1
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Sloan DB, Conover JL, Grover CE, Wendel JF, Sharbrough J. Polyploid plants take cytonuclear perturbations in stride. THE PLANT CELL 2024; 36:829-839. [PMID: 38267606 PMCID: PMC10980399 DOI: 10.1093/plcell/koae021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/05/2024] [Accepted: 01/05/2024] [Indexed: 01/26/2024]
Abstract
Hybridization in plants is often accompanied by nuclear genome doubling (allopolyploidy), which has been hypothesized to perturb interactions between nuclear and organellar (mitochondrial and plastid) genomes by creating imbalances in the relative copy number of these genomes and producing genetic incompatibilities between maternally derived organellar genomes and the half of the allopolyploid nuclear genome from the paternal progenitor. Several evolutionary responses have been predicted to ameliorate these effects, including selection for changes in protein sequences that restore cytonuclear interactions; biased gene retention/expression/conversion favoring maternal nuclear gene copies; and fine-tuning of relative cytonuclear genome copy numbers and expression levels. Numerous recent studies, however, have found that evolutionary responses are inconsistent and rarely scale to genome-wide generalities. The apparent robustness of plant cytonuclear interactions to allopolyploidy may reflect features that are general to allopolyploids such as the lack of F2 hybrid breakdown under disomic inheritance, and others that are more plant-specific, including slow sequence divergence in organellar genomes and preexisting regulatory responses to changes in cell size and endopolyploidy during development. Thus, cytonuclear interactions may only rarely act as the main barrier to establishment of allopolyploid lineages, perhaps helping to explain why allopolyploidy is so pervasive in plant evolution.
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Affiliation(s)
- Daniel B Sloan
- Department of Biology, Colorado State University,
Fort Collins, CO, USA
| | - Justin L Conover
- Department of Ecology and Evolutionary Biology, University of
Arizona, Tucson, AZ, USA
- Department of Molecular and Cellular Biology, University of
Arizona, Tucson, AZ, USA
| | - Corrinne E Grover
- Department of Ecology, Evolution, and Organismal Biology, Iowa State
University, Ames, IA, USA
| | - Jonathan F Wendel
- Department of Ecology, Evolution, and Organismal Biology, Iowa State
University, Ames, IA, USA
| | - Joel Sharbrough
- Department of Biology, New Mexico Institute of Mining and
Technology, Socorro, NM, USA
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2
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Duran L, López JM, Avalos JL. ¡Viva la mitochondria!: harnessing yeast mitochondria for chemical production. FEMS Yeast Res 2021; 20:5863938. [PMID: 32592388 DOI: 10.1093/femsyr/foaa037] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 06/12/2020] [Indexed: 12/11/2022] Open
Abstract
The mitochondria, often referred to as the powerhouse of the cell, offer a unique physicochemical environment enriched with a distinct set of enzymes, metabolites and cofactors ready to be exploited for metabolic engineering. In this review, we discuss how the mitochondrion has been engineered in the traditional sense of metabolic engineering or completely bypassed for chemical production. We then describe the more recent approach of harnessing the mitochondria to compartmentalize engineered metabolic pathways, including for the production of alcohols, terpenoids, sterols, organic acids and other valuable products. We explain the different mechanisms by which mitochondrial compartmentalization benefits engineered metabolic pathways to boost chemical production. Finally, we discuss the key challenges that need to be overcome to expand the applicability of mitochondrial engineering and reach the full potential of this emerging field.
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Affiliation(s)
- Lisset Duran
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - José Montaño López
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - José L Avalos
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
- Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ 08544, USA
- Princeton Environmental Institute, Princeton University, Princeton, NJ 08544, USA
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3
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Banerjee R, Kumar A, Satpati P, Nagotu S. Mimicking human Drp1 disease-causing mutations in yeast Dnm1 reveals altered mitochondrial dynamics. Mitochondrion 2021; 59:283-295. [PMID: 34157431 DOI: 10.1016/j.mito.2021.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/14/2021] [Accepted: 06/17/2021] [Indexed: 12/15/2022]
Abstract
The dynamin-related protein 1 (Drp1) and its homologs in various eukaryotes are essential to maintain mitochondrial morphology and regulate mitochondrial division. Several mutations in different domains of Drp1 have been reported, which result in debilitating conditions. Four such disease-causing mutations of the middle domain of Drp1 were mimicked in the yeast dynamin-related GTPase (Dnm1) and were characterized in this study. Mitochondrial morphology and protein function were observed to be altered to a variable extent in cells expressing the mutated variants of Dnm1. Several aspects related to the protein such as punctate formation, localization to mitochondria, dynamic behavior and structure were analyzed by microscopy, biochemical studies and molecular dynamics simulations. Significant effects on the protein structure and function were observed in cells expressing A430D and G397D mutations. Overall, our data provide insight into the molecular and cellular alterations resulting from middle domain mutations in Dnm1.
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Affiliation(s)
- Riddhi Banerjee
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Abhishek Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Priyadarshi Satpati
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Shirisha Nagotu
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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4
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Yang Y, Hu Y, Wu L, Zhang P, Shang J. dnm1 deletion blocks mitochondrial fragmentation in Δfzo1 cells. Yeast 2021; 38:197-205. [PMID: 33125774 DOI: 10.1002/yea.3524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial division and fusion play critical roles in maintaining functional mitochondria. Fzo1 is an outer mitochondrial membrane GTPase that played an essential role in mitochondrial fusion in budding yeast Saccharomyces cerevisiae. Here, we report the characterization of the Schizosaccharomyces pombe homologue of S. cerevisiae Fzo1p, Fzo1. Disruption of the fzo1 gene in S. pombe results in a fragmented mitochondrial morphology and a dramatically reduced growth on glycerol medium phenotype, indicating that deletion of fzo1 compromises respiratory function. Fluorescence microscopy shows that Fzo1p is located in the mitochondria. Overexpressing Fzo1 from a heterologous promoter induces mitochondrial aggregation. We also find that dnm1 mutations could both block mitochondrial fragmentation and rescue respiration growth defect in Δfzo1 single mutant cells. Our results proposed that a genetic interaction between fzo1 and a balance between division- and fusion-controlled mitochondrial shape and function in S. pombe. This study represents the first report of Fzo1 mediator of mitochondrial fusion in S. pombe.
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Affiliation(s)
- Yanmei Yang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 1 Wen Yuan Rd., Nanjing, 210023, China
| | - Yinzhi Hu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 1 Wen Yuan Rd., Nanjing, 210023, China
| | - Lin Wu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 1 Wen Yuan Rd., Nanjing, 210023, China
| | - Pan Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 1 Wen Yuan Rd., Nanjing, 210023, China
| | - Jinjie Shang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, 1 Wen Yuan Rd., Nanjing, 210023, China
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5
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Mitochondrial Fission and Fusion Dynamics Generate Efficient, Robust, and Evenly Distributed Network Topologies in Budding Yeast Cells. Cell Syst 2020; 10:287-297.e5. [PMID: 32105618 DOI: 10.1016/j.cels.2020.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 10/22/2019] [Accepted: 02/04/2020] [Indexed: 11/22/2022]
Abstract
The simplest configuration of mitochondria in a cell is as small separate organellar units. Instead, mitochondria often form a dynamic, intricately connected network. A basic understanding of the topological properties of mitochondrial networks, and their influence on cell function is lacking. We performed an extensive quantitative analysis of mitochondrial network topology, extracting mitochondrial networks in 3D from live-cell microscopic images of budding yeast cells. In the presence of fission and fusion, mitochondrial network structures exhibited certain topological properties similar to other real-world spatial networks. Fission and fusion dynamics were required to efficiently distribute mitochondria throughout the cell and generate highly interconnected networks that can facilitate efficient diffusive search processes. Thus, mitochondrial fission and fusion combine to regulate the underlying topology of mitochondrial networks, which may independently impact cell function.
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6
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Ota A, Ishihara T, Ishihara N. Mitochondrial nucleoid morphology and respiratory function are altered in Drp1-deficient HeLa cells. J Biochem 2019; 167:287-294. [DOI: 10.1093/jb/mvz112] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/04/2019] [Indexed: 12/22/2022] Open
Abstract
Abstract
Mitochondria are dynamic organelles that frequently divide and fuse with each other. The dynamin-related GTPase protein Drp1 has a key role in mitochondrial fission. To analyse the physiological roles of Drp1 in cultured human cells, we analysed Drp1-deficient HeLa cells established by genome editing using CRISPR/Cas9. Under fluorescent microscopy, not only mitochondria were elongated but their DNA (mtDNA) nucleoids were extremely enlarged in bulb-like mitochondrial structures (‘mito-bulbs’) in the Drp1-deficient HeLa cells. We further found that respiratory activity, as measured by oxygen consumption rates, was severely repressed in Drp1-deficient HeLa cells and that this was reversible by the co-repression of mitochondrial fusion factors. Although mtDNA copy number was not affected, several respiratory subunits were repressed in Drp1-deficient HeLa cells. These results suggest that mitochondrial fission is required for the maintenance of active respiratory activity and the morphology of mtDNA nucleoids in human cells.
