enzymes called F1FO-ATP synthases on the inner membrane form pairs with one another. These F1FO-ATP synthase pairs stabilize the cristae membranes as they curve to form the sac-like structure. Later on, the formation of a group of proteins called the MICOS complex halts the fusion process to prevent the lamellar cristae from completely separating from the rest of the inner membrane. Harner et al. also found that tubular cristae form using a different mechanism when the inner membrane of the mitochondria grows inwards. This process also requires pairs of F1FO-ATP synthases and the MICOS complex, but does not involve Mgm1/Opa1. Together, these findings show that lamellar and tubular cristae in yeast form using two different mechanisms. Since the key components of these mechanisms are also found in virtually all other eukaryotes, the findings of Harner et al. are also likely to apply to many other organisms including animals. DOI:http://dx.doi.org/10.7554/eLife.18853.002
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Affiliation(s)
- Max E Harner
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Ann-Katrin Unger
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Willie Jc Geerts
- Biomolecular Imaging, Bijvoet Center, Universiteit Utrecht, Utrecht, Netherlands
| | - Muriel Mari
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Toshiaki Izawa
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Maria Stenger
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Stefan Geimer
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Fulvio Reggiori
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Benedikt Westermann
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Walter Neupert
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Anatomy and Cell Biology, Biomedical Center, Ludwig-Maximilians Universität München, Martinsried, Germany
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Barbot M, Meinecke M. Reconstitutions of mitochondrial inner membrane remodeling. J Struct Biol 2016; 196:20-28. [DOI: 10.1016/j.jsb.2016.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 02/03/2023]
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Plecitá-Hlavatá L, Ježek P. Integration of superoxide formation and cristae morphology for mitochondrial redox signaling. Int J Biochem Cell Biol 2016; 80:31-50. [PMID: 27640755 DOI: 10.1016/j.biocel.2016.09.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 12/16/2022]
Abstract
The mitochondrial network provides the central cell's energetic and regulatory unit, which besides ATP and metabolite production participates in cellular signaling through regulated reactive oxygen species (ROS) production and various protein/ion fluxes. The inner membrane forms extensive folds, called cristae, i.e. cavities enfolded from and situated perpendicularly to its inner boundary membrane portion, which encompasses an inner cylinder within the outer membrane tubule. Mitochondrial cristae ultramorphology reflects various metabolic, physiological or pathological states. Since the mitochondrion is typically a predominant superoxide source and generated ROS also serve for the creation of information redox signals, we review known relationships between ROS generation within the respiratory chain complexes of cristae and cristae morphology. Notably, it is emphasized that cristae shape is governed by ATP-synthase dimers, MICOS complexes, OPA1 isoforms and the umbrella of their regulation, and also dependent on local protonmotive force (electrical potential component) in cristae. Cristae are also affected by redox-sensitive kinases/phosphatases or p66SHC. ATP-synthase dimers decrease in the inflated intracristal space, diminishing pH and hypothetically having minimal superoxide formation. Matrix-released signaling superoxide/H2O2 is predominantly integrated along mitochondrial tubules, whereas the diffusion of intracristal signaling ROS species is controlled by crista junctions, the widening of which enables specific retrograde redox signaling such as during hypoxic cell adaptation. Other physiological cases of H2O2 release from the mitochondrion include the modulation of insulin release in pancreatic β-cells, enhancement of insulin signaling in peripheral tissues, signaling by T-cell receptors, retrograde signaling during the cell cycle and cell differentiation, specifically that of adipocytes.