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Affiliation(s)
- Azusa Ota
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-machi, Toyonaka, Osaka 560-0043, Japan
- Department of Protein Biochemistry, Institute of Life Science, Kurume University, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Takaya Ishihara
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-machi, Toyonaka, Osaka 560-0043, Japan
- Department of Protein Biochemistry, Institute of Life Science, Kurume University, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
| | - Naotada Ishihara
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-machi, Toyonaka, Osaka 560-0043, Japan
- Department of Protein Biochemistry, Institute of Life Science, Kurume University, 67 Asahi-machi, Kurume, Fukuoka 830-0011, Japan
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7
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Kondadi AK, Anand R, Reichert AS. Functional Interplay between Cristae Biogenesis, Mitochondrial Dynamics and Mitochondrial DNA Integrity. Int J Mol Sci 2019; 20:ijms20174311. [PMID: 31484398 PMCID: PMC6747513 DOI: 10.3390/ijms20174311] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are vital cellular organelles involved in a plethora of cellular processes such as energy conversion, calcium homeostasis, heme biogenesis, regulation of apoptosis and ROS reactive oxygen species (ROS) production. Although they are frequently depicted as static bean-shaped structures, our view has markedly changed over the past few decades as many studies have revealed a remarkable dynamicity of mitochondrial shapes and sizes both at the cellular and intra-mitochondrial levels. Aberrant changes in mitochondrial dynamics and cristae structure are associated with ageing and numerous human diseases (e.g., cancer, diabetes, various neurodegenerative diseases, types of neuro- and myopathies). Another unique feature of mitochondria is that they harbor their own genome, the mitochondrial DNA (mtDNA). MtDNA exists in several hundreds to thousands of copies per cell and is arranged and packaged in the mitochondrial matrix in structures termed mt-nucleoids. Many human diseases are mechanistically linked to mitochondrial dysfunction and alteration of the number and/or the integrity of mtDNA. In particular, several recent studies identified remarkable and partly unexpected links between mitochondrial structure, fusion and fission dynamics, and mtDNA. In this review, we will provide an overview about these recent insights and aim to clarify how mitochondrial dynamics, cristae ultrastructure and mtDNA structure influence each other and determine mitochondrial functions.
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Affiliation(s)
- Arun Kumar Kondadi
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
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8
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Aouacheria A, Baghdiguian S, Lamb HM, Huska JD, Pineda FJ, Hardwick JM. Connecting mitochondrial dynamics and life-or-death events via Bcl-2 family proteins. Neurochem Int 2017; 109:141-161. [PMID: 28461171 DOI: 10.1016/j.neuint.2017.04.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 04/17/2017] [Indexed: 12/12/2022]
Abstract
The morphology of a population of mitochondria is the result of several interacting dynamical phenomena, including fission, fusion, movement, elimination and biogenesis. Each of these phenomena is controlled by underlying molecular machinery, and when defective can cause disease. New understanding of the relationships between form and function of mitochondria in health and disease is beginning to be unraveled on several fronts. Studies in mammals and model organisms have revealed that mitochondrial morphology, dynamics and function appear to be subject to regulation by the same proteins that regulate apoptotic cell death. One protein family that influences mitochondrial dynamics in both healthy and dying cells is the Bcl-2 protein family. Connecting mitochondrial dynamics with life-death pathway forks may arise from the intersection of Bcl-2 family proteins with the proteins and lipids that determine mitochondrial shape and function. Bcl-2 family proteins also have multifaceted influences on cells and mitochondria, including calcium handling, autophagy and energetics, as well as the subcellular localization of mitochondrial organelles to neuronal synapses. The remarkable range of physical or functional interactions by Bcl-2 family proteins is challenging to assimilate into a cohesive understanding. Most of their effects may be distinct from their direct roles in apoptotic cell death and are particularly apparent in the nervous system. Dual roles in mitochondrial dynamics and cell death extend beyond BCL-2 family proteins. In this review, we discuss many processes that govern mitochondrial structure and function in health and disease, and how Bcl-2 family proteins integrate into some of these processes.
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Affiliation(s)
- Abdel Aouacheria
- Institute of Evolutionary Sciences of Montpellier (ISEM), CNRS UMR 5554, University of Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Stephen Baghdiguian
- Institute of Evolutionary Sciences of Montpellier (ISEM), CNRS UMR 5554, University of Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Heather M Lamb
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | - Jason D Huska
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | - Fernando J Pineda
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA; Department of Biostatistics, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA.
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9
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Prasai K. Regulation of mitochondrial structure and function by protein import: A current review. ACTA ACUST UNITED AC 2017; 24:107-122. [PMID: 28400074 DOI: 10.1016/j.pathophys.2017.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 12/14/2022]
Abstract
By generating the majority of a cell's ATP, mitochondria permit a vast range of reactions necessary for life. Mitochondria also perform other vital functions including biogenesis and assembly of iron-sulfur proteins, maintenance of calcium homeostasis, and activation of apoptosis. Accordingly, mitochondrial dysfunction has been linked with the pathology of many clinical conditions including cancer, type 2 diabetes, cardiomyopathy, and atherosclerosis. The ongoing maintenance of mitochondrial structure and function requires the import of nuclear-encoded proteins and for this reason, mitochondrial protein import is indispensible for cell viability. As mitochondria play central roles in determining if cells live or die, a comprehensive understanding of mitochondrial structure, protein import, and function is necessary for identifying novel drugs that may destroy harmful cells while rescuing or protecting normal ones to preserve tissue integrity. This review summarizes our current knowledge on mitochondrial architecture, mitochondrial protein import, and mitochondrial function. Our current comprehension of how mitochondrial functions maintain cell homeostasis and how cell death occurs as a result of mitochondrial stress are also discussed.
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Affiliation(s)
- Kanchanjunga Prasai
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
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10
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Extending calibration-free force measurements to optically-trapped rod-shaped samples. Sci Rep 2017; 7:42960. [PMID: 28220855 PMCID: PMC5318951 DOI: 10.1038/srep42960] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/17/2017] [Indexed: 12/14/2022] Open
Abstract
Optical trapping has become an optimal choice for biological research at the microscale due to its non-invasive performance and accessibility for quantitative studies, especially on the forces involved in biological processes. However, reliable force measurements depend on the calibration of the optical traps, which is different for each experiment and hence requires high control of the local variables, especially of the trapped object geometry. Many biological samples have an elongated, rod-like shape, such as chromosomes, intracellular organelles (e.g., peroxisomes), membrane tubules, certain microalgae, and a wide variety of bacteria and parasites. This type of samples often requires several optical traps to stabilize and orient them in the correct spatial direction, making it more difficult to determine the total force applied. Here, we manipulate glass microcylinders with holographic optical tweezers and show the accurate measurement of drag forces by calibration-free direct detection of beam momentum. The agreement between our results and slender-body hydrodynamic theoretical calculations indicates potential for this force-sensing method in studying protracted, rod-shaped specimens.
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11
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Mitochondrial Ubiquitin Ligase in Cardiovascular Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:327-333. [PMID: 28551795 DOI: 10.1007/978-3-319-55330-6_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial dynamics play a critical role in cellular responses and physiological process. However, their dysregulation leads to a functional degradation, which results in a diverse array of common disorders, including cardiovascular disease. In this background, the mitochondrial ubiquitin ligase has been attracting substantial research interest in recent years. Mitochondrial ubiquitin ligase is localized in the mitochondrial outer membrane, where it plays an essential role in the regulation of mitochondrial dynamics and apoptosis. In this chapter, we provide a comprehensive overview of the functions of mitochondrial ubiquitin ligases identified hitherto, with a special focus on cardiovascular disorders.
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12
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Liu Y, Meng F, Tang Y, Yu X, Lin W. A photostable fluorescent probe for rapid monitoring and tracking of a trans-membrane process and mitochondrial fission and fusion dynamics. NEW J CHEM 2016. [DOI: 10.1039/c5nj02821c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The MT-PVIM probe was capable of monitoring and tracking a trans membrane process and mitochondrial fission and fusion dynamics.
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Affiliation(s)
- Yong Liu
- Institute of Fluorescent Probes for Biological Imaging
- School of Chemistry and Chemical Engineering
- School of Biological Science and Technology
- University of Jinan
- Jinan
| | - Fangfang Meng
- Institute of Fluorescent Probes for Biological Imaging
- School of Chemistry and Chemical Engineering
- School of Biological Science and Technology
- University of Jinan
- Jinan
| | - Yonghe Tang
- Institute of Fluorescent Probes for Biological Imaging
- School of Chemistry and Chemical Engineering
- School of Biological Science and Technology
- University of Jinan
- Jinan
| | - Xiaoqiang Yu
- Center of Bio & Micro/Nano Functional Materials
- State Key Laboratory of Crystal Materials
- Shandong University
- Jinan
- P. R. China
| | - Weiying Lin
- Institute of Fluorescent Probes for Biological Imaging
- School of Chemistry and Chemical Engineering
- School of Biological Science and Technology
- University of Jinan
- Jinan
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13
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Khan IA, Ning G, Liu X, Feng X, Lin F, Lu J. Mitochondrial fission protein MoFis1 mediates conidiation and is required for full virulence of the rice blast fungus Magnaporthe oryzae. Microbiol Res 2015; 178:51-8. [PMID: 26302847 DOI: 10.1016/j.micres.2015.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 06/06/2015] [Accepted: 06/07/2015] [Indexed: 01/21/2023]
Abstract
The mitochondrial fission protein Fis1 regulates yeast mitochondrial fission and is required for ethanol-induced mitochondrial fragmentation and apoptosis. To examine the function of Fis1 in a plant pathogenic fungus, we cloned the MoFIS1 gene, a homolog of Saccharomyces cerevisiae FIS1, from Magnaporthe oryzae and characterized its function by targeted gene deletion and mutant phenotypic analysis. MoFIS1 deletion mutants were unaltered in conidial germination, appressorium formation, and mating tests, but were severely defective in colony growth, conidiation, virulence on rice and barley, growth under nitrogen and glucose deficiency, and growth under osmotic stress. Blast lesions on rice leaves caused by the ΔMofis1 strain were significantly reduced, were non-proliferating, and were less coalesced as compared to the highly coalesced and proliferating lesions resulting from infection with the wild-type strain. The defects in growth, conidiation, and virulence of the mutant were restored in a complementation strain of ΔMofis1. A MoFis1-GFP fusion protein co-localized with Mitotracker red in mitochondria. These results show that MoFIS1 encodes a mitochondrial protein that regulates fungal growth, conidiation, and virulence in M. oryzae.
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Affiliation(s)
- Irshad Ali Khan
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, Zhejiang Province, China; University of Swabi, Khyber Pakhtunkhwa, Pakistan
| | - Guoao Ning
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, Zhejiang Province, China
| | - Xiaohong Liu
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, Zhejiang Province, China
| | - Xiaoxiao Feng
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, Zhejiang Province, China
| | - Fucheng Lin
- State Key Laboratory for Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, Zhejiang Province, China; China Tobacco Gene Research Center, Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou 450001, Henan Province, China
| | - Jianping Lu
- College of Life Sciences, Zhejiang University, Hangzhou 310058, Zhejiang Province, China.
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14
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Teixeira V, Medeiros TC, Vilaça R, Pereira AT, Chaves SR, Côrte-Real M, Moradas-Ferreira P, Costa V. Ceramide signalling impinges on Sit4p and Hog1p to promote mitochondrial fission and mitophagy in Isc1p-deficient cells. Cell Signal 2015; 27:1840-9. [PMID: 26079297 DOI: 10.1016/j.cellsig.2015.06.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 06/06/2015] [Indexed: 11/19/2022]
Abstract
Mitochondria function as the powerhouses of the cell for energy conversion through the oxidative phosphorylation process. Accumulation of dysfunctional mitochondria promotes a bioenergetic crisis and cell death by apoptosis. Yeast cells lacking Isc1p, an orthologue of mammalian neutral sphingomyelinase type 2, exhibit mitochondrial dysfunction and shortened lifespan associated with the accumulation of specific ceramide species and activation of the PP2A-like protein phosphatase Sit4p and of the Hog1p kinase. Here, we show that isc1Δ cells display hyperactivation of mitophagy that is suppressed by downregulating Sit4p, Hog1p or the TORC1-Sch9p pathway. Notably, isc1Δ cells also have high levels of Dnm1p associated with unbalanced mitochondrial fission, leading to mitochondrial fragmentation, and DNM1 deletion suppressed the oxidative stress sensitivity and shortened lifespan of isc1Δ cells. Moreover, Isc1p and Dnm1p physically interact, suggesting a possible regulatory role for Isc1p in mitochondrial dynamics. Overall, our work demonstrates that Isc1p-mediated ceramide signalling regulates mitophagy and mitochondrial dynamics in yeast with impact on mitochondrial function and lifespan. Since ceramides have been implicated in ageing and diseases associated with mitochondrial dysfunction, our findings suggest that therapeutic strategies targeting ceramide signalling may improve mitochondrial function and human healthspan.
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Affiliation(s)
- Vitor Teixeira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Departamento de Biologia Molecular, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Tânia C Medeiros
- IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - Rita Vilaça
- IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - Andreia T Pereira
- IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - Susana R Chaves
- Departamento de Biologia, Centro de Biologia Molecular e Ambiental, Universidade do Minho, Braga, Portugal
| | - Manuela Côrte-Real
- Departamento de Biologia, Centro de Biologia Molecular e Ambiental, Universidade do Minho, Braga, Portugal
| | - Pedro Moradas-Ferreira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Departamento de Biologia Molecular, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Vítor Costa
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC, Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Departamento de Biologia Molecular, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
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15
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Tang SY, Yi P, Soffe R, Nahavandi S, Shukla R, Khoshmanesh K. Using dielectrophoresis to study the dynamic response of single budding yeast cells to Lyticase. Anal Bioanal Chem 2015; 407:3437-48. [DOI: 10.1007/s00216-015-8529-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/21/2015] [Accepted: 01/30/2015] [Indexed: 02/03/2023]
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16
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Integrity of the yeast mitochondrial genome, but not its distribution and inheritance, relies on mitochondrial fission and fusion. Proc Natl Acad Sci U S A 2015; 112:E947-56. [PMID: 25730886 DOI: 10.1073/pnas.1501737112] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial DNA (mtDNA) is essential for mitochondrial and cellular function. In Saccharomyces cerevisiae, mtDNA is organized in nucleoprotein structures termed nucleoids, which are distributed throughout the mitochondrial network and are faithfully inherited during the cell cycle. How the cell distributes and inherits mtDNA is incompletely understood although an involvement of mitochondrial fission and fusion has been suggested. We developed a LacO-LacI system to noninvasively image mtDNA dynamics in living cells. Using this system, we found that nucleoids are nonrandomly spaced within the mitochondrial network and observed the spatiotemporal events involved in mtDNA inheritance. Surprisingly, cells deficient in mitochondrial fusion and fission distributed and inherited mtDNA normally, pointing to alternative pathways involved in these processes. We identified such a mechanism, where we observed fission-independent, but F-actin-dependent, tip generation that was linked to the positioning of mtDNA to the newly generated tip. Although mitochondrial fusion and fission were dispensable for mtDNA distribution and inheritance, we show through a combination of genetics and next-generation sequencing that their absence leads to an accumulation of mitochondrial genomes harboring deleterious structural variations that cluster at the origins of mtDNA replication, thus revealing crucial roles for mitochondrial fusion and fission in maintaining the integrity of the mitochondrial genome.
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17
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Busch KB, Kowald A, Spelbrink JN. Quality matters: how does mitochondrial network dynamics and quality control impact on mtDNA integrity? Philos Trans R Soc Lond B Biol Sci 2015; 369:20130442. [PMID: 24864312 DOI: 10.1098/rstb.2013.0442] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Mammalian mtDNA encodes for 13 core proteins of oxidative phosphorylation. Mitochondrial DNA mutations and deletions cause severe myopathies and neuromuscular diseases. Thus, the integrity of mtDNA is pivotal for cell survival and health of the organism. We here discuss the possible impact of mitochondrial fusion and fission on mtDNA maintenance as well as positive and negative selection processes. Our focus is centred on the important question of how the quality of mtDNA nucleoids can be assured when selection and mitochondrial quality control works on functional and physiological phenotypes constituted by oxidative phosphorylation proteins. The organelle control theory suggests a link between phenotype and nucleoid genotype. This is discussed in the light of new results presented here showing that mitochondrial transcription factor A/nucleoids are restricted in their intramitochondrial mobility and probably have a limited sphere of influence. Together with recent published work on mitochondrial and mtDNA heteroplasmy dynamics, these data suggest first, that single mitochondria might well be internally heterogeneous and second, that nucleoid genotypes might be linked to local phenotypes (although the link might often be leaky). We discuss how random or site-specific mitochondrial fission can isolate dysfunctional parts and enable their elimination by mitophagy, stressing the importance of fission in the process of mtDNA quality control. The role of fusion is more multifaceted and less understood in this context, but the mixing and equilibration of matrix content might be one of its important functions.
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Affiliation(s)
- Karin B Busch
- Division of Mitochondrial Dynamics, School of Biology and Chemistry, University of Osnabrück, 49069 Osnabrück, Germany
| | - Axel Kowald
- Centre for Integrated Systems Biology of Ageing and Nutrition, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK
| | - Johannes N Spelbrink
- Department of Pediatrics, Nijmegen Centre for Mitochondrial Disorders, Radboud University Medical Centre, Geert Grooteplein 10, PO Box 9101, 6500 HB Nijmegen, The Netherlands FinMIT Centre of Excellence, Institute of Biomedical Technology and Tampere University Hospital, Pirkanmaa Hospital District, 33014 Tampere, Finland
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18
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Sanderson TH, Raghunayakula S, Kumar R. Release of mitochondrial Opa1 following oxidative stress in HT22 cells. Mol Cell Neurosci 2015; 64:116-22. [PMID: 25579226 DOI: 10.1016/j.mcn.2014.12.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 11/07/2014] [Accepted: 12/22/2014] [Indexed: 12/01/2022] Open
Abstract
Cellular mechanisms involved in multiple neurodegenerative diseases converge on mitochondria to induce overproduction of reactive oxygen species, damage to mitochondria, and subsequent cytochrome c release. Little is currently known regarding the contribution mitochondrial dynamics play in cytochrome c release following oxidative stress in neurodegenerative disease. Here we induced oxidative stress in the HT22 cell line with glutamate and investigated key mediators of mitochondrial dynamics to determine the role this process may play in oxidative stress induced neuronal death. We report that glutamate treatment in HT22 cells induces increase in reactive oxygen species (ROS), release of the mitochondrial fusion protein Opa1 into the cytosol, with concomitant release of cytochrome c. Furthermore, following the glutamate treatment alterations in cell signaling coincide with mitochondrial fragmentation which culminates in significant cell death in HT22 cells. Finally, we report that treatment with the antioxidant tocopherol attenuates glutamate induced-ROS increase, release of mitochondrial Opa1 and cytochrome c, and prevents cell death.
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Affiliation(s)
- Thomas H Sanderson
- Department of Emergency Medicine, Wayne State University School of Medicine, 550 E. Canfield, Detroit, MI, USA; Cardiovascular Research Institute, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, USA; Department of Physiology, Wayne State University School of Medicine, 550 E. Canfield, Detroit, MI, USA
| | - Sarita Raghunayakula
- Department of Emergency Medicine, Wayne State University School of Medicine, 550 E. Canfield, Detroit, MI, USA
| | - Rita Kumar
- Department of Emergency Medicine, Wayne State University School of Medicine, 550 E. Canfield, Detroit, MI, USA; Cardiovascular Research Institute, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, USA; Department of Physiology, Wayne State University School of Medicine, 550 E. Canfield, Detroit, MI, USA.
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19
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Regulation of mitochondrial genome inheritance by autophagy and ubiquitin-proteasome system: implications for health, fitness, and fertility. BIOMED RESEARCH INTERNATIONAL 2014; 2014:981867. [PMID: 25028670 PMCID: PMC4083708 DOI: 10.1155/2014/981867] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/01/2014] [Accepted: 04/07/2014] [Indexed: 01/07/2023]
Abstract
Mitochondria, the energy-generating organelles, play a role in numerous cellular functions including adenosine triphosphate (ATP) production, cellular homeostasis, and apoptosis. Maternal inheritance of mitochondria and mitochondrial DNA (mtDNA) is universally observed in humans and most animals. In general, high levels of mitochondrial heteroplasmy might contribute to a detrimental effect on fitness and disease resistance. Therefore, a disposal of the sperm-derived mitochondria inside fertilized oocytes assures normal preimplantation embryo development. Here we summarize the current research and knowledge concerning the role of autophagic pathway and ubiquitin-proteasome-dependent proteolysis in sperm mitophagy in mammals, including humans. Current data indicate that sperm mitophagy inside the fertilized oocyte could occur along multiple degradation routes converging on autophagic clearance of paternal mitochondria. The influence of assisted reproductive therapies (ART) such as intracytoplasmic sperm injection (ICSI), mitochondrial replacement (MR), and assisted fertilization of oocytes from patients of advanced reproductive age on mitochondrial function, inheritance, and fitness and for the development and health of ART babies will be of particular interest to clinical audiences. Altogether, the study of sperm mitophagy after fertilization has implications in the timing of evolution and developmental and reproductive biology and in human health, fitness, and management of mitochondrial disease.