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Affiliation(s)
- Lydie Plecitá-Hlavatá
- Department of Membrane Transport Biophysics, No.75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Petr Ježek
- Department of Membrane Transport Biophysics, No.75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Biosynthesis, remodeling and turnover of mitochondrial cardiolipin. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:3-7. [PMID: 27556952 DOI: 10.1016/j.bbalip.2016.08.010] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 08/03/2016] [Accepted: 08/17/2016] [Indexed: 12/15/2022]
Abstract
Among mitochondrial lipids, cardiolipin occupies a unique place. It is the only phospholipid that is specific to mitochondria and although it is merely a minor component, accounting for 10-20% of the total phospholipid content, cardiolipin plays an important role in the molecular organization, and thus the function of the cristae. This review covers the formation of cardiolipin, a phospholipid dimer containing two phosphatidyl residues, and its assembly into mitochondrial membranes. While a large body of literature exists on this topic, the review focuses on papers that appeared in the past three years. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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van der Laan M, Horvath SE, Pfanner N. Mitochondrial contact site and cristae organizing system. Curr Opin Cell Biol 2016; 41:33-42. [DOI: 10.1016/j.ceb.2016.03.013] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/19/2016] [Accepted: 03/23/2016] [Indexed: 10/22/2022]
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Jayashankar V, Mueller IA, Rafelski SM. Shaping the multi-scale architecture of mitochondria. Curr Opin Cell Biol 2016; 38:45-51. [PMID: 26907992 DOI: 10.1016/j.ceb.2016.02.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/21/2016] [Accepted: 02/03/2016] [Indexed: 11/25/2022]
Abstract
Mitochondria are complex organelles with a highly regulated architecture across all levels of organization. The architecture of the inner mitochondrial membrane (IMM) provides a crucial platform for many mitochondrial functions while mitochondrial network architecture is crucial for coordinating these activities throughout the cell. This review summarizes the recent findings regarding the most important shaping factors that regulate IMM organization, how IMM architecture supports bioenergetic functions and how IMM morphology adapts to meet other physiological needs of the cell. This review also highlights recent work suggesting that the functional connectivity of mitochondrial networks can be achieved not just by matrix continuity but also by inter-mitochondrial contact sites, which generate conductive continuity within a matrix-discontinuous mitochondrial network.
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Affiliation(s)
- Vaishali Jayashankar
- Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California, Irvine, CA 92697, USA
| | - Irina A Mueller
- Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California, Irvine, CA 92697, USA
| | - Susanne M Rafelski
- Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California, Irvine, CA 92697, USA.
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Plecitá-Hlavatá L, Engstová H, Alán L, Špaček T, Dlasková A, Smolková K, Špačková J, Tauber J, Strádalová V, Malínský J, Lessard M, Bewersdorf J, Ježek P. Hypoxic HepG2 cell adaptation decreases ATP synthase dimers and ATP production in inflated cristae by mitofilin down-regulation concomitant to MICOS clustering. FASEB J 2016; 30:1941-57. [PMID: 26887443 DOI: 10.1096/fj.201500176] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 01/24/2016] [Indexed: 01/25/2023]
Abstract
The relationship of the inner mitochondrial membrane (IMM) cristae structure and intracristal space (ICS) to oxidative phosphorylation (oxphos) is not well understood. Mitofilin (subunit Mic60) of the mitochondrial contact site and cristae organizing system (MICOS) IMM complex is attached to the outer membrane (OMM) via the sorting and assembly machinery/topogenesis of mitochondrial outer membrane β-barrel proteins (SAM/TOB) complex and controls the shape of the cristae. ATP synthase dimers determine sharp cristae edges, whereas trimeric OPA1 tightens ICS outlets. Metabolism is altered during hypoxia, and we therefore studied cristae morphology in HepG2 cells adapted to 5% oxygen for 72 h. Three dimensional (3D), super-resolution biplane fluorescence photoactivation localization microscopy with Eos-conjugated, ICS-located lactamase-β indicated hypoxic ICS expansion with an unchanged OMM (visualized by Eos-mitochondrial fission protein-1). 3D direct stochastic optical reconstruction microscopy immunocytochemistry revealed foci of clustered mitofilin (but not MICOS subunit Mic19) in contrast to its even normoxic distribution. Mitofilin mRNA and protein decreased by ∼20%. ATP synthase dimers vs monomers and state-3/state-4 respiration ratios were lower during hypoxia. Electron microscopy confirmed ICS expansion (maximum in glycolytic cells), which was absent in reduced or OMM-detached cristae of OPA1- and mitofilin-silenced cells, respectively. Hypoxic adaptation is reported as rounding sharp cristae edges and expanding cristae width (ICS) by partial mitofilin/Mic60 down-regulation. Mitofilin-depleted MICOS detaches from SAM while remaining MICOS with mitofilin redistributes toward higher interdistances. This phenomenon causes partial oxphos dormancy in glycolytic cells via disruption of ATP synthase dimers.-Plecitá-Hlavatá, L., Engstová, H., Alán, L., Špaček, T., Dlasková, A., Smolková, K., Špačková, J., Tauber, J., Strádalová, V., Malínský, J., Lessard, M., Bewersdorf, J., Ježek, P. Hypoxic HepG2 cell adaptation decreases ATP synthase dimers and ATP production in inflated cristae by mitofilin down-regulation concomitant to MICOS clustering.