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20
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Mutlu N, Garipler G, Akdoğan E, Dunn CD. Activation of the pleiotropic drug resistance pathway can promote mitochondrial DNA retention by fusion-defective mitochondria in Saccharomyces cerevisiae. G3 (BETHESDA, MD.) 2014; 4:1247-58. [PMID: 24807265 PMCID: PMC4455774 DOI: 10.1534/g3.114.010330] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 05/05/2014] [Indexed: 11/18/2022]
Abstract
Genetic and microscopic approaches using Saccharomyces cerevisiae have identified many proteins that play a role in mitochondrial dynamics, but it is possible that other proteins and pathways that play a role in mitochondrial division and fusion remain to be discovered. Mutants lacking mitochondrial fusion are characterized by rapid loss of mitochondrial DNA. We took advantage of a petite-negative mutant that is unable to survive mitochondrial DNA loss to select for mutations that allow cells with fusion-deficient mitochondria to maintain the mitochondrial genome on fermentable medium. Next-generation sequencing revealed that all identified suppressor mutations not associated with known mitochondrial division components were localized to PDR1 or PDR3, which encode transcription factors promoting drug resistance. Further studies revealed that at least one, if not all, of these suppressor mutations dominantly increases resistance to known substrates of the pleiotropic drug resistance pathway. Interestingly, hyperactivation of this pathway did not significantly affect mitochondrial shape, suggesting that mitochondrial division was not greatly affected. Our results reveal an intriguing genetic connection between pleiotropic drug resistance and mitochondrial dynamics.
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Affiliation(s)
- Nebibe Mutlu
- Department of Molecular Biology and Genetic, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Görkem Garipler
- Department of Molecular Biology and Genetic, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Emel Akdoğan
- Department of Molecular Biology and Genetic, Koç University, Sarıyer, İstanbul, 34450, Turkey
| | - Cory D Dunn
- Department of Molecular Biology and Genetic, Koç University, Sarıyer, İstanbul, 34450, Turkey
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21
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Bioenergetic role of mitochondrial fusion and fission. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1833-8. [DOI: 10.1016/j.bbabio.2012.02.033] [Citation(s) in RCA: 432] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/24/2012] [Accepted: 02/25/2012] [Indexed: 11/22/2022]
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22
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Munoz AJ, Wanichthanarak K, Meza E, Petranovic D. Systems biology of yeast cell death. FEMS Yeast Res 2012; 12:249-65. [PMID: 22188402 DOI: 10.1111/j.1567-1364.2011.00781.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 12/08/2011] [Accepted: 12/09/2011] [Indexed: 11/29/2022] Open
Abstract
Programmed cell death (PCD) (including apoptosis) is an essential process, and many human diseases of high prevalence such as neurodegenerative diseases and cancer are associated with deregulations in the cell death pathways. Yeast Saccharomyces cerevisiae, a unicellular eukaryotic organism, shares with multicellular organisms (including humans) key components and regulators of the PCD machinery. In this article, we review the current state of knowledge about cell death networks, including the modeling approaches and experimental strategies commonly used to study yeast cell death. We argue that the systems biology approach will bring valuable contributions to our understanding of regulations and mechanisms of the complex cell death pathways.
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Affiliation(s)
- Ana Joyce Munoz
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden
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23
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Zhang Y, Jiang L, Hu W, Zheng Q, Xiang W. Mitochondrial dysfunction during in vitro hepatocyte steatosis is reversed by omega-3 fatty acid-induced up-regulation of mitofusin 2. Metabolism 2011; 60:767-75. [PMID: 20817187 DOI: 10.1016/j.metabol.2010.07.026] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/01/2010] [Accepted: 07/14/2010] [Indexed: 12/17/2022]
Abstract
We examined the effects and mechanisms of omega-3 polyunsaturated fatty acid (PUFA) administration on mitochondrial morphology and function in an in vitro steatotic hepatocyte model created using HepG2 cells. Reverse transcriptase polymerase chain reaction and Western blot analyses were performed to determine the expression levels of mitofusin 2 (Mfn2), and immunofluorescent MitoTracker Mitochondrion-Selective Probes were used to detect changes in mitochondrial morphology. Adenosine triphosphate (ATP) synthesis and reactive oxygen species (ROS) production were measured to assess mitochondrial function. Mitofusin 2 expression was significantly suppressed (P < .05), ATP levels were decreased (P < .05), ROS production was increased (P < .05), and the normal tubular network of mitochondria was fragmented into short rods or spheres. Model cells were incubated with eicosapentaenoic acid or docosahexaenoic acid at a final concentration of 50 μmol/L for 1 hour. Both eicosapentaenoic acid and docosahexaenoic acid increased the expression of Mfn2 (P < .01) and caused an increase in the length of mitochondrial tubules. The omega-3 PUFAs also increased the levels of ATP (P < .05) and decreased the ROS production (P < .05). However, these changes were not seen in Mfn2-depleted steatotic HepG2 cells, created by RNA interference before incubation with the omega-3 PUFAs. This study demonstrated that, in steatotic hepatocytes, omega-3 PUFAs may change mitochondrial morphology and have beneficial effects on recovery of mitochondrial function by increasing the expression of Mfn2.
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MESH Headings
- Adenosine Triphosphate/metabolism
- Azo Compounds
- Blotting, Western
- Cells, Cultured
- Coloring Agents
- Fatty Acids, Omega-3/therapeutic use
- Fatty Liver/drug therapy
- Fatty Liver/pathology
- Fluorometry
- GTP Phosphohydrolases
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Hepatocytes/pathology
- Humans
- Image Processing, Computer-Assisted
- Membrane Proteins/biosynthesis
- Microscopy, Fluorescence
- Mitochondria, Liver/drug effects
- Mitochondria, Liver/pathology
- Mitochondria, Liver/ultrastructure
- Mitochondrial Proteins/biosynthesis
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Small Interfering/pharmacology
- Reactive Oxygen Species/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Up-Regulation/drug effects
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Affiliation(s)
- Yong Zhang
- Department of General Surgery, Union Hospital, Huazhong University of Science and Technology, China, 430022
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24
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Kageyama Y, Zhang Z, Sesaki H. Mitochondrial division: molecular machinery and physiological functions. Curr Opin Cell Biol 2011; 23:427-34. [PMID: 21565481 DOI: 10.1016/j.ceb.2011.04.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/10/2011] [Accepted: 04/18/2011] [Indexed: 01/12/2023]
Abstract
Mitochondrial division has emerged as a key mechanism for this essential organelle to maintain its structural integrity, intracellular distribution, and functional competence. An evolutionarily conserved dynamin-related GTPase, Dnm1p/Drp1, interacts with other proteins to form the core machinery involved in mitochondrial division. We summarize recent progress in understanding how the division machinery assembles onto mitochondria and how mitochondrial division contributes to cellular physiology and human diseases.
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Affiliation(s)
- Yusuke Kageyama
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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25
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Muster B, Kohl W, Wittig I, Strecker V, Joos F, Haase W, Bereiter-Hahn J, Busch K. Respiratory chain complexes in dynamic mitochondria display a patchy distribution in life cells. PLoS One 2010; 5:e11910. [PMID: 20689601 PMCID: PMC2912852 DOI: 10.1371/journal.pone.0011910] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 07/07/2010] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Mitochondria, the main suppliers of cellular energy, are dynamic organelles that fuse and divide frequently. Constraining these processes impairs mitochondrial is closely linked to certain neurodegenerative diseases. It is proposed that functional mitochondrial dynamics allows the exchange of compounds thereby providing a rescue mechanism. METHODOLOGY/PRINCIPAL FINDINGS The question discussed in this paper is whether fusion and fission of mitochondria in different cell lines result in re-localization of respiratory chain (RC) complexes and of the ATP synthase. This was addressed by fusing cells containing mitochondria with respiratory complexes labelled with different fluorescent proteins and resolving their time dependent re-localization in living cells. We found a complete reshuffling of RC complexes throughout the entire chondriome in single HeLa cells within 2-3 h by organelle fusion and fission. Polykaryons of fused cells completely re-mixed their RC complexes in 10-24 h in a progressive way. In contrast to the recently described homogeneous mixing of matrix-targeted proteins or outer membrane proteins, the distribution of RC complexes and ATP synthase in fused hybrid mitochondria, however, was not homogeneous but patterned. Thus, complete equilibration of respiratory chain complexes as integral inner mitochondrial membrane complexes is a slow process compared with matrix proteins probably limited by complete fusion. In co-expressing cells, complex II is more homogenously distributed than complex I and V, resp. Indeed, this result argues for higher mobility and less integration in supercomplexes. CONCLUSION/SIGNIFICANCE Our results clearly demonstrate that mitochondrial fusion and fission dynamics favours the re-mixing of all RC complexes within the chondriome. This permanent mixing avoids a static situation with a fixed composition of RC complexes per mitochondrion.
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Affiliation(s)
- Britta Muster
- Institute of Kinematic Cell Research, Department of Biology, University of Frankfurt, Frankfurt/Main, Germany
| | - Wladislaw Kohl
- Institute of Kinematic Cell Research, Department of Biology, University of Frankfurt, Frankfurt/Main, Germany
- Laboratory for Mitochondrial Dynamics, Department of Biology, University of Osnabrueck, Osnabrueck, Germany
| | - Ilka Wittig
- Institute of Molecular Bioenergetics, Medical School, University of Frankfurt, Frankfurt/Main, Germany
| | - Valentina Strecker
- Institute of Molecular Bioenergetics, Medical School, University of Frankfurt, Frankfurt/Main, Germany
| | - Friederike Joos
- Electron Facility, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Winfried Haase
- Electron Facility, Max Planck Institute of Biophysics, Frankfurt/Main, Germany
| | - Jürgen Bereiter-Hahn
- Institute of Kinematic Cell Research, Department of Biology, University of Frankfurt, Frankfurt/Main, Germany
| | - Karin Busch
- Institute of Kinematic Cell Research, Department of Biology, University of Frankfurt, Frankfurt/Main, Germany
- Laboratory for Mitochondrial Dynamics, Department of Biology, University of Osnabrueck, Osnabrueck, Germany
- * E-mail:
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26
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Ashrafian H, Docherty L, Leo V, Towlson C, Neilan M, Steeples V, Lygate CA, Hough T, Townsend S, Williams D, Wells S, Norris D, Glyn-Jones S, Land J, Barbaric I, Lalanne Z, Denny P, Szumska D, Bhattacharya S, Griffin JL, Hargreaves I, Fernandez-Fuentes N, Cheeseman M, Watkins H, Dear TN. A mutation in the mitochondrial fission gene Dnm1l leads to cardiomyopathy. PLoS Genet 2010; 6:e1001000. [PMID: 20585624 PMCID: PMC2891719 DOI: 10.1371/journal.pgen.1001000] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 05/25/2010] [Indexed: 12/03/2022] Open
Abstract
Mutations in a number of genes have been linked to inherited dilated cardiomyopathy (DCM). However, such mutations account for only a small proportion of the clinical cases emphasising the need for alternative discovery approaches to uncovering novel pathogenic mutations in hitherto unidentified pathways. Accordingly, as part of a large-scale N-ethyl-N-nitrosourea mutagenesis screen, we identified a mouse mutant, Python, which develops DCM. We demonstrate that the Python phenotype is attributable to a dominant fully penetrant mutation in the dynamin-1-like (Dnm1l) gene, which has been shown to be critical for mitochondrial fission. The C452F mutation is in a highly conserved region of the M domain of Dnm1l that alters protein interactions in a yeast two-hybrid system, suggesting that the mutation might alter intramolecular interactions within the Dnm1l monomer. Heterozygous Python fibroblasts exhibit abnormal mitochondria and peroxisomes. Homozygosity for the mutation results in the death of embryos midway though gestation. Heterozygous Python hearts show reduced levels of mitochondria enzyme complexes and suffer from cardiac ATP depletion. The resulting energy deficiency may contribute to cardiomyopathy. This is the first demonstration that a defect in a gene involved in mitochondrial remodelling can result in cardiomyopathy, showing that the function of this gene is needed for the maintenance of normal cellular function in a relatively tissue-specific manner. This disease model attests to the importance of mitochondrial remodelling in the heart; similar defects might underlie human heart muscle disease.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Cardiomyopathy, Dilated/congenital
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Dynamins
- Embryo, Mammalian/metabolism
- Embryo, Mammalian/pathology
- GTP Phosphohydrolases/chemistry
- GTP Phosphohydrolases/genetics
- GTP Phosphohydrolases/metabolism
- Genes, Mitochondrial
- Genetic Predisposition to Disease
- Male
- Mice
- Mice, Inbred BALB C
- Microscopy, Electron, Transmission
- Microtubule-Associated Proteins/chemistry
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Models, Molecular
- Molecular Sequence Data
- Mutation
- Protein Structure, Quaternary
- Sequence Alignment
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Affiliation(s)
- Houman Ashrafian
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Louise Docherty
- Mammalian Genetics of Disease Unit, School of Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Vincenzo Leo
- Leeds Institute of Molecular Medicine, Wellcome Trust Brenner Building, St. James's University Hospital, Leeds, United Kingdom
| | - Christopher Towlson
- Mammalian Genetics of Disease Unit, School of Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Monica Neilan
- Mammalian Genetics of Disease Unit, School of Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Violetta Steeples
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Craig A. Lygate
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Tertius Hough
- Leeds Institute of Molecular Medicine, Wellcome Trust Brenner Building, St. James's University Hospital, Leeds, United Kingdom
| | - Stuart Townsend
- Leeds Institute of Molecular Medicine, Wellcome Trust Brenner Building, St. James's University Hospital, Leeds, United Kingdom
| | - Debbie Williams
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Sara Wells
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Dominic Norris
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Sarah Glyn-Jones
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - John Land
- Neurometabolic Unit, National Hospital, London, United Kingdom
| | - Ivana Barbaric
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Zuzanne Lalanne
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Paul Denny
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Dorota Szumska
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Shoumo Bhattacharya
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Julian L. Griffin
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Iain Hargreaves
- Neurometabolic Unit, National Hospital, London, United Kingdom
| | - Narcis Fernandez-Fuentes
- Leeds Institute of Molecular Medicine, Wellcome Trust Brenner Building, St. James's University Hospital, Leeds, United Kingdom
| | - Michael Cheeseman
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
| | - Hugh Watkins
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - T. Neil Dear
- Mammalian Genetics of Disease Unit, School of Medicine, University of Sheffield, Sheffield, United Kingdom
- Leeds Institute of Molecular Medicine, Wellcome Trust Brenner Building, St. James's University Hospital, Leeds, United Kingdom
- Mary Lyon Centre and Mammalian Genetics Unit, Medical Research Council, Harwell, United Kingdom
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27
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Hammermeister M, Schödel K, Westermann B. Mdm36 is a mitochondrial fission-promoting protein in Saccharomyces cerevisiae. Mol Biol Cell 2010; 21:2443-52. [PMID: 20505073 PMCID: PMC2903673 DOI: 10.1091/mbc.e10-02-0096] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mdm36 is a novel component of mitochondrial fission in yeast. Genetic and cytological approaches suggest that Mdm36 promotes the formation of attachment sites for mitochondria at the cell cortex. These Dnm1- and Num1-containing structures seem to be important for dynamin-mediated membrane fission and link mitochondrial motility and division. The division of mitochondrial membranes is a complex process mediated by the dynamin-related protein Dnm1 in yeast, acting in concert with several cofactors. We have identified Mdm36 as a mitochondria-associated protein required for efficient mitochondrial division. Δmdm36 mutants contain highly interconnected mitochondrial networks that strikingly resemble known fission mutants. Furthermore, mitochondrial fission induced by depolymerization of the actin cytoskeleton is blocked in Δmdm36 mutants, and the number of Dnm1 clusters on mitochondrial tips is reduced. Double mutant analyses indicate that Mdm36 acts antagonistically to fusion-promoting components, such as Fzo1 and Mdm30. The cell cortex-associated protein Num1 was shown previously to interact with Dnm1 and promote mitochondrial fission. We observed that mitochondria are highly motile and that their localization is not restricted to the cell periphery in Δmdm36 and Δnum1 mutants. Intriguingly, colocalization of Num1 and Dnm1 is abolished in the absence of Mdm36. These data suggest that Mdm36 is required for mitochondrial division by facilitating the formation of protein complexes containing Dnm1 and Num1 at the cell cortex. We propose a model that Mdm36-dependent formation of cell cortex anchors is required for the generation of tension on mitochondrial membranes to promote mitochondrial fission by Dnm1.
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28
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Chen S, Liu D, Finley RL, Greenberg ML. Loss of mitochondrial DNA in the yeast cardiolipin synthase crd1 mutant leads to up-regulation of the protein kinase Swe1p that regulates the G2/M transition. J Biol Chem 2010; 285:10397-407. [PMID: 20086012 DOI: 10.1074/jbc.m110.100784] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The anionic phospholipid cardiolipin and its precursor phosphatidylglycerol are synthesized and localized in the mitochondrial inner membrane of eukaryotes. They are required for structural integrity and optimal activities of a large number of mitochondrial proteins and complexes. Previous studies showed that loss of anionic phospholipids leads to cell inviability in the absence of mitochondrial DNA. However, the mechanism linking loss of anionic phospholipids to petite lethality was unclear. To elucidate the mechanism, we constructed a crd1Deltarho degrees mutant, which is viable and mimics phenotypes of pgs1Delta in the petite background. We found that loss of cardiolipin in rho degrees cells leads to elevated expression of Swe1p, a morphogenesis checkpoint protein. Moreover, the retrograde pathway is activated in crd1Deltarho degrees cells, most likely due to the exacerbation of mitochondrial dysfunction. Interestingly, the expression of SWE1 is dependent on retrograde regulation as elevated expression of SWE1 is suppressed by deletion of RTG2 or RTG3. Taken together, these findings indicate that activation of the retrograde pathway leads to up-regulation of SWE1 in crd1Deltarho degrees cells. These results suggest that anionic phospholipids are required for processes that are essential for normal cell division in rho degrees cells.
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Affiliation(s)
- Shuliang Chen
- Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA
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29
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Bereiter-Hahn J, Jendrach M. Mitochondrial dynamics. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 284:1-65. [PMID: 20875628 DOI: 10.1016/s1937-6448(10)84001-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial dynamics is a key feature for the interaction of mitochondria with other organelles within a cell and also for the maintenance of their own integrity. Four types of mitochondrial dynamics are discussed: Movement within a cell and interactions with the cytoskeleton, fusion and fission events which establish coherence within the chondriome, the dynamic behavior of cristae and their components, and finally, formation and disintegration of mitochondria (mitophagy). Due to these essential functions, disturbed mitochondrial dynamics are inevitably connected to a variety of diseases. Localized ATP gradients, local control of calcium-based messaging, production of reactive oxygen species, and involvement of other metabolic chains, that is, lipid and steroid synthesis, underline that physiology not only results from biochemical reactions but, in addition, resides on the appropriate morphology and topography. These events and their molecular basis have been established recently and are the topic of this review.
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Affiliation(s)
- Jürgen Bereiter-Hahn
- Center of Excellence Macromolecular Complexes, Institute for Cell Biology and Neurosciences, Goethe University, Frankfurt am Main, Germany
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30
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Hofmann L, Saunier R, Cossard R, Esposito M, Rinaldi T, Delahodde A. A nonproteolytic proteasome activity controls organelle fission in yeast. J Cell Sci 2009; 122:3673-83. [PMID: 19773362 DOI: 10.1242/jcs.050229] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
To understand the processes underlying organelle function, dynamics and inheritance, it is necessary to identify and characterize the regulatory components involved. Recently in yeast and mammals, proteins of the membrane fission machinery (Dnm1-Mdv1-Caf4-Fis1 in yeast and DLP1-FIS1 in human) have been shown to have a dual localization on mitochondria and peroxisomes, where they control mitochondrial fission and peroxisome division. Here, we show that whereas vacuole fusion is regulated by the proteasome degradation function, mitochondrial fission and peroxisomal division are not controlled by the proteasome activity but rather depend on a new function of the proteasomal lid subunit Rpn11. Rpn11 was found to regulate the Fis1-dependent fission machinery of both organelles. These findings indicate a unique role of the Rpn11 protein in mitochondrial fission and peroxisomal proliferation that is independent of its role in proteasome-associated deubiquitylation.