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Affiliation(s)
- Lydie Plecitá-Hlavatá
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Hana Engstová
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Lukáš Alán
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Tomáš Špaček
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Andrea Dlasková
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Katarína Smolková
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Jitka Špačková
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Jan Tauber
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
| | - Vendula Strádalová
- Microscopy Unit, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Jan Malínský
- Microscopy Unit, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Mark Lessard
- Institute for Molecular Biophysics, The Jackson Laboratory, Bar Harbor, Maine, USA; and
| | - Joerg Bewersdorf
- Department of Cell Biology, Yale University, New Haven, Connecticut, USA
| | - Petr Ježek
- Department of Membrane Transport Biophysics, Department No. 75, Institute of Physiology, and
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Muñoz-Gómez SA, Slamovits CH, Dacks JB, Wideman JG. The evolution of MICOS: Ancestral and derived functions and interactions. Commun Integr Biol 2015; 8:e1094593. [PMID: 27065250 PMCID: PMC4802753 DOI: 10.1080/19420889.2015.1094593] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 09/06/2015] [Accepted: 09/08/2015] [Indexed: 11/25/2022] Open
Abstract
The MItochondrial Contact Site and Cristae Organizing System (MICOS) is required for the biogenesis and maintenance of mitochondrial cristae as well as the proper tethering of the mitochondrial inner and outer membranes. We recently demonstrated that the core components of MICOS, Mic10 and Mic60, are near-ubiquitous eukaryotic features inferred to have been present in the last eukaryote common ancestor. We also showed that Mic60 could be traced to α-proteobacteria, which suggests that mitochondrial cristae evolved from α-proteobacterial intracytoplasmic membranes. Here, we extend our evolutionary analysis to MICOS-interacting proteins (e.g., Sam50, Mia40, DNAJC11, DISC-1, QIL1, Aim24, and Cox17) and discuss the implications for both derived and ancestral functions of MICOS.
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Affiliation(s)
- Sergio A Muñoz-Gómez
- Centre for Comparative Genomics and Evolutionary Bioinformatics; Department of Biochemistry and Molecular Biology; Dalhousie University ; Halifax, Nova Scotia, Canada
| | - Claudio H Slamovits
- Centre for Comparative Genomics and Evolutionary Bioinformatics; Department of Biochemistry and Molecular Biology; Dalhousie University; Halifax, Nova Scotia, Canada; Canadian Institute for Advanced Research; Halifax, Nova Scotia, Canada
| | - Joel B Dacks
- Department of Cell Biology; Faculty of Medicine and Dentistry; University of Alberta ; Edmonton, Alberta, Canada
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Gaspard GJ, McMaster CR. Cardiolipin metabolism and its causal role in the etiology of the inherited cardiomyopathy Barth syndrome. Chem Phys Lipids 2015; 193:1-10. [PMID: 26415690 DOI: 10.1016/j.chemphyslip.2015.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 09/14/2015] [Accepted: 09/16/2015] [Indexed: 01/11/2023]
Abstract
Cardiolipin (CL) is a phospholipid with many unique characteristics. CL is synthesized in the mitochondria and resides almost exclusively within the mitochondrial inner membrane. Unlike most phospholipids that have two fatty acyl chains, CL possesses four fatty acyl chains resulting in unique biophysical characteristics that impact several biological processes including membrane fission and fusion. In addition, several proteins directly bind CL including proteins within the electron transport chain, the ADP/ATP carrier, and proteins that mediate mitophagy. Tafazzin is an enzyme that remodels saturated fatty acyl chains within CL to unsaturated fatty acyl chains, loss of function mutations in the TAZ gene encoding tafazzin are causal for the inherited cardiomyopathy Barth syndrome. Cells from Barth syndrome patients as well as several models of Barth have reduced mitochondrial functions including impaired electron transport chain function and increased reactive oxygen species (ROS) production. Mitochondria in cells from Barth syndrome patients, as well as several model organism mimics of Barth syndrome, are large and lack cristae consistent with the recently described role of CL participating in the generation of mitochondrial membrane contact sites. Cells with an inactive TAZ gene have also been shown to have a decreased capacity to undergo mitophagy when faced with stresses such as increased ROS or decreased mitochondrial quality control. This review describes CL metabolism and how defects in CL metabolism cause Barth syndrome, the etiology of Barth syndrome, and known modifiers of Barth syndrome phenotypes some of which could be explored for their amelioration of Barth syndrome in higher organisms.
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Affiliation(s)
- Gerard J Gaspard
- Departments of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Christopher R McMaster
- Departments of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada; Departments of Pharmacology, Dalhousie University, Halifax, NS, Canada.
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