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Affiliation(s)
- Line Hofmann
- University of Paris-Sud, CNRS, UMR 8621, Institute of Genetics and Microbiology, Orsay 91405, France
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31
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Abstract
Dynamin-related proteins (DRPs) can generate forces to remodel membranes. In cells, DRPs require additional proteins [DRP-associated proteins (DAPs)] to conduct their functions. To dissect the mechanistic role of a DAP, we used the yeast mitochondrial division machine as a model, which requires the DRP Dnm1, and two other proteins, Mdv1 and Fis1. Mdv1 played a postmitochondrial targeting role in division by specifically interacting and coassembling with the guanosine triphosphate-bound form of Dnm1. This regulated interaction nucleated and promoted the self-assembly of Dnm1 into helical structures, which drive membrane scission. The nucleation of DRP assembly probably represents a general regulatory strategy for this family of filament-forming proteins, similar to F-actin regulation.
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Affiliation(s)
- Laura L Lackner
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
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32
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Lackner LL, Nunnari JM. The molecular mechanism and cellular functions of mitochondrial division. Biochim Biophys Acta Mol Basis Dis 2008; 1792:1138-44. [PMID: 19100831 DOI: 10.1016/j.bbadis.2008.11.011] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 11/19/2008] [Accepted: 11/20/2008] [Indexed: 11/27/2022]
Abstract
Mitochondria are highly dynamic organelles that continuously divide and fuse. These dynamic processes regulate the size, shape, and distribution of the mitochondrial network. In addition, mitochondrial division and fusion play critical roles in cell physiology. This review will focus on the dynamic process of mitochondrial division, which is highly conserved from yeast to humans. We will discuss what is known about how the essential components of the division machinery function to mediate mitochondrial division and then focus on proteins that have been implicated in division but whose functions remain unclear. We will then briefly discuss the cellular functions of mitochondrial division and the problems that arise when division is disrupted.
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Affiliation(s)
- Laura L Lackner
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
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33
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Benard G, Rossignol R. Ultrastructure of the mitochondrion and its bearing on function and bioenergetics. Antioxid Redox Signal 2008; 10:1313-42. [PMID: 18435594 DOI: 10.1089/ars.2007.2000] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The recently ascertained network and dynamic organization of the mitochondrion, as well as the demonstration of energy proteins and metabolites subcompartmentalization, have led to a reconsideration of the relationships between organellar form and function. In particular, the impact of mitochondrial morphological changes on bioenergetics is inseparable. Several observations indicate that mitochondrial energy production may be controlled by structural rearrangements of the organelle both interiorly and globally, including the remodeling of cristae morphology and elongation or fragmentation of the tubular network organization, respectively. These changes are mediated by fusion or fission reactions in response to physiological signals that remain unidentified. They lead to important changes in the internal diffusion of energy metabolites, the sequestration and conduction of the electric membrane potential (Delta Psi), and possibly the delivery of newly synthesized ATP to various cellular areas. Moreover, the physiological or even pathological context also determines the morphology of the mitochondrion, suggesting a tight and mutual control between mitochondrial form and bioenergetics. In this review, we delve into the link between mitochondrial structure and energy metabolism.
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34
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Nasr P, Sullivan PG, Smith GM. Mitochondrial imaging in dorsal root ganglion neurons following the application of inducible adenoviral vector expressing two fluorescent proteins. J Neurosci Methods 2008; 172:185-94. [PMID: 18541307 PMCID: PMC2657596 DOI: 10.1016/j.jneumeth.2008.04.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 04/06/2008] [Accepted: 04/22/2008] [Indexed: 01/31/2023]
Abstract
Mitochondrial morphology and dynamics are known to vary considerably depending on the cell type and organism studied. The objective of this study was to assess the potential application of adenoviral-fluorescent protein constructs for long-term tracking of mitochondria in neurons. An adenoviral vector containing two fluorescent proteins, the enhanced green fluorescent protein (eGFP) targeted to the cytoplasm to highlight the neuronal processes, and the red fluorescent protein (RFP) directed to mitochondria under the control of an inducible promoter, facilitated an efficient and accurate method to study mitochondrial dynamics in long-term studies. Dorsal root ganglion neurons from rat embryos were cultured and infected. The infected neurons exhibited green fluorescence after 24h, while 16 h following induction with doxycycline, red fluorescence protein began to localize within mitochondria. The red fluorescent protein was transported into mitochondria at the cell body followed by distribution within processes. As the neurons aged, the expression of red fluorescent protein was confined to cytoplasmic vacuoles and not mitochondria. Further analysis suggested that the cytoplasmic vacuoles were likely of lysosomal origin. Taken together, the current study presents novel strategies to study the life history of cellular organelles such as mitochondria in long-term studies.
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Affiliation(s)
- Payman Nasr
- Department of Biological Sciences, Kent State University, Ashtabula, OH 44004, United States.
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35
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Tamai S, Iida H, Yokota S, Sayano T, Kiguchiya S, Ishihara N, Hayashi JI, Mihara K, Oka T. Characterization of the mitochondrial protein LETM1, which maintains the mitochondrial tubular shapes and interacts with the AAA-ATPase BCS1L. J Cell Sci 2008; 121:2588-600. [PMID: 18628306 DOI: 10.1242/jcs.026625] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
LETM1 is located in the chromosomal region that is deleted in patients suffering Wolf-Hirschhorn syndrome; it encodes a homolog of the yeast protein Mdm38 that is involved in mitochondrial morphology. Here, we describe the LETM1-mediated regulation of the mitochondrial volume and its interaction with the mitochondrial AAA-ATPase BCS1L that is responsible for three different human disorders. LETM1 is a mitochondrial inner-membrane protein with a large domain extruding to the matrix. The LETM1 homolog LETM2 is a mitochondrial protein that is expressed preferentially in testis and sperm. LETM1 downregulation caused mitochondrial swelling and cristae disorganization, but seemed to have little effect on membrane fusion and fission. Formation of the respiratory-chain complex was impaired by LETM1 knockdown. Cells lacking mitochondrial DNA lost active respiratory chains but maintained mitochondrial tubular networks, indicating that mitochondrial swelling caused by LETM1 knockdown is not caused by the disassembly of the respiratory chains. LETM1 was co-precipitated with BCS1L and formation of the LETM1 complex depended on BCS1L levels, suggesting that BCS1L stimulates the assembly of the LETM1 complex. BCS1L knockdown caused disassembly of the respiratory chains as well as LETM1 downregulation and induced distinct changes in mitochondrial morphology.
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Affiliation(s)
- Shoko Tamai
- Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
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36
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Oka T, Sayano T, Tamai S, Yokota S, Kato H, Fujii G, Mihara K. Identification of a novel protein MICS1 that is involved in maintenance of mitochondrial morphology and apoptotic release of cytochrome c. Mol Biol Cell 2008; 19:2597-608. [PMID: 18417609 PMCID: PMC2397309 DOI: 10.1091/mbc.e07-12-1205] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/26/2008] [Accepted: 04/03/2008] [Indexed: 11/11/2022] Open
Abstract
Mitochondrial morphology dynamically changes in a balance of membrane fusion and fission in response to the environment, cell cycle, and apoptotic stimuli. Here, we report that a novel mitochondrial protein, MICS1, is involved in mitochondrial morphology in specific cristae structures and the apoptotic release of cytochrome c from the mitochondria. MICS1 is an inner membrane protein with a cleavable presequence and multiple transmembrane segments and belongs to the Bi-1 super family. MICS1 down-regulation causes mitochondrial fragmentation and cristae disorganization and stimulates the release of proapoptotic proteins. Expression of the anti-apoptotic protein Bcl-XL does not prevent morphological changes of mitochondria caused by MICS1 down-regulation, indicating that MICS1 plays a role in maintaining mitochondrial morphology separately from the function in apoptotic pathways. MICS1 overproduction induces mitochondrial aggregation and partially inhibits cytochrome c release during apoptosis, regardless of the occurrence of Bax targeting. MICS1 is cross-linked to cytochrome c without disrupting membrane integrity. Thus, MICS1 facilitates the tight association of cytochrome c with the inner membrane. Furthermore, under low-serum condition, the delay in apoptotic release of cytochrome c correlates with MICS1 up-regulation without significant changes in mitochondrial morphology, suggesting that MICS1 individually functions in mitochondrial morphology and cytochrome c release.
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Affiliation(s)
- Toshihiko Oka
- *Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Tomoko Sayano
- *Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Shoko Tamai
- *Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Sadaki Yokota
- Section of Functional Morphology, Faculty of Pharmaceutical Science, Nagasaki International University, 859-3298 Nagasaki, Japan; and
| | - Hiroki Kato
- *Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
| | - Gen Fujii
- Pathology Division, National Cancer Center Research Institute, 104-0045 Tokyo, Japan
| | - Katsuyoshi Mihara
- *Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
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37
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Altmann K, Frank M, Neumann D, Jakobs S, Westermann B. The class V myosin motor protein, Myo2, plays a major role in mitochondrial motility in Saccharomyces cerevisiae. ACTA ACUST UNITED AC 2008; 181:119-30. [PMID: 18391073 PMCID: PMC2287292 DOI: 10.1083/jcb.200709099] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The actin cytoskeleton is essential for polarized, bud-directed movement of cellular membranes in Saccharomyces cerevisiae and thus ensures accurate inheritance of organelles during cell division. Also, mitochondrial distribution and inheritance depend on the actin cytoskeleton, though the precise molecular mechanisms are unknown. Here, we establish the class V myosin motor protein, Myo2, as an important mediator of mitochondrial motility in budding yeast. We found that mutants with abnormal expression levels of Myo2 or its associated light chain, Mlc1, exhibit aberrant mitochondrial morphology and loss of mitochondrial DNA. Specific mutations in the globular tail of Myo2 lead to aggregation of mitochondria in the mother cell. Isolated mitochondria lacking functional Myo2 are severely impaired in their capacity to bind to actin filaments in vitro. Time-resolved fluorescence microscopy revealed a block of bud-directed anterograde mitochondrial movement in cargo binding–defective myo2 mutant cells. We conclude that Myo2 plays an important and direct role for mitochondrial motility and inheritance in budding yeast.
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Affiliation(s)
- Katrin Altmann
- Institut für Zellbiologie, Universität Bayreuth, 95440 Bayreuth, Germany
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38
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Ichishita R, Tanaka K, Sugiura Y, Sayano T, Mihara K, Oka T. An RNAi screen for mitochondrial proteins required to maintain the morphology of the organelle in Caenorhabditis elegans. J Biochem 2008; 143:449-54. [PMID: 18174190 DOI: 10.1093/jb/mvm245] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mitochondria are dynamic organelles that frequently divide and fuse together, resulting in the formation of intracellular tubular networks. In yeast and mammals, several factors including Drp1/Dnm1 and Mfn/Fzo1 are known to regulate mitochondrial morphology by controlling membrane fission or fusion. Here, we report the systematic screening of Caenorhabditis elegans mitochondrial proteins required to maintain the morphology of the organelle using an RNA interference feeding library. In C. elegans body wall muscle cells, mitochondria usually formed tubular structures and were severely fragmented by the mutation in fzo-1 gene, indicating that the body wall muscle cells are suitable for monitoring changes in mitochondrial morphology due to gene silencing. Of 719 genes predicted to code for most of mitochondrial proteins, knockdown of >80% of them caused abnormal mitochondrial morphology, including fragmentation and elongation. These findings indicate that most fundamental mitochondrial functions, including metabolism and oxidative phosphorylation, are necessary for maintenance of the tubular networks as well as membrane fission and fusion. This is the first evidence that known mitochondrial activities are prerequisite for regulating the morphology of the organelle. Furthermore, 88 uncharacterized or poorly characterized genes were found in the screening to be implicated in mitochondrial morphology.
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Affiliation(s)
- Ryohei Ichishita
- Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan
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39
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Jourdain I, Sontam D, Johnson C, Dillies C, Hyams JS. Dynamin-dependent biogenesis, cell cycle regulation and mitochondrial association of peroxisomes in fission yeast. Traffic 2007; 9:353-65. [PMID: 18088324 DOI: 10.1111/j.1600-0854.2007.00685.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Peroxisomes were visualized for the first time in living fission yeast cells. In small, newly divided cells, the number of peroxisomes was low but increased in parallel with the increase in cell length/volume that accompanies cell cycle progression. In cells grown in oleic acid, both the size and the number of peroxisomes increased. The peroxisomal inventory of cells lacking the dynamin-related proteins Dnm1 or Vps1 was similar to that in wild type. By contrast, cells of the double mutant dnm1Delta vps1Delta contained either no peroxisomes at all or a small number of morphologically aberrant organelles. Peroxisomes exhibited either local Brownian movement or longer-range linear displacements, which continued in the absence of either microtubules or actin filaments. On the contrary, directed peroxisome motility appeared to occur in association with mitochondria and may be an indirect function of intrinsic mitochondrial dynamics. We conclude that peroxisomes are present in fission yeast and that Dnm1 and Vps1 act redundantly in peroxisome biogenesis, which is under cell cycle control. Peroxisome movement is independent of the cytoskeleton but is coupled to mitochondrial dynamics.
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Affiliation(s)
- Isabelle Jourdain
- Institute of Molecular Biosciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.
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40
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Cerveny KL, Tamura Y, Zhang Z, Jensen RE, Sesaki H. Regulation of mitochondrial fusion and division. Trends Cell Biol 2007; 17:563-9. [PMID: 17959383 DOI: 10.1016/j.tcb.2007.08.006] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 08/22/2007] [Accepted: 08/22/2007] [Indexed: 12/20/2022]
Abstract
In many organisms, ranging from yeast to humans, mitochondria fuse and divide to change their morphology in response to a multitude of signals. During the past decade, work using yeast and mammalian cells has identified much of the machinery required for fusion and division, including the dynamin-related GTPases--mitofusins (Fzo1p in yeast) and OPA1 (Mgm1p in yeast) for fusion and Drp1 (Dnm1p) for division. However, the mechanisms by which cells regulate these dynamic processes have remained largely unknown. Recent studies have uncovered regulatory mechanisms that control the activity, assembly, distribution and stability of the key components for mitochondrial fusion and division. In this review, we discuss how mitochondrial dynamics are controlled and how these events are coordinated with cell growth, mitosis, apoptosis and human diseases.
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Affiliation(s)
- Kara L Cerveny
- Department of Anatomy and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
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41
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Conant GC, Wolfe KH. Increased glycolytic flux as an outcome of whole-genome duplication in yeast. Mol Syst Biol 2007; 3:129. [PMID: 17667951 PMCID: PMC1943425 DOI: 10.1038/msb4100170] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Accepted: 06/27/2007] [Indexed: 11/08/2022] Open
Abstract
After whole-genome duplication (WGD), deletions return most loci to single copy. However, duplicate loci may survive through selection for increased dosage. Here, we show how the WGD increased copy number of some glycolytic genes could have conferred an almost immediate selective advantage to an ancestor of Saccharomyces cerevisiae, providing a rationale for the success of the WGD. We propose that the loss of other redundant genes throughout the genome resulted in incremental dosage increases for the surviving duplicated glycolytic genes. This increase gave post-WGD yeasts a growth advantage through rapid glucose fermentation; one of this lineage's many adaptations to glucose-rich environments. Our hypothesis is supported by data from enzyme kinetics and comparative genomics. Because changes in gene dosage follow directly from post-WGD deletions, dosage selection can confer an almost instantaneous benefit after WGD, unlike neofunctionalization or subfunctionalization, which require specific mutations. We also show theoretically that increased fermentative capacity is of greatest advantage when glucose resources are both large and dense, an observation potentially related to the appearance of angiosperms around the time of WGD.
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Affiliation(s)
- Gavin C Conant
- Smurfit Institute of Genetics, Trinity College, University of Dublin, Dublin, Ireland.
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42
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Abstract
Reactive oxygen species (ROS) damage biomolecules, accelerate aging, and shorten life span, whereas antioxidant enzymes mitigate these effects. Because mitochondria are a primary site of ROS generation and also a primary target of ROS attack, they have become a major focus area of aging studies. Here, we employed yeast genetics to identify mitochondrial antioxidant genes that are important for replicative life span. In our studies, it was found that among the known mitochondrial antioxidant genes (TTR1, CCD1, SOD1, GLO4, TRR2, TRX3, CCS1, SOD2, GRX5, PRX1), deletion of only three genes, SOD1 (Cu, Zn superoxide dismutase), SOD2 (Manganese-containing superoxide dismutase), and CCS1 (Copper chaperone), shortened the life span enormously. The life span decreased 40% for Deltasod1 mutant, 72% for Deltasod2 mutant, and 50% for Deltaccs1 mutant. Deletion of the other genes had little or no effect on life span.
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Affiliation(s)
- Ercan Selcuk Unlu
- Department of Biology, Izmir Institute of Technology, 35430 Urla, Izmir, Turkey
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43
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Cerveny KL, Studer SL, Jensen RE, Sesaki H. Yeast mitochondrial division and distribution require the cortical num1 protein. Dev Cell 2007; 12:363-75. [PMID: 17336903 DOI: 10.1016/j.devcel.2007.01.017] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 11/10/2006] [Accepted: 01/19/2007] [Indexed: 01/14/2023]
Abstract
Yeast mitochondrial division requires the dynamin-related Dnm1 protein. By isolating high-copy suppressors of a dominant-negative Dnm1p mutant, we uncovered an unexpected role in mitochondrial division and inheritance for Num1p, a protein previously shown to facilitate nuclear migration. num1 mutants contain an interconnected network of mitochondrial tubules, remarkably similar to cells lacking Dnm1p, and time-lapse microscopy confirms that mitochondrial fission is greatly reduced in num1Delta cells. We also find that Num1p assembles into punctate structures, which often colocalize with mitochondrial-bound Dnm1p particles. Suggesting a role for both Num1p and Dnm1p in mitochondrial inheritance, we find that num1 dnm1 double mutants accumulate mitochondria in daughter buds and that mother cells are frequently devoid of all mitochondria. Thus, our studies have revealed an additional role for Dnm1p in mitochondrial transmission through its interaction with Num1p, thereby providing a link between mitochondrial division and inheritance.
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Affiliation(s)
- Kara L Cerveny
- Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
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44
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Coonrod EM, Karren MA, Shaw JM. Ugo1p Is a Multipass Transmembrane Protein with a Single Carrier Domain Required for Mitochondrial Fusion. Traffic 2007; 8:500-11. [PMID: 17451553 DOI: 10.1111/j.1600-0854.2007.00550.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The outer mitochondrial membrane protein Ugo1 forms a complex with the Fzo1p and Mgm1p GTPases that regulates mitochondrial fusion in yeast. Ugo1p contains two putative carrier domains (PCDs) found in mitochondrial carrier proteins (MCPs). Mitochondrial carrier proteins are multipass transmembrane proteins that actively transport molecules across the inner mitochondrial membrane. Mitochondrial carrier protein transport requires functional carrier domains with the consensus sequence PX(D/E)XX(K/R). Mutation of charged residues in this consensus sequence disrupts transport function. In this study, we used targeted mutagenesis to show that charge reversal mutations in Ugo1p PCD2, but not PCD1, disrupt mitochondrial fusion. Ugo1p is reported to be a single-pass transmembrane protein despite the fact that it contains several additional predicted transmembrane segments. Using a combination of protein targeting and membrane extraction experiments, we provide evidence that Ugo1p contains additional transmembrane domains and is likely a multipass transmembrane protein. These studies identify PCD2 as a functional domain of Ugo1p and provide the first experimental evidence for a multipass topology of this essential fusion component.
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Affiliation(s)
- Emily M Coonrod
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97401, USA
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45
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Lee S, Kim S, Sun X, Lee JH, Cho H. Cell cycle-dependent mitochondrial biogenesis and dynamics in mammalian cells. Biochem Biophys Res Commun 2007; 357:111-7. [PMID: 17400185 DOI: 10.1016/j.bbrc.2007.03.091] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Accepted: 03/15/2007] [Indexed: 11/29/2022]
Abstract
During cell cycle progression and division, how cells coordinate mitochondrial biogenesis, distribution, and partitions remains to be clarified. Here, we show that mitochondrial mass and mitochondrial membrane potential increased from early G(1) to G(1)/S and further gradually elevated to mitotic phase, indicating that mitochondrial biogenesis begins from early G(1) phase. In addition, mitochondrial DNA contents appeared to increase from G(1)/S to G(2) phase during which a slight but consistent increase of NRF-1 level was observed. However, other transcriptional factors regulating mitochondrial biogenesis, mtTFA and PRC, were not changed. During interphase, heterogeneous mitochondrial population with different morphology and sizes were observed but reorganized into relatively homogeneous population of mitotic cells. Moreover, microtubule and dynein complex, p150(Glued) and dynein intermediate chain, strongly associate with mitochondria during interphase but dissociated from them during mitosis. Taken together, our results suggest that mitochondrial biogenesis and dynamics are tightly regulated during cell cycle progression.
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Affiliation(s)
- Seungmin Lee
- Department of Biochemistry, Ajou University School of Medicine, Suwon, Republic of Korea
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46
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Cheng WC, Berman SB, Ivanovska I, Jonas EA, Lee SJ, Chen Y, Kaczmarek LK, Pineda F, Hardwick JM. Mitochondrial factors with dual roles in death and survival. Oncogene 2006; 25:4697-705. [PMID: 16892083 DOI: 10.1038/sj.onc.1209596] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
At least in mammals, we have some understanding of how caspases facilitate mitochondria-mediated cell death, but the biochemical mechanisms by which other factors promote or inhibit programmed cell death are not understood. Moreover, most of these factors are only studied after treating cells with a death stimulus. A growing body of new evidence suggests that cell death regulators also have 'day jobs' in healthy cells. Even caspases, mitochondrial fission proteins and pro-death Bcl-2 family proteins appear to have normal cellular functions that promote cell survival. Here, we review some of the supporting evidence and stretch beyond the evidence to seek an understanding of the remaining questions.
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Affiliation(s)
- W-C Cheng
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
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47
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Sesaki H, Dunn CD, Iijima M, Shepard KA, Yaffe MP, Machamer CE, Jensen RE. Ups1p, a conserved intermembrane space protein, regulates mitochondrial shape and alternative topogenesis of Mgm1p. ACTA ACUST UNITED AC 2006; 173:651-8. [PMID: 16754953 PMCID: PMC2063882 DOI: 10.1083/jcb.200603092] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mgm1p is a conserved dynamin-related GTPase required for fusion, morphology, inheritance, and the genome maintenance of mitochondria in Saccharomyces cerevisiae. Mgm1p undergoes unconventional processing to produce two functional isoforms by alternative topogenesis. Alternative topogenesis involves bifurcate sorting in the inner membrane and intramembrane proteolysis by the rhomboid protease Pcp1p. Here, we identify Ups1p, a novel mitochondrial protein required for the unique processing of Mgm1p and for normal mitochondrial shape. Our results demonstrate that Ups1p regulates the sorting of Mgm1p in the inner membrane. Consistent with its function, Ups1p is peripherally associated with the inner membrane in the intermembrane space. Moreover, the human homologue of Ups1p, PRELI, can fully replace Ups1p in yeast cells. Together, our findings provide a conserved mechanism for the alternative topogenesis of Mgm1p and control of mitochondrial morphology.
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Affiliation(s)
- Hiromi Sesaki
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Meisinger C, Wiedemann N, Rissler M, Strub A, Milenkovic D, Schönfisch B, Müller H, Kozjak V, Pfanner N. Mitochondrial Protein Sorting. J Biol Chem 2006; 281:22819-26. [PMID: 16760475 DOI: 10.1074/jbc.m602679200] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial outer membrane contains two distinct machineries for protein import and protein sorting that function in a sequential manner: the general translocase of the outer membrane (TOM complex) and the sorting and assembly machinery (SAM complex), which is dedicated to beta-barrel proteins. The SAM(core) complex consists of three subunits, Sam35, Sam37, and Sam50, that can associate with a fourth subunit, the morphology component Mdm10, to form the SAM(holo) complex. Whereas the SAM(core) complex is required for the biogenesis of all beta-barrel proteins, Mdm10 and the SAM(holo) complex play a selective role in beta-barrel biogenesis by promoting assembly of Tom40 but not of porin. We report that Tom7, a conserved subunit of the TOM complex, functions in an antagonistic manner to Mdm10 in biogenesis of Tom40 and porin. We show that Tom7 promotes segregation of Mdm10 from the SAM(holo) complex into a low molecular mass form. Upon deletion of Tom7, the fraction of Mdm10 in the SAM(holo) complex is significantly increased, explaining the opposing functions of Tom7 and Mdm10 in beta-barrel sorting. Thus the role of Tom7 is not limited to the TOM complex. Tom7 functions in mitochondrial protein biogenesis by a new mechanism, segregation of a sorting component, leading to a differentiation of beta-barrel assembly.
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Affiliation(s)
- Chris Meisinger
- Institut für Biochemie und Molekularbiologie and the Fakultät für Biologie, Universität Freiburg, 79104 Freiburg
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Yonashiro R, Ishido S, Kyo S, Fukuda T, Goto E, Matsuki Y, Ohmura-Hoshino M, Sada K, Hotta H, Yamamura H, Inatome R, Yanagi S. A novel mitochondrial ubiquitin ligase plays a critical role in mitochondrial dynamics. EMBO J 2006; 25:3618-26. [PMID: 16874301 PMCID: PMC1538564 DOI: 10.1038/sj.emboj.7601249] [Citation(s) in RCA: 284] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Accepted: 06/29/2006] [Indexed: 11/08/2022] Open
Abstract
In this study, we have identified a novel mitochondrial ubiquitin ligase, designated MITOL, which is localized in the mitochondrial outer membrane. MITOL possesses a Plant Homeo-Domain (PHD) motif responsible for E3 ubiquitin ligase activity and predicted four-transmembrane domains. MITOL displayed a rapid degradation by autoubiquitination activity in a PHD-dependent manner. HeLa cells stably expressing a MITOL mutant lacking ubiquitin ligase activity or MITOL-deficient cells by small interfering RNA showed an aberrant mitochondrial morphology such as fragmentation, suggesting the enhancement of mitochondrial fission by MITOL dysfunction. Indeed, a dominant-negative expression of Drp1 mutant blocked mitochondrial fragmentation induced by MITOL depletion. We found that MITOL associated with and ubiquitinated mitochondrial fission protein hFis1 and Drp1. Pulse-chase experiment showed that MITOL overexpression increased turnover of these fission proteins. In addition, overexpression phenotype of hFis1 could be reverted by MITOL co-overexpression. Our finding indicates that MITOL plays a critical role in mitochondrial dynamics through the control of mitochondrial fission proteins.
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Affiliation(s)
- Ryo Yonashiro
- Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
| | - Satoshi Ishido
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Tsurumi-ku, Yokohama, Kanagawa, Japan
- Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan. Tel.: +81 45 503 7022; Fax: +81 45 503 7021; E-mail:
| | - Shinkou Kyo
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
| | - Toshifumi Fukuda
- Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan
| | - Eiji Goto
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Yohei Matsuki
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Mari Ohmura-Hoshino
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Kiyonao Sada
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
| | - Hak Hotta
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
| | - Hirohei Yamamura
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
| | - Ryoko Inatome
- Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan
- Department of Genome Science, Kobe University Graduate School of Medicine, Chuo-Ku, Kobe, Japan
| | - Shigeru Yanagi
- Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan
- Laboratory of Molecular Biochemistry, School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan. Tel.: +81 42 676 7146; Fax: +81 42 676 4149; E-mail:
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Padmanabhan R, Al-Menhali NM, Tariq S, Shafiullah M. Mitochondrial dysmorphology in the neuroepithelium of rat embryos following a single dose of maternal hyperthermia during gestation. Exp Brain Res 2006; 173:298-308. [PMID: 16847614 DOI: 10.1007/s00221-006-0489-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Accepted: 04/01/2006] [Indexed: 12/16/2022]
Abstract
Hyperthermia is teratogenic to human and animal embryos and induces mainly anomalies of the nervous system. However, the teratogenic mechanism is poorly understood. Mammalian embryos are known to switch from anaerobic to aerobic metabolism around the time of neural tube closure. This critical event might be sensitive to hyperthermia. The objective of the present study was to evaluate the ultrastructural changes of the mitochondria of the neuroepithelium (NE) of rat embryos following maternal exposure to hyperthermia. Pregnant rats were heat stressed for an hour on gestation day (GD) 9 and embryos were examined by electron microscopy on GD 10. NE presented extensive apoptosis. Intercellular junctions were weakened and copious cellular debris projected into the ventricle. The mitochondria were of diverse size and shape. Most of them were swollen and had short cristae and electron dense matrix. Hydropic changes were also observed in numerous mitochondria. Lipid-laden mitochondria were found in the apical portions of neuroblasts. The mesenchyme (ME) of heat-treated embryos showed paucity of cells and only as frequent apoptosis as the controls. Their mitochondria also showed changes similar to those of the NE. Additionally extensive lipid accumulation was observed in and in the vicinity of mitochondria, often surrounded by short strands of endoplasmic reticulum. Whereas mitochondrial pathology was associated with profound apoptosis in the NE, growth restriction and lipid accumulation accompanied mitochondrial changes in the ME. The results of this study indicate that the embryonic response to maternal heat shock is tissue-specific and morphologically distinct in this species.
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Affiliation(s)
- Rengasamy Padmanabhan
- Department of Anatomy, Faculty of Medicine and Health Sciences, UAE University, P.O. Box 17666, Al Ain, United Arab Emirates.
